Impacts of climate change and habitat loss on the distribution of the endangered crested capuchin monkey (Sapajus robustus).

The crested capuchin monkey (Sapajus robustus) is endemic to the Atlantic Forest and its transition areas within Cerrado in Brazil. The species is currently threatened by habitat loss and has been classified as endangered by the IUCN Red List of Threatened Species since 2015. We used ecological niche models built with MaxEnt to predict the potential impact of climate change on the distribution of this species. The models were projected onto the reference climate, considering six climate scenarios (three Global Climate Models and two Representative Concentration Pathways) from IPCC for 2050 and 2070. We showed that while the amount of suitable area is expected to change little across the species' range in most evaluated climate scenarios, climatic conditions may significantly deteriorate by 2070 in the pessimistic scenario, especially in currently warmer and dryer areas to the west. As seen on other capuchin monkeys, the potential use of tools by crested capuchins may increase the chances of the species adaptation to novel harsher environmental conditions. The major negative impacts across the species range also include habitat loss and fragmentation so that the conservation of the species relies on the protection of the forest remnants in the center of its distribution, which can harbor populations of the species in current and future climate scenarios.

Thanatology in the northern muriqui (Brachyteles hypoxanthus).

Primate thanatology, or the study of primate responses to dying and death, has become increasingly relevant in recent years. However, the number of reports remains small and the quality of published records is highly variable. Here, we extend the literature on comparative thanatology with observations on a population of the northern muriqui (Brachyteles hypoxanthus). We compiled all seven cases of muriqui responses to dead, dying, or abandoned infants observed by trained researchers of the Muriqui Project of Caratinga between 1998 and 2020. Four different adult females were observed carrying their dead offspring (n = 4) and one of these females was also observed carrying her dead grand-offspring (n = 1). Five of the seven cases involved dead newborns, one involved a newborn abandoned by its mother on the forest floor, and one involved a 1.6-year-old infant that was visibly ill and died after its mother left it on the ground. Dead newborns were carried for 1-3 days, and all cases occurred during the dry season months. No other age-sex classes were observed to interact with the dead or dying immatures. Our observations are consistent with hypotheses concerning the predominance of dead-infant carrying in other primates, and with the effects of climate on rates of corpse disintegration. They also show the value of long-term studies for obtaining and understanding anecdotal records of rare behavior.

Diet, activity patterns, and home range use in forest and cultivated areas for one wild group of endangered crested capuchin monkeys (Sapajus robustus) in Reserva Natural Vale, Espírito Santo, Brazil.

Robust capuchin monkeys (Sapajus spp.) are distributed widely in the Neotropics and may be able to survive in modified landscapes because of their omnivorous, opportunistic diet. The poorly known and endangered crested capuchin monkey (Sapajus robustus) is endemic to the Atlantic Forest in Bahia, Minas Gerais and Espírito Santo states, Brazil. We collected data on diet and home range for a crested capuchin group with access to forest and cultivated areas. We hypothesized that with access to cultivated exotic fruit, capuchins would use cultivated areas more for feeding during the season of fruit scarcity in the surrounding forest and have a small home range size because of higher fruit availability. Both the forest and the cultivated areas peaked in fruit availability in the wet season, with a low proportion of trees producing fruit in the dry season; cultivated areas had a higher proportion of trees in fruit compared to the forest throughout the study. While monkeys consumed exotic fruits like jackfruit and oil palm, we recorded more samples of them eating forest fruits than exotic fruits in all but 1 month, and they consumed a more diverse array of forest fruits (56 species) but only six exotic species. Home range size was relatively small compared with other studies: 120.5 ha across the year (wet season 102 ha, dry season 111.5 ha). Natural and human-intensified fruit sources in a protected area without hunting may have allowed monkeys to maintain a smaller home range size. The group composition changed during the study; this also likely influenced home range use. Studies focused on robust capuchin groups that utilize agricultural or cultivated foods may underestimate home range needs for groups without access to human-intensified food sources. Studying crested capuchin ecology in additional locations will be important for establishing a sound species conservation program.

Fragmentation dynamics and loss of area of potential occupancy within the distribution limits of the endangered crested capuchin monkey (Sapajus robustus).

Habitat loss is one of the main threats to biodiversity. Fragmentation resulting from this process may restrict available habitat for primates, limiting their persistence in a given region. In this study, we aimed to quantify deforestation and fragmentation by identifying forest remnants capable of maintaining populations of the endangered crested capuchin monkey (Sapajus robustus) within its distributional limits in the states of Bahia, Espírito Santo, and Minas Gerais, Brazil. We used Landsat images from 1985 to 2010 to generate three time-interval mosaics classified by natural and non-natural vegetation. We then calculated the size of the forest remnants and the distance of each fragment of natural vegetation to its nearest neighbor. Between the first (1985-1990) and second (1995-2000) mosaics there was a vegetation loss of 41.4%, and between the second and third (2005-2010) mosaics there was a natural vegetation gain of 1%. The third mosaic showed smaller and more isolated fragments in comparison to the first mosaic. Across the three periods, Bahia was the state with the highest rate of deforestation. While Espírito Santo had fewer identified forest remnants, it retained the most natural vegetation within these small fragments. The landscape within the currently recognized distributional limits of the crested capuchin monkey is dominated by agriculture and livestock. Both decreasing fragment size and increasing species isolation by distance between fragments can negatively affect primate populations, increasing their risk of extinction. Isolation makes it difficult for migration and recolonization events to occur. Therefore, habitat restoration should be prioritized to reduce isolation between populations. Our findings may serve as a resource for future conservation efforts and management of the crested capuchin monkey.

Reduced range of the endangered crested capuchin monkey (Sapajus robustus) and a possible hybrid zone with Sapajus nigritus.

The crested capuchin monkey (Sapajus robustus) is an endangered species endemic to the highly fragmented Atlantic Forest of Brazil. Surveys for S. robustus were carried out over a 25-month period (2003-2005) to obtain more precise geographical limits for the western range of the species. Previously published localities for S. robustus were mapped, and each point was given a 25-km radius "buffer zone." The largest forest remnants in the buffer zones (>300 ha) in Minas Gerais were visited in order to interview the local people and/or survey the forests directly using playback recordings of S. robustus. Camera traps were used in key localities if interviews suggested the presence of capuchins but no animals were sighted during the surveys. Of 127 valid interviews, only 39 people reported the presence of Sapajus in nearby forest fragments. We confirmed the presence of Sapajus in only 19 of these. S. robustus occurred in four, and S. libidinosus, S. nigritus, S. xanthosternos, or S. robustus × S. nigritus (hybrids?) occurred in the remaining 15. Based on our study, the estimated geographical distribution of S. robustus is 119,654 km2 , which represents a reduction of more than 70,000 km2 when compared to its formerly described range. The geographical limits as defined in this study are: northeast-the Jequitinhonha River; northwest and west-the Jequitinhonha River; southwest-the Suaçuí Grande River and the Espinhaço mountains; southeast-the Doce River; east-the Atlantic Ocean. A probable hybrid zone where capuchin monkeys have morphological features of both S. nigritus and S. robustus was found between the Santo Antônio and the Suaçuí Grande rivers. The elucidation of the geographical distribution of S. robustus is important for its conservation, facilitating the delineation of priority areas for the creation of reserves and the initiation of studies of the species' ecology and behavior.

A case of infant swapping by wild northern muriquis (Brachyteles hypoxanthus).

Allo-parenting has been observed in a variety of female primates, and typically infants are reunited with their biological mothers assuming that their mothers are alive. We observed an exception to this pattern when two wild northern muriquis (Brachyteles hypoxanthus) exchanged infants of different sexes and then reared their adopted infants through weaning. The process of this exchange began when the infants were 4 and 8 days old, respectively. The mother of a 4-day old female carried and nursed her own daughter and the 8-day old son of a second female. The exchange ended when the second mother was first observed carrying the wrong infant 1.5 days later. This observation raises questions about the age and mechanisms of mother-infant recognition in this species, and about assumptions of mother-infant relatedness based on behavioral observations alone.

Comunidade de besouros rola-bosta (Coleoptera: Scarabaeidae) ao longo de um ecótono natural entre floresta e cerrado em Minas Gerais / Dung beetle (Coleoptera: Scarabaeidae) assemblages across a natural forest-cerrado ecotone in Minas Gerais, Brazil

Variações em comunidades ao longo de ecótonos fornecem exemplos claros de como os organismos percebem e respondem a mudanças ambientais, mesmo em escalas reduzidas. Besouros rola-bosta (Scarabaeidae) têm sido usados como bioindicadores de qualidade de hábitat devido à sua sensibilidade a mudanças ambientais. Neste estudo, foram feitas amostragens de escarabeídeos ao longo de um ecótono natural entre hábitats de floresta e cerrado no Brasil e examinaram-se as mudanças associadas na estrutura da comunidade. Também foram examinados os efeitos de borda, aqui definidos como mudanças consistentes em atributos da comunidade em relação à distância da borda entre os dois hábitats. Densidades de indivíduos e espécies foram maiores na floresta do que no cerrado, porém a riqueza total foi similar entre os dois hábitats depois que as diferenças em tamanho amostral foram controladas. A composição de espécies foi bastante diferente entre a floresta e o cerrado, e as espécies compartilhadas pelos dois hábitats foram consistentemente mais abundantes em um ou outro. Efeitos de borda não foram detectados na riqueza ou composição de espécies, e apenas efeitos sutis foram observados na abundância. Conclui-se que o tipo de hábitat tem um efeito muito mais acentuado na estrutura da comunidade do que a presença da borda: escarabeídeos responderam fortemente à mudança de hábitat, mas muito mais sutilmente à proximidade da borda entre os dois hábitats.

Variations in assemblage attributes across ecotones provides clear examples on how organisms perceive and respond to environmental changes, even at small scales. Dung beetles(Scarabaeidae) have been used as bioindicators of habitat quality due to their sensitivity to environmental changes. Dung beetles were sampled across a natural forest-cerrado ecotone in Brazil, and associated changes in assemblage structure were examined. Edge effects, here defined as consistentchanges in assemblage parameters in relation to the distance to the forest-cerrado border, were also examined. Density of individuals and species were higher in the forest than in the cerrado, but overall richness was similar between habitats after controlling for sample sizes. Species composition differed greatly between habitats, and shared species were consistently more abundant in one or another habitat. Edge effects were not detected on richness nor species composition, and only weak effects were observed on abundance. It is concluded that the effect of the habitat (forest vs. cerrado) has a much stronger effect on the assemblage structure than the presence of the edge: dung beetles responded strongly to change in habitats, but weakly to the proximity of the edge between these habitats.

Age at first reproduction in philopatric female muriquis ( Brachyteles arachnoides hypoxanthus).

Female northern muriquis ( Brachyteles arachnoides hypoxanthus or B. hypoxanthus) at the Estação Biológica de Caratinga/RPPN-FMA, Minas Gerais, Brazil typically disperse from their natal groups at an average age of 6.1+/-0.6 years (median =6.0 years, range =5.3-7.8 years, n =22), prior to the onset of puberty and sexual activity. Immigrants do not conceive until at least their second mating season, and the minimum interval from immigration to first reproduction has been 2.0 years. Age at first reproduction in dispersing females, previously estimated at 8.9 years, has now been documented at 9.0 and 9.25 years for two females whose birth dates are known. This is older than the 7.5 years at which the only female previously known to have reproduced in her natal group gave birth. Here, we present new data from a second female that reproduced in her natal group. This female (BA) was first observed to copulate at 5.5 years, and gave birth to her first infant at 7.25 years of age. Her 1.75-year cycling-to-first conception delay was only slightly shorter than the minimum recorded for immigrant females, and thus was not responsible for her young age at first reproduction compared to dispersing females. Although our sample size is small, our findings suggest that early puberty may permit females to reproduce in their natal group, implying a possible link between life history trade-offs and dispersal patterns. Because the only two females that have reproduced in their natal group were maternal sisters, it is also possible that maternal effects on age at puberty can impact dispersal patterns, particularly in small populations of primates.