Glucocorticoid Production, Activity Levels, And Personality Traits Of Fennec Foxes (Vulpes zerda) Managed For Different Roles In Zoos
Fecal glucocorticoid metabolite (FGM) concentrations, activity, and personality were assessed for 35 fennec foxes (Vulpes zerda) to determine whether animals managed as ambassadors differed from exhibit or off-exhibit animals. A FGM assay, pedometer, and personality assessment tool were validated. Then, fecal samples and movement data were collected during winter and summer periods. Handling was recorded, […]
Circadian Rhythm of Salivary Immunoglobulin A and Associations with Cortisol as A Stress Biomarker in Captive Asian Elephants (Elephas maximus)
Salivary immunoglobulin A (sIgA) has been proposed as a potential indicator of welfare for various species, including Asian elephants, and may be related to adrenal cortisol responses. This study aimed to distinguish circadian rhythm effects on sIgA in male and female Asian elephants and compare patterns to those of salivary cortisol, information that could potentially […]
Diel and infradian (7-day) activity rhythms in Mexican spider monkeys (Ateles geoffroyi) kept with and without visitor contact
Diel activity rhythms in mammals are regulated by an endogenous (circadian) timing system which is synchronized by environmental 24-hr periodicities called zeitgebers. Additional direct responses to stochastic environmental factors ensure the fine-tuning to the actual situation and may mask the circadian time course. Following an observational study on behavioral effects of visitor activities in a […]
Social influences on circadian behavioural rhythms in vertebrates
Although photoperiodic cycles are known to be the most powerful entraining agent of circadian rhythms in homeotherms, social factors can also play a role in synchronizing activity rhythms. Here we review social influences on circadian behavioural rhythms in vertebrates, focusing on the types of possible effects and the types of stimuli eliciting these effects. Social […]
Variation of the phase of the 24-h activity period in different large herbivore species under European and African conditions
The variation of daily rhythms were analysed in relation to environmental factors. Activity phases were determined for Przewalski horses (Equus ferus przewalskii), feral domestic horses (Equus caballus), and mouflon (Ovis orientalis musimon) in Europe under semi-natural conditions by storage telemetry (ETHOSYS 1 ) and compared to samples from plain zebra (Equus burchelli) and blesbok (Damaliscus […]
A note on the circadian rhythm and feeding behaviour of heep fitted with a light weight GPS collar
The circadian rhythm and feeding behaviour (bite rate) of 16 Scottish Blackface ewes of which eight were fitted with a lightweight (863 g) GPS collar were examined. The collar consisted of a leather harness and a 0.5 l aluminium box and represented 2.2% of the average body mass of the study ewes. No differences in […]
Circadian rhythms in metabolic variables in Caenorhabditis elegans
Circadian rhythms govern a wide variety of physiological and metabolic functions in most organisms through neural networks, hormones and gene expression. In this work, we studied the circadian variation in metabolic variables of adult C. elegans such as food consumption, pharyngeal contractions, defecation and oxygen consumption. Feeding behavior was clearly rhythmic under LD conditions, with […]
The circadian body temperature rhythm of Djungarian Hamsters (Phodopus sungorus) revealing different circadian phenotypes
Djungarian hamsters (Phodopus sungorus) of our breeding stock show three rhythmic phenotypes: wild type (WT) animals which start their activity shortly after “lights-off” and are active until “lights-on”; delayed activity onset (DAO) hamsters whose activity onset is delayed after “lights-off” but activity offset coincides with “lights-on”; and arrhythmic hamsters (AR) that are episodically active throughout […]
Effects of environmental enrichment on behavioral responses to novelty, learning, and memory, and the circadian rhythm in cortisol in growing pigs
Previously we showed that pigs reared in an enriched environment had higher baseline salivary cortisol concentrations during the light period than pigs reared under barren conditions. In the present experiment, it was investigated whether these higher baseline salivary cortisol concentrations were a real difference in cortisol concentration or merely represented a phase difference in circadian […]
Analyzing corticosterone metabolites in fecal samples of mice: a noninvasive technique to monitor stress hormones
In small animals like mice, the monitoring of endocrine functions over time is constrained seriously by the adverse effects of blood sampling. Therefore, noninvasive techniques to monitor, for example, stress hormones in these animals are highly demanded in laboratory as well as in field research. The aim of our study was to evaluate the biological […]