International Journal of Primatology最新文献

An accurate representation of species diversity is critical in primatology; most of the questions in evolutionary biology, ecology, and conservation hinge on species as a fundamental unit of analysis. Galagos are among the least-known primates. Because of their cryptic morphology, broad distribution, and sampling challenges arising from elusive habits and political instability, substantial knowledge gaps about their taxonomy, evolutionary history, and biogeography remain. Despite these limitations, recent research that integrated field surveys, acoustic, morphological, and genetic analyses helped us to better understand the taxonomic diversity of this primate group. In this paper, we (1) review the current status of galagid taxonomy; (2) synthesize our current understanding of their phylogenetics, origins, and biogeography; and (3) explore current and future approaches to elucidate galagid cryptic species diversity. The onset of galago systematics dates back to the early 19^th century, with taxonomic descriptions following natural history expeditions and comparative anatomy studies. Although morphology has historically dominated systematic research on galagos, the coupling of acoustic analyses with genetic data has revolutionized the field. Taxonomic rearrangements include the discovery of new species in the wild (e.g., Galagoides kumbirensis) and the description of a new genus (Paragalago). Technological advances have allowed the collection of acoustic data in remote areas, and molecular techniques have the potential to help researchers fill important geographic gaps. Improving the resolution of galago species diversity also has implications for the conservation of wild populations, as a better understanding of species boundaries and ranges can aid in the implementation of conservation strategies.

Temperate living primates cope with a variety of environmental stressors, which may vary by body mass. We studied two sympatric galagos, the thick-tailed greater galago, Otolemur crassicaudatus (1.5 kg) and the southern lesser galago, Galago moholi (146 g), living in a South African northern mistbelt forest. We used 75 nightly encounter walks using thermal imaging from July 2017 to June 2018 to locate galagos (245 thick-tailed greater galago encounters, 207 southern lesser galago encounters). For each species’ encounters we documented survey location, growing season, insect and gum availability, ambient temperature, temperature season, rainfall, humidity, night length, hour, moon phase and fraction of moon illumination. We encountered the southern lesser galago at both cooler and warmer temperatures, later in the night, and more often during greater lunar illumination, e.g., they were lunarphilic. We had few encounters of the thick-tailed greater galago during very cold and very warm temperatures, more encounters earlier in the night, and more encounters during periods of low lunar illumination, e.g., they were lunarphobic. Our results can be understood in terms of body mass differences. A smaller body mass requires greater and more consistent energy, meaning the southern lesser galago needs to both maintain energy needs across different temperature regimes and to forage more extensively later in the night to attain enough food to support them throughout the following day. The thick-tailed greater galago’s larger body mass may buffer them during colder periods and allow them to forage earlier in the night. Being either lunarphobic or lunarphilic may relate to activity patterns of their predators. The southern lesser galago are visually oriented insect predators and being lunarphilic may facilitate both predator detection and enhance successful insect predation. Understanding how body mass may facilitate or hinder physiological and behavioral responses to environmental stressors is thus relevant to understanding species’ resilience to climate change.

The expansion of shared spaces between humans and wildlife, particularly resulting from agricultural encroachment on natural habitats, leads to increasing interactions between humans and non-human primates (hereafter “primates”). We explored how crop-foraging Barbary macaques adapt their behavior to anthropogenic disturbances and identified deterrents implemented by farmers and their effectiveness. We observed three groups of crop-foraging Barbary macaques in Aïn Leuh, Morocco, in 2021–2022. We estimated their activity budgets from 7185 scan records and tested whether they were influenced by habitat (forest, fruit orchard, and cereal field). Additionally, we examined the impact of time of day, month, and age-sex class (adult female, adult male, immature) on macaque presence in cultivated areas. We also analyzed macaque responses to encounters with humans and dogs. Macaques primarily focused on feeding in cultivated areas while allocating more time to resting and socializing in forested areas. They used cultivated areas extensively during periods of human activity. Cereal fields, but not orchards, were predominantly visited by adult females rather than males or immatures. Macaques experienced 0.34 to 0.67 anthropogenic encounters per hour, with variation across months, and high rates of aggression from humans and dogs. Preemptive deterrence measures, such as using slingshots before macaques entered the crops, were more effective than confrontations inside the cultivated areas. While crop-guarding with slingshots was effective, it poses risks to the macaques. This study highlights the high risk of crop-foraging for Endangered Barbary macaques and the need to develop safer and more sustainable crop-guarding strategies to mitigate conflicts and promote human-Barbary macaque cohabitation.

Epidemics have significant impacts on primate populations. In 2016, yellow fever spread rapidly to the most densely populated states of Brazil, resulting in the death of hundreds of humans and thousands of nonhuman primates. The Yellow Fever Surveillance Program (Programa de Vigilância da Febre Amarela) implemented by the Brazilian government was designed to prevent and control yellow fever outbreaks. In 2020, the regional reference laboratory at the Oswaldo Cruz Institute in Rio de Janeiro state in Brazil, responsible for yellow fever diagnosis, gave us access to 24 DNA samples from capuchin monkeys, which had tested negative for yellow fever virus. The samples were all from sites in Brazil where Sapajus nigritus is the only species of capuchin monkey present. We attempted to sequence two mitochondrial molecular markers commonly used for Cebidae, but five samples did not amplify. In this study, we performed additional DNA amplification and the Basic Local Alignment Search Tool (BLAST) to confirm the species identity of the 19 samples, which amplified and identify the taxon of the five samples that had failed to amplify. Among the 19 samples correctly identified as Sapajus, one was not Sapajus nigritus but another Sapajus species. Of the five samples that previously failed to amplify, three were similar to Callicebus nigrifrons, one was similar to Alouatta guariba clamitans, and one failed to amplify successfully for any marker. These findings show an error rate of 5/24 (21%) in the original taxonomic identification. Misidentification occurred at the genus level as well as the species level. Our findings highlight the importance of precise taxonomic classification in obtaining reliable data on the consequences of the yellow fever epidemic for primates.

Ranging behavior, including home range use and daily travel distance, provides valuable information on the behavioral responses of primates to their habitats. We evaluated the ranging behavior of wild silvery lutungs (Trachypithecus cristatus) inhabiting a coastal forest in West Sumatra, Indonesia, for 614 h over 15 months in 2018–2021, focusing on the relationships between ranging behavior and activity budgets, dietary composition, and food availability. The annual home range was 8.1 ha (minimum convex polygon) and 11.7 ha (95% kernel), and the mean (± standard deviation [SD]) daily travel distance was 926 ± 385 m. Daily travel distance showed a positive correlation with percent resting and negative correlations with percent feeding and moving. Furthermore, daily travel distance was correlated positively with percent young leaf feeding and negatively with percent mature leaf feeding, ripe fruit feeding, and dietary diversity. In contrast, home range size did not vary significantly across the study period, and we found few significant correlations between home range size and dietary composition or activity budget. The longer daily travel distances in food scarce season are likely due to the lutungs needing to travel further to find trees bearing young leaves. We conclude that the silvery lutungs’ ranging behavior is linked to their high-risk, high-return strategy.

The conservation of endangered primates often relies on data on population dynamics and health obtained from individuals captured with baited traps. This could increase the risk of injury or predation by attracting competitors and predators to the baited locations. It also can lead to unforeseen interactions of ecological significance among nontarget species. We evaluated these hypotheses by monitoring visits by multiple species to capture platforms for endangered golden lion tamarins (Leontopithecus rosalia). We placed camera traps on ten platforms baited with bananas resulting in more than 1500 species records. We calculated species richness and temporal patterns of visitation overlap among lion tamarins, predators, and competitor species. We also fitted a lion tamarin group with a GPS telemetry transmitter to assess whether movements toward and visits to the platform occurred more than expected by chance. Thirteen mammals and 12 bird species visited the platforms. There was high temporal overlap, albeit with peaks at different times, with the tayra (Eira barbara)—a main predator. Introduced hybrid marmosets (Callithrix spp.) were present on the platforms in 42% of visits by lion tamarins, and we recorded fights between the two species. There was significant temporal overlap between lion tamarins and capuchin monkeys. The lion tamarin visitation rate to platforms did not differ from random locations, nor did they show significant recursive behavior. Lion tamarins were vigilant in 90% of platform visits and emitted mild alarm calls, mobbing calls, and food calls. Their vocal output increased when marmosets were on the platforms. We suggest that lion tamarins consider the platforms an attractive, albeit risky, food resource. Baited platforms attract species beyond the target species and create conditions for unintended potentially negative effects on multiple species.