Three sympatric Hapalemur species (H. g. griseus, H. aureus, and H. (Prolemur) simus) in Ranomafana National Park, Madagascar are known to eat bamboo food parts that contain cyanide. How these lemurs avoid cyanide poisoning remains unknown. In this…
In vivo laboratory-based studies describing jaw-muscle activity and mandibular bone strain during mastication provide the empirical basis for most evolutionary hypotheses linking primate masticatory apparatus form to diet. However, the laboratory…
Descriptive and quantitative analyses of electromyograms (EMG) from the jaw adductors during feeding in mammals have demonstrated both similarities and differences among species in chewing motor patterns. These observations have led to a number of…
In vivo studies, of jaw-muscle behavior have been integral factors in the development of our current understanding of the primate masticatory apparatus. However, even though it has been shown that food textures and mechanical properties influence…
We investigated patterns of jaw-muscle coordination during rhythmic mastication in three species of ungulates displaying the marked transverse jaw movements typical of many large mammalian herbivores. In order to quantify consistent motor patterns…
The Feeding Experiments End-user Database (FEED) is a research tool developed by the Mammalian Feeding Working Group at the National Evolutionary Synthesis Center that permits synthetic, evolutionary analyses of the physiology of mammalian feeding.…
We lack a general understanding of how primates perform physiologically during feeding to cope with the challenges of their natural environments. We here discuss several methods for studying the ecological physiology of feeding in mantled howlers…
A realistic understanding of primate morphological adaptations requires a multidisciplinary approach including experimental studies of physiological performance and field studies documenting natural behaviors and reproductive success. For primate…
Recent morphometric analyses have led to dissimilar conclusions about whether the jaws of tree-gouging primates are designed to resist the purportedly large forces generated during this biting behavior. We further address this question by comparing…
There are numerous records of conjoined twinning in humans and domesticated animals, but many fewer for wild animals because of the early death of conjoined twins. We here describe the incidental discovery and skeletal anatomy of a wild-caught bat…
Resource distribution shapes many aspects of primate behavioral ecology. Though the spatial patterning of fruits, leaves, and insects has been explored among primate foods, comparatively less is known about exudate distributions. Tree exudates are a…
Many primates display within-species variation in social organization and mating system. Individuals of these species may be confronted with both the challenges of between-group competition to exclude same-sex competitors as well as within-group…
Arboreal primates actively navigate a complex thermal environment that exhibits spatial, daily, and seasonal temperature changes. Thus, temperature measurements from stationary recording devices in or near a forest likely do not reflect the thermal…
Animals must overcome the physical properties protecting foods to obtain nutrition. While animals can experience selection for traits that facilitate resource exploitation, specific feeding behaviors may entail multiple, different mechanical…
P>Although there are several isolated references to the olfactory anatomy of mysticetes, it is usually thought that olfaction is rudimentary in this group. We investigated the olfactory anatomy of bowhead whales and found that these whales have a…
The embryology of cetaceans documents features that elucidate the interaction between form and function in modern species, as well as their evolution from extinct ones. Prenatal specimens of the dolphin Stenella attenuata demonstrate critical aspects…
We describe pads on the thumb of five vespertilionoid bats based on microanatomy and scanning microscopy and make inferences about their function. The pad of Thyroptera adheres by means of suction, and that of Tylonycteris uses dry adhesion. The pad…
Amphibians overwintering in ice-covered aquatic environments encounter levels of hypoxia that present significant challenges to the maintenance of aerobic metabolism. Earlier laboratory experiments showed that cold-submerged frogs will seek out lower…
Tympanic bullae and baleen plates from bowhead whales of the Western Arctic population were examined. Growth layer groups (GLGs) in the involucrum of the tympanic bone were used to estimate age of the whales, and compared to stable isotope signatures…
As the study of bone disease in recent and fossil amphibians and reptiles has evolved from observational speculation to analysis of testable hypotheses, so too has recognition of its contribution to our understanding of diseases and organisms. Given…
Diagnosis of diseases of bone, without benefit of soft tissue, in vivo observation, or blood component analysis requires the development of new criteria for diagnosis. Analyzing chimpanzee skeletal populations, applying such criteria (e.g., lesion…
Bone pathology provides a window to environment and predation, allowing confident comparison of fossils and subfossils with their modern descendents. Exclusive of modern contaminated environments, the frequency of bone disease in frogs does not seem…
Analyses of New World skeletal populations for the presence of erosions an other osseous alterations and their character, distribution, and radiologic appearance shows that osteoarthritis is predominantly a disease of animals raised in artificially…
The first mammalian metapodial (MP1) has periodically been argued to actually be a phalanx, because the first ray has one less element than the four posterior rays, and because the MP1 growth plate is proximal like those of all phalanges, rather than…
Mammalian metapodials (metacarpals and metatarsals), unlike most long bones, form a single growth plate, and undergo longitudinal growth at only one end. The growth dynamics of non-mammalian tetrapod metapodials have not been systematically examined…
The marsupial middle ear performs an anatomical impedance matching for acoustic energy travelling in air to reach the cochlea. The size of the middle ear sets constraints for the frequencies transmitted. For generalized placental mammals, it has been…
In odontocetes the mandibular bone serves two functions: to capture prey, and as a means of the reception and transmission of sound waves through a fat body in the mandibular canal, which opens posteriorly as the mandibular foramen. The posterior…
Cytochrome P450s are enzymes involved in the oxidative metabolism of numerous endogenous and exogenous molecules. The enzyme cytochrome debrisoquine/sparteine-type monoxygenase is a specific form of cytochrome P450 and is found in the liver and the…
The hypothesis that flower shape affects nectar-feeding performance was examined for the nectarivorous bat, Syconycteris australis. Experiments using feeders with artificial flowers of different diameters demonstrated that the narrow flower diameter…
