Abstract Forest restoration has become a conservation priority in Madagascar, with most initiatives guided by current national or international forest restoration standards. These frameworks predominantly focus on tree species composition, often considering food trees for targeted conservation taxa, but neglect structural habitat requirements of forest-dependent fauna. Given the long-term perspective of forest restoration, we argue that the needs of animals should be explicitly considered from the initial phase of project design. Using a nation-wide comparison of tree characteristics, we demonstrate that 17-18 species of the Malagasy lemur genus Lepilemur from 24 sites show rather consistent associations with large trees. We interpret this association as an indication of the reliance on vertical structures to facilitate their locomotion by clinging and leaping and for tree holes as shelter for resting, thermoregulation or predation. To facilitate locomotion, some fast growth tree species might provide the supports needed for efficient locomotion. Because a substantial time lag exists between tree establishment and the development of suitable cavities, artificial shelters (e.g., nest-boxes) could be one option to make growing forests more attractive not only for colonisation by some lemur species, but also for a large variety of other taxa, ranging from fungi to many vertebrate species. Planting tree species known to produce cavities rather quickly would accelerate the development towards comprehensive ecological restoration.
Abstract Among herbivorous mammals, body size closely predicts interspecific differences in feeding time and dietary composition. Accordingly, sexual size dimorphism is often associated with marked divergence in feeding ecology between the sexes. Though primates display considerable sexual mass dimorphism (M:F ratio 0.92-2.45), and sex differences in feeding ecology are well-documented, the influence of mass dimorphism on these differences remains unclear. To assess the influence of mass dimorphism on feeding differences between males and females, we compiled published data ( taxa) and performed interspecies comparisons using phylogenetically informed least-squares regressions of sexual mass dimorphism ratio (M:F) on the ratio of the proportion of time spent feeding and the proportion of fruits, leaves, flowers, and animal matter consumed. Increased mass dimorphism was not associated with sex differences in the proportion of time spent feeding. Likewise, there was no association between mass dimorphism and the proportion of different food types (fruits, leaves, flowers, and animal matter) consumed. The results suggest that mass dimorphism is not the primary predictor of divergence in feeding time or general dietary composition between the sexes in primates. We suspect that primates may differ from other terrestrial herbivores in the degree of difference between sexes. The tendency to form stable, mixed-sex social groupings and the comparatively low metabolic rates of primates compared to similarly sized mammals may result in a different pattern. Reduced metabolic differences between sexes, combined with female reproductive energetic demands, may weaken the expected relationship between mass dimorphism and feeding divergence. Future studies should incorporate more fine-scale measures of food intake, diet type, and nutritional geometry to assess whether the rate of food and nutrient intake differs rather than absolute time spent feeding and to capture a more detailed comparison of dietary composition between sexes.
Abstract Omnivorous primates may be at increased risk of parasitic infection due to the incorporation of pathogen-carrying invertebrates in their diets. However, primates may offset these risks by feeding on plants with medicinal, anti-parasitic properties. We hypothesize that Cebus imitator switch to a diet more concentrated on plant pith, the spongy interior of a stem, during times of increased invertebrate-borne parasite risk, using invertebrate consumption as a proxy. We expect a strong positive association between pith and invertebrate foraging. We used 1938 hours of point sample data collected during 234 all-day focal follows on 9 individuals in 2 groups around the Lomas Barbudal Biological Reserve, Guanacaste, Costa Rica (10.510°N, 85.380°W) from June 2022-August 2023. Our model shows that pith and invertebrate consumption are positively associated (ZINB: , 95% CI: 0.02-0.08), fruit and pith are negatively associated (ZINB: , 95% CI: −0.06 to −0.02), and daily maximum temperature and pith foraging are negatively associated (ZINB: , 95% CI: −2.67 to −0.09). Results partially support our hypothesis by suggesting that pith consumption increases around the same time as invertebrate consumption, and therefore invertebrate-borne parasitic infection risk. However, the strong inverse relationship between pith consumption and fruit consumption suggests that pith is consumed as a fallback food in response to low fruit availability. The possibility remains open that the medicinal benefits from pith foraging may be realized during a time of elevated entomophagy and parasite exposure. The present study highlights the context-dependent nature of plant pith consumption, providing foundational exploration for future studies to examine evolved feeding adaptations.
Behaviours of animals in captivity tend to differ from those in the wild. This is particularly true for nocturnal species, which are often kept indoors under reversed light cycles. Knowledge of Africa's slow-moving nocturnal primates, the pottos, in captivity is lacking and wild data of the three currently recognised species are scarce. Perodicticus edwardsi, the only species studied for more than a year in the wild, lives in social pairs, spending a third of their time together during the active period, alongside sharing sleeping sites. We investigated the activity budgets and substrate use of two individuals (a female with a tail, light brown pelage and facial markings, a male with no tail, dark pelage and facial markings) at Birmingham Wildlife Conservation Park, United Kingdom. We collected data from June to August 2024 between 10:00 h and 16:00 h via 5-minute focal instantaneous sampling, totalling 240 hours. We observed 43 of 55 behaviours, suggesting that the captive environment was suitably enriching. Despite being in a relatively small enclosure, pottos spent an average of 17% of their activity in social interactions. No race walk and less bridging was observed in the study individuals as seen in other lorisids. To stimulate those behaviours, those keeping this genus in captivity need to provide interconnected bridges in the form of ropes or rubber tubes in enclosures.
The study of sleeping site selection in primates is fundamental to the development of appropriate conservation strategies. Here we present data on the characteristics and usage of sleeping sites of the northern sportive lemurs (Lepilemur septentrionalis) at Montagne des Français, Madagascar. The study was conducted on three individuals over a period of seven months from December 2018 to June 2019. The research objective is to describe the sleeping site characteristics and usage patterns of L. septentrionalis in the dry forest of Montagne des Français. The northern sportive lemurs in this study used three types of sleeping sites: tree holes, vine tangles, and branches. Among the tree species used as sleeping sites by L. septentrionalis, Strychnos madagascariensis was used most frequently, and most of these sleeping sites were food trees. We most often observed L. septentrionalis using tall trees with large diameters at breast height. Tree holes are generally found in living trees rather than in dead or partially dead trees. We observed a significant difference in the frequency of sleeping sites reuse, with repeated use of tree holes being particularly noticeable. There is no variation in distance between the different types of sleeping sites and the first or last feeding trees. The results of this study suggest that L. septentrionalis depends primarily on large trees with tree holes. The reuse of sleeping sites may serve as a strategy for predator avoidance or for easy access to food resources, while the use of food trees as sleeping sites may be a strategy to reduce the cost of travel to access food resources. Sampling efforts must be considered to better understand the sleeping sites selection preferences of this species.
