Basal metabolic rate of canidae from hot deserts to cold arctic climates

Canids form the most widely distributed family within the order Carnivora, with members present in a multitude of different environments from cold arctic to hot, dry deserts. We reviewed the literature and compared 24 data sets available on the basal metabolic rate (BMR) of 12 canid species, accounting for body mass and climate, to examine inter- and intraspecific variations in mass-adjusted BMR between 2 extreme climates (arctic and hot desert). Using both conventional and phylogenetically independent analysis of covariance, we found that canids from the arctic climate zone had significantly higher mass-adjusted BMR than species from hot deserts. Canids not associated with either arctic or desert climates had an intermediate and more variable mass-adjusted BMR. The climate effect also was significant at the intraspecific level in species for which we had data in 2 different climates. Arctic and desert climates represent contrasting combinations of ambient temperatures and water accessibility that require opposite physiological adaptations in terms of metabolism. The fact that BMR varies within species when individuals are subjected to different climate regimes further suggests that climate is an important determinant of BMR

Foraging innovations and kleptoparasitism in birds

The ability to invent new solutions to old or novel problems is often equated with intelligence, both in humans and non-human animals. Behavioural flexibility can be defined operationally by looking at the frequency of novel or unusual behaviours, i.e. innovations, in different taxa. Despite the potential survival benefits of behavioural flexibility in the face of changing conditions, there is variation among taxa in the propensity to innovate. Here, I examine in detail one foraging innovation, dunking behaviour (the immersion of food items in water) in Carib grackles (Quiscalus lugubris) of Barbados. I show that the rarity of dunking behaviour in the field is not due to the inability of most individuals to learn and/or perform it, but rather to the balance of costs and benefits not being favourable to its expression in most field conditions. In this population, dunking functions as a proto-tool food-processing technique speeding the ingestion of items that are difficult to swallow. The frequency of the behaviour depends on food characteristics, travel costs between the food source and water, and the probability of losing items to conspecifics. Dunking renders grackles vulnerable to food theft because it involves releasing food items in water, where there is often a build-up of conspecifics. When faced with a high risk of kleptoparasitism, grackles reduce the frequency of dunking, engage in aggressive displays, and keep items in the bill while dunking. Kleptoparasitism not only reduces the rate of dunking by increasing costs to the behaviour, but also by constituting an alternative foraging tactic. The payoffs to this tactic are frequency-dependent; i.e. they decrease as the frequency of kleptoparasites increases in the group. A comparative study on ecological, morphological and behavioural predictors of the occurrence of kleptoparasitic tactics among bird families point to an important role of predation and cognitive abilities in favouring the evolution of kleptoparasitism. Thus, avian food-stealing should not be regarded as a "cognitively simpler" alternative to intelligent behaviour, but as another form of behavioural flexibility. Large-brained primates and birds share the ability to learn quickly, innovate, use tools and engage in exploitative tactics, suggesting that these abilities have not been traded-off against each other, but have instead evolved together

The repeatability of cognitive performance: a meta-analysis

International audienceOne contribution of 15 to a theme issue 'Causes and consequences of individual differences in cognitive abilities'. Behavioural and cognitive processes play important roles in mediating an individual's interactions with its environment. Yet, while there is a vast literature on repeatable individual differences in behaviour, relatively little is known about the repeatability of cognitive performance. To further our understanding of the evolution of cogni-tion, we gathered 44 studies on individual performance of 25 species across six animal classes and used meta-analysis to assess whether cognitive performance is repea-table. We compared repeatability (R) in performance (1) on the same task presented at different times (temporal repeat-ability), and (2) on different tasks that measured the same putative cognitive ability (contextual repeatability). We also addressed whether R estimates were influenced by seven extrinsic factors (moderators): type of cognitive performance measurement, type of cognitive task, delay between tests, origin of the subjects, experimental context, taxonomic class and publication status. We found support for both temporal and contextual repeatability of cognitive performance, with mean R estimates ranging between 0.15 and 0.28. Repeatability estimates were mostly influenced by the type of cognitive performance measures and publication status. Our findings highlight the widespread occurrence of consistent inter-individual variation in cog-nition across a range of taxa which, like behaviour, may be associated with fitness outcomes. This article is part of the theme issue 'Causes and consequences of individual differences in cognitive abilities'

An Arduino-Based RFID Platform for Animal Research

Radio Frequency Identification (RFID) technology has been broadly applied in the biological sciences to yield new insights into behavior, cognition, population biology, and distributions. RFID systems entail wireless communication between small tags that, when stimulated by an appropriate radio frequency transmission, emit a weak, short-range wireless signal that conveys a unique ID number. These tags, which often operate without a battery, can be attached to animals such that their presence at a particular location can be detected by an RFID reader. This paper describes an RFID data-logging system that can serve as the core for a wide variety of field and laboratory applications for monitoring the activities of individual animals. The core electronics are modeled on an Arduino circuit board, which is a hobbyist electronics system. Users can customize the hardware and software to accommodate their needs. We demonstrate the utility of the system with cursory descriptions of three real-world research applications. The first is a large-scale deployment that was used to examine individual breeding behaviors across four local populations of Wood Ducks. The second application employed an array of RFID-enabled bird feeders that allowed for tests of spatial cognition. Third, we describe a nest-box monitoring system that both records visits from breeding birds and administers experimental treatments, such as increasing temperature or playing audio recordings, in accordance to the presence/absence of individual birds. With these examples we do not attempt to relate details with regard to research findings; rather our intent is to demonstrate some of the possibilities enabled by our low-cost RFID system. Detailed descriptions, design files, and code are made available by means of the Open Science Framework.Open Access fees paid for in whole or in part by the University of Oklahoma LibrariesYe

Tool Use in Fishes

Tool use was once considered the sole domain of humans. Over the last 40 years, however, it has become apparent that tool use may be widespread across the animal kingdom. Pioneering studies in primates have shaped the way we think about tool use in animals, but have also lead to a bias both in terms of our expectations about which animals should be capable of using tools and the working definition of tool use. Here I briefly examine tool use in terrestrial animals and consider the constraints of the current working definition of tool use in fishes. Fishes lack grasping limbs and operate underwater where there are clear constraints with respect to the physics of tool use that differ dramatically from the terrestrial environment. I then examine all of the documented accounts of tool use in fishes. The review reveals that tool use seems to be confined to a limited number of fish taxa, particularly the wrasse, which may show similarities with the greater than expected number of examples of tool use in primates and corvids amongst mammals and birds, respectively. As fish are seldom studied as intensely as birds and mammals, there is a clear need for further observation of tool use in fishes. It is likely that further examples will be unveiled allowing us to perform comparative analyses of the evolution of tool use in fish

Cognitive performance is linked to group size and affects fitness in Australian magpies

This is the author accepted manuscript. The final version is available from Springer Nature via the DOI in this recordThe social intelligence hypothesis states that the demands of social life drive cognitive evolution. This idea receives support from comparative studies that link variation in group size or mating systems with cognitive and neuroanatomical differences across species, but findings are contradictory and contentious. To understand the cognitive consequences of sociality, it is also important to investigate social variation within species. Here we show that in wild, cooperatively breeding Australian magpies, individuals that live in large groups show increased cognitive performance, which is linked to increased reproductive success. Individual performance was highly correlated across four cognitive tasks, indicating a 'general intelligence factor' that underlies cognitive performance. Repeated cognitive testing of juveniles at different ages showed that the correlation between group size and cognition emerged in early life, suggesting that living in larger groups promotes cognitive development. Furthermore, we found a positive association between the task performance of females and three indicators of reproductive success, thus identifying a selective benefit of greater cognitive performance. Together, these results provide intraspecific evidence that sociality can shape cognitive development and evolution.This work was funded by an ARC Discovery grant awarded to A.R.R., A.T. and M. B. V. Bell, and a University of Western Australia International Postgraduate Research Scholarship and Endeavour Research Fellowship awarded to B.J.A. A.T. received additional support from a BBSRC David Phillips Fellowship (BB/H021817/1)

The repeatability of cognitive performance:A meta-analysis

This is the author accepted manuscript. The final version is available from The Royal Society via the DOI in this record.Behavioural and cognitive processes play important roles in mediating an individual's interactions with its environment. Yet, while there is a vast literature on repeatable individual differences in behaviour, relatively little is known about the repeatability of cognitive performance. To further our understanding of the evolution of cognition, we gathered 44 studies on individual performance of 25 species across six animal classes and used meta-analysis to assess whether cognitive performance is repeatable. We compared repeatability (R) in performance (1) on the same task presented at different times (temporal repeatability), and (2) on different tasks that measured the same putative cognitive ability (contextual repeatability). We also addressed whether R estimates were influenced by seven extrinsic factors (moderators): type of cognitive performance measurement, type of cognitive task, delay between tests, origin of the subjects, experimental context, taxonomic class and publication status. We found support for both temporal and contextual repeatability of cognitive performance, with mean R estimates ranging between 0.15 and 0.28. Repeatability estimates were mostly influenced by the type of cognitive performance measures and publication status. Our findings highlight the widespread occurrence of consistent inter-individual variation in cognition across a range of taxa which, like behaviour, may be associated with fitness outcomes.PKYC is supported by Japan Society for the Promotion of Science (PE1801); JOvH was funded by an ERC consolidator grant (616474). MC and this research was supported by a grant from the Human Frontier Science Program to ASC and JM-F (RGP0006/2015)