Social behavior in animals

Evidence for conceptual semantics is well established in monkeys, however this basis of human language is less evident in the great apes. In order to study semantic communications in chimpanzees, I analyzed alarm calls produced towards a blimp as it was flying overhead. I then replayed a set of these alarm calls to the chimps on a different day. The chimps appeared to act in a manner consistent with the presence of the blimp. The calls they produced in response to the playback stimuli were nearly identical to the calls that were produced during the actual flyover. Though the data collected were not sufficient to support a definitive claim, it does appear that the chimpanzees of the study have a meaning-laden vocalization for the aerial stimuli. Whether this call is specific to the blimp or generalizable to other aerial threats is yet to be determined.

Demographic changes, through immigration/emigration (or death) can affect the social and community structure of a population. This study reports on the effects of demographic changes following 2 intense hurricanes on two sympatric delphinid species: Atlantic bottlenose dolphins, Tursiops truncatus, and Atlantic spotted dolphins Stenella frontalis. Thirty percent of the bottlenose population was lost after the hurricanes, with an influx of roughly the same number of immigrants. The stable community split into two cohesive units. Preferences in association in relation to reproductive status and sex remained. Immigrants assimilated well into the population, especially males. There is a conflict of interest between resident males and females in accepting immigrants and often females find more resistance than males. Long-term analysis of spotted dolphins revealed a community structure defined by long-term site fidelity, natal philopatry of both sexes and three social clusters.

A crucial aspect of captive animal care is enrichment, ranging from simple additions of flora to complicated foraging puzzles. Enrichments are vital in creating an environment for animals that is similar to their wild habitat and eliciting natural behaviors. Enrichment is also used to inhibit unnatural or harmful behaviors, like pacing. Commonly, enrichment techniques are not scientifically tested, and the universality of enrichments is rarely scrutinized. This study explores the universality of a "Snak'n'Trim", a hollow ball 10 inches in diameter with a 1 inch opening for food items to be inserted into the ball. Four bears, (two male, two female) were observed for ten weeks, five in the summer and five in the winter. Daily observations were made during baseline and enrichment trials. Behavior frequency was calculated and results indicate a significant (p<.01) difference between baseline and enrichment trials, providing evidence for the efficacy of the Snak'n'Trim.