Catalogue Search | MBRL
Are you sure you want to remove the book from the shelf?
{{itemTitle}}
6,565
result(s) for
"Primates -- Ecology"
Sort by:
Fine-scaled climate variation in equatorial Africa revealed by modern and fossil primate teeth
Variability in resource availability is hypothesized to be a significant driver of primate adaptation and evolution, but most paleoclimate proxies cannot recover environmental seasonality on the scale of an individual lifespan. Oxygen isotope compositions (δ18O values) sampled at high spatial resolution in the dentitions of modern African primates (n = 2,352 near weekly measurements from 26 teeth) track concurrent seasonal precipitation, regional climatic patterns, discrete meteorological events, and niche partitioning. We leverage these data to contextualize the first δ18O values of two 17 Ma Afropithecus turkanensis individuals from Kalodirr, Kenya, from which we infer variably bimodal wet seasons, supported by rainfall reconstructions in a global Earth system model. Afropithecus’ δ18O fluctuations are intermediate in magnitude between those measured at high resolution in baboons (Papio spp.) living across a gradient of aridity and modern forest-dwelling chimpanzees (Pan troglodytes verus). This large-bodied Miocene ape consumed seasonally variable food and water sources enriched in 18O compared to contemporaneous terrestrial fauna (n = 66 fossil specimens). Reliance on fallback foods during documented dry seasons potentially contributed to novel dental features long considered adaptations to hard-object feeding. Developmentally informed microsampling recovers greater ecological complexity than conventional isotope sampling; the two Miocene apes (n = 248 near weekly measurements) evince as great a range of seasonal δ18O variation as more time-averaged bulk measurements from 101 eastern African Plio-Pleistocene hominins and 42 papionins spanning 4 million y. These results reveal unprecedented environmental histories in primate teeth and suggest a framework for evaluating climate change and primate paleoecology throughout the Cenozoic.
Journal Article
Comparative Primate Socioecology
Comparative studies have become both more frequent and more important as a means for understanding the biology, behaviour and evolution of mammals. Primates have complex social relationships and diverse ecologies, and represent a large species radiation. This book draws together a wide range of experts from fields as diverse as reproductive biology and foraging energetics to place recent field research into a synthetic perspective. The chapters tackle controversial issues in primate biology and behaviour, including the role of brain expansion and infanticide in the evolution of primate behavioural strategies. The book also presents an overview of comparative methodologies as applied to recent primate research which will provide new approaches to comparative research. It will be of particular interest to primatologists, behavioural ecologists and those interested in the evolution of human social behaviour.
eBook
Fallback Foods, Optimal Diets, and Nutritional Targets: Primate Responses to Varying Food Availability and Quality
Eating is a risky affair. All animals have to offset risks of feeding such as exposure to plant toxins, increased vulnerability to predation, or conspecific aggression with a food's energetic and nutritional return. What, when, and where an individual eats can impact fitness and, ultimately, species-level adaptations. Here, we explore the variables that influence primate feeding preference: food availability, chemical defense, and nutrient content. We present information demonstrating that consumers manipulate nutrient and energy intake, indicating that what may be a less-than-optimal food for one state of an animal's phenotype may not be for another. This evidence suggests that factors previously assumed to be constraints in Optimal Foraging Theory, Functional Response, and-recently-Fallback Food feeding models would be better categorized as variables. We conclude that \"fallback\" is not an intrinsic state of the food or the consumer and that this conclusion complicates the application of this concept to morphological features in the fossil record.
Journal Article
Macronutrient and Energy Contributions of Insects to the Diet of a Frugivorous Monkey (Cercopithecus ascanius)
Most extant primates feed on insects to some degree, yet the nutritional contributions of insects to primate diets are poorly characterized. Like many small-bodied frugivorous primates, redtail monkeys (
Cercopithecus ascanius
) also eat insects. We quantified the nutritional contributions of insects to the diets of female redtail monkeys in Kibale National Park, Uganda, from July 2010 to June 2012 through full day follows (
N
= 64) using weight-based estimates of food intake. Female redtail monkeys targeted insects for 41 % of feeding bouts, plant reproductive parts (including ripe fruits, unripe fruits, flowers, seeds) for 15 % of feeding bouts, and leaves (including young leaves, mature leaves, leaf petioles, leaf buds) for 17 % of feeding bouts. However, females spent just under 10 % of feeding time on insects, in contrast to 42 % on plant reproductive parts and 39 % on leaves. Redtail monkeys fed primarily on solitary, as opposed to eusocial, insects. Identification of consumed insects is challenging, but of consumed insects that could be identified 74 % were cicadas (order Homoptera), 14 % caterpillars (order Lepidoptera), and 7 % long-horned grasshoppers (order Orthoptera). On a dry matter basis, insects were fairly low in fat (<10 %, except for caterpillars) and high in crude protein content (mean
ca.
69 %) compared to other foods, and contained low levels of indigestible chitin. Because insects are small, an insect feeding bout is much shorter than a feeding bout on vegetation or fruit. Despite the small proportion of time spent feeding on insects, redtail monkeys obtained a mean of 24 % of their daily protein intake and 14 % of energy through insectivory, though intake varied widely across females. Our findings demonstrate that female redtail monkeys gain more nutrients than expected given that they spend <10 % of feeding time ingesting insects. The many primates that complement plant diet items with insects may gain substantial nutrition through minimal feeding time.
Journal Article
On the Move around the Clock: Correlates and Determinants of Cathemeral Activity in Wild Redfronted Lemurs (Eulemur fulvus rufus)
Whether animals are active at night or during the day has profound consequences for many aspects of their behavioral ecology. Because of ecological and physiological trade-offs, most animals, including primates, are either strictly nocturnal or diurnal. However, a few primate species exhibit cathemeral activity, i.e., their activity is irregularly distributed throughout the 24-h cycle. Details and determinants of this unusual activity pattern are poorly understood because long-term 24-h observations are not feasible in the field. We therefore used small data loggers to record the activity of cathemeral redfronted lemurs (Eulemur fulvus rufus) from several neighboring groups quantitatively and continuously over a complete annual cycle in order to evaluate various proposed proximate and ultimate determinants of cathemeral activity. Activity data were examined for variation as a function of ambient temperature, time of day, lunar phase, and season. We found that cathemeral activity occurred year-round and that, on average, 3.5 times more activity occurred during the day. Total and diurnal activity increased during the long days of the austral summer. Nocturnal activity increased during the longer nights of the cool dry season. Irrespective of season, lunar phase had a significant effect on the distribution of activity across the 24-h cycle, with most nocturnal activity recorded during parts of the night with greatest brightness. These data indicate that light availability is the primary proximate determinant for the patterning of cathemeral activity. Several lines of evidence suggest that cathemerality in lemurs has evolved from nocturnal ancestors and that it represents a transitory state on the way to the diurnal niche.
Journal Article
Host age, sex, and reproductive seasonality affect nematode parasitism in wild Japanese macaques
Parasites are characteristically aggregated within hosts, but identifying the mechanisms underlying such aggregation can be difficult in wildlife populations. We examined the influence of host age and sex over an annual cycle on the eggs per gram of feces (EPG) of nematode parasites infecting wild Japanese macaques (Macaca fuscata yakui) on Yakushima Island. Five species of nematode were recorded from 434 fecal samples collected from an age-structured group of 50 individually recognizable macaques. All parasites exhibited aggregated EPG distributions. The age-infection profiles of all three directly transmitted species (Oesophagostomum aculeatum, Strongyloides fuelleborni, and Trichuris trichiura) exhibited convex curves, but concavity better characterized the age-infection curves of the two trophically transmitted species (Streptopharagus pigmentatus and Gongylonema pulchrum). There was a male bias in EPG and prevalence of infection with directly transmitted species, except in the prevalence of O. aculeatum, and no sex bias in the other parasites. Infection with O. aculeatum showed a female bias in prevalence among young adults, and additional interactions with sex and seasonality show higher EPG values in males during the mating season (fall) but in females during the birth season (spring). These patterns suggest that an immunosuppressive role by reproductive hormones may be regulating direct, but not indirect, life-cycle parasites. Exposure at an early age may trigger an immune response that affects all nematodes, but trophically transmitted species appear to accumulate thereafter. Although it is difficult to discern clear mechanistic explanations for parasite distributions in wildlife populations, it is critical to begin examining these patterns in host species that are increasingly endangered by anthropogenic threats.
Journal Article