Tactile stimulation reduces aggressiveness but does not lower stress in a territorial fish

Body tactile stimulation has a positive effect upon highly social animals, such as mammals and cleaner-client coral-reef fish, by relieving stress and improving health. Conversely, some tactile contacts are naturally detrimental, such as those resulted from aggressive interactions. To study whether positive responses from tactile stimulation are generalized among vertebrates, we tested its effect on […]

The Emergence and Behavioral Stability of Social Status in Green Anole Lizard (Anolis carolinensis) Dyads

Male green anole lizards engage in behavioral displays and stress-hormone mediated color changes during territorial aggression. We examined 12 male dyads during two weeks of cohabitation to document the aggressive behavior of dominant and subordinate animals and to examine the emergence and behavioral stability of dominant/subordinate social status. Two hour observations conducted on alternating days […]

Lizards perceived abiotic and biotic stressors independently when competing for shade in terrestrial mesocosms

Hormones such as glucocorticoids and androgens enable animals to respond adaptively to environmental stressors. For this reason, circulating glucocorticoids became a popular biomarker for estimating the quality of an environment, and circulating androgens are frequently used to indicate social dominance. Here, we show that access to thermal resources influence the hormones and behavior of male […]

Oxytocin modulates mate-guarding behavior in marmoset monkeys

In socially-monogamous species, intolerance of interactions between a pairmate and a sexual rival (i.e., mate-guarding) promotes the preservation of long-lasting partnerships. One promising neurobiological candidate for the regulation of mate-guarding behavior in monogamous primates is the oxytocin (OT) system, given its established role in both the development of monogamous bonds and the behavioral processes that […]

Mixed support for state maintaining risky personality traits in yellow-bellied marmots

In a variety of taxa, individuals behave in consistently different ways. However, there are relatively few studies that empirically test the potential mechanisms underlying the causes and maintenance of these personality differences. Several hypotheses for the causes and maintenance of risky personality traits have been suggested but all have received mixed support. Both the pace-of-life […]

Friend or foe: reconciliation between males and females in wild chacma baboons

Male aggression towards females is a common and often costly occurrence in species that live in bisexual groups. But preferential heterosexual relationships are also known to confer numerous fitness advantages to both sexes—making it of interest to explore how aggression is managed among male–female dyads through strategies like reconciliation (i.e. postconflict affiliative reunions between former […]

Pilot study evaluating surface temperature in dogs with or without fear-based aggression

The use of a standardized physiological measure in veterinary behavior evaluations would improve both accuracy of the diagnosis and monitoring of the treatment response. Infrared thermography (IRT) is a noninvasive, remote assessment tool used primarily in research to evaluate changes in surface body temperature resulting from underlying physiological processes. IRT has not been examined widely […]

Aggression in working mules and subsequent aggressive treatment by their handlers in Egyptian brick kilns—Cause or effect?

Mules found working in Egyptian brick kilns are often faced with poor welfare from being over worked, overloaded, having multiple lesions from ill-fitted harnesses, poor body scores, and receiving aversive treatment by handlers. Reports have frequently revealed aggressive responses by mules toward their handlers. The main goal of this study was to investigate whether mule […]

Behavioral Decisions for Managing Social Distance and Aggression in Captive Polar Bears (Ursus maritimus)

The polar bear (Ursus maritimus) in most zoos attracts high levels of public attention and can play an important role in conservation education. Polar bears in the wild are typically solitary; bears in captivity often house socially. This study reported behavioral evidence on how bears manage this situation and whether proximity leads to aggression. The […]

Dominance, aggression, and glucocorticoid levels in social carnivores

In social animals, reproductive success is often related to social dominance. In cooperatively breeding birds and mammals, reproductive rates are usually lower for social subordinates than for dominants, and it is common for reproduction in subordinates to be completely suppressed. Early research with captive animals showed that losing fights can increase glucocorticoid (GC) secretion, a […]