The family Ramphastidae includes five different genera and 36 species of toucans and toucanets that are spread widely throughout the Neotropical Region. They occupy a variety of habitats, with some species performing seasonal, regional, and altitudinal movements in search of food resources. Representatives of different genera that carry out such regional movements include the white-throated toucan Ramphastos tucanus, chestnut-eared aracari Pteroglossus castanotis, and yellow-eared toucanet Selenidera spectabilis, the behaviors of which remain poorly understood (Winkler et al., 2020).

The genus Selenidera includes six species, five of which are found in Brazil (Pacheco et al., 2021). The spot-billed toucanet Selenidera maculirostris is the sole representative of the genus in the Atlantic Forest, to which it is endemic (Vale et al., 2018). The species is discrete and somewhat elusive (It vocalizes little and at specific times of the day, generally at dawn and dusk, and does not have a very agitated movement behavior, actively moving between the trees), occurring in large, dense, humid forest patches. Juçara palm (Euterpe edulis) fruits are among the main food sources of this toucanet, which also feeds on other types of fruits, invertebrates, and small vertebrates. These birds usually occur alone or in male–female pairs in the mid strata of the forest, but often gather in small groups during the fruiting period of some plants, including palm trees (Goeldi, 1894; Sick, 1997; Sigrist, 2006; Short, 2021).

Originally with a wide geographical distribution in the state of São Paulo, in the southeastern part of Brazil, Selenidera maculirostris was extinguished from the forests of the interior of the state beginning in the 1970s due to extensive deforestation and forest fragmentation, leaving it restricted to forests of the eastern part, mainly in the Serra do Mar (Willis, 1979; Magalhães, 1999; Willis and Oniki, 2003). This habitat reduction and the low number of field records earned this species a classification as Vulnerable in the list of animals threatened with extinction in the state of São Paulo (São Paulo, 2018). The species has been regularly reported in the forests surrounding the São Paulo Metropolitan Region (SPMR), in the eastern part of the state, since 1889, including some individuals within the urban area (Almeida et al., 2003; Willis and Oniki, 2003). Pinto (1945) attributed the presence of a single individual at an urban site within the city of São Paulo in June 1943 to the relative proximity of large forest patches surrounding the city (Serra da Cantareira to the north and Serra do Mar to the south). Another hypothesis suggested by Pinto is that the individual was observed during the coldest period of the year (June) and was probably performing some sort of migratory movement from Serra do Mar. The same author noted the same pattern for other bird species at the same location, such as the Pileated Parrot Pionopsitta pileata.

As SPMR is the largest urban area in South America, with approximately 21.5 million inhabitants (IBGE, 2023), and a high current rate of deforestation and environmental degradation (Natalini, 2020), we organized available data (scientific and citizen science) and produced field data to better understand the current geographic distribution of S. maculirostris in this region of the state of São Paulo and the possible movements described by Pinto (1945), thus contributing to the natural history, ecology, and conservation of this Atlantic Forest endemic.

We compiled a total of 200 records of S. maculirostris for SPMR between 1889 and 2024 for 45 localities and 15 of the 39 existing municipalities. Of this total, 91 were published by different traditional sources (e.g., scientific articles); 100 were available from online platforms (eBird, WikiAves, and Xeno-Canto); two were from third parties (people); and seven were unpublished field records made by the authors. One literature record (Almeida et al., 2003; locality 42) and one unpublished record (locality 38) refer to birds that were found inside homes in urban areas. Twenty-five of the 45 locations with records are in protected reserves, of which 21 are in eight public reserves and 4 are in two private reserves ( Figure 1 ; Supplementary Material 1 ).

Field data for S. maculirostris include 71 records for Núcleo Curucutu, obtained between 2007 and 2021. The species was registered at least once during each of the first 18 fieldtrips (between 2007 and 2011), especially in Dense Ombrophilous Forest formations, with an atypical record in a region of natural fields (locality Campos) of a bird moving between cloud forests. The species was found at 7 out of 10 localities within the park during this first survey period. The altitudes of these records range from 15 to 820 m. Fifty-one of the 71 records made at Núcleo Curucutu were visual, auditory, or both, and on 20 occasions, a total of 15 individuals were netted among four localities (localities 14, 16, 17, and 18; Figure 1 ; Supplementary Material 1 ). On these occasions, the 15th individual was banded, four of which were recaptured at the original locality (one individual twice), but on different dates. The species was recorded at two other localities between 2012 and 2022: locality 34 in October and locality 10 in December, both in 2015 ( Supplementary Material 1 ).

The author MLSR and his family made seven records (pairs or small groups) of S. maculirostris between 2020 and 2024, except 2022, in the months of March and April (autumn), on the farm where they reside on Boa Vista road, 3 km north of Núcleo Curucutu ( Figure 1 ; Supplementary Material 1 ). The individuals were feeding on the fruits of Bangalow palm (Archontophoenix cunninghamiana) and of a type of persimmon (Diospyros spp.). Both the palm tree and the persimmon are non-native plants in Brazil. Although the area was full of Juçara palms, they did not possess any fruit when the toucanets were registered. MLSR continued to record S. maculirostris for consecutive days (e.g., five, six) until the end of fruiting. The birds were always observed feeding on the same plants during the 4 years of observation.

Two other records by third parties are worth mentioning. The first was in May 2018 at Ponte Seca road, a rural region with connectivity to the Serra do Mar forest matrix. This record was of a female feeding at a local bird feeder. The second record was of another adult female, which was rescued by environmental police in the Vargem Grande neighborhood, an urban area located just 8 km from the main urban area of the city of São Paulo ( Figure 1 ; Supplementary Material 1 ).

Of the total number of records of S. maculirostris obtained for SPMR (200), 79% (n = 158) are for the geographic location of Serra do Mar (proportional records for the four seasons of the year) and 21% (n = 42) for the geographic location of outside Serra do Mar (records for the four seasons of the year, because of the data from Morro Grande Reserve, but with a slightly greater concentration in autumn–winter) ( Supplementary Material 1 ; Figure 2 ). When environment type within SPMR is also considered, the southern forests have 193 records with 67% (n = 129) for Southern native forests (Serra do Mar and Morro Grande, high and dense forests), with occurrence in the four seasons of the year, and 33% (n = 64) for Southern altered forests (including forest fragments and open and anthropic environments), with predominant occurrence in autumn–winter. Northern forests (Serra da Cantareira and Serra do Japi) had 2% (n = 4) of the records, with occurrence restricted to autumn, as did Urban sites (2%, n = 3, main urban and satellite region), with occurrence restricted to autumn–winter ( Figure 3 ; Supplementary Material 1 ).

There were varied occurrences among the five locations in SPMR with the most records of S. maculirostris. Records for Núcleo Curucutu (Serra do Mar), the largest, most natural, and best-preserved forest area in SPMR (location with the most available data), are common and proportional throughout the four seasons of the year. Records for Morro Grande (an area far from the main block of the Serra do Mar), one of the largest and best-preserved forest fragments in SPMR, are more frequent in the winter and spring, but in smaller numbers during all seasons of the year. Records for Espinheiro Negro, also in the Serra do Mar but in a rural and partially fragmented area (approximately 1,500 m from the most preserved main area), are concentrated in winter and autumn, being less common in spring and especially in summer. Records for Paranapiacaba, also in Serra do Mar but in marginal environments and continuous with the more preserved area, are also concentrated in autumn and winter, with no detections in spring and few in summer. Lastly, records for Estrada da Bela Vista, also in Serra do Mar but in a rural and fragmented area, where the author MLSR lives, are practically exclusive to autumn, with the only summer record being made in the last 2 days of that season (March 18), when the climate is already more similar to the next season—autumn ( Figures 1 , 4 ; Supplementary Material 1 ).

Selenidera maculirostris is widely distributed throughout the São Paulo Metropolitan Region, where it has been documented since the end of the 19th century. Most records of it, including quantitative and biological data, were obtained in the Serra do Mar region (region near the Atlantic slope) via ornithological field research, such as the long-term work developed at Núcleo Curucutu of Serra do Mar State Park (Schunck et al., 2019). However, bird watchers and photographers have been increasingly contributing to the generation of data on the occurrence of the species in SPMR over the last 10 years, including locations with unpublished records (eBird, 2024; WikiAves, 2024; Xeno-Canto, 2024).

The available data show that S. maculirostris is a typical and resident species of Serra do Mar, where most of its historical and current records are concentrated. This finding was expected, given the size and excellent conservation status of the forest in this area of the state of São Paulo. Additionally, 55.5% of the records were made in protected reserves, which is a good sign for an endangered species that occurs in a region with constant deforestation (Natalini, 2020). Nonetheless, the protected natural areas of SPMR need to be expanded to protect this and dozens of other threatened species of the state of São Paulo (Bressan et al., 2009; São Paulo, 2018).

The finding of only three records for Cantareira leads to three main explanations. The first is imperfect detection, as mentioned by Tonetti et al. (2017), of a species that has always been resident in the region. However, Cantareira is one of the most visited locations by researchers and bird watchers in southeastern Brazil, which reduces the chances of a resident species going unnoticed, even if it is elusive. The second explanation is that the population is small and not very dense and thus difficult to detect in the field. This scenario is possible given that the Cantareira region has been deforested in the past (Tonetti et al., 2017). The third explanation is that its presence is due to the seasonal movement of birds from the Serra do Mar during the autumn–winter period of southeastern Brazil (between March 20 and September 23), as mentioned by Pinto (1945), and that the local population had gone extinct prior to the 1970s, when extinctions of this species are mentioned for forest fragments in the interior of the state of São Paulo (Willis, 1979; Magalhães, 1999; Willis and Oniki, 2003). This explanation is supported by the period of the year when the three available records were made. In 1965, six individuals were collected on two different days in early June (winter); individuals generally live alone or in pairs and usually gather in small groups such as this only when there is an abundant food source (Goeldi, 1894; Sigrist, 2006; Short, 2021). The 2010 record was made between 20 and 29 April, at the beginning of autumn, although there are no further details about the number of birds observed (DERSA, 2010; Tonetti et al., 2017). These three explanations also apply to the recent record made in Serra do Japi (May 2018), approximately 30 km north of Serra da Cantareira.

When present, S. maculirostris is relatively easy to detect. The species was recorded on all 18 trips to Núcleo Curucutu between 2007 and 2011, and 82% of the recorded individuals were either heard or seen, while 18% of the records were from mist nets. Although the species tends to vocalize little and more often low at dusk, its croaking vocalization is very characteristic and easily distinguished from other Atlantic Forest toucan and toucanet species (Sigrist, 2006; Short, 2021).

The Morro Grande Forest Reserve, located in a region intermediate between the southern and northern forests, also draws attention due to the occurrence of S. maculirostris. The species was not detected by the 2001–2003 field study conducted by Develey and Martensen (2006), who attributed its absence in the region to the poor quality of the environment (part of the region comprised secondary forests) and low food availability (fruits), mainly the low density and presence of young Juçara palm plants. However, beginning in 2016, 13 years later, the species began to be detected continuously by bird watchers, which may indicate an improvement in the quality of the environment (more mature forests) and an increase in food availability, mainly adult Juçara palm plants, which are currently found in greater quantities. The available data indicate that S. maculirostris may be a resident species in the region, although the greater number of records in winter and autumn suggests some type of movement, perhaps the arrival of more individuals from other regions, something that needs further investigation.

The few occurrences in urban environments (3), including one detection in 1943 by Pinto (1945), lead us to believe that these were free-living birds moving outside their typical habitat of dense and humid forests, as this bird is not captured to serve as a pet.

The low number of records for the urban area of SPMR hinders rigorous testing of the hypothesis of the seasonal presence of S. maculirostris in urban areas during autumn and winter, which would characterize the possible seasonal movement proposed by Pinto (1945), even though all records were made in the autumn–winter period, indicating this possibility. The records for the SPMR indicate a proportional occurrence among the seasons of the year for both the Serra do Mar and the region outside the Serra do Mar, indicating that the species is resident in the SPMR. However, when only records from the southern forests of the SPMR are considered, a pattern of proportional occurrence during the seasons of the year is observed for well-preserved areas, but greater occurrence during the autumn–winter period in altered forests. This pattern is even clearer when considering the locations with the most records in Serra do Mar. In Núcleo Curucutu, the species is common in all four seasons of the year, but in adjacent continuous forests (surrounded by anthropized areas) and in forest fragments close to the main preserved matrix, there is a greater occurrence in autumn–winter. Isolated examples, such as Espinheiro Negro and Paranapiacaba, where most records occur during the autumn–winter period, indicate potential regional movement. Especially notable is Estrada da Bela Vista, where in recent years, birds have been appearing only in autumn, with one record in the last days of the season, likely in search of food resources ( Figure 4 ; Supplementary Material 1 ).

Regional movement has been observed for different species of frugivorous birds, including ramphastids (Sick, 1997; Short, 2021; Winkler et al., 2020). There are fewer fruiting plants in autumn–winter in the Atlantic Forest of southeastern Brazil (Lorenzi, 2002a, b), which forces many frugivorous species to move regionally in search of resources (Sick, 1997). Exotic plants that bear fruits during autumn and winter in rural areas may favor regional movements of S. maculirostris, as well as other bird species, since these fruits are an extra food resource during the harshest period of the year for survival.

Considering the time of the year of records of S. maculirostris for SPMR made outside the tall, dark, and humid forests of Serra do Mar, its typical habitat, suggests seasonal movements. Together, the urban records made in autumn and winter, records for the northern region made in autumn, two records for Curucutu outside the preserved forest in an open and altered environment made in autumn and winter, and the records from Estrada da Bela Vista made in autumn, including a record of a roadkill bird on Estrada do Mambú (MZUSP 92445) near banana plantations approximately 7 km from the continuous forest of the lower portion of Núcleo Curucutu ( Figure 1 ), reveal a certain frequency of birds moving through different environments in the driest and coldest period of the year in southeastern Brazil (when they are not reproducing), that is indicative of regional movements.

Although the records presented here indicate regular seasonal movements for S. maculirostris during the coldest months of the year, the low number of records outside Serra do Mar reveals that it may only be part of the population that moves. A similar observation was reported for the S. spectabilis in Central America (Short, 2020). All individuals of S. maculirostris recorded outside Serra do Mar were adults, which rules out the possibility that only young birds looking for new territories wander out of the main forest regions. Still, another issue that deserves future study is the types of displacements made by S. maculirostris between the Atlantic slope and the coastal plain of the state of São Paulo.

The movements carried out by some species of the family Ramphastidae are still little known and studied (Winkler et al., 2020). The increasing destruction of the last unprotected forest remnants in SPMR, which has more than 20 million human inhabitants, is the biggest issue regarding the S. maculirostris population therein. This scenario may further compromise the use of those last habitats as areas for food, rest, and even as “springboards” during their movements during the coldest periods of the year. This environmental issue may not only prevent future studies of S. maculirostris but also hinder the conservation of the rich biodiversity that exists and is already widely threatened in this region of the eastern part of the state of São Paulo (Malagoli et al., 2008; Bressan et al., 2009; Natalini, 2020).

Selenidera maculirostris has been known to be part of the avifauna of the São Paulo Metropolitan Region for 125 years. Therein, the species occurs between 15 and 1,250 m elevation and occupies mostly tall and dark forests but may also occasionally use different types of habitats, including cloud forests and rural and urban areas. The species can be found year-round along the forest matrix of Serra do Mar. At least part of the population from Serra do Mar performs seasonal regional movements during the autumn–winter period to small urban green areas in the plateau. Future research is needed to better understand aspects of the natural history of this toucanet and explore whether it performs seasonal movements in search of food or for climatic reasons. We recommend that this species be kept on the list of endangered animals of the state of São Paulo due to increasing deforestation in different regions of the São Paulo Metropolitan Region.