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<journal-meta>
<journal-id journal-id-type="publisher-id">Front. Mar. Sci.</journal-id>
<journal-title-group>
<journal-title>Frontiers in Marine Science</journal-title>
<abbrev-journal-title abbrev-type="pubmed">Front. Mar. Sci.</abbrev-journal-title>
</journal-title-group>
<issn pub-type="epub">2296-7745</issn>
<publisher>
<publisher-name>Frontiers Media S.A.</publisher-name>
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<article-meta>
<article-id pub-id-type="doi">10.3389/fmars.2026.1735150</article-id>
<article-version article-version-type="Version of Record" vocab="NISO-RP-8-2008"/>
<article-categories>
<subj-group subj-group-type="heading">
<subject>Original Research</subject>
</subj-group>
</article-categories>
<title-group>
<article-title>Improving marine protected area zoning through species-oriented analysis using wildlife remote sensing</article-title>
</title-group>
<contrib-group>
<contrib contrib-type="author" equal-contrib="yes">
<name><surname>Zhao</surname><given-names>Peng</given-names></name>
<xref ref-type="aff" rid="aff1"><sup>1</sup></xref>
<xref ref-type="aff" rid="aff2"><sup>2</sup></xref>
<xref ref-type="aff" rid="aff3"><sup>3</sup></xref>
<xref ref-type="author-notes" rid="fn003"><sup>&#x2020;</sup></xref>
<uri xlink:href="https://loop.frontiersin.org/people/1774180/overview"/>
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<contrib contrib-type="author" equal-contrib="yes">
<name><surname>Liu</surname><given-names>Shuming</given-names></name>
<xref ref-type="aff" rid="aff4"><sup>4</sup></xref>
<xref ref-type="author-notes" rid="fn003"><sup>&#x2020;</sup></xref>
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<contrib contrib-type="author">
<name><surname>Wang</surname><given-names>Fengxia</given-names></name>
<xref ref-type="aff" rid="aff5"><sup>5</sup></xref>
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<contrib contrib-type="author" corresp="yes">
<name><surname>Li</surname><given-names>Jiarui</given-names></name>
<xref ref-type="aff" rid="aff4"><sup>4</sup></xref>
<xref ref-type="corresp" rid="c001"><sup>*</sup></xref>
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<name><surname>Zhang</surname><given-names>Jian</given-names></name>
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<xref ref-type="corresp" rid="c001"><sup>*</sup></xref>
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<aff id="aff1"><label>1</label><institution>School of Marine Science and Engineering, Hainan University</institution>, <city>Haikou</city>,&#xa0;<country country="cn">China</country></aff>
<aff id="aff2"><label>2</label><institution>Engineering Research Center of Hainan Province for Blue Carbon and Coastal Wetland Conservation and Restoration</institution>, <city>Haikou</city>,&#xa0;<country country="cn">China</country></aff>
<aff id="aff3"><label>3</label><institution>International Joint Research Center of Hainan Province for Blue Carbon and Coastal Wetland</institution>, <city>Haikou</city>,&#xa0;<country country="cn">China</country></aff>
<aff id="aff4"><label>4</label><institution>National Marine Data &amp; Information Service</institution>, <city>Tianjin</city>,&#xa0;<country country="cn">China</country></aff>
<aff id="aff5"><label>5</label><institution>College of International Tourism and Public Administration, Hainan University</institution>, <city>Haikou</city>,&#xa0;<country country="cn">China</country></aff>
<author-notes>
<corresp id="c001"><label>*</label>Correspondence: Jiarui Li, <email xlink:href="mailto:lijiarui@nmdis.org.cn">lijiarui@nmdis.org.cn</email>; Jian Zhang, <email xlink:href="mailto:zhangjian198612@outlook.com">zhangjian198612@outlook.com</email></corresp>
<fn fn-type="equal" id="fn003">
<p>&#x2020;These authors have contributed equally to this work</p></fn>
</author-notes>
<pub-date publication-format="electronic" date-type="pub" iso-8601-date="2026-03-02">
<day>02</day>
<month>03</month>
<year>2026</year>
</pub-date>
<pub-date publication-format="electronic" date-type="collection">
<year>2026</year>
</pub-date>
<volume>13</volume>
<elocation-id>1735150</elocation-id>
<history>
<date date-type="received">
<day>29</day>
<month>10</month>
<year>2025</year>
</date>
<date date-type="accepted">
<day>30</day>
<month>01</month>
<year>2026</year>
</date>
<date date-type="rev-recd">
<day>26</day>
<month>01</month>
<year>2026</year>
</date>
</history>
<permissions>
<copyright-statement>Copyright &#xa9; 2026 Zhao, Liu, Wang, Li and Zhang.</copyright-statement>
<copyright-year>2026</copyright-year>
<copyright-holder>Zhao, Liu, Wang, Li and Zhang</copyright-holder>
<license>
<ali:license_ref start_date="2026-03-02">https://creativecommons.org/licenses/by/4.0/</ali:license_ref>
<license-p>This is an open-access article distributed under the terms of the <ext-link ext-link-type="uri" xlink:href="https://creativecommons.org/licenses/by/4.0/">Creative Commons Attribution License (CC BY)</ext-link>. The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.</license-p>
</license>
</permissions>
<abstract>
<p>Designing protected area zones that align with species&#x2019; space use and key habitat requirements is critical for effective biodiversity conservation. This study presents a species-oriented approach using very high-resolution (VHR) satellite imagery to assess and optimize the spatial zoning of a national nature reserve in China. We identified individual whooper swans (Cygnus cygnus) and analyzed their abundance and distribution from 2009 to 2016, including a detailed overwintering period. The satellite-derived data revealed substantial shifts in habitat use, including a tripling of swan numbers on the western shores and a sharp decline in Yangyuchi Bay. Over half of the swans were located in mudflats and unprotected or under-designated areas. By comparing swan distribution with existing zoning, we proposed a rezoning strategy that adds 301.8 hectares to the core zone. Our findings demonstrate how satellite-based wildlife monitoring can support adaptive, species-informed management of protected areas and contribute to the global target of conserving 30% of land and sea areas by 2030.</p>
</abstract>
<kwd-group>
<kwd>30&#xd7;30 biodiversity target</kwd>
<kwd>population distribution</kwd>
<kwd>population dynamics</kwd>
<kwd>spatial zoning</kwd>
<kwd>VHR satellite imagery</kwd>
<kwd>whooper swan (<italic>Cygnus cygnus</italic>)</kwd>
</kwd-group>
<funding-group>
<funding-statement>The author(s) declared that financial support was received for this work and/or its publication. This research was supported by the National Natural Science Foundation of China (Grant No. 42366007), the Hainan Provincial International Science and Technology Cooperation Project (Grant No. GHYF2024014), and the Hainan Provincial Science and Technology Special Project for Aerospace Applications (Land&#x2013;Sea&#x2013;Air Integration Program, 2024.02). We thank all field and technical staff involved in data acquisition and processing. We also appreciate the constructive suggestions provided by anonymous reviewers, which helped improve the manuscript.</funding-statement>
</funding-group>
<counts>
<fig-count count="4"/>
<table-count count="5"/>
<equation-count count="1"/>
<ref-count count="49"/>
<page-count count="10"/>
<word-count count="4664"/>
</counts>
<custom-meta-group>
<custom-meta>
<meta-name>section-at-acceptance</meta-name>
<meta-value>Marine Conservation and Sustainability</meta-value>
</custom-meta>
</custom-meta-group>
</article-meta>
</front>
<body>
<sec id="s1" sec-type="intro">
<label>1</label>
<title>Introduction</title>
<p>Global biodiversity continues to decline under the combined pressures of habitat loss, climate change, pollution, and overexploitation, placing nearly one million species at risk of extinction (<xref ref-type="bibr" rid="B9">Diaz et&#xa0;al., 2019</xref>). This alarming trend calls urgent and transformative actions. Since their emergence in the nineteenth century, protected areas have become a cornerstone of biodiversity conservation, originally established to preserve natural landscapes and wildlife (<xref ref-type="bibr" rid="B27">Pacifici et&#xa0;al., 2020</xref>; <xref ref-type="bibr" rid="B42">Watson et&#xa0;al., 2014</xref>). The <italic>Kunming-Montreal Global Biodiversity Framework</italic> has reaffirmed the importance of area-based conservation by setting an ambitious target of effectively conserving and managing at least 30% of the planet&#x2019;s terrestrial, inland water, and coastal and marine areas by 2030 (<xref ref-type="bibr" rid="B39">Stephens, 2023</xref>; <xref ref-type="bibr" rid="B25">Neugarten et&#xa0;al., 2024</xref>). However, many scientists remain skeptical about the feasibility of this target, citing the limitations of the previous Aichi Targets and the risk of repeating similar shortcomings (<xref ref-type="bibr" rid="B28">Phang et&#xa0;al., 2020</xref>; <xref ref-type="bibr" rid="B32">Rochette et&#xa0;al., 2014</xref>; <xref ref-type="bibr" rid="B43">Watson et&#xa0;al., 2023</xref>).</p>
<p>Recent research emphasizes that effectively safeguarding areas of high ecological and biological value requires more than simply increasing the number or total area of protected sites (<xref ref-type="bibr" rid="B16">Gurney et&#xa0;al., 2023</xref>; <xref ref-type="bibr" rid="B22">Li et&#xa0;al., 2023</xref>; <xref ref-type="bibr" rid="B24">Maxwell et&#xa0;al., 2020</xref>). Studies highlight that a focus purely on spatial extent can inadvertently lead to the downgrading of existing protected areas in favor of establishing new sites that may lack ecological significance (<xref ref-type="bibr" rid="B21">Jonas et&#xa0;al., 2024</xref>; <xref ref-type="bibr" rid="B38">Sovinc and Kr&#x17e;i&#x10d;, 2025</xref>). In practice, protected areas are often designated in locations with low socio-economic conflict rather than where threatened species are most concentrated (<xref ref-type="bibr" rid="B40">Visconti et&#xa0;al., 2019</xref>; <xref ref-type="bibr" rid="B8">Dasgupta et&#xa0;al., 2025</xref>). To fulfill global conservation commitments and reverse biodiversity loss, conservation strategies must prioritize ecological representativeness and management effectiveness. This includes ensuring that protected areas encompass viable populations and their required habitats, not merely meeting area-based quotas (<xref ref-type="bibr" rid="B3">Barnes et&#xa0;al., 2018</xref>; <xref ref-type="bibr" rid="B6">Cui et&#xa0;al., 2025</xref>). Zoning approaches should thus emphasize the identification and protection of critical habitats, integrating species&#x2019; spatial needs into the functional layout of conservation areas (<xref ref-type="bibr" rid="B17">Herrera-Montes, 2018</xref>; <xref ref-type="bibr" rid="B30">Pressey et&#xa0;al., 2007</xref>; <xref ref-type="bibr" rid="B35">Rotich, 2012</xref>). Therefore, zoning should not only delineate areas for conservation and sustainable use, but also emphasize the protection of key habitats, forming a foundation for effective biodiversity conservation.</p>
<p>Understanding population dynamics and spatial distribution is essential for identifying biologically important areas and assessing the effectiveness of protected area design (<xref ref-type="bibr" rid="B44">Williams et&#xa0;al., 2017</xref>). However, conducting wildlife censuses is often labor-intensive, time-consuming, and logistically challenging (<xref ref-type="bibr" rid="B45">Witmer, 2005</xref>). Over the past few decades, aerial surveys have become widely used to estimate the abundance and distribution of various terrestrial and marine species, including rhinoceroses (<xref ref-type="bibr" rid="B15">Goddard, 1967</xref>), seabirds (<xref ref-type="bibr" rid="B4">Buckland et&#xa0;al., 2012</xref>), seals (<xref ref-type="bibr" rid="B7">Cunningham et&#xa0;al., 2010</xref>), turtles (<xref ref-type="bibr" rid="B12">Fernandes et&#xa0;al., 2025</xref>), manatee (<xref ref-type="bibr" rid="B36">Sanchez-Galan et&#xa0;al., 2025</xref>) and dugongs (<xref ref-type="bibr" rid="B29">Preen, 2004</xref>). Satellite remote sensing has further expanded our ability to monitor biodiversity at large spatial scales. Early efforts relied on indirect indicators such as guano stains (<xref ref-type="bibr" rid="B37">Schwaller et&#xa0;al., 1989</xref>), vegetation degradation, or burrows (<xref ref-type="bibr" rid="B23">Loffler and Margules, 1980</xref>) to infer animal presence and abundance.</p>
<p>Since the launch of Ikonos in 1999, a growing number of very high-resolution (VHR) satellite platforms with sub-meter resolution have enabled direct detection of individual animals (<xref ref-type="bibr" rid="B41">Wang et&#xa0;al., 2019</xref>). The use of VHR imagery for wildlife monitoring offers key advantages&#x2014;high spatial and temporal resolution, broad coverage, minimal habitat disturbance, and retrospective analysis through archival data. These capabilities make VHR imagery a powerful tool for studying animal population dynamics and for conservation planning. Case studies involving whales, seals, and albatrosses have demonstrated its feasibility and accuracy in estimating population size, mapping habitat use, and assessing conservation outcomes (<xref ref-type="bibr" rid="B1">Attard et&#xa0;al., 2025</xref>; <xref ref-type="bibr" rid="B5">Cubaynes et&#xa0;al., 2024</xref>; <xref ref-type="bibr" rid="B11">Duporge et&#xa0;al., 2025</xref>; <xref ref-type="bibr" rid="B13">Fretwell et&#xa0;al., 2017</xref>; <xref ref-type="bibr" rid="B49">Zhao et&#xa0;al., 2021</xref>). Unlike most previous applications that focus on species detection, our approach links remote sensing data directly with reserve zoning performance, offering a novel framework for species-oriented conservation planning. Extensive archives of VHR imagery generated over the past two decades provide a long-term record of species distributions and habitats, offering valuable information for conservation at relatively low cost.</p>
<p>In this study, we apply a species-oriented conservation approach to assess and improve the spatial zoning of a national nature reserve in China, focusing on the wintering behavior of the whooper swan (<italic>Cygnus cygnus</italic>). Using a series of archived VHR satellite images, we estimated the abundance and distribution of wintering swans from 2008 to 2016, with a particular focus on the 2015&#x2013;2016 overwintering season. By comparing swan spatial distribution with the reserve&#x2019;s existing core, buffer, and experimental zones, we identified spatial mismatches between functional zoning and actual animal habitat use. Based on these findings, we propose a rezoning strategy that aligns protected areas more closely with the ecological needs of the target species. This approach illustrates how satellite-derived animal distribution data can support evidence-informed zoning assessments. The findings offer practical guidance for protected area managers by illustrating how satellite-derived animal distribution data can inform adaptive zoning and enhance conservation outcomes. The case study further underscores the broader value of integrating animal remote sensing into protected area management, providing insights for evidence-based conservation and contributing to the 30 &#xd7; 30 global biodiversity target.</p>
</sec>
<sec id="s2">
<label>2</label>
<title>Methods</title>
<sec id="s2_1">
<label>2.1</label>
<title>Study area</title>
<p>The Rongcheng Whooper Swan National Nature Reserve, located at the eastern extremity of China&#x2019;s Shandong Peninsula (36&#xb0;58&#x2032;&#x2013;37&#xb0;25&#x2032;N, 122&#xb0;23&#x2032;&#x2013;122&#xb0;35&#x2032;E), serves as a critical overwintering site for whooper swans in East Asia. Covering approximately 1,650 hectares, the reserve is divided into core, buffer, and experimental zones (see <xref ref-type="fig" rid="f1"><bold>Figure&#xa0;1</bold></xref>). From November to March, whooper swans primarily gather in the Yuehu Lagoon, Yangyuchi Bay, and a shallow bay near Yandunjiao Village. Their diet consists mainly of eelgrass (Zostera marina) seedlings, kelp (Laminaria japonica), and crops from nearby wheat fields. The reserve was designated as a national nature reserve in 2007 and is part of the East Asian&#x2013;Australasian Flyway, providing essential habitat for migratory waterbirds.</p>
<fig id="f1" position="float">
<label>Figure&#xa0;1</label>
<caption>
<p>The location and spatial zoning of the Rongcheng Whooper Swan National Nature Reserve.</p>
</caption>
<graphic mimetype="image" mime-subtype="tiff" xlink:href="fmars-13-1735150-g001.tif">
<alt-text content-type="machine-generated">Satellite map showing a coastal zone near Weihai, China, with north, west Yuchu, Yangyuchi, and Yundunjiao areas outlined in yellow. Legend distinguishes boundary, core, buffer, and experimental zones. Insets display regional location relative to Beijing and Weihai.</alt-text>
</graphic></fig>
</sec>
<sec id="s2_2">
<label>2.2</label>
<title>Data</title>
<p>The choice of resolution for remote sensing imagery is critically dependent on the morphological parameters of the animals being studied, as individuals must cover at least two pixels to ensure reliable detection. Based on our previous measurements of whooper swans in the study region (body length = 82.55 &#xb1; 6.39 cm; body width = 38.33 &#xb1; 3.59 cm) (<xref ref-type="bibr" rid="B49">Zhao et&#xa0;al., 2021</xref>), we used imagery with a spatial resolution finer than 0.6 m. Archived VHR satellite images from 2009 and 2013 were selected, together with three cloud-free scenes from the 2015&#x2013;2016 overwintering period (<xref ref-type="table" rid="T1"><bold>Table&#xa0;1</bold></xref>). All scenes included four multispectral bands and one panchromatic band, and only the panchromatic band was used because the strong contrast between white swans and surrounding water facilitates accurate detection.</p>
<table-wrap id="T1" position="float">
<label>Table&#xa0;1</label>
<caption>
<p>Satellite remote sensing data used in this study.</p>
</caption>
<table frame="hsides">
<thead>
<tr>
<th valign="middle" align="center">No.</th>
<th valign="middle" align="center">Sensors</th>
<th valign="middle" align="center">Dates</th>
<th valign="middle" align="center">Transit time</th>
<th valign="middle" align="center">Resolutions</th>
</tr>
</thead>
<tbody>
<tr>
<td valign="middle" align="center">Feb 2009</td>
<td valign="middle" align="center">worldview-1</td>
<td valign="middle" align="center">2009/02/08</td>
<td valign="middle" align="center">10:46am</td>
<td valign="middle" align="center">0.5m</td>
</tr>
<tr>
<td valign="middle" align="left">Feb 2013</td>
<td valign="middle" align="center">Pleiades</td>
<td valign="middle" align="center">2013/02/15</td>
<td valign="middle" align="center">10:43am</td>
<td valign="middle" align="center">0.46m</td>
</tr>
<tr>
<td valign="middle" align="center">Dec 2015</td>
<td valign="middle" align="center">GeoEye-1</td>
<td valign="middle" align="center">2015/12/19</td>
<td valign="middle" align="center">10:53am</td>
<td valign="middle" align="center">0.5m</td>
</tr>
<tr>
<td valign="middle" align="center">Jan 2016</td>
<td valign="middle" align="center">GeoEye-1</td>
<td valign="middle" align="center">2016/01/26</td>
<td valign="middle" align="center">10:40am</td>
<td valign="middle" align="center">0.5m</td>
</tr>
<tr>
<td valign="middle" align="center">Feb 2016</td>
<td valign="middle" align="center">GeoEye-1</td>
<td valign="middle" align="center">2016/02/06</td>
<td valign="middle" align="center">10:42am</td>
<td valign="middle" align="center">0.5m</td>
</tr>
</tbody>
</table>
</table-wrap>
<p>Before analysis, all images underwent orthorectification and co-registration to a common geographic coordinate system in ENVI 5.4, achieving sub-pixel alignment across acquisition dates. These preprocessing steps minimized geometric distortions and ensured robust multi-temporal comparison. To reduce inter-scene brightness differences and radiometric inconsistencies among multi-temporal images, a rapid atmospheric (radiometric) correction was applied to the panchromatic imagery using the QUAC module in ENVI. This correction was used to improve relative comparability across dates rather than to retrieve absolute surface reflectance.</p>
</sec>
<sec id="s2_3">
<label>2.3</label>
<title>Population abundance estimation and distribution mapping</title>
<p>We developed our population estimation approach based on a previously validated satellite-derived brightness model (<xref ref-type="bibr" rid="B49">Zhao et&#xa0;al., 2021</xref>), and further extended it to accommodate multi-temporal analysis and spatial zoning assessment under complex habitat conditions. This method estimates population abundance by quantifying the area occupied by whooper swans using VHR satellite imagery, leveraging a linear relationship between pixel brightness and the proportion of area covered by individual swans. In each image, pixels representing open background show baseline brightness, whereas pixels fully occupied by swans exhibit higher reflectance. By converting pixel brightness values into the proportion of swan coverage and summing across the image, we obtained the total swan-occupied area. Population size (N) was calculated using the formula:</p>
<disp-formula>
<mml:math display="block" id="M1"><mml:mrow><mml:mtext>N</mml:mtext><mml:mo>=</mml:mo><mml:mi>r</mml:mi><mml:mo>&#xd7;</mml:mo><mml:msub><mml:mi>S</mml:mi><mml:mn>0</mml:mn></mml:msub><mml:mo>&#xd7;</mml:mo><mml:mfenced><mml:mrow><mml:msub><mml:mi>B</mml:mi><mml:mi>i</mml:mi></mml:msub><mml:mo>&#x2212;</mml:mo><mml:msub><mml:mi>B</mml:mi><mml:mrow><mml:mi>m</mml:mi><mml:mi>i</mml:mi><mml:mi>n</mml:mi></mml:mrow></mml:msub></mml:mrow></mml:mfenced><mml:mo stretchy="false">/</mml:mo><mml:mfenced><mml:mrow><mml:msub><mml:mi>B</mml:mi><mml:mrow><mml:mi>m</mml:mi><mml:mi>a</mml:mi><mml:mi>x</mml:mi></mml:mrow></mml:msub><mml:mo>&#x2212;</mml:mo><mml:msub><mml:mi>B</mml:mi><mml:mrow><mml:mi>m</mml:mi><mml:mi>i</mml:mi><mml:mi>n</mml:mi></mml:mrow></mml:msub></mml:mrow></mml:mfenced><mml:mo stretchy="false">/</mml:mo><mml:msub><mml:mi>S</mml:mi><mml:mi>a</mml:mi></mml:msub><mml:mo>,</mml:mo></mml:mrow></mml:math>
</disp-formula>
<p>Where, r represents the maximum probability of a swan filling a pixel, <italic>S</italic><sub>0</sub> is the pixel area, <italic>S</italic><sub>a</sub> denotes the individual swan&#x2019;s area from an orthographic view, <italic>B</italic><sub>i</sub> is the brightness of Pixel <italic>i</italic>, <italic>B</italic><sub>min</sub> is the background brightness, and <italic>B</italic><sub>max</sub> is the brightness of a pixel fully covered by a swan.</p>
<p>To improve estimation accuracy in heterogeneous environments such as shorelines, where water and mudflat brightness vary, shorelines and mudflats, we segmented the imagery into background-specific regions of interest (ROI) and dynamically adjusted <italic>B</italic><sub>max</sub> and <italic>B</italic><sub>min</sub> values within each ROI. For each ROI, we identified the maximum and minimum brightness levels for swans (<italic>B</italic><sub>a</sub>) and the background (<italic>B</italic><sub>ROI</sub>), including water and mudflat. <italic>B</italic><sub>max</sub> was set as the highest Ba within each ROI. <italic>B</italic><sub>min</sub> was determined as follows: if the highest <italic>B</italic><sub>ROI</sub> was lower than the lowest <italic>B</italic><sub>a</sub>, then the highest <italic>B</italic><sub>ROI</sub> was selected as <italic>B</italic><sub>min</sub>, otherwise, the lowest <italic>B</italic><sub>a</sub> was selected. Manual visual interpretation was used to remove noise and ensure the accuracy of swan detection.</p>
<p>The resulting raster data were converted to point features and spatially classified by location for distribution analysis. To validate the accuracy of population estimates, approximately 30 swan groups were randomly selected from each image for manual counting, and results were compared with satellite-based estimates.</p>
<p>This extended application enables more robust swan detection across spatially variable scenes and facilitates its integration with functional zoning layers of protected areas. The approach allows for large-scale, non-invasive population estimation and is particularly suitable for species that aggregate in open, low-canopy environments such as coastal wetlands.</p>
</sec>
<sec id="s2_4">
<label>2.4</label>
<title>Spatial zoning assessment and adjustment</title>
<p>We overlaid swan abundance and distribution data onto the spatial zoning map of the reserve using ArcGIS Pro, examining temporal and spatial patterns within the core, buffer, and experimental zones. According to China&#x2019;s National Standard for Nature Reserve Zoning (GB/T 35822-2018), core zones must cover areas with high densities of rare or endangered species and should constitute at least 30% of the total reserve area. Buffer zones should provide ecological protection for the core area and reduce external disturbances. Experimental zones, which should not exceed 50% of the total area, are allocated for activities with limited ecological impact, such as education and community livelihoods.</p>
<p>Our analysis revealed several key areas with high swan population size located in buffer and experimental zones, likely due to legacy zoning decisions based on hydrological features rather than species distribution data. We recommend that all consistently used habitats be reclassified into the core zone to enhance protection. Simultaneously, areas currently designated as core zones but lacking swan presence and heavily influenced by human activities should be downgraded to experimental zones. This data-driven framework offers a practical tool for adaptive reserve management and can be applied to other wetland or coastal nature reserves to align functional zoning with actual species ecology.</p>
</sec>
<sec id="s2_5">
<label>2.5</label>
<title>Workflow</title>
<p>The workflow presented in <xref ref-type="fig" rid="f2"><bold>Figure&#xa0;2</bold></xref> summarizes the main steps followed in this study. The process begins with the acquisition of suitable very high-resolution satellite imagery, including the selection of the target species and the required spatial resolution. The images are then preprocessed through orthorectification, atmospheric correction, radiometric normalization and co-registration to ensure comparability across years. After preprocessing, individual animals are identified using a brightness-based approach in which characteristic pixel values are examined, thresholds are selected, and individual targets are mapped. The resulting distribution maps are subsequently compared with existing zoning boundaries to determine whether key habitats fall within appropriate management zones and to identify areas where adjustments to zoning boundaries and zone designation may be needed. This workflow provides a clear structure for linking satellite-derived animal distribution information with assessments of protected area zoning.</p>
<fig id="f2" position="float">
<label>Figure&#xa0;2</label>
<caption>
<p>Workflow summarizing the main steps of the analysis, including data acquisition, image preprocessing, brightness-based detection of individual animals, and the evaluation of zoning effectiveness through spatial overlay with protected area boundaries.</p>
</caption>
<graphic mimetype="image" mime-subtype="tiff" xlink:href="fmars-13-1735150-g002.tif">
<alt-text content-type="machine-generated">Flowchart illustrating four sequential steps in analyzing animal distribution with satellite imagery: Data Acquisition, Image Preprocessing, Animal Detection and Distribution Analysis, and Zoning Overlay and Effectiveness Evaluation, each linked to specific tasks such as orthorectification and habitat identification.</alt-text>
</graphic></fig>
</sec>
</sec>
<sec id="s3" sec-type="results">
<label>3</label>
<title>Results</title>
<sec id="s3_1">
<label>3.1</label>
<title>Population distribution dynamics</title>
<p>Across all five satellite images, whooper swans were predominantly concentrated along the northern and western shores of Yuehu Lagoon, on the water surface of Yuehu itself, and at Yandunjiao (<xref ref-type="fig" rid="f3"><bold>Figure&#xa0;3</bold></xref>). Notably, the northern shores of Yuehu and Yandunjiao&#x2014;areas easily accessible to tourists&#x2014;accounted for approximately 66.35 &#xb1; 9.94% of the total observed swan population. Swans were observed on the surface of Yangyuchi Bay in 2009 and 2016 but were absent in 2013. The percentage of swans occupying mudflat habitats increased substantially, rising from approximately 30% in 2009 to nearly 80% by 2016. Nevertheless, data from December 2015 confirmed the continued ecological importance of open water, which still supported a significant portion of the swan population at that time (<xref ref-type="table" rid="T1"><bold>Table&#xa0;1</bold></xref>).</p>
<fig id="f3" position="float">
<label>Figure&#xa0;3</label>
<caption>
<p>Whooper swans&#x2019; distribution in the reserve during 2009 to 2016 and within the winter period during 2015 to 2016.</p>
</caption>
<graphic mimetype="image" mime-subtype="tiff" xlink:href="fmars-13-1735150-g003.tif">
<alt-text content-type="machine-generated">Six-panel map graphic displays whooper swan distributions across a reserve in February 2009, February 2013, February 2016, December 2015, January 2016, and February 2016, with core, buffer, and experimental zones clearly marked.</alt-text>
</graphic></fig>
</sec>
<sec id="s3_2">
<label>3.2</label>
<title>Population abundance dynamics</title>
<p>The abundance of whooper swans showed clear temporal fluctuations across the years 2009, 2013, and 2016, as well as during the overwintering period of 2015&#x2013;2016 (<xref ref-type="table" rid="T2"><bold>Table&#xa0;2</bold></xref>). In February of each year, the proportion of swans along the northern shores remained relatively stable at around 30%. In contrast, the western shores of Yuehu Lagoon exhibited a marked increase in swan abundance, growing from 6.62% in 2009 to 18.73% in 2016. The swan population at Yandunjiao nearly doubled, rising from 24.61% in 2009 to 46.82% in 2013, followed by a slight decrease to 34.33% in 2016. In Yangyuchi Bay, a notable decline was observed: approximately 20% of the swans were present there in 2009, but this dropped to less than 2% in subsequent years.</p>
<table-wrap id="T2" position="float">
<label>Table&#xa0;2</label>
<caption>
<p>The number of whooper swans in different locations and backgrounds of the reserve during 2009~2016 and the overwinter period of 2015~2016.</p>
</caption>
<table frame="hsides">
<thead>
<tr>
<th valign="middle" rowspan="3" align="center">Time</th>
<th valign="middle" rowspan="3" align="center">Total</th>
<th valign="middle" colspan="10" align="center">Locations</th>
<th valign="middle" colspan="4" align="center">Backgrounds</th>
</tr>
<tr>
<th valign="middle" colspan="2" align="center">Northern shores</th>
<th valign="middle" colspan="2" align="center">Western shores</th>
<th valign="middle" colspan="2" align="center">Yuehu Lagoon</th>
<th valign="middle" colspan="2" align="center">Yangyuchi Bay</th>
<th valign="middle" colspan="2" align="center">Yandunjiao</th>
<th valign="middle" colspan="2" align="center">Mudflat</th>
<th valign="middle" colspan="2" align="center">Water</th>
</tr>
<tr>
<th valign="middle" align="center">No.</th>
<th valign="middle" align="center">%</th>
<th valign="middle" align="center">No.</th>
<th valign="middle" align="center">%</th>
<th valign="middle" align="center">No.</th>
<th valign="middle" align="center">%</th>
<th valign="middle" align="center">No.</th>
<th valign="middle" align="center">%</th>
<th valign="middle" align="center">No.</th>
<th valign="middle" align="center">%</th>
<th valign="middle" align="center">No.</th>
<th valign="middle" align="center">%</th>
<th valign="middle" align="center">No.</th>
<th valign="middle" align="center">%</th>
</tr>
</thead>
<tbody>
<tr>
<th valign="middle" colspan="16" align="left">2009~2016</th>
</tr>
<tr>
<td valign="middle" align="center">Feb 2009</td>
<td valign="middle" align="center">1662</td>
<td valign="middle" align="center">501</td>
<td valign="middle" align="center">30.14</td>
<td valign="middle" align="center">110</td>
<td valign="middle" align="center">6.62</td>
<td valign="middle" align="center">310</td>
<td valign="middle" align="center">18.65</td>
<td valign="middle" align="center">332</td>
<td valign="middle" align="center">19.98</td>
<td valign="middle" align="center">409</td>
<td valign="middle" align="center">24.61</td>
<td valign="middle" align="center">479</td>
<td valign="middle" align="center">28.82</td>
<td valign="middle" align="center">1183</td>
<td valign="middle" align="center">71.18</td>
</tr>
<tr>
<td valign="middle" align="center">Feb 2013</td>
<td valign="middle" align="center">1124</td>
<td valign="middle" align="center">342</td>
<td valign="middle" align="center">30.45</td>
<td valign="middle" align="center">122</td>
<td valign="middle" align="center">10.88</td>
<td valign="middle" align="center">134</td>
<td valign="middle" align="center">11.88</td>
<td valign="middle" align="center">0</td>
<td valign="middle" align="center">0.00</td>
<td valign="middle" align="center">526</td>
<td valign="middle" align="center">46.82</td>
<td valign="middle" align="center">560</td>
<td valign="middle" align="center">49.82</td>
<td valign="middle" align="center">564</td>
<td valign="middle" align="center">50.18</td>
</tr>
<tr>
<td valign="middle" align="center">Feb 2016</td>
<td valign="middle" align="center">1879</td>
<td valign="middle" align="center">560</td>
<td valign="middle" align="center">29.80</td>
<td valign="middle" align="center">352</td>
<td valign="middle" align="center">18.73</td>
<td valign="middle" align="center">299</td>
<td valign="middle" align="center">15.91</td>
<td valign="middle" align="center">23</td>
<td valign="middle" align="center">1.22</td>
<td valign="middle" align="center">645</td>
<td valign="middle" align="center">34.33</td>
<td valign="middle" align="center">1348</td>
<td valign="middle" align="center">71.74</td>
<td valign="middle" align="center">531</td>
<td valign="middle" align="center">28.26</td>
</tr>
<tr>
<th valign="middle" colspan="16" align="left">Overwinter period of 2015~2016</th>
</tr>
<tr>
<td valign="middle" align="center">Dec 2015</td>
<td valign="middle" align="center">2190</td>
<td valign="middle" align="center">484</td>
<td valign="middle" align="center">22.10</td>
<td valign="middle" align="center">410</td>
<td valign="middle" align="center">18.72</td>
<td valign="middle" align="center">523</td>
<td valign="middle" align="center">23.88</td>
<td valign="middle" align="center">23</td>
<td valign="middle" align="center">1.05</td>
<td valign="middle" align="center">750</td>
<td valign="middle" align="center">34.25</td>
<td valign="middle" align="center">691</td>
<td valign="middle" align="center">31.55</td>
<td valign="middle" align="center">1499</td>
<td valign="middle" align="center">68.45</td>
</tr>
<tr>
<td valign="middle" align="center">Jan 2016</td>
<td valign="middle" align="center">1287</td>
<td valign="middle" align="center">406</td>
<td valign="middle" align="center">31.55</td>
<td valign="middle" align="center">238</td>
<td valign="middle" align="center">18.49</td>
<td valign="middle" align="center">0</td>
<td valign="middle" align="center">0.00</td>
<td valign="middle" align="center">0</td>
<td valign="middle" align="center">0.00</td>
<td valign="middle" align="center">643</td>
<td valign="middle" align="center">49.96</td>
<td valign="middle" align="center">1004</td>
<td valign="middle" align="center">78.01</td>
<td valign="middle" align="center">283</td>
<td valign="middle" align="center">21.99</td>
</tr>
<tr>
<td valign="middle" align="center">Feb 2016</td>
<td valign="middle" align="center">1879</td>
<td valign="middle" align="center">560</td>
<td valign="middle" align="center">29.80</td>
<td valign="middle" align="center">352</td>
<td valign="middle" align="center">18.73</td>
<td valign="middle" align="center">299</td>
<td valign="middle" align="center">15.91</td>
<td valign="middle" align="center">23</td>
<td valign="middle" align="center">1.22</td>
<td valign="middle" align="center">645</td>
<td valign="middle" align="center">34.33</td>
<td valign="middle" align="center">1348</td>
<td valign="middle" align="center">71.74</td>
<td valign="middle" align="center">531</td>
<td valign="middle" align="center">28.26</td>
</tr>
</tbody>
</table>
</table-wrap>
<p>During the overwintering period of 2015&#x2013;2016, dynamic shifts in habitat use were evident. A sharp decline in the proportion of swans utilizing water surfaces was recorded, plummeting from 68.45% in December to only 21.99% in January. A modest increase to 28.26% followed in February. This dramatic decrease likely reflects the effects of freezing conditions, which restricted access to open water and forced swans to seek alternative habitats. Overall swan abundance in the reserve also declined during this period, from 2,190 individuals in December to 1,287 in January. Despite this reduction, populations increased at both the northern shore and Yandunjiao sites, suggesting their role as critical refuges during extreme cold. Meanwhile, the western shore maintained a relatively stable population, indicating a consistent habitat preference.</p>
<p>The average estimation error across the five satellite images was 4.65% (SE = 2.15) (<xref ref-type="table" rid="T2"><bold>Table&#xa0;2</bold></xref>). The highest error occurred in January 2016 (7.90%), likely due to widespread ice coverage in Yuehu Lagoon that affected swan detectability. However, no statistically significant differences in estimation accuracy were found across different dates, locations, or habitat types.</p>
</sec>
<sec id="s3_3">
<label>3.3</label>
<title>Spatial zoning assessment</title>
<p>Despite being designated to protect the majority of rare and endangered species, the core zone of the reserve supported only a limited proportion of the whooper swan population throughout the study period. The proportion of swans within the core zone declined from 35.80% in 2009 to just 10.73% in 2013, with only a modest recovery to 25.60% in 2016. In January 2016, only 10 individuals were recorded in the core zone&#x2014;the lowest number observed (<xref ref-type="table" rid="T3"><bold>Table&#xa0;3</bold></xref>).</p>
<table-wrap id="T3" position="float">
<label>Table&#xa0;3</label>
<caption>
<p>The estimation error of whooper swan population number in different images.</p>
</caption>
<table frame="hsides">
<thead>
<tr>
<th valign="middle" colspan="5" align="right">Unit: %</th>
</tr>
<tr>
<th valign="middle" align="center">Time</th>
<th valign="middle" align="center">Mean</th>
<th valign="middle" align="center">Standard error</th>
<th valign="middle" colspan="2" align="center">95% confidence interval</th>
</tr>
</thead>
<tbody>
<tr>
<td valign="middle" align="center">Feb 2009</td>
<td valign="middle" align="center">4.49</td>
<td valign="middle" align="center">1.68</td>
<td valign="middle" align="center">1.08</td>
<td valign="middle" align="center">7.90</td>
</tr>
<tr>
<td valign="middle" align="center">Feb 2013</td>
<td valign="middle" align="center">4.80</td>
<td valign="middle" align="center">1.88</td>
<td valign="middle" align="center">0.99</td>
<td valign="middle" align="center">8.61</td>
</tr>
<tr>
<td valign="middle" align="center">Dec 2015</td>
<td valign="middle" align="center">4.18</td>
<td valign="middle" align="center">2.23</td>
<td valign="middle" align="center">-0.32</td>
<td valign="middle" align="center">8.67</td>
</tr>
<tr>
<td valign="middle" align="center">Jan 2016</td>
<td valign="middle" align="center">7.90</td>
<td valign="middle" align="center">2.13</td>
<td valign="middle" align="center">3.53</td>
<td valign="middle" align="center">12.26</td>
</tr>
<tr>
<td valign="middle" align="center">Feb 2016</td>
<td valign="middle" align="center">1.87</td>
<td valign="middle" align="center">1.77</td>
<td valign="middle" align="center">-1.71</td>
<td valign="middle" align="center">5.45</td>
</tr>
<tr>
<td valign="middle" align="center">on average</td>
<td valign="middle" align="center">4.65 &#xb1; 2.15</td>
<td valign="middle" align="left"/>
<td valign="middle" align="center"/>
<td valign="middle" align="center"/>
</tr>
</tbody>
</table>
</table-wrap>
<p>In contrast, the buffer zone consistently hosted around 40% of the swan population across all years, while the experimental zone exhibited a gradual increase in swan use from 2009 to 2016. Occasional swan sightings were also recorded outside the reserve boundary at Yandunjiao. The overwintering period of 2015&#x2013;2016 revealed pronounced shifts in spatial use. The proportion of swans in the core zone dropped from 30.41% in December 2015 to a mere 0.78% in January 2016. Meanwhile, the buffer and experimental zones together supported nearly the entire population during that month, underscoring the critical function of these areas in providing refuge during extreme winter conditions (<xref ref-type="table" rid="T4"><bold>Table&#xa0;4</bold></xref>).</p>
<table-wrap id="T4" position="float">
<label>Table&#xa0;4</label>
<caption>
<p>Whooper swans in different zones of the reserve during 2009~2016 and the overwinter period of 2015~2016.</p>
</caption>
<table frame="hsides">
<thead>
<tr>
<th valign="middle" rowspan="2" align="center">Time</th>
<th valign="middle" rowspan="2" align="center">Total</th>
<th valign="middle" colspan="2" align="center">Core zone</th>
<th valign="middle" colspan="2" align="center">Buffer zone</th>
<th valign="middle" colspan="2" align="center">Experimental zone</th>
<th valign="middle" colspan="2" align="center">Outside the reserve</th>
</tr>
<tr>
<th valign="middle" align="center">No.</th>
<th valign="middle" align="center">%</th>
<th valign="middle" align="center">No.</th>
<th valign="middle" align="center">%</th>
<th valign="middle" align="center">No.</th>
<th valign="middle" align="center">%</th>
<th valign="middle" align="center">No.</th>
<th valign="middle" align="center">%</th>
</tr>
</thead>
<tbody>
<tr>
<th valign="middle" colspan="10" align="center">2009~2016</th>
</tr>
<tr>
<td valign="middle" align="center">Feb 2009</td>
<td valign="middle" align="center">1662</td>
<td valign="middle" align="center">595</td>
<td valign="middle" align="center">35.80</td>
<td valign="middle" align="center">658</td>
<td valign="middle" align="center">39.59</td>
<td valign="middle" align="center">409</td>
<td valign="middle" align="center">24.61</td>
<td valign="middle" align="center">0</td>
<td valign="middle" align="center">0.00</td>
</tr>
<tr>
<td valign="middle" align="center">Feb 2013</td>
<td valign="middle" align="center">1124</td>
<td valign="middle" align="center">121</td>
<td valign="middle" align="center">10.73</td>
<td valign="middle" align="center">420</td>
<td valign="middle" align="center">37.34</td>
<td valign="middle" align="center">475</td>
<td valign="middle" align="center">42.30</td>
<td valign="middle" align="center">108</td>
<td valign="middle" align="center">9.65</td>
</tr>
<tr>
<td valign="middle" align="center">Feb 2016</td>
<td valign="middle" align="center">1879</td>
<td valign="middle" align="center">481</td>
<td valign="middle" align="center">25.60</td>
<td valign="middle" align="center">770</td>
<td valign="middle" align="center">40.98</td>
<td valign="middle" align="center">600</td>
<td valign="middle" align="center">31.93</td>
<td valign="middle" align="center">28</td>
<td valign="middle" align="center">1.49</td>
</tr>
<tr>
<th valign="middle" colspan="10" align="center">Overwinter period of 2015~2016</th>
</tr>
<tr>
<td valign="middle" align="center">Dec 2015</td>
<td valign="middle" align="center">2190</td>
<td valign="middle" align="center">666</td>
<td valign="middle" align="center">30.41</td>
<td valign="middle" align="center">794</td>
<td valign="middle" align="center">36.26</td>
<td valign="middle" align="center">697</td>
<td valign="middle" align="center">31.83</td>
<td valign="middle" align="center">33</td>
<td valign="middle" align="center">1.51</td>
</tr>
<tr>
<td valign="middle" align="center">Jan 2016</td>
<td valign="middle" align="center">1287</td>
<td valign="middle" align="center">10</td>
<td valign="middle" align="center">0.78</td>
<td valign="middle" align="center">634</td>
<td valign="middle" align="center">49.26</td>
<td valign="middle" align="center">643</td>
<td valign="middle" align="center">49.96</td>
<td valign="middle" align="center">0</td>
<td valign="middle" align="center">0.00</td>
</tr>
<tr>
<td valign="middle" align="center">Feb 2016</td>
<td valign="middle" align="center">1879</td>
<td valign="middle" align="center">481</td>
<td valign="middle" align="center">25.60</td>
<td valign="middle" align="center">770</td>
<td valign="middle" align="center">40.98</td>
<td valign="middle" align="center">600</td>
<td valign="middle" align="center">31.93</td>
<td valign="middle" align="center">28</td>
<td valign="middle" align="center">1.49</td>
</tr>
</tbody>
</table>
</table-wrap>
</sec>
<sec id="s3_4">
<label>3.4</label>
<title>Spatial zoning adjustment</title>
<p>To improve habitat protection and ensure alignment between zoning and actual swan distribution, we recommend reclassifying key swan aggregation areas as core zones. Specifically, we propose converting 257.07 hectares from the buffer zone (including parts of Yuehu Lagoon and Yangyuchi Bay), 41.4 hectares from the experimental zone, and 9.54 hectares from an unzoned area at Yandunjiao into new core zones (<xref ref-type="fig" rid="f4"><bold>Figure&#xa0;4</bold></xref>). To facilitate reserve management, the boundaries of the proposed core zones follow the natural coastline.</p>
<fig id="f4" position="float">
<label>Figure&#xa0;4</label>
<caption>
<p>The distribution of whooper swans interpreted from 5 very high-resolution satellite images during February 2009 to February 2016 and suggested zoning adjustment for the Rongcheng Whooper Swan National Natural Reserve, China.</p>
</caption>
<graphic mimetype="image" mime-subtype="tiff" xlink:href="fmars-13-1735150-g004.tif">
<alt-text content-type="machine-generated">Map illustrating habitat usage and management zones for whooper swans, marked by small black dots, with multiple zone designations visually differentiated and a legend explaining each type of land use classification. North arrow and scale bar are present.</alt-text>
</graphic></fig>
<p>In addition, we suggest reassigning 150.97 hectares of the current core zone&#x2014;primarily offshore waters beyond Yangyuchi Bay that are used for seaweed farming and lack bird activity&#x2014;to the experimental zone. Following these adjustments, the total proportion of core zones within the reserve would increase from 38.82% to 48.06% (<xref ref-type="table" rid="T5"><bold>Table&#xa0;5</bold></xref>), enhancing protection for the whooper swan population while maintaining zoning balance in accordance with national conservation guidelines.</p>
<table-wrap id="T5" position="float">
<label>Table&#xa0;5</label>
<caption>
<p>The matrix of suggested zone changes for the Rongcheng Whooper Swan National Natural Reserve, China.</p>
</caption>
<table frame="hsides">
<thead>
<tr>
<th valign="middle" colspan="7" align="right">Unit: hectares</th>
</tr>
<tr>
<th valign="middle" rowspan="2" colspan="2" align="center"/>
<th valign="middle" colspan="4" align="center">Suggested zoning</th>
<th valign="middle" rowspan="2" align="center">In total</th>
</tr>
<tr>
<th valign="middle" align="center">Core zone</th>
<th valign="middle" align="center">Buffer zone</th>
<th valign="middle" align="center">Experimental zone</th>
<th valign="middle" align="center">Unreserved area</th>
</tr>
</thead>
<tbody>
<tr>
<td valign="middle" rowspan="4" align="center">Present&#xa0;zoning</td>
<td valign="middle" align="center">Core zone</td>
<td valign="middle" align="right">489.23</td>
<td valign="middle" align="right">0</td>
<td valign="middle" align="right">150.97</td>
<td valign="middle" align="center">0</td>
<td valign="middle" align="right">640.2</td>
</tr>
<tr>
<td valign="middle" align="center">Buffer zone</td>
<td valign="middle" align="right">257.07</td>
<td valign="middle" align="right">404.26</td>
<td valign="middle" align="right">0</td>
<td valign="middle" align="center">0</td>
<td valign="middle" align="right">661.33</td>
</tr>
<tr>
<td valign="middle" align="center">Experimental zone</td>
<td valign="middle" align="right">41.4</td>
<td valign="middle" align="right">0</td>
<td valign="middle" align="right">306.28</td>
<td valign="middle" align="center">0</td>
<td valign="middle" align="right">347.68</td>
</tr>
<tr>
<td valign="middle" align="center">Unreserved area</td>
<td valign="middle" align="right">9.54</td>
<td valign="middle" align="right">0</td>
<td valign="middle" align="right">0</td>
<td valign="middle" align="center">0</td>
<td valign="middle" align="right">9.54</td>
</tr>
<tr>
<td valign="middle" colspan="2" align="center">In total</td>
<td valign="middle" align="right">797.24</td>
<td valign="middle" align="right">404.26</td>
<td valign="middle" align="right">457.25</td>
<td valign="middle" align="center">0</td>
<td valign="middle" align="right">1658.75</td>
</tr>
</tbody>
</table>
</table-wrap>
</sec>
</sec>
<sec id="s4" sec-type="discussion">
<label>4</label>
<title>Discussions</title>
<p>Aligning the spatial configuration of protected areas with the ecological requirements of target species is a fundamental principle in conservation science and practice (<xref ref-type="bibr" rid="B10">Dudley, 2008</xref>; <xref ref-type="bibr" rid="B14">Geldmann et&#xa0;al., 2013</xref>; <xref ref-type="bibr" rid="B33">Rodrigues and Cazalis, 2020</xref>). Remote sensing has emerged as a powerful tool in conservation, offering opportunities to optimize protected area networks and evaluate the effectiveness of conservation interventions (<xref ref-type="bibr" rid="B34">Rose et&#xa0;al., 2015</xref>). This study provides a case-based demonstration of how satellite-derived data on species abundance and distribution can be directly applied to assess and refine spatial zoning, highlighting the potential of wildlife remote sensing for advancing species-oriented conservation planning.</p>
<p>Historically, the whooper swan was prevalent across Rongcheng&#x2019;s coastal lagoons and bays, with reports of over 10,000 individuals in the 1960s and 1990s. However, due to human activities such as sea reclamation and aquaculture pond construction, their presence in other coastal waters has dwindled over the past two decades, making the reserve their final refuge in the region. Yuehu Lagoon, part of the reserve, annually hosted approximately 3,000 to 4,000 swans between 1988 and 1994, with numbers ranging from 595 to 1086 during the 2015&#x2013;2016 overwintering period. This declining trend is confirmed by our findings. The population&#x2019;s fluctuations across different locations during the overwinter period, reflecting shifts in habitat preference, are attributed to variations in food availability, ice coverage, and other factors, a pattern also validated by other studies (<xref ref-type="bibr" rid="B20">Jia et&#xa0;al., 2019</xref>; <xref ref-type="bibr" rid="B31">Rees et&#xa0;al., 1997</xref>). In December 2015, the swans in Yuehu Lagoon fed on seagrass seedlings in shallow waters, but the population dwindled, possibly due to ice formation and seedling consumption. The relatively stable swan numbers on the northern shores of Yuehu and at Yandunjiao might be due to feeding by reserve staff and tourists.</p>
<p>Although the reserve was initially zoned to protect water bodies, our findings reveal a mismatch between current zoning boundaries and key habitats used by whooper swans. In particular, critical mudflat areas were excluded from the core zones despite their significance for resting and foraging, especially during the winter months when water bodies are frozen. Major congregation areas&#x2014;including the northern and western shores of Yuehu Lagoon and the shoreline at Yandunjiao&#x2014;currently fall within buffer or experimental zones. This spatial misalignment undermines the reserve&#x2019;s effectiveness in meeting national conservation standards. We therefore recommend revising the zoning scheme to designate these swan aggregation areas as core zones.</p>
<p>Habitat use patterns observed during the study also reflect ongoing shifts in ecological suitability. Yangyuchi Bay, which previously hosted large numbers of swans, now supports few individuals, possibly due to seagrass loss or habitat degradation. Unlike Yuehu Lagoon, where seagrass restoration efforts have been documented (<xref ref-type="bibr" rid="B48">Zhang et&#xa0;al., 2015</xref>), no similar initiatives have been implemented in Yangyuchi Bay. Our results suggest the need to initiate habitat assessments and potential restoration in this area. The growing swan presence on the western shore&#x2014;a relatively undisturbed area shaped by a small river&#x2014;may indicate an emerging habitat preference. Conversely, the sustained high numbers at sites receiving artificial feeding suggest an ongoing reliance on human support. For long-term sustainability, reserve management should prioritize the enhancement of natural habitats over artificial feeding.</p>
<p>While this study demonstrates the effectiveness of VHR satellite imagery for wildlife monitoring and conservation planning, several limitations should be acknowledged. The method is most effective for species that aggregate in open, unvegetated habitats; its applicability is limited in areas with dense vegetation or canopy cover. The applicability of the approach also depends on the characteristics of the species and the surrounding environment. It performs best for large-bodied and high-contrast species that can be clearly distinguished from the background in open coastal wetlands, mudflats or grasslands. Although this study focuses on whooper swans, the general framework can be applied to other colonial or flocking species, provided that habitat openness and target contrast are sufficient for reliable detection. For more complex ecosystems or species with limited spectral contrast, additional sensors or analytical techniques may be required to achieve accurate identification. Image availability, weather conditions, and acquisition timing may also affect detection accuracy. Furthermore, the cost of commercial VHR imagery may pose challenges for routine monitoring. Future work should explore the integration of emerging technologies such as low-cost high-resolution satellites, unmanned aerial systems, and machine learning algorithms (<xref ref-type="bibr" rid="B18">Hollings et&#xa0;al., 2018</xref>) to broaden the method&#x2019;s applicability across species and ecosystems.</p>
<p>Artificial intelligence has been increasingly applied to image-based wildlife surveys in recent years, and its performance in recognizing large, well-defined targets in aerial and ground imagery has improved rapidly, as evidenced by recent reviews and empirical studies demonstrating significant progress in animal detection across aerial, drone and satellite platforms (<xref ref-type="bibr" rid="B47">Xu et&#xa0;al., 2024</xref>; <xref ref-type="bibr" rid="B46">Wu et&#xa0;al., 2023</xref>; <xref ref-type="bibr" rid="B2">Axford et&#xa0;al., 2024</xref>). However, recent reviews and empirical studies suggest that automated detection methods may struggle when targets occupy only a few pixels, when background complexity is high, or when animals cluster densely, conditions that are common for colonial waterbirds and marine mammals in satellite scenes (<xref ref-type="bibr" rid="B26">Nikouei et&#xa0;al., 2025</xref>; <xref ref-type="bibr" rid="B19">Hua and Chen, 2025</xref>). Under these conditions, AI-based detection methods may merge adjacent individuals or fail to separate them from the background with sufficient accuracy. These constraints are a key reason why AI techniques were not adopted in the present study, and why a brightness-based workflow provided more reliable results for identifying individual swans. As analytical tools continue to advance, future work should examine how AI methods can be adapted to improve small-target detection and to distinguish tightly aggregated individuals in satellite images.</p>
</sec>
<sec id="s5" sec-type="conclusions">
<label>5</label>
<title>Conclusion</title>
<p>This study highlights the practical value of integrating satellite-based wildlife monitoring with protected area management. By using very high-resolution (VHR) satellite imagery to estimate the abundance and distribution of whooper swans, we demonstrated how remote sensing data can support adaptive spatial zoning and identify mismatches between designated conservation zones and actual habitat use. The findings emphasize the need for species-oriented zoning strategies that account for seasonal shifts, habitat degradation, and human-induced changes. Incorporating animal remote sensing into conservation planning offers a scalable, non-invasive, and cost-effective approach to enhance biodiversity protection, especially for migratory species. Our results provide a replicable framework for aligning conservation targets with ecological realities and advancing the implementation of global biodiversity goals.</p>
</sec>
</body>
<back>
<sec id="s6" sec-type="data-availability">
<title>Data availability statement</title>
<p>The original contributions presented in the study are included in the article/supplementary material. Further inquiries can be directed to the corresponding author.</p></sec>
<sec id="s7" sec-type="ethics-statement">
<title>Ethics statement</title>
<p>The animal study was approved by the ethics committee of Hainan University. The study was conducted in accordance with the local legislation and institutional requirements.</p></sec>
<sec id="s8" sec-type="author-contributions">
<title>Author contributions</title>
<p>PZ: Conceptualization, Methodology, Writing &#x2013; original draft, Writing &#x2013; review &amp; editing. LS: Investigation, Data curation, Validation, Writing &#x2013; original draft. FW: Investigation, Data curation, Writing &#x2013; original draft. LJ: Supervision, Project administration, Resources, Funding acquisition, Validation, Writing &#x2013; review &amp; editing. JZ: Conceptualization, Supervision, Writing &#x2013; review &amp; editing.</p></sec>
<sec id="s10" sec-type="COI-statement">
<title>Conflict of interest</title>
<p>The author(s) declared that this work was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.</p></sec>
<sec id="s11" sec-type="ai-statement">
<title>Generative AI statement</title>
<p>The author(s) declared that generative AI was not used in the creation of this manuscript.</p>
<p>Any alternative text (alt text) provided alongside figures in this article has been generated by Frontiers with the support of artificial intelligence and reasonable efforts have been made to ensure accuracy, including review by the authors wherever possible. If you identify any issues, please contact us.</p></sec>
<sec id="s12" sec-type="disclaimer">
<title>Publisher&#x2019;s note</title>
<p>All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.</p></sec>
<ref-list>
<title>References</title>
<ref id="B1">
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Attard</surname> <given-names>M. R. G.</given-names></name>
<name><surname>Phillips</surname> <given-names>R. A.</given-names></name>
<name><surname>Oppel</surname> <given-names>S.</given-names></name>
<name><surname>Bowler</surname> <given-names>E.</given-names></name>
<name><surname>Fretwell</surname> <given-names>P. T.</given-names></name>
</person-group> (<year>2025</year>). 
<article-title>Feasibility of using very high-resolution satellite imagery to monitor <italic>Tristan albatrosses Diomedea dabbenena</italic> on Gough Island</article-title>. <source>Endangered Species Res.</source> <volume>56</volume>, <fpage>187</fpage>&#x2013;<lpage>199</lpage>. doi:&#xa0;<pub-id pub-id-type="doi">10.3354/esr01396</pub-id>, PMID: <pub-id pub-id-type="pmid">41366600</pub-id>
</mixed-citation>
</ref>
<ref id="B2">
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Axford</surname> <given-names>D.</given-names></name>
<name><surname>Sohel</surname> <given-names>F.</given-names></name>
<name><surname>Vanderklift</surname> <given-names>M. A.</given-names></name>
<name><surname>Simon</surname> <given-names>K</given-names></name>
</person-group>. (<year>2024</year>). 
<article-title>Collectively advancing deep learning for animal detection in drone imagery: successes, challenges, and research gaps</article-title>. <source>Ecological Informatics</source>, <volume>83</volume>, <elocation-id>102842</elocation-id>. doi:&#xa0;<pub-id pub-id-type="doi">10.1016/j.ecoinf.2024.102842</pub-id>, PMID: <pub-id pub-id-type="pmid">41737640</pub-id>
</mixed-citation>
</ref>
<ref id="B3">
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Barnes</surname> <given-names>M. D.</given-names></name>
<name><surname>Glew</surname> <given-names>L.</given-names></name>
<name><surname>Wyborn</surname> <given-names>C.</given-names></name>
<name><surname>Craigie</surname> <given-names>I. D.</given-names></name>
<name><surname>Barr</surname> <given-names>L. M.</given-names></name>
<name><surname>Butchart</surname> <given-names>S. H. M.</given-names></name>
<etal/>
</person-group>. (<year>2018</year>). 
<article-title>Prevent perverse outcomes from global protected area policy. Nature Ecology &amp; Evolution</article-title>, <volume>2</volume>, <fpage>759</fpage>&#x2013;<lpage>762</lpage>. doi:&#xa0;<pub-id pub-id-type="doi">10.1038/s41559-018-0501-y</pub-id>, PMID: <pub-id pub-id-type="pmid">29556080</pub-id>
</mixed-citation>
</ref>
<ref id="B4">
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Buckland</surname> <given-names>S. T.</given-names></name>
<name><surname>Burt</surname> <given-names>M. L.</given-names></name>
<name><surname>Rexstad</surname> <given-names>E.</given-names></name>
<name><surname>Mellor</surname> <given-names>M.</given-names></name>
<name><surname>Williams</surname> <given-names>A. E.</given-names></name>
<name><surname>Woodward</surname> <given-names>R.</given-names></name>
</person-group> (<year>2012</year>). 
<article-title>Aerial surveys of seabirds: the advent of digital methods</article-title>. <source>J. Appl. Ecol.</source> <volume>49</volume>, <fpage>960</fpage>&#x2013;<lpage>967</lpage>. doi:&#xa0;<pub-id pub-id-type="doi">10.1111/j.1365-2664.2012.02150.x</pub-id>, PMID: <pub-id pub-id-type="pmid">41738386</pub-id>
</mixed-citation>
</ref>
<ref id="B5">
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Cubaynes</surname> <given-names>H. C.</given-names></name>
<name><surname>Forcada</surname> <given-names>J.</given-names></name>
<name><surname>Kovacs</surname> <given-names>K. M.</given-names></name>
<name><surname>Lydersen</surname> <given-names>C.</given-names></name>
<name><surname>Downie</surname> <given-names>R.</given-names></name>
<name><surname>Fretwell</surname> <given-names>P. T.</given-names></name>
</person-group> (<year>2024</year>). 
<article-title>Walruses from space: Walrus counts in simultaneous remotely piloted aircraft system versus very high-resolution satellite imagery</article-title>. <source>Remote Sens. Ecol. Conserv.</source> <volume>10</volume>, <fpage>584</fpage>&#x2013;<lpage>596</lpage>. doi:&#xa0;<pub-id pub-id-type="doi">10.1002/rse2.391</pub-id>, PMID: <pub-id pub-id-type="pmid">41737730</pub-id>
</mixed-citation>
</ref>
<ref id="B6">
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Cui</surname> <given-names>Y.</given-names></name>
<name><surname>Carmona</surname> <given-names>C. P.</given-names></name>
<name><surname>Wang</surname> <given-names>Z</given-names></name>
</person-group>. (<year>2025</year>). 
<article-title>Identifying global conservation priorities for terrestrial vertebrates based on multiple dimensions of biodiversity</article-title>. <source>Conservation Biology</source>, <volume>38</volume>, <elocation-id>e14205</elocation-id>. doi:&#xa0;<pub-id pub-id-type="doi">10.1111/cobi.14205</pub-id>, PMID: <pub-id pub-id-type="pmid">37855155</pub-id>
</mixed-citation>
</ref>
<ref id="B7">
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Cunningham</surname> <given-names>L.</given-names></name>
<name><surname>Baxter</surname> <given-names>J. M.</given-names></name>
<name><surname>Boyd</surname> <given-names>I. L.</given-names></name>
</person-group> (<year>2010</year>). 
<article-title>Variation in harbour seal counts obtained using aerial surveys</article-title>. <source>J. Mar. Biol. Assoc. United Kingdom</source> <volume>90</volume>, <fpage>1659</fpage>&#x2013;<lpage>1666</lpage>. doi:&#xa0;<pub-id pub-id-type="doi">10.1017/S002531540999155X</pub-id>, PMID: <pub-id pub-id-type="pmid">41694064</pub-id>
</mixed-citation>
</ref>
<ref id="B8">
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Dasgupta</surname> <given-names>S.</given-names></name>
<name><surname>Wheeler</surname> <given-names>D.</given-names></name>
<name><surname>Blankespoor</surname> <given-names>B.</given-names></name>
</person-group> (<year>2025</year>). 
<article-title>Pathways to 30 &#xd7; 30: evidence-based lessons from global case studies in biodiversity conservation</article-title>. <source>Diversity</source> <volume>17</volume>, <elocation-id>401</elocation-id>. doi:&#xa0;<pub-id pub-id-type="doi">10.3390/d17060401</pub-id>, PMID: <pub-id pub-id-type="pmid">41725453</pub-id>
</mixed-citation>
</ref>
<ref id="B9">
<mixed-citation publication-type="book">
<person-group person-group-type="author">
<name><surname>Diaz</surname> <given-names>S.</given-names></name>
<name><surname>Settele</surname> <given-names>J.</given-names></name>
<name><surname>Brond&#xed;zio</surname> <given-names>E.</given-names></name>
<name><surname>Ngo</surname> <given-names>H. T.</given-names></name>
<name><surname>Gueze</surname> <given-names>M.</given-names></name>
<name><surname>Agard</surname> <given-names>J.</given-names></name>
<etal/>
</person-group>. (<year>2019</year>). <source>Summary for policymakers of the global assessment report on biodiversity and ecosystem services of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services</source>. <publisher-loc>Bonn, Germany</publisher-loc>: 
<publisher-name>Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES)</publisher-name>.
</mixed-citation>
</ref>
<ref id="B10">
<mixed-citation publication-type="book">
<person-group person-group-type="author">
<name><surname>Dudley</surname> <given-names>N.</given-names></name>
</person-group> (<year>2008</year>). <source>Guidelines for applying protected area management categories</source> (<publisher-loc>Gland, Switzerland</publisher-loc>: 
<publisher-name>Iucn</publisher-name>).
</mixed-citation>
</ref>
<ref id="B11">
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Duporge</surname> <given-names>I.</given-names></name>
<name><surname>Lin</surname> <given-names>X.</given-names></name>
<name><surname>Palnitkar</surname> <given-names>A.</given-names></name>
<name><surname>Suresh</surname> <given-names>A.</given-names></name>
<name><surname>Isupova</surname> <given-names>O.</given-names></name>
<name><surname>Rubenstein</surname> <given-names>D. I.</given-names></name>
<etal/>
</person-group>. (<year>2025</year>). 
<article-title>Automated rhinoceros detection in satellite imagery using deep learning</article-title>. <source>Sci. Rep.</source> <volume>15</volume>, <fpage>39352</fpage>. doi:&#xa0;<pub-id pub-id-type="doi">10.1038/s41598-025-24178-2</pub-id>, PMID: <pub-id pub-id-type="pmid">41214078</pub-id>
</mixed-citation>
</ref>
<ref id="B12">
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Fernandes</surname> <given-names>L. D. A.</given-names></name>
<name><surname>Gama</surname> <given-names>B. A. P.</given-names></name>
<name><surname>Monteiro-Neto</surname> <given-names>C.</given-names></name>
</person-group> (<year>2025</year>). 
<article-title>Use of unmanned aerial system for monitoring sea turtles in coastal areas</article-title>. <source>Regional Stud. Mar. Sci.</source> <volume>52</volume>, <elocation-id>104002</elocation-id>. doi:&#xa0;<pub-id pub-id-type="doi">10.1016/j.rsma.2024.104002</pub-id>, PMID: <pub-id pub-id-type="pmid">41737640</pub-id>
</mixed-citation>
</ref>
<ref id="B13">
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Fretwell</surname> <given-names>P. T.</given-names></name>
<name><surname>Scofield</surname> <given-names>P.</given-names></name>
<name><surname>Phillips</surname> <given-names>R. A.</given-names></name>
</person-group> (<year>2017</year>). 
<article-title>Using super-high resolution satellite imagery to census threatened albatrosses</article-title>. <source>Ibis</source> <volume>159</volume>, <fpage>481</fpage>&#x2013;<lpage>490</lpage>. doi:&#xa0;<pub-id pub-id-type="doi">10.1111/ibi.12482</pub-id>, PMID: <pub-id pub-id-type="pmid">41738386</pub-id>
</mixed-citation>
</ref>
<ref id="B14">
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Geldmann</surname> <given-names>J.</given-names></name>
<name><surname>Barnes</surname> <given-names>M.</given-names></name>
<name><surname>Coad</surname> <given-names>L.</given-names></name>
<name><surname>Craigie</surname> <given-names>I. D.</given-names></name>
<name><surname>Hockings</surname> <given-names>M.</given-names></name>
<name><surname>Burgess</surname> <given-names>N. D.</given-names></name>
</person-group> (<year>2013</year>). 
<article-title>Effectiveness of terrestrial protected areas in reducing habitat loss and population declines</article-title>. <source>Biol. Conserv.</source> <volume>161</volume>, <fpage>230</fpage>&#x2013;<lpage>238</lpage>. doi:&#xa0;<pub-id pub-id-type="doi">10.1016/j.biocon.2013.02.018</pub-id>, PMID: <pub-id pub-id-type="pmid">41737640</pub-id>
</mixed-citation>
</ref>
<ref id="B15">
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Goddard</surname> <given-names>J.</given-names></name>
</person-group> (<year>1967</year>). 
<article-title>The validity of censusing black rhinoceros populations from the air</article-title>. <source>Afr. J. Ecol.</source> <volume>5</volume>, <fpage>18</fpage>&#x2013;<lpage>23</lpage>. doi:&#xa0;<pub-id pub-id-type="doi">10.1111/j.1365-2028.1967.tb00757.x</pub-id>, PMID: <pub-id pub-id-type="pmid">41738386</pub-id>
</mixed-citation>
</ref>
<ref id="B16">
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Gurney</surname> <given-names>G. G.</given-names></name>
<name><surname>Adams</surname> <given-names>V. M.</given-names></name>
<name><surname>&#xc1;lvarez-Romero</surname> <given-names>J. G.</given-names></name>
<name><surname>Claudet</surname> <given-names>J.</given-names></name>
</person-group> (<year>2023</year>). 
<article-title>Area-based conservation: Taking stock and looking ahead</article-title>. <source>One Earth</source> <volume>6</volume>, <fpage>98</fpage>&#x2013;<lpage>104</lpage>. doi:&#xa0;<pub-id pub-id-type="doi">10.1016/j.oneear.2023.01.012</pub-id>, PMID: <pub-id pub-id-type="pmid">41737640</pub-id>
</mixed-citation>
</ref>
<ref id="B17">
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Herrera-Montes</surname> <given-names>M. I.</given-names></name>
</person-group> (<year>2018</year>). 
<article-title>Protected area zoning as a strategy to preserve natural soundscapes, reduce anthropogenic noise intrusion, and conserve biodiversity</article-title>. <source>Trop. Conserv. Sci.</source> <volume>11</volume>, <fpage>1940082918804344</fpage>. doi:&#xa0;<pub-id pub-id-type="doi">10.1177/1940082918804344</pub-id>, PMID: <pub-id pub-id-type="pmid">41732152</pub-id>
</mixed-citation>
</ref>
<ref id="B18">
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Hollings</surname> <given-names>T.</given-names></name>
<name><surname>Burgman</surname> <given-names>M. A.</given-names></name>
<name><surname>Van Andel</surname> <given-names>M.</given-names></name>
<name><surname>Gilbert</surname> <given-names>M.</given-names></name>
<name><surname>Robinson</surname> <given-names>T. P.</given-names></name>
<name><surname>Robinson</surname> <given-names>A. P.</given-names></name>
</person-group> (<year>2018</year>). 
<article-title>How do you find the green sheep? A critical review of the use of remotely sensed imagery to detect and count animals</article-title>. <source>Methods Ecol. Evol.</source> <volume>9</volume>, <fpage>881</fpage>&#x2013;<lpage>892</lpage>. doi:&#xa0;<pub-id pub-id-type="doi">10.1111/2041-210X.12973</pub-id>, PMID: <pub-id pub-id-type="pmid">41738386</pub-id>
</mixed-citation>
</ref>
<ref id="B19">
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Hua</surname> <given-names>W.</given-names></name>
<name><surname>Chen</surname> <given-names>Q. A.</given-names></name>
</person-group> (<year>2025</year>). 
<article-title>survey of small object detection based on deep learning in aerial images</article-title>. <source>Artif. Intell. Rev.</source> <volume>58</volume>, <fpage>162</fpage>. doi:&#xa0;<pub-id pub-id-type="doi">10.1007/s10462-025-11150-9</pub-id>, PMID: <pub-id pub-id-type="pmid">41737715</pub-id>
</mixed-citation>
</ref>
<ref id="B20">
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Jia</surname> <given-names>R.</given-names></name>
<name><surname>Li</surname> <given-names>S. H.</given-names></name>
<name><surname>Meng</surname> <given-names>W. Y.</given-names></name>
<name><surname>Lu</surname> <given-names>J.</given-names></name>
<name><surname>Gao</surname> <given-names>R. Y.</given-names></name>
<name><surname>Ru</surname> <given-names>W. D.</given-names></name>
<etal/>
</person-group>. (<year>2019</year>). 
<article-title>Wintering home range and habitat use of the whooper swan (Cygnus cygnus) in Sanmenxia Wetland, China</article-title>. <source>Ecological Research</source>, <volume>34</volume>(<issue>5</issue>), <fpage>637</fpage>&#x2013;<lpage>643</lpage>. doi:&#xa0;<pub-id pub-id-type="doi">10.1111/1440-1703.12031</pub-id>, PMID: <pub-id pub-id-type="pmid">41738386</pub-id>
</mixed-citation>
</ref>
<ref id="B21">
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Jonas</surname> <given-names>H. D.</given-names></name>
<name><surname>Bingham</surname> <given-names>H.</given-names></name>
<name><surname>Bennett</surname> <given-names>N.</given-names></name>
<name><surname>Woodley</surname> <given-names>S.</given-names></name>
<name><surname>Zlatanova</surname> <given-names>R.</given-names></name>
<name><surname>Howland</surname> <given-names>E.</given-names></name>
<etal/>
</person-group>. (<year>2024</year>). 
<article-title>Global status and emerging contribution of other effective area-based conservation measures (oecms) towards the &#x2018;30x30&#x2019; biodiversity target 3</article-title>. <source>Front. Conserv. Sci.</source> <volume>5</volume>. doi:&#xa0;<pub-id pub-id-type="doi">10.3389/fcosc.2024.1447434</pub-id>, PMID: <pub-id pub-id-type="pmid">41738048</pub-id>
</mixed-citation>
</ref>
<ref id="B22">
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Li</surname> <given-names>J.</given-names></name>
<name><surname>Sun</surname> <given-names>Y.</given-names></name>
<name><surname>Wang</surname> <given-names>L.</given-names></name>
<name><surname>Wang</surname> <given-names>Y.</given-names></name>
</person-group> (<year>2023</year>). 
<article-title>Bridging the gap between the scale of protected areas and the conservation target of Kunming-Montreal Global Biodiversity Framework in Anhui Province</article-title>. <source>Ecol. Indic.</source> <volume>155</volume>, <fpage>110994</fpage>. doi:&#xa0;<pub-id pub-id-type="doi">10.1016/j.ecolind.2023.110994</pub-id>, PMID: <pub-id pub-id-type="pmid">41737640</pub-id>
</mixed-citation>
</ref>
<ref id="B23">
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Loffler</surname> <given-names>E.</given-names></name>
<name><surname>Margules</surname> <given-names>C.</given-names></name>
</person-group> (<year>1980</year>). 
<article-title>Wombats detected from space</article-title>. <source>Remote Sens. Environ.</source> <volume>9</volume>, <fpage>47</fpage>&#x2013;<lpage>56</lpage>. doi:&#xa0;<pub-id pub-id-type="doi">10.1016/0034-4257(80)90046-2</pub-id>
</mixed-citation>
</ref>
<ref id="B24">
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Maxwell</surname> <given-names>S. L.</given-names></name>
<name><surname>Cazalis</surname> <given-names>V.</given-names></name>
<name><surname>Dudley</surname> <given-names>N.</given-names></name>
<name><surname>Hoffmann</surname> <given-names>M.</given-names></name>
<name><surname>Rodrigues</surname> <given-names>A. S. L.</given-names></name>
<name><surname>Stolton</surname> <given-names>S.</given-names></name>
<etal/>
</person-group>. (<year>2020</year>). 
<article-title>Area-based conservation in the twenty-first century</article-title>. <source>Nature</source> <volume>586</volume>, <fpage>217</fpage>&#x2013;<lpage>227</lpage>. doi:&#xa0;<pub-id pub-id-type="doi">10.1038/s41586-020-2773-z</pub-id>, PMID: <pub-id pub-id-type="pmid">33028996</pub-id>
</mixed-citation>
</ref>
<ref id="B25">
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Neugarten</surname> <given-names>R.</given-names></name>
<name><surname>Chaplin-Kramer</surname> <given-names>R.</given-names></name>
<name><surname>Sharp</surname> <given-names>R.</given-names></name>
<name><surname>Schuster</surname> <given-names>R.</given-names></name>
<name><surname>Strimas-Mackey</surname> <given-names>M.</given-names></name>
<name><surname>Roehrdanz</surname> <given-names>P.</given-names></name>
<etal/>
</person-group>. (<year>2024</year>). 
<article-title>Mapping the planet&#x2019;s critical areas for biodiversity and nature&#x2019;s contributions to people</article-title>. <source>Nat. Commun.</source> <volume>15</volume>, <elocation-id>43832</elocation-id>. doi:&#xa0;<pub-id pub-id-type="doi">10.1038/s41467-023-43832-9</pub-id>, PMID: <pub-id pub-id-type="pmid">38199986</pub-id>
</mixed-citation>
</ref>
<ref id="B26">
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Nikouei</surname> <given-names>M.</given-names></name>
<name><surname>Baroutian</surname> <given-names>B.</given-names></name>
<name><surname>Nabavi</surname> <given-names>S.</given-names></name>
<name><surname>Taraghi</surname> <given-names>F.</given-names></name>
<name><surname>Aghaei</surname> <given-names>A.</given-names></name>
<name><surname>Sajedi</surname> <given-names>A.</given-names></name>
<etal/>
</person-group>. (<year>2025</year>). 
<article-title>Small object detection: A comprehensive survey on challenges, techniques and real-world applications</article-title>. <source>Comput. Electrical Eng.</source> <volume>106</volume>, <elocation-id>108410</elocation-id>. doi:&#xa0;<pub-id pub-id-type="doi">10.1016/j.compeleceng.2025.108410</pub-id>, PMID: <pub-id pub-id-type="pmid">41737640</pub-id>
</mixed-citation>
</ref>
<ref id="B27">
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Pacifici</surname> <given-names>M.</given-names></name>
<name><surname>Di Marco</surname> <given-names>M.</given-names></name>
<name><surname>Watson</surname> <given-names>J. E. M.</given-names></name>
</person-group> (<year>2020</year>). 
<article-title>Protected areas are now the last strongholds for many imperiled mammal species</article-title>. <source>Conserv. Lett.</source> <volume>13</volume>, <elocation-id>e12748</elocation-id>. doi:&#xa0;<pub-id pub-id-type="doi">10.1111/conl.12748</pub-id>, PMID: <pub-id pub-id-type="pmid">41738386</pub-id>
</mixed-citation>
</ref>
<ref id="B28">
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Phang</surname> <given-names>S. C.</given-names></name>
<name><surname>Failler</surname> <given-names>P.</given-names></name>
<name><surname>Bridgewater</surname> <given-names>P.</given-names></name>
</person-group> (<year>2020</year>). 
<article-title>Addressing the implementation challenge of the global biodiversity framework</article-title>. <source>Biodiversity Conserv.</source> <volume>29</volume>, <fpage>3061</fpage>&#x2013;<lpage>3066</lpage>. doi:&#xa0;<pub-id pub-id-type="doi">10.1007/s10531-020-02009-2</pub-id>, PMID: <pub-id pub-id-type="pmid">32836919</pub-id>
</mixed-citation>
</ref>
<ref id="B29">
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Preen</surname> <given-names>A.</given-names></name>
</person-group> (<year>2004</year>). 
<article-title>Distribution, abundance and conservation status of dugongs and dolphins in the southern and western Arabian Gulf</article-title>. <source>Biol. Conserv.</source> <volume>118</volume>, <fpage>205</fpage>&#x2013;<lpage>218</lpage>. doi:&#xa0;<pub-id pub-id-type="doi">10.1016/j.biocon.2003.08.014</pub-id>, PMID: <pub-id pub-id-type="pmid">41737640</pub-id>
</mixed-citation>
</ref>
<ref id="B30">
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Pressey</surname> <given-names>R. L.</given-names></name>
<name><surname>Cabeza</surname> <given-names>M.</given-names></name>
<name><surname>Watts</surname> <given-names>M. E.</given-names></name>
<name><surname>Cowling</surname> <given-names>R. M.</given-names></name>
<name><surname>Wilson</surname> <given-names>K. A.</given-names></name>
</person-group> (<year>2007</year>). 
<article-title>Conservation planning in a changing world</article-title>. <source>Trends Ecol. Evol.</source> <volume>22</volume>, <fpage>583</fpage>&#x2013;<lpage>592</lpage>. doi:&#xa0;<pub-id pub-id-type="doi">10.1016/j.tree.2007.10.001</pub-id>, PMID: <pub-id pub-id-type="pmid">17981360</pub-id>
</mixed-citation>
</ref>
<ref id="B31">
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Rees</surname> <given-names>E. C.</given-names></name>
<name><surname>Kirby</surname> <given-names>J. S.</given-names></name>
<name><surname>Gilburn</surname> <given-names>A.</given-names></name>
</person-group> (<year>1997</year>). 
<article-title>Site selection by swans wintering in Britain and Ireland; the importance of habitat and geographic location</article-title>. <source>Ibis</source> <volume>139</volume>, <fpage>337</fpage>&#x2013;<lpage>352</lpage>. doi:&#xa0;<pub-id pub-id-type="doi">10.1111/j.1474-919X.1997.tb04633.x</pub-id>, PMID: <pub-id pub-id-type="pmid">41738386</pub-id>
</mixed-citation>
</ref>
<ref id="B32">
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Rochette</surname> <given-names>J.</given-names></name>
<name><surname>Gjerde</surname> <given-names>K.</given-names></name>
<name><surname>Druel</surname> <given-names>E.</given-names></name>
<name><surname>Ardron</surname> <given-names>J. A.</given-names></name>
<name><surname>Craw</surname> <given-names>A.</given-names></name>
<name><surname>Halpin</surname> <given-names>P.</given-names></name>
<etal/>
</person-group>. (<year>2014</year>). 
<article-title>Delivering the Aichi target 11: challenges and opportunities for marine areas beyond national jurisdiction</article-title>. <source>Aquat. Conservation: Mar. Freshw. Ecosyst.</source> <volume>24</volume>, <fpage>31</fpage>&#x2013;<lpage>43</lpage>. doi:&#xa0;<pub-id pub-id-type="doi">10.1002/aqc.2507</pub-id>, PMID: <pub-id pub-id-type="pmid">41737730</pub-id>
</mixed-citation>
</ref>
<ref id="B33">
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Rodrigues</surname> <given-names>A. S. L.</given-names></name>
<name><surname>Cazalis</surname> <given-names>V.</given-names></name>
</person-group> (<year>2020</year>). 
<article-title>The multifaceted challenge of evaluating protected area effectiveness</article-title>. <source>Nat. Commun.</source> <volume>11</volume>, <fpage>5147</fpage>. doi:&#xa0;<pub-id pub-id-type="doi">10.1038/s41467-020-18989-2</pub-id>, PMID: <pub-id pub-id-type="pmid">33051446</pub-id>
</mixed-citation>
</ref>
<ref id="B34">
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Rose</surname> <given-names>R. A.</given-names></name>
<name><surname>Byler</surname> <given-names>D.</given-names></name>
<name><surname>Eastman</surname> <given-names>J. R.</given-names></name>
<name><surname>Fleishman</surname> <given-names>E.</given-names></name>
<name><surname>Geller</surname> <given-names>G.</given-names></name>
<name><surname>Goetz</surname> <given-names>S.</given-names></name>
<etal/>
</person-group>. (<year>2015</year>). 
<article-title>Ten ways remote sensing can contribute to conservation</article-title>. <source>Conserv. Biol.</source> <volume>29</volume>, <fpage>350</fpage>&#x2013;<lpage>359</lpage>. doi:&#xa0;<pub-id pub-id-type="doi">10.1111/cobi.12397</pub-id>, PMID: <pub-id pub-id-type="pmid">25319024</pub-id>
</mixed-citation>
</ref>
<ref id="B35">
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Rotich</surname> <given-names>D.</given-names></name>
</person-group> (<year>2012</year>). 
<article-title>Concept of zoning management in protected areas</article-title>. <source>J. Environ. Earth Sci.</source> <volume>2</volume>, <fpage>173</fpage>&#x2013;<lpage>183</lpage>.
</mixed-citation>
</ref>
<ref id="B36">
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Sanchez-Galan</surname> <given-names>J. E.</given-names></name>
<name><surname>Contreras</surname> <given-names>K.</given-names></name>
<name><surname>Denoce</surname> <given-names>A.</given-names></name>
<name><surname>Poveda</surname> <given-names>H.</given-names></name>
<name><surname>Merchan</surname> <given-names>F.</given-names></name>
<name><surname>Guzm&#xe1;n</surname> <given-names>H. M.</given-names></name>
</person-group> (<year>2025</year>). 
<article-title>Drone-based detection and classification of greater caribbean manatees in the Panama canal basin</article-title>. <source>Drones</source> <volume>9</volume>, <elocation-id>230</elocation-id>. doi:&#xa0;<pub-id pub-id-type="doi">10.3390/drones9040230</pub-id>, PMID: <pub-id pub-id-type="pmid">41725453</pub-id>
</mixed-citation>
</ref>
<ref id="B37">
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Schwaller</surname> <given-names>M. R.</given-names></name>
<name><surname>Olson</surname> <given-names>C. E.</given-names></name>
<name><surname>Ma</surname> <given-names>Z. Q.</given-names></name>
<name><surname>Zhu</surname> <given-names>Z.</given-names></name>
<name><surname>Dahmer</surname> <given-names>P.</given-names></name>
</person-group> (<year>1989</year>). 
<article-title>A remote sensing analysis of Ad&#xe9;lie penguin rookeries</article-title>. <source>Remote Sens. Environ.</source> <volume>28</volume>, <fpage>199</fpage>&#x2013;<lpage>206</lpage>. doi:&#xa0;<pub-id pub-id-type="doi">10.1016/0034-4257(89)90113-2</pub-id>
</mixed-citation>
</ref>
<ref id="B38">
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Sovinc</surname> <given-names>A.</given-names></name>
<name><surname>Kr&#x17e;i&#x10d;</surname> <given-names>A.</given-names></name>
</person-group> (<year>2025</year>). 
<article-title>Overview of marine protected areas and sites of particular biodiversity value in the adriatic&#x2014;ionian region (eusair)</article-title>. <source>Diversity</source> <volume>17</volume>, <elocation-id>131</elocation-id>. doi:&#xa0;<pub-id pub-id-type="doi">10.3390/d17020131</pub-id>, PMID: <pub-id pub-id-type="pmid">41725453</pub-id>
</mixed-citation>
</ref>
<ref id="B39">
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Stephens</surname> <given-names>T.</given-names></name>
</person-group> (<year>2023</year>). 
<article-title>The kunming&#x2013;montreal global biodiversity framework</article-title>. <source>Int. Legal Materials</source> <volume>62</volume>, <fpage>1</fpage>&#x2013;<lpage>20</lpage>. doi:&#xa0;<pub-id pub-id-type="doi">10.1017/ilm.2023.16</pub-id>, PMID: <pub-id pub-id-type="pmid">41694064</pub-id>
</mixed-citation>
</ref>
<ref id="B40">
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Visconti</surname> <given-names>P.</given-names></name>
<name><surname>Butchart</surname> <given-names>S. H. M.</given-names></name>
<name><surname>Brooks</surname> <given-names>T. M.</given-names></name>
<name><surname>Langhammer</surname> <given-names>P. F.</given-names></name>
<name><surname>Marnewick</surname> <given-names>D.</given-names></name>
<name><surname>Vergara</surname> <given-names>S.</given-names></name>
<etal/>
</person-group>. (<year>2019</year>). 
<article-title>Protected area targets post-2020</article-title>. <source>Science</source> <volume>364</volume>, <fpage>239</fpage>&#x2013;<lpage>241</lpage>. doi:&#xa0;<pub-id pub-id-type="doi">10.1126/science.aav6886</pub-id>, PMID: <pub-id pub-id-type="pmid">30975769</pub-id>
</mixed-citation>
</ref>
<ref id="B41">
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Wang</surname> <given-names>D. L.</given-names></name>
<name><surname>Shao</surname> <given-names>Q. Q.</given-names></name>
<name><surname>Yue</surname> <given-names>H. Y.</given-names></name>
</person-group> (<year>2019</year>). 
<article-title>Surveying wild animals from satellites, manned aircraft and unmanned aerial systems (UASs): A review</article-title>. <source>Remote Sens.</source> <volume>11</volume>. doi:&#xa0;<pub-id pub-id-type="doi">10.3390/rs11111308</pub-id>, PMID: <pub-id pub-id-type="pmid">41725453</pub-id>
</mixed-citation>
</ref>
<ref id="B42">
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Watson</surname> <given-names>J. E. M.</given-names></name>
<name><surname>Dudley</surname> <given-names>N.</given-names></name>
<name><surname>Segan</surname> <given-names>D. B.</given-names></name>
<name><surname>Hockings</surname> <given-names>M.</given-names></name>
</person-group> (<year>2014</year>). 
<article-title>The performance and potential of protected areas</article-title>. <source>Nature</source> <volume>515</volume>, <fpage>67</fpage>&#x2013;<lpage>73</lpage>. doi:&#xa0;<pub-id pub-id-type="doi">10.1038/nature13947</pub-id>, PMID: <pub-id pub-id-type="pmid">25373676</pub-id>
</mixed-citation>
</ref>
<ref id="B43">
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Watson</surname> <given-names>J. E. M.</given-names></name>
<name><surname>Venegas-Li</surname> <given-names>R.</given-names></name>
<name><surname>Grantham</surname> <given-names>H.</given-names></name>
<name><surname>Dudley</surname> <given-names>N.</given-names></name>
<name><surname>Stolton</surname> <given-names>S.</given-names></name>
<name><surname>Rao</surname> <given-names>M.</given-names></name>
<etal/>
</person-group>. (<year>2023</year>). 
<article-title>Priorities for protected area expansion so nations can meet their Kunming-Montreal Global Biodiversity Framework commitments</article-title>. <source>Integr. Conserv.</source> <volume>2</volume>, <fpage>140</fpage>&#x2013;<lpage>155</lpage>. doi:&#xa0;<pub-id pub-id-type="doi">10.1002/inc3.24</pub-id>, PMID: <pub-id pub-id-type="pmid">41737730</pub-id>
</mixed-citation>
</ref>
<ref id="B44">
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Williams</surname> <given-names>P. J.</given-names></name>
<name><surname>Hooten</surname> <given-names>M. B.</given-names></name>
<name><surname>Womble</surname> <given-names>J. N.</given-names></name>
<name><surname>Bower</surname> <given-names>M. R.</given-names></name>
</person-group> (<year>2017</year>). 
<article-title>Estimating occupancy and abundance using aerial images with imperfect detection</article-title>. <source>Methods Ecol. Evol.</source> <volume>8</volume>, <fpage>1679</fpage>&#x2013;<lpage>1689</lpage>. doi:&#xa0;<pub-id pub-id-type="doi">10.1111/2041-210X.12815</pub-id>, PMID: <pub-id pub-id-type="pmid">41738386</pub-id>
</mixed-citation>
</ref>
<ref id="B45">
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Witmer</surname> <given-names>G. W.</given-names></name>
</person-group> (<year>2005</year>). 
<article-title>Wildlife population monitoring: some practical considerations</article-title>. <source>Wildlife Res.</source> <volume>32</volume>, <fpage>259</fpage>&#x2013;<lpage>263</lpage>. doi:&#xa0;<pub-id pub-id-type="doi">10.1071/WR04003</pub-id>, PMID: <pub-id pub-id-type="pmid">41161682</pub-id>
</mixed-citation>
</ref>
<ref id="B46">
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Wu</surname> <given-names>Z.</given-names></name>
<name><surname>Zhang</surname> <given-names>C.</given-names></name>
<name><surname>Gu</surname> <given-names>X.</given-names></name>
<name><surname>Duporge</surname> <given-names>I.</given-names></name>
<name><surname>Hughey</surname> <given-names>L. F.</given-names></name>
<name><surname>Stabach</surname> <given-names>J. A.</given-names></name>
<etal/>
</person-group>. (<year>2023</year>). 
<article-title>Deep learning enables satellite-based monitoring of large populations of terrestrial mammals across heterogeneous landscape</article-title>. <source>Nat. Commun.</source> <volume>14</volume>, <fpage>3072</fpage>. doi:&#xa0;<pub-id pub-id-type="doi">10.1038/s41467-023-38901-yNature+1</pub-id>, PMID: <pub-id pub-id-type="pmid">41730936</pub-id>
</mixed-citation>
</ref>
<ref id="B47">
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Xu</surname> <given-names>Z.</given-names></name>
<name><surname>Wang</surname> <given-names>T.</given-names></name>
<name><surname>Skidmore</surname> <given-names>A. K.</given-names></name>
<name><surname>Lamprey</surname> <given-names>R.</given-names></name>
</person-group> (<year>2024</year>). 
<article-title>A review of deep learning techniques for detecting animals in aerial and satellite images</article-title>. <source>Int. J. Appl. Earth Observation Geoinformation</source> <volume>128</volume>, <elocation-id>103732</elocation-id>. doi:&#xa0;<pub-id pub-id-type="doi">10.1016/j.jag.2024.103732</pub-id>, PMID: <pub-id pub-id-type="pmid">41737640</pub-id>
</mixed-citation>
</ref>
<ref id="B48">
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Zhang</surname> <given-names>X.</given-names></name>
<name><surname>Zhou</surname> <given-names>Y.</given-names></name>
<name><surname>Liu</surname> <given-names>P.</given-names></name>
<name><surname>Wang</surname> <given-names>F.</given-names></name>
<name><surname>Liu</surname> <given-names>B.</given-names></name>
<name><surname>Liu</surname> <given-names>X.</given-names></name>
<etal/>
</person-group>. (<year>2015</year>). 
<article-title>Temporal pattern in biometrics and nutrient stoichiometry of the intertidal seagrass Zostera japonica and its adaptation to air exposure in a temperate marine lagoon (China): Implications for restoration and management</article-title>. <source>Mar. pollut. Bull.</source> <volume>94</volume>, <fpage>103</fpage>&#x2013;<lpage>113</lpage>. doi:&#xa0;<pub-id pub-id-type="doi">10.1016/j.marpolbul.2015.03.004</pub-id>, PMID: <pub-id pub-id-type="pmid">25799915</pub-id>
</mixed-citation>
</ref>
<ref id="B49">
<mixed-citation publication-type="journal">
<person-group person-group-type="author">
<name><surname>Zhao</surname> <given-names>P.</given-names></name>
<name><surname>Liu</surname> <given-names>S. M.</given-names></name>
<name><surname>Zhou</surname> <given-names>Y.</given-names></name>
<name><surname>Lynch</surname> <given-names>T.</given-names></name>
<name><surname>Lu</surname> <given-names>W. H.</given-names></name>
<name><surname>Zhang</surname> <given-names>T.</given-names></name>
<etal/>
</person-group>. (<year>2021</year>). 
<article-title>Estimating animal population size with very high-resolution satellite imagery</article-title>. <source>Conserv. Biol.</source> <volume>35</volume>, <fpage>316</fpage>&#x2013;<lpage>324</lpage>. doi:&#xa0;<pub-id pub-id-type="doi">10.1111/cobi.13613</pub-id>, PMID: <pub-id pub-id-type="pmid">32839996</pub-id>
</mixed-citation>
</ref>
</ref-list>
<fn-group>
<fn id="n1" fn-type="custom" custom-type="edited-by">
<p>Edited by: <ext-link ext-link-type="uri" xlink:href="https://loop.frontiersin.org/people/2126275">Salil Bharany</ext-link>, Chitkara University, India</p></fn>
<fn id="n2" fn-type="custom" custom-type="reviewed-by">
<p>Reviewed by: <ext-link ext-link-type="uri" xlink:href="https://loop.frontiersin.org/people/218714">Andrew M. Fischer</ext-link>, University of Tasmania, Australia</p>
<p><ext-link ext-link-type="uri" xlink:href="https://loop.frontiersin.org/people/3269059">Shiyuan Wang</ext-link>, China University of Geosciences Wuhan, China</p></fn>
</fn-group>
</back>
</article>