Abstract: Camera trapping is a relatively new addition to the wildlife survey repertoire in Australia. Its rapid adoption has been unparalleled in ecological science, but objective evaluation of camera traps and their application has not kept pace. With the aim of motivating practitioners to think more about selection and deployment of camera trap models in relation to research goals, we reviewed Australian camera trapping studies to determine how camera traps have been used and how their technological constraints may have affected reported results and conclusions. In the 54 camera trapping articles published between 1991 and 2013, mammals (86%) were studied more than birds (10%) and reptiles (3%), with small to medium-sized mammals being most studied. Australian camera trapping studies, like those elsewhere, have changed from more qualitative to more complex quantitative investigations. However, we found that camera trap constraints and limitations were rarely acknowledged, and we identified eight key issues requiring consideration and further research. These are: camera model, camera detection system, camera placement and orientation, triggering and recovery, camera trap settings, temperature differentials, species identification and behavioural responses of the animals to the cameras. In particular, alterations to animal behaviour by camera traps potentially have enormous influence on data quality, reliability and interpretation. The key issues were not considered in most Australian camera trap papers and require further study to better understand the factors that influence the analysis and interpretation of camera trap data and improve experimental design.

Abstract: Innovative behaviors such as exploiting novel food sources can grant significant fitness benefits for animals, yet little is known about the mechanisms driving such phenomena, and the role of physiology is virtually unexplored in wild species. Two hypotheses predict opposing effects of physiological state on innovation success. On one hand, poor physiological condition may promote innovations by forcing individuals with poor competitive abilities to invent alternative solutions. On the other hand, superior physiological condition may ensure greater cognitive capacity and thereby better problem-solving and learning performance. To test these hypotheses, we studied the behavior of wild-caught house sparrows (Passer domesticus) in 4 novel tasks of food acquisition, one of which was presented to the birds in repeated trials, and we investigated the relationships of individual performance with relevant physiological traits. We found that problem-solving performance across the 4 tasks was moderately consistent within individuals. Birds with lower integrated levels of corticosterone, the main avian stress hormone, solved the most difficult task faster and were more efficient learners in the repeated task than birds with higher corticosterone levels. Birds with higher concentration of total glutathione, a key antioxidant, solved 2 relatively easy tasks faster, whereas birds with fewer coccidian parasites tended to solve the difficult task more quickly. Our results, thus, indicate that aspects of physiological state influence problem-solving performance in a context-dependent manner, and these effects on problem-solving capacity, probably including cognitive abilities, are more likely to drive individual innovation success than necessity due to poor condition.

Abstract: Evidence suggests that behavioural affective reactions to sweet and bitter substances are homologous in humans, nonhuman primates, and rodents. The sweet taste of sucrose elicits facial responses that include rhythmic tongue protrusions whereas the bitter taste of quinine elicits facial responses that include gapes, featuring an opening of the mouth and protrusion of the tongue. The present study using the horse (Equus caballus) was undertaken for three reasons: (1) there is debate about the presence of a sweet receptor gene in the horse, (2) there is a need to expand the examination of facial reactions to taste in lineages other than the closely related lineages of rodents and primates, and (3) the horse provides an opportunity to test the hypothesis that some social signals derive from movements related to taste reaction. The horses were given oral infusions of either sucrose or quinine and their behaviour was examined using frame-by-frame video analysis. Control groups were exposed received water or syringe insertion only. Amongst the many responses made to the infusions, the distinctive response to sucrose was a bob coupled with a slight tongue protrusion and forward movement of the ears; the distinctive response to quinine was a head extension and mouth gape accompanied by a large tongue protrusion and backward movement of the ears. Sucrose Bobs and Quinine Gapes are discussed with respect to: (1) the relevance of facial reactions to both sucrose and quinine to taste receptors in horses, (2) the similarity of features of taste expression in horses to those documented in rodents and primates, and (3) the dissimilarity between facial reactions to taste and other social signals displayed by horses.

Abstract: Behavioural innovations have become central to our thinking about how animals adjust to changing environments. It is now well established that animals vary in their ability to innovate, but understanding why remains a challenge. This is because innovations are rare, so studying innovation requires alternative experimental assays that create opportunities for animals to express their ability to invent new behaviours, or use pre-existing ones in new contexts. Problem solving of extractive foraging tasks has been put forward as a suitable experimental assay. We review the rapidly expanding literature on problem solving of extractive foraging tasks in order to better understand to what extent the processes underpinning problem solving, and the factors influencing problem solving, are in line with those predicted, and found, to underpin and influence innovation in the wild. Our aim is to determine whether problem solving can be used as an experimental proxy of innovation. We find that in most respects, problem solving is determined by the same underpinning mechanisms, and is influenced by the same factors, as those predicted to underpin, and to influence, innovation. We conclude that problem solving is a valid experimental assay for studying innovation, propose a conceptual model of problem solving in which motor diversity plays a more central role than has been considered to date, and provide recommendations for future research using problem solving to investigate innovation. This article is part of a Special Issue entitled: Cognition in the wild.