Primates最新文献

Global climate change is directly influenced by human actions due to land use and occupation. In this way, factors related to environments conditions, concomitant with anthropogenic impacts, determine the suitability of environments for species. We analyze the present-day and future suitability of environments for Saguinus martinsi, a primate species endemic to the Brazilian Amazon region. We analyzed two different greenhouse gas emission scenarios, known as Shared Socioeconomic Pathways (SSPs), one "optimistic" (SSP2-4.5) and the other "pessimistic" (SSP5-8.5), described by the Coupled Model Intercomparison Project. We created the models using climatic, edaphic, and topographic variables based on the Euclidean Distance algorithm. Our results indicate that S. martinsi may face severe threats in the near future as a consequence of climate change, given that no environmentally suitable areas were identified for the species in either of the future climate scenarios analyzed. We understand that it is necessary to expand searches for the presence and/or absence of the species in potentially environmentally suitable areas, in addition to consolidating measures to mitigate environmental impacts for the conditions found.

Social play requires communicative abilities that start developing since the first phases of life. Due to their paedomorphic nature, bonobos (Pan paniscus) tend to maintain a playful attitude also in adulthood. Here, we present the case of an adult bonobo (Congo) that has never had any contact with conspecifics in the first 40 years of life. In 2023, Congo underwent an introduction protocol at the Wilhelma Zoo. Prior to the data collection period, he had spent 8 months within the group. The aim was evaluating Congo's playful social competence and his ability to react in a resilient way to others' stimuli. The play sessions involving Congo and two juveniles (CPSs) were compared with play sessions occurring in other adult-juvenile pairs (OPSs). Compared to OPSs, CPSs were shorter and more punctuated by grooming pauses that were totally absent during OPSs. Despite increased grooming, CPSs had a higher risk of escalation into overt aggression from Congo frequently screaming during the interaction. Unlike other adults, Congo never rapidly replicated the partners' playful facial displays, a phenomenon known as rapid facial mimicry. Despite Congo appearing to struggle to manage social play, he responded to other's invitations, thus indicating a presence of play motivation. Albeit being just a case report, our findings emphasize the importance of adult play as a mechanism for social integration, even in individuals entirely unfamiliar with its nuances. Although animals engage in play early in life, it is never too late to play the game and strengthen social bonds.

In primates, mothers are crucial for the survival and integration of young offspring into their social group. Usually, mothers adjust their behaviour to the offspring's age and needs, but maternal experience might modulate developmental changes in such allocation. In this study, we conducted behavioural observations on 7 mother-offspring dyads of captive western lowland gorillas (Gorilla gorilla gorilla) to assess whether multiparous mothers adjusted to the changing requirements of their offspring differently from primiparous mothers, and better facilitated their social integration into the group. Our results showed that, compared to primiparous mothers, multiparous mothers were more likely in body contact with younger offspring and less with older offspring. However, maternal experience neither predicted nor mediated how likely mothers were to start or end body contact, nor did it mediate developmental changes in the offspring's social behaviour toward other group members. Our study provides preliminary evidence of some limited differences in how primiparous and multiparous mothers allocate maternal behaviour in western lowland gorillas.

Predation influences foraging strategies, as primates must avoid being preyed on while feeding. Some populations of capuchin monkeys are the only neotropical primates that customarily use the ground for nut-cracking. This time-consuming and focus-demanding foraging activity may increase susceptibility to predation events. However, there is currently no data on predation in tool-using Sapajus populations. We report a snake's (Boa constrictor) predatory attack on a bearded capuchin monkey (S. libidinosus) in a tool-using population, as well as the other monkeys' alarm calling and threat displays. We confirm these monkeys' predation vulnerability and discuss how they balance foraging requirements with predation risk.

Muriquis (Brachyteles sp.) are endemic to the Brazilian Atlantic Forest; its genus is divided into two species, the northern muriqui (Brachyteles hypoxanthus), and the southern muriqui (Brachyteles arachnoides), both assessed as Critically Endangered by the IUCN Red List. The endangered status of muriquis is associated with habitat loss, fragmentation, hunting, and other anthropogenic actions, confining the species to fragments, mostly, in protected areas. One of these important protected areas is in the Serra da Mantiqueira, the Environmental Protection Area Serra da Mantiqueira, that has a sizable continuous remnant of the Atlantic Forest with a high degree of biological diversification, where both species of muriquis occur. This designation highlights the region as one of the most critical regions for the genus Brachyteles. Nonetheless, new records may fill gaps in the distribution limit between the two muriquis species, identifying whether there is a possible barrier or possible overlapping area. However, recording and estimating primate populations over large areas through standard field techniques, such as linear transects, can be costly in terms of time and financial resources. In addition, given its altitude gradient, the Serra da Mantiqueira region is remote and difficult to access for systematic biodiversity surveys. Thus, aerial surveys were carried out using thermal sensors attached to drones, which made it possible to record two new groups of southern muriquis in Serra da Mantiqueira. Thus, we confirm that this new method represents an effective way to survey highly threatened primates.

This report documents the predation of Macaca cyclopis (Taiwanese macaque) on the flying adults of ground-nesting leaf-cutting bee, Trachusa formosanum. With observations and video recordings of an incident in the wild, we detail how adult and juvenile macaques capture and consume bees during their flight, with varying success rates. Seizing the correct timing when the bees fly low to approach their nests is the key skill for bee hunting. This predation occurs during the breeding season of T. formosanum, when the bees' nests are spatially concentrated, making them a spatially and temporally predictable food source for the macaques. The findings highlight that M. cyclopis do exploit seasonal high-protein food resources, and provide new insights into their dietary habits, with potential implications for understanding foraging-relevant social learning in primates. Further studies are needed to explore the potential nutritional significance of this behavior and its role in macaque reproductive strategies.

Spider monkeys (Ateles sp.) are among the most endangered primates in tropical forests, ranging from Central to South America. The current consensus on their classification is split into 7 species. However, species identification of Ateles individuals is challenging because their intraspecific and interspecific morphological traits gradually change and diversify among species, especially in pelage color and patterning. This problem makes it challenging to perform conservation in both wild (in situ) and captive (ex situ) populations. Currently, there are approximately 150 captive spider monkeys in around 30 Japanese zoos, reflecting more than 120 years of generational changes. To understand the genetic structure of the Ateles population in Japan and promote its ex situ conservation, we performed a population genetic analysis. Genomic DNA was extracted from 127 individuals using their fresh hair follicles. We determined the nucleotide sequences of three mitochondrial DNA regions and the nucleotide lengths of nine nuclear microsatellite loci in all individuals. Our analysis revealed the maternal lineages of four species (A. chamek, A. fusciceps, A. geoffroyi, and A. hybridus) from mitochondrial DNA analysis, and we identified novel haplotypes not previously reported. By comparing the maternal lineages of each individual with zoos' breeding records, we discovered at least 29 hybrid individuals, comprising about 20% of the current Japanese population. The results of the nuclear microsatellite analysis confirmed the genetic structure of hybrid individuals and suggested the presence of additional hybrids that could not be identified based on maternal lineage analysis and zoos' breeding records alone. These findings can contribute to the more appropriate management of spider monkeys toward ex situ conservation.

Long-term monitoring data on population abundance and distribution are essential for developing and refining conservation strategies, particularly for endangered species like the proboscis monkey (Nasalis larvatus), for which data remain limited across much of their range in Borneo. Previous studies conducted in 2004/2005 and 2014 in the Klias Peninsula, western Sabah, northern Borneo, provided important insights into population trends and distribution. Building on this foundation, we reassessed the proboscis monkey population in 2022 after an 8-year interval and investigated changes in land use and land cover during the same period. Our findings indicate a lower overall estimate of population abundance (number of individuals); however, the number of observed groups is comparable to previous studies, suggesting some stability. Distribution patterns have remained relatively stable, with population strongholds in the central part of the Klias Peninsula, underscoring the continued importance of areas like Padas Damit Forest Reserve for proboscis monkey conservation. Our data also reveal concerning trends, including a decline in group sizes (number of individuals per group) within breeding units and the presence of very small populations in fragmented sites such as Bongawan, presenting ongoing conservation challenges. Our land-use and land-cover change findings further revealed that less than half of the available proboscis monkey habitats in this region are fully protected. Vegetation analysis showed that tree species richness positively influences proboscis monkey abundance, emphasizing the critical role of food resource diversity. These findings have important conservation implications for the long-term survival of this endangered primate in the Klias Peninsula region.