Bard K.A.,University of Portsmouth |
Dunbar S.,University College London |
Maguire-Herring V.,University of Portsmouth |
Veira Y.,State University of New York at Buffalo |
And 2 more authors.
American Journal of Primatology | Year: 2014
Communicative skills of chimpanzees are of significant interest across many domains, such as developmental psychology (how does communication emerge in prelinguistic beings?), evolution (e.g., did human language evolve from primate gestures?), and in comparative psychology (how does the nonverbal communication of chimpanzees and humans compare?). Here we ask about how gestures develop in chimpanzee infants (n=16) that were raised in an interactive program designed to study skill development. Data on socio-communicative development were collected following 4hr of daily interaction with each infant, longitudinally from birth through the first year of life. A consistent and significant developmental pattern was found across the contexts of tickle play, grooming, and chase play: Infant chimpanzees first engaged in interactions initiated by others, then they initiated interactions, and finally, they requested others to join them in the interaction. Gestures were documented for initiating and requesting tickle play, for initiating and requesting grooming, and for initiating and requesting chase play. Gestural requests emerged significantly later than gestural initiations, but the age at which gestures emerged was significantly different across contexts. Those gestures related to hierarchical rank relations, that is, gestures used by subordinates in interaction with more dominant individuals, such as wrist presenting and rump presenting, did not emerge in the same manner as the other gestures. This study offers a new view on the development of gestures, specifically that many develop through interaction and communicate socio-emotional desires, but that not all gestures emerge in the same manner. Am. J. Primatol. 76:14-29, 2014. © 2013 Wiley Periodicals, Inc.
Thurber M.I.,Stanford University |
O'Connell-Rodwell C.E.,Stanford University |
Turner W.C.,University of California at Berkeley |
Nambandi K.,University of Namibia |
And 5 more authors.
Journal of Wildlife Diseases | Year: 2011
Wild African elephants (Loxodonta africana) are commonly infected with intestinal strongyle parasites. Our objective was to determine baseline fecal strongyle egg counts for elephants in the northeast region of Etosha National Park, Namibia and determine if these numbers were affected by annual rainfall, elephant demography (age of individuals and composition of groups), and hormonal state of males. We found that matriarchal family group members have significantly higher fecal egg counts than male elephants (bulls). Among family group members, strongyle egg counts increased with age, whereas among bulls, strongyle egg counts decreased with age. Years of higher rainfall were correlated with decreased numbers of strongyle eggs among bulls. Finally, bulls were not affected by their physiologic (hormonal) status (musth vs. nonmusth). These results suggest that infection by strongyle parasites in Namibian African elephants is a dynamic process affected by intrinsic and extrinsic factors including host demography and rainfall. © Wildlife Disease Association 2011.
O'Connell-Rodwell C.E.,Stanford University |
Wood J.D.,University of Washington |
Kinzley C.,Oakland Zoo |
Rodwell T.C.,University of California at San Diego |
And 3 more authors.
Ethology Ecology and Evolution | Year: 2011
Linear dominance hierarchies are thought to form within groups of social animals to minimize conflict over access to resources. Dominance in both male and female African elephants (Loxodonta africana) is based mostly on intrinsic factors relating to age, and dominance hierarchies have been described within and between family groups of females. Very little is reported about male elephant social structure and dominance has only been described at the level of one-on-one contests. We test the hypothesis that male African elephants form linear hierarchies when resources are limited by monitoring a known group of elephants in Etosha National Park, Namibia, and measuring dominance interactions between males (outside the context of reproduction) during the dry season of 4 consecutive years. We show that males form a stable linear dominance hierarchy under normal arid conditions (in 2005 and 2007) when water is limited and resource competition is high. In unusually wet years with increased water availability (in 2006 and 2008), there is no linearity to the dominance hierarchy, less interaction between individuals and more agonistic behaviors exhibited, particularly in lower ranking individuals. This is the first study to quantify the existence of a linear dominance hierarchy in male African elephants as well as the effect of climatic fluctuations on dominance from year to year. © 2011 Dipartimento di Biologia Evoluzionistica dell'Università, Firenze, Italia.
Goodnight A.L.,Oakland Zoo |
Gottfried S.D.,1410 Monument Boulevard |
Emanuelson K.,Oakland Zoo
Journal of Zoo and Wildlife Medicine | Year: 2011
An 18-yr-old male bobcat (Lynx rufus) presented with chronic moderate weight loss and acute onset of anorexia and lethargy. Hypercalcemia and azotemia were present on the serum chemistry panel. Abdominal ultrasound revealed hyperechoic renal cortices, but no evidence of neoplasia. Ionized calcium and 25-hydroxyvitamin D were mildly elevated, intact parathyroid hormone was severely elevated, and parathormone-related protein was undetected, suggesting primary hyperparathyroidism with possible renal dysfunction. Azotemia lessened in severity following diuresis, but hypercalcemia persisted; thus primary hyperparathyroidism was considered the most probable differential diagnosis. A second ultrasound including the cervical region revealed a solitary intraparenchymal left thyroid nodule. The nodule was surgically excised; histopathology confirmed a parathyroid adenoma. Although primary hyperparathyroidism was suspected, diagnosis was not achieved from serum chemistry values alone. This case emphasizes the importance of diagnostic imaging and histopathology in the investigation of persistently abnormal laboratory values. © American Association of Zoo Veterinarians. Copyright 2011 by American Association of Zoo Veterinarians.
News Article | November 1, 2015
Along with zombies, ghosts and other terrifying phantasms, bats are one of the ultimate symbols that represent Halloween, and experts say that there are several noteworthy reasons for it. The mammal's association with the creepy holiday can be traced back to its migration habits, one of the experts said. Nate Fuller, bat biology program graduate student at Boston University, explained that during autumn, swarms of bats in the Northeastern part of the United States flood the skies to prepare for hibernation or for migrating into the south. Fuller said that mid-1800s Scottish and Irish immigrants who brought the Celtic holiday of Samhain to the country possibly saw these swarming bats and begun to associate the winged creatures' presence with the autumn holiday. Samhain eventually led to Halloween, he said. Certain bat species go south for the winter, while other bat species in the West often do not have to hibernate or migrate because of the warm enough climate in the area, said Shannon Curie from Bat Organization. "By late October most bats from Chicago to Boston and north have already started to hibernate in a mine or cave or have migrated well south of (the northern) area," explained Professor Allen Kurta, a bat specialist from Eastern Michigan University. Moreover, traditional tales and pop culture influences have associated bats with dread and fear. Certain stories include blood-drinking vampires who have the ability to turn into bats, and these tales have spread into the Halloween folklore. However, experts say that in reality, these mammals are actually quite harmless. Most bats do not contain rabies and only eat insects, Fuller clarified. Three to five percent of bats were discovered to be positive with rabies, and this debunks the myth that all bats are carriers of the disease. "Most people don't realize how small vampire bats are," said Oakland Zoo senior bat keeper Andrea Dugall. "The larger bats like to eat fruit, flowers, leaves - they don't eat people. I offered one an insect once, and he looked at me like I was crazy." Bat conservationists hope that the public perception toward these winged mammals becomes optimistic. Massachusetts Division of Fisheries and Wildlife Assistant Director Tom French said that Northern Long-eared bats have been recently added to the list of federal endangered species. He added that in recent years, there has been an outpouring of concern for the decline of bat population in the U.S., and it was something he never expected to happen. It was a positive albeit small sign that awareness has shifted the image of these winged animals to the public, and researchers hope that more positive exposure can be done to save these mammals.