Nelly Ménard

We documented the influence of the section of the annual life cycle when crops were not available by tracking space use by two male Barbary macaques Macaca sylvanus that had access to the same cultivated area with cherry and walnut trees, adjacent to an oak forest near Ifrane NP, Morocco. Both individuals remained within a few kilometers of the orchards, even when there was no fruit available. They visited the orchards the most at the beginning of the study when walnuts were available and the herbaceous layer grew, leading to a peak in home range overlap, as predicted by the resource dispersion hypothesis. By contrast, they visited the orchards the least when cherries were available at the end of the study. These results indicated that the orchards and their vicinity hold resources that sustained the macaques outside of the cherry and walnut seasons, and confirmed that the wardens who were hired for this purpose efficiently protected the cherry crop.

Demographic analyses provide valuable insights that can significantly enhance reintroduction planning and decision‐making, helping to improve the likelihood of reintroduction success. We developed a model to evaluate the chances of success for a reintroduction of the endangered Barbary macaque ( Macaca sylvanus ). The model incorporates age‐specific vital rates estimated from 11 years of demographic data on a wild population, reductions in survival and reproduction due to potential release costs, demographic and environmental stochasticity, reinforcement releases, and catastrophic events. Based on the available individuals considered as best candidates for reintroduction, we compared extinction risks under two release strategies. One strategy entails releasing all individuals as one large social group, while the other entails forming and releasing two smaller, separate groups. Our results suggest that the best strategy for Barbary macaques is to release two separate social groups, for which extinction risks remain low (< 5% in the absence of catastrophic events) as long as survival suffers minimal release costs. Sensitivity testing showed that extinction risks are more sensitive to changes in release costs on survival than on reproduction, and that sensitivity to initial sex ratio depends on initial group size. Extinction risk is dramatically affected by catastrophic events, although it is not highly sensitive to variations in the probability of occurrence of such events. Reinforcement releases help counter the effects of high release costs on survival, thus considerably improving probabilities of population persistence. Our model presents highly promising prospects for the successful reintroduction of a Barbary macaque population, and for the conservation of this species, which is the only extant nonhuman primate in North Africa.

As wildlife is increasingly affected by environmental change, identifying how vital rates vary with ecological factors is essential to predict the consequences of environmental perturbations on wild population dynamics. We explored the effects of habitat constraints on the demographic and life history patterns of two Barbary macaque (Macaca sylvanus) populations living in two contrasted habitats in Algeria. Using 11 years of field data, we estimated age‐specific survival rates of females and of infants of both sexes, as well as female reproduction rates. We investigated how these vital rates were influenced by both intra‐ and inter‐habitat environmental variations. We parameterized age‐structured female‐only transition matrices and conducted a prospective analysis to estimate the contribution of each vital rate to the populations' asymptotic growth rates (λ). A retrospective analysis (LTRE, Life Table Response Experiment) was also conducted to determine how each vital rate contributed to the observed differences in λ between populations. The macaques exhibited common patterns of survival and reproduction (low rates at young ages, and then high and stable until a decrease at old ages), with first evidence of both actuarial and reproductive senescence. Both populations were growing. In both populations, adult and immature survival had the highest elasticities, and remained stable in changing environmental conditions. By contrast, infant survival and female reproduction had low elasticities, and varied more with environmental variations. As Barbary macaque habitats are increasingly degrading, we provide robust estimates of their vital rates with conservation implications, in particular to predict population responses to anthropogenic perturbations.

Les changements des habitats des animaux sauvages s’accélèrent à l’époque de l’Anthropocène, en relation avec le développement des activités humaines. L’Anthropocène, ou « ère de l’humain », peut-être considéré comme une nouvelle époque géologique, actuelle, marquée par une incidence significative et accélérée des activités humaines sur les écosystèmes, telle qu’elle constitue une « force géologique ». Ces changements rapides consistent souvent en des nuisances qui c

Background: Numerous Ebola virus outbreaks have occurred in Equatorial Africa over the past decades. Besides human fatalities, gorillas and chimpanzees have also succumbed to the fatal virus. The 2004 outbreak at the Odzala-Kokoua National Park (Republic of Congo) alone caused a severe decline in the resident western lowland gorilla ( Gorilla gorilla gorilla ) population, with a 95% mortality rate. Here, we explore the immediate genetic impact of the Ebola outbreak in the western lowland gorilla population. Results: Associations with survivorship were evaluated by utilizing DNA obtained from fecal samples from 16 gorilla individuals declared missing after the outbreak (non-survivors) and 15 individuals observed before and after the epidemic (survivors). We used a target enrichment approach to capture the sequences of 123 genes previously associated with immunology and Ebola virus resistance and additionally analyzed the gut microbiome which could influence the survival after an infection. Our results indicate no changes in the population genetic diversity before and after the Ebola outbreak, and no significant differences in microbial community composition between survivors and non-survivors. However, and despite the low power for an association analysis, we do detect six nominally significant missense mutations in four genes that might be candidate variants associated with an increased chance of survival. Conclusion: This study offers the first insight to the genetics of a wild great ape population before and after an Ebola outbreak using target capture experiments from fecal samples, and presents a list of candidate loci that may have facilitated their survival.

Social dispersal is an important feature of population dynamics. When female mammals occur in polygynous groups, their dispersal decisions are conditioned by various female‐, male‐, and group‐related factors. Among them, the influence of disease often remains difficult to assess. To address this challenge, we used long‐term monitoring data from two gorilla populations (Gorilla gorilla gorilla) affected by infectious skin disease lesions. After controlling for other potentially influential factors, we investigated to which extent disease avoidance drives the dispersal decisions of gorilla females. We showed that the infection of a silverback of a breeding group by the skin disease increased the probability of adult females to emigrate. Moreover, adult females avoided breeding groups with a high prevalence of skin disease by emigrating from them and immigrating into healthier ones. Age of the breeding group was also an important factor. Adult females left older groups, near the end of a male tenure, to join younger ones led by younger fully grown silverbacks that could be of high reproductive and protective value. Our study highlights that, although females select for high‐quality males, disease avoidance is a critical driver of their dispersion decision.