The Atlantic-Gaspésie caribou (Rangifer tarandus caribou) population is a small isolated relict herd considered endangered according to the Canadian Species at Risk Act (SARA). This population has low recruitment and survival rates but the potential role of parasites on individual fitness is unknown. In this context, we explored the parasite status of this population with the aim of 1) assessing the occurrence and intensity of parasite infections and the spatial, temporal and individual variations, 2) quantifying parasite richness and investigating factors such as sex and host body condition that may be associated with this variable and 3) evaluating the effects of parasite infections on survival in the Atlantic-Gaspésie caribou population. We examined fecal samples from 32 animals captured in 2013–2014 for eggs, oocysts and larvae of parasites and detected 7 parasite species: dorsal-spined larvae protostrongylids, presumably Parelaphostrongylus andersoni based on PCR identification of a subset, Nematodirus odocoilei and other unidentified Strongyles, Trichuris sp., Capillaria sp., Moniezia sp. and Eimeria sp. For each caribou, mean parasite species richness was 1.8 ± 1.1 (SD). Sex, body condition, year and capture location did not explain parasite prevalence, intensity of infection or richness except for intensity of infection of Capillaria sp. that was positively influenced by body condition. Parasites did not influence survival although mortality was higher for males than for females. We suggest that the relatively low and common gastrointestinal and protostrongylid parasite infections will not be a short-term threat leading to extinction.

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Human-driven environmental changes affect behavior, morphology, life history, and population dynamics of wild species. Artificial food sources in anthropogenic environments benefit some species and may lead to faster somatic growth and larger body size, which affects survival and reproduction, thus contributing to a species' success in modified environments. Using raccoons (Procyon lotor (L., 1758)) as a model, we documented age-specific body-mass pattern and evaluated the influence of human activities (human density, area with artificial food sources, edges of forested area bordering corn (Zea mays L.) fields) and weather (index of winter severity and mean annual precipitation) on body-mass variation at multiple spatial scales. The effect of human-driven changes on raccoon mass varied with age, sex, and spatial scale, suggesting that anthropogenic changes affect raccoons differentially according to gender and life stages. Human activity had consistently opposing effects between the sexes. Weather covariates represented >50% of the total variance in body mass explained by our models. Previous winter severity and mean annual precipitation affected body mass negatively and positively, respectively. Our results emphasize the importance of multiscale, sex-and age-specific analyses when studying influences of human activity on wildlife.Résumé : Les changements anthropogéniques influence le comportement, la morphologie, l'histoire de vie et la dynamique de population des espèces sauvages. Les sources de nourriture artificielles, provenant des ordures et de l'agriculture, peuvent être bénéfiques pour certaines espèces, menant à une croissance corporelle rapide, à une masse plus grande affectant ultimement la survie et la reproduction. Nous avons documenté les patrons de masse âge-spécifique et évalué l'importance relative de l'activité humaine (densité de population humaine, aires avec source de nourriture artificielle, densité de lisière forêt/champs de maïs (Zea mays L.)) et du climat (sévérité de l'hiver et moyenne des précipitations) sur la masse corporelle du raton laveur (Procyon lotor (L., 1758)) à plusieurs échelles spatiales. L'effet des changements anthropiques sur la masse des ratons laveurs variait avec l'âge, le sexe et l'échelle, suggérant une influence différentielle selon le stade de vie. L'activité humaine avait un effet opposé selon le sexe. Les variables du climat expliquaient plus de la moitié de la variance totale des modèles. La sévérité de l'hiver précédent et les précipitations moyennes annuelles affectaient la masse négativement et positivement, respectivement. Ces résultats soulignent l'importance de faire des analyses âge-spécifiques et à plusieurs échelles pour évaluer l'influence de l'activité humaine sur les espèces sauvages.