Keel bone fractures affect laying hens' mobility, but no evidence for reciprocal effects.

Keel bone fractures (KBF) are prevalent in commercial laying hens and are considered one of the greatest welfare concerns in the egg-production industry. While clear associations exist between KBF and animal mobility, suggesting that KBF impair mobility, the effect of mobility on KBF remains unclear. We combined data from three studies that assessed keel bone fracture severity through radiographs and monitored hens' transitions between different zones of a multi-tier aviary system (the three tiers, a littered floor, and a winter garden) the week prior to radiograph.

Commercial hatchery practices have long-lasting effects on laying hens' spatial behaviour and health.

The commercial hatchery process is globally standardized and exposes billions of day-old layer chicks to stress every year. By alleviating this early stress, on-farm hatching is thought to improve animal welfare, yet little is known about its effects throughout production. This study compared welfare indicators and spatial behaviours during the laying period of hens hatched in an on-farm environment (OFH) to those hatched in a commercial hatchery and transferred at one day-old to a rearing barn (STAN).

Commercial laying hens exhibit long-term consistent individual differences and behavioural syndromes in spatial traits.

Past research has supported the importance of animal personalities for the productivity and welfare of farm animals. However, current assessments of personality traits are commonly conducted over short periods using standardized assays and may not reflect all important aspects of behaviours in commercial settings throughout the production period. This study aimed to evaluate consistent behavioural differences between 194 commercial laying hens within an aviary across most of the production period (eight months).

Intra-individual variation of hen movements is associated with later keel bone fractures in a quasi-commercial aviary.

Measuring intra- and inter-individual variation in movement can bring important insights into the fundamental ecology of animals and their welfare. Although previous studies identified consistent differences in movements of laying hens within commercial aviaries, the level of consistency was not quantified, limiting our capacity to understand the importance of individual movements for welfare. We aimed to quantify the scope of intra- and inter-individual differences in movements of commercial laying hens and examined their associations with indicators of welfare at the end of production.

Intra- and interspecific variation in self-control capacities of parrots in a delay of gratification task.

Forgoing immediate satisfaction for higher pay-offs in the future (delayed gratification) could be adaptive in situations that wild animals may encounter. To explain species-differences in self-control, hypotheses based on social complexity, feeding ecology, brain size and metabolic rate have been proposed. To explore these hypotheses in a comparative setting, we tested three macaw species (neotropical parrots)-great green macaws (N = 8), blue-throated macaws (N = 6), blue-headed macaws (N = 6)-and the distantly related African grey parrots (afrotropical parrots; N = 8) in a modified rotating tray task, in which subjects are required to inhibit consuming a constantly available low-quality reward in favour of a high-quality reward that becomes available only after an increasing delay (min.

Tameness does not correlate with the learning of an appetitive association in a wild canid.

Individual differences in cognition have been shown to be common in some animal taxa, and recent evidence suggests that an individual's personality can be associated with an individual's cognitive strategy. We tested whether wild bat-eared foxes differ in a risk-taking behavior (tameness) and whether this trait correlated with appetitive association learning performance. While our result shows that individuals differed in their tameness, we found no association between this personality trait and learning the appetitive association.

Oxytocin Experiments Shed Light on Mechanisms Shaping Prosocial and Antisocial Behaviors in Non-human Mammals.

Oxytocin has gained a reputation in popular culture as a simple "love drug" or "cuddle hormone", yet emerging biological evidence indicates that the effects of oxytocin are complex, mediating a suite of behavioral traits that range from ultrasocial to antisocial. Here we provide a comprehensive review to assess the salience of oxytocin in the lives of free-living social mammals. We reviewed the literature to understand the potential effects of oxytocin in promoting prosocial and antisocial behaviors in non-human mammals.

Social associations between California sea lions influence the use of a novel foraging ground.

Social relationships define an individual's position in its social network, which can influence the acquisition and spread of information and behavioural variants through the population. Thus, when nuisance behaviours spread through wildlife populations, identifying central individuals may provide valuable insights for problem-species management. We studied the effects of network position on California sea lion () discovery and foraging success at a novel foraging ground-the salmonids that aggregate at the Bonneville Dam tail-race, 235 km up the Columbia River.

The effect of maternal glucocorticoid levels on juvenile docility in yellow-bellied marmots.

Maternal effects can have significant and long-term consequences on offspring behavior and survival, while consistent individual differences (i.e., personality) can have profound impacts on individual fitness.