Abstract: Horse trailers are a common form of transportation for horses and ponies and often require the animal to travel alone or with a single companion. The current study investigated the effect of transporting horses alone, in company or with an acrylic safety mirror (measuring 81cm61.5cm) that provided surrogate companionship. The behavioural and physiological responses of 12 mature horses during a 30-min journey by trailer under the three treatments were compared. Behaviours (vocalisation, eating, head-tossing, pawing, and head-turning) were recorded. In order to assess circulatory changes that occur as part of the response to transport, heart rate (HR), rectal (Tr) and ear-pinna (Tp) temperatures were recorded. When travelling with a live companion significantly less time was spent vocalising (p<0.001), head-turning (p<0.001), head-tossing (p<0.01) and pawing (p<0.01); eating behaviour increased (p<0.05). Physiological responses (increases in HR and Tr and decreases in Tp) were also significantly reduced when travelling with a live companion (p<0.01). Travelling with the mirror did not significantly affect physiological responses compared with travelling alone, but the rise in Tr and fall in Tp was reduced (p=0.052 and p=0.051, respectively) and can be considered a trend. When travelling with a mirror significantly less time was spent turning the head (p<0.01), vocalising (p<0.05) and head-tossing (p<0.05); eating behaviour increased (p<0.05). The only significant difference between travelling with a live companion and a mirror was that the time spent turning the head round was less with a live companion (p<0.05). The provision of surrogate companionship in the form of a mirror was found to be preferable to travel alone, but where possible a live companion is recommended. Isolation during transportation was found to suppress feeding behaviour. Although peripheral blood flow (Tp) has been used to assess transport stress in other species it has not previously been used in the horse. Further evaluation of this non-invasive measure is now required.

Abstract: Glucocorticoids (GC) are lipophilic hormones commonly used as therapeutics in acute and chronic inflammatory disorders such as inflammatory bowel disease due to their attributed anti-inflammatory and immunosuppressive actions. Although the adrenal glands are the major source of endogenous GC, there is increasing evidence for the production of extra-adrenal GC in the brain, thymus, skin, vasculature, and the intestine. However, the physiological relevance of extra-adrenal-produced GC remains still ambiguous. Therefore, this review attracts attention to discuss possible biological benefits of extra-adrenal-synthesized GC, especially focusing on the impact of locally synthesized GC in the regulation of intestinal immune responses.

Abstract: Abstract  Until recently, few studies have used social network theory (SNT) and metrics to examine how social network structure (SNS) might influence social behavior and social dynamics in non-human animals. Here, we present an overview of why and how the social network approach might be useful for behavioral ecology. We first note four important aspects of SNS that are commonly observed, but relatively rarely quantified: (1) that within a social group, differences among individuals in their social experiences and connections affect individual and group outcomes; (2) that indirect connections can be important (e.g., partners of your partners matter); (3) that individuals differ in their importance in the social network (some can be considered keystone individuals); and (4) that social network traits often carry over across contexts (e.g., SN position in male–male competition can influence later male mating success). We then discuss how these four points, and the social network approach in general, can yield new insights and questions for a broad range of issues in behavioral ecology including: mate choice, alternative mating tactics, male–male competition, cooperation, reciprocal altruism, eavesdropping, kin selection, dominance hierarchies, social learning, information flow, social foraging, and cooperative antipredator behavior. Finally, we suggest future directions including: (1) integrating behavioral syndromes and SNT; (2) comparing space use and SNS; (3) adaptive partner choice and SNS; (4) the dynamics and stability (or instability) of social networks, and (5) group selection shaping SNS.

Abstract: Reconciliation (i.e. the post-conflict exchange of friendly behaviour between former opponents) functions to control for the detrimental effects that aggression may have on social relationships. Studies conducted so far have investigated intra-individual sources of variation in post-conflict behaviour, showing that animals have a stronger increase in anxiety and are more likely to reconcile after conflicts with valuable partners, such as kin. Much less attention has been given to how differences between individuals in emotional profiles affect post-conflict behaviour. Our aim was to analyse whether inter-individual differences in baseline anxiety levels predicted the magnitude of the increase in anxiety following a conflict and the occurrence of reconciliation. We collected data on two groups of wild Japanese macaques (Macaca fuscata yakui). Animals having a higher baseline level of anxiety had a more dramatic anxious response following a conflict while controlling for a series of factors (e.g. relationship quality between opponents). These more anxious animals were also less likely to reconcile than more relaxed individuals. Therefore, more anxious animals face some social costs by being less able to cope with the post-conflict condition. We propose that differences in anxiety levels may be interpreted as tradeoffs between benefits and costs across conditions. For example, more anxious animals, who are less able to reconcile conflicts, might also be less exploratory and thus face a lower risk to eat unknown, poisonous food.

Abstract: Although homeotherms likely experience costs of both predation risk and thermoregulation while foraging, it is unclear how foragers contend with these costs. We used foraging trays placed in sheltered microsites to determine whether temperature, a direct cue of predator presence (predator urine) and an indirect cue of predation risk (cloudy nights) affect foraging of white-footed mice, Peromyscus leucopus, in winter. Mice were presented with urine from bobcats, Lynx rufus, red foxes, Vulpes vulpes, and coyotes, Canis latrans, an herbivore (whitetailed deer, Odocoileus virginianus), and a water control. To measure rodent foraging, we used seeds of millet mixed with sand to quantify giving-up densities (the number of seeds left in each foraging tray). Giving-up density was not affected by predator urine. Rather, rodent foraging was affected by an interaction of temperature and weather. On overcast nights, when predation risk was likely lower, mice foraged more when soil temperature was higher, presumably reducing thermoregulatory costs. On clear nights, foraging was low regardless of soil temperature, presumably because foraging was more risky. These results suggest that mice consider thermoregulatory costs and predation risk when making foraging decisions, and that the indirect cue afforded by weather, rather than the direct cue of predator urine, is among the cues used to make foraging decisions. Moreover, these results suggest that sensitivity to a particular cue is likely to be context-dependent.