Behavior and Habitat Use Remain Diverse and Variable in Modern Zoological Exhibits over the Long-Term: Case Studies in 5 Species of Ursidae
Long-term evaluations of whether modern zoological exhibits help to maintain variation in the behavior of zoo animals are lacking despite the hope that animals avoid falling into monotonous patterns of behavior or boredom. This study evaluated changes in behavior and habitat use over multi-year periods in nine individuals of five bear species at two zoological […]
Relationship between androgens, environmentalfactors and reproductive behavior in male white rhinoceros (Ceratotherium simum simum)
We conducted a longitudinal study of the endocrine activity of free-range male white rhinos. An enzyme immunoassay to measure androgens in the feces was developed and validated to show that it can be used to study testicular activity. We identified two fecal metabolites similar to testosterone and dihydrotestosterone. Several lines of evidence suggest that these […]
Seasonal variations in daily rhythms of activity in athletic horses
Circadian rhythms reflect extensive programming of biological activity that meets and exploits the challenges and opportunities offered by the periodic nature of the environment. In the present investigation, we recorded the total activity of athletic horses kept at four different times of the year (vernal equinox, summer solstice, autumn equinox and winter solstice), to evaluate […]
Testosterone-dependency of male solo song in a duetting songbird — Evidence from females
For male songbirds of the temperate zone there is a tight link between seasonal song behaviour and circulating testosterone levels. Such a relationship does not seem to hold for tropical species where singing can occur year-round and breeding seasons are often extended. White-browed sparrow weavers (Plocepasser mahali) are cooperatively breeding songbirds with a dominant breeding […]
Differences in Fecal Androgen Patterns of Breeding and Nonbreeding Kori Bustards (Ardeotis kori)
To better understand breeding conditions to promote reproduction in captive kori bustards, fundamental endocrine studies measuring fecal androgen metabolites in male and female kori bustards were conducted. Feces collected weekly from males and females were analyzed for testosterone using enzyme-linked immunoassay. Results from adult males (n = 5), adult females (n = 10), immature males […]