RESUMO
Several primates show sex-based differences in activity patterns and social interactions during infancy. These differences have been associated with adult social and reproductive functions of males and females and are related to male-male competition. Our goal was to describe behavioral patterns of wild Alouatta caraya male and female infants, a species with sexual dimorphism in body size and behavioral strategies during adulthood. We also examined the relationship between life history variables, infant sex and age, activity patterns, and social interactions in order to determine whether males and females follow different trajectories during early growth. Over a 27-month study, we observed 21 male infants and 14 female infants across two similar sites in northern Argentina. Data were analyzed using generalized linear mixed model (GLMM) tests. We found no differences in suckling time or weaning age between males and females (9.7 vs. 9.4 months), but male infants spent more time feeding on solid food and resting than female infants. Males also invested more time in contact with their mothers than did female infants, and mothers rejected and broke contact with males more frequently than with females. Other behavioral categories did not differ between the sexes. Our results suggest that higher nutritional demands of males compared with females may affect some behaviors. However, mothers of sons did not experience immediate trade-offs between current and future reproduction. Other behaviors, similarly expressed by the two sexes, suggest a similar developmental trajectory between male and female A. caraya infants, meaning that most differences emerge following the infant period.
Assuntos
Alouatta/fisiologia , Características de História de Vida , Comportamento Social , Alouatta/crescimento & desenvolvimento , Animais , Feminino , Masculino , Fatores SexuaisRESUMO
For most mammals, including nonhuman primates, diet composition varies temporally in response to differences in food availability. Because diet influences gut microbiota composition, it is likely that the gut microbiota of wild mammals varies in response to seasonal changes in feeding patterns. Such variation may affect host digestive efficiency and, ultimately, host nutrition. In this study, we investigate the temporal variation in diet and gut microbiota composition and function in two groups (N = 13 individuals) of wild Mexican black howler monkeys (Alouatta pigra) over a 10-month period in Palenque National Park, Mexico. Temporal changes in the relative abundances of individual bacterial taxa were strongly correlated with changes in host diet. For example, the relative abundance of Ruminococcaceae was highest during periods when energy intake was lowest, and the relative abundance of Butyricicoccus was highest when young leaves and unripe fruit accounted for 68 % of the diet. Additionally, the howlers exhibited increased microbial production of energy during periods of reduced energy intake from food sources. Because we observed few changes in howler activity and ranging patterns during the course of our study, we propose that shifts in the composition and activity of the gut microbiota provided additional energy and nutrients to compensate for changes in diet. Energy and nutrient production by the gut microbiota appears to provide an effective buffer against seasonal fluctuations in energy and nutrient intake for these primates and is likely to have a similar function in other mammal species.
Assuntos
Alouatta/microbiologia , Dieta/veterinária , Trato Gastrointestinal/microbiologia , Microbiota , Animais , Comportamento Alimentar , Feminino , Frutas , Masculino , México , Folhas de Planta , Estações do AnoRESUMO
The gastrointestinal (GI) microbiome contributes significantly to host nutrition and health. However, relationships involving GI microbes, their hosts and host macrohabitats remain to be established. Here, we define clear patterns of variation in the GI microbiomes of six groups of Mexican black howler monkeys (Alouatta pigra) occupying a gradation of habitats including a continuous evergreen rainforest, an evergreen rainforest fragment, a continuous semi-deciduous forest and captivity. High throughput microbial 16S ribosomal RNA gene sequencing indicated that diversity, richness and composition of howler GI microbiomes varied with host habitat in relation to diet. Howlers occupying suboptimal habitats consumed less diverse diets and correspondingly had less diverse gut microbiomes. Quantitative real-time PCR also revealed a reduction in the number of genes related to butyrate production and hydrogen metabolism in the microbiomes of howlers occupying suboptimal habitats, which may impact host health.