The face of animal cognition

As an increasing number of researchers investigate the cognitive abilities of an ever‐wider range of animals, animal cognition is currently among the most exciting fields within animal behavior. Tinbergen would be proud: all four of his approaches are being pursued and we are learning much about how animals collect information and how they use that information to make decisions for their current and future states as well as what animals do not perceive or choose to ignore. Here I provide an overview of this productivity, alighting only briefly on any single example, to showcase the diversity of species, of approaches and the sheer mass of research effort currently under way. We are getting closer to understanding the minds of other animals and the evolution of cognition at an increasingly rapid rate.PostprintPeer reviewe

Animal cognition

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It began in ponds and rivers : charting the beginnings of the ecology of fish cognition

But fish cognitive ecology did not begin in rivers and streams. Rather, one of the starting points for work on fish cognitive ecology was work done on the use of visual cues by homing pigeons. Prior to working with fish, Victoria Braithwaite helped to establish that homing pigeons rely not just on magnetic and olfactory cues but also on visual cues for successful return to their home loft. Simple, elegant experiments on homing established Victoria's ability to develop experimental manipulations to examine the role of visual cues in navigation by fish in familiar areas. This work formed the basis of a rich seam of work whereby a fish's ecology was used to propose hypotheses and predictions as to preferred cue use, and then cognitive abilities in a variety of fish species, from model systems (Atlantic salmon and sticklebacks) to the Panamanian Brachyraphis episcopi. Cognitive ecology in fish led to substantial work on fish pain and welfare, but was never left behind, with some of Victoria's last work addressed to determining the neural instantiation of cognitive variation.Publisher PDFPeer reviewe

Object manipulation without hands

Funding: This work was supported by BBSRC Discovery Fellowship (BB/S01019X/1) to S.S.Our current understanding of manipulation is based on primate hands, resulting in a detailed but narrow perspective of ways to handle objects. Although most other animals lack hands, they are still capable of flexible manipulation of diverse objects, including food and nest materials, and depend on dexterity in object handling to survive and reproduce. Birds, for instance, use their bills and feet to forage and build nests, while insects carry food and construct nests with their mandibles and legs. Bird bills and insect mandibles are much simpler than a primate hand, resembling simple robotic grippers. A better understanding of manipulation in these and other species would provide a broader comparative perspective on the origins of dexterity. Here we contrast data from primates, birds and insects, describing how they sense and grasp objects, and the neural architectures that control manipulation. Finally, we outline techniques for collecting comparable manipulation data from animals with diverse morphologies and describe the practical applications of studying manipulation in a wide range of species, including providing inspiration for novel designs of robotic manipulators.PostprintPeer reviewe

A comparative study of how British tits encode predator threat in their mobbing calls

This research funded by NERC (NE/J018694/1), the Royal Society (RG2012R2), the M. J. Murdock Charitable Trust (2014199) and the University of St Andrews (University of St Andrews 600th Year Scholarship and the St Leonard's Fee Scholarship).Many species use antipredator vocalizations to signal information about potential predators, including the level of threat posed by a particular predator. It is not clear, however, why only some prey species do this. Because they use multiple mechanisms to encode threat-specific information about predators, North American Paridae species have been a particularly useful model for studying antipredator signals. Paridae as a group are also useful for examining phylogenetic conservation of vocal signals because all of these species (at least those studied previously) employ similar ways of encoding information about predator threat. To test whether the ways in which predator threat information is encoded (here measured by a bird's vocal output) are conserved across a family with similar vocalizations, we used taxidermy mounts to simulate low- and high-threat predators to induce mobbing in six species across five genera of British Paridae. We found that, like North American species, British tits all increased their call rate in response to predators compared with nonthreatening control mounts, but they all varied in the number and types of additional ways they encoded this information. Some species (blue and willow tits) used all four ways to differentiate between different threat predators, while others used only two (crested tits), one (great and coal tits) or none at all (willow tits). The variation in the way each species encoded predator threat information in their calls was not explained by phylogenetic relatedness or by variation in life history. To better understand patterns of information encoding across related species, we suggest that playback experiments to determine how encoded information is used by conspecifics and heterospecifics might provide insights about why some species encode information about predator threat in multiple ways.PostprintPeer reviewe

Hoo are you? Tits do not respond to novel predators as threats

The Natural Environment Research Council (NE/J018694/1), the Royal Society (RG2012R2), the M. J. Murdock Charitable Trust (2014199) and the University of St Andrews (University of St Andrews 600th Year Scholarship and the St Leonard’s Fee Scholarship) provided funding.To combat the threat of predation, prey species have developed a variety of ways to recognize and respond appropriately to novel predators. While there is evidence that predator recognition does not require learning in certain species, learning appears to play an important role for other species. In systems where learning is important, it is less clear whether predator identification requires prior experience with specific predators or, whether general experience with predators provides sufficient tools for identifying similar species of novel predators. Here we test whether wild-living adult birds recognize a dangerous predator that occurs in only part of their geographical range. We presented taxidermy mounts of little owls, Athene noctua, and sparrowhawks, Accipiter nisus, to blue tits, Cyanistes caeruleus, and great tits, Parus major. All populations of both tit species co-occur with sparrowhawks, but populations differ in their prior experience with little owls. We found that tits that overlap geographically with little owls responded to little owls using the same intensity of mobbing behaviour exhibited toward sparrowhawks. In populations with no historical contact with little owls, however, both blue and great tits treated little owls as a lower threat than sparrowhawks. These results suggest that blue tits and great tits do not generalize ‘predatory features’ to novel predators and instead need prior experience with specific predators before they assign the correct level of threat.Publisher PDFPeer reviewe

Reproductive consequences of material use in avian nest construction

This study was funded by the School of Biology and a St. Leonard’s College Scholarship at the University of St. Andrews, UK (both to A.J.B.), and by the Biotechnology and Biological Sciences Research Council (Anniversary Future Leader Fellowship to L.M.G.; grant number: BBSRC – BB/M013944/1).Birds’ nests represent a rich behavioural ‘fingerprint’, comprising several important decisions—not the least of which is the selection of appropriate material. Material selection in nest-building birds is thought to reflect, in part, builder-birds’ use of the ‘best’ material—in terms of physical properties (e.g., rigidity)—refined across generations. There is, however, little experimental evidence to link the physical properties of nest material to both birds’ nest building and breeding performance. We examined individual-level material-use consequences for breeding zebra finches by manipulating the kind of material available to laboratory-housed pairs: stiff or flexible same-length string. We show that higher fledgling numbers were related to (i) fewer pieces used in nest construction by stiff-string builders; and conversely, (ii) more pieces used in nest construction by flexible-string builders. Together, these data suggest that physical differences in nest material can affect avian reproduction (here, the trade-off between nest-construction investment and breeding success), highlighting the adaptive significance of nest-building birds’ material selectivity.PostprintPeer reviewe

Bird nest building : visions for the future

Templeton World Charity Foundation and National Geographic Society (M.C.T.-R.: TWCF 0210, EC-58859R-19) and Marie Skłodowska-Curie Actions (M.H.).Successful reproduction for most birds requires them to have built ‘good’ nests. The remarkable diversity of nests across approximately 10 000 species of living birds suggests that ‘good’ nest design depends critically on a species' microhabitat, life history and behaviour. Unravelling the key drivers of nest diversity remains a key research priority—bolstered by renewed appreciation for nest museum collections and increasing correlational field and experimental laboratory data. Phylogenetic analyses—coupled with powerful datasets of nest traits—are increasingly shedding light on the evolution of nest morphology and there are functional questions yet to be addressed. For birds, at least, developmental and mechanistic analyses of building (behaviour, hormones, neuroscience) itself, rather than measurements and analyses of nest morphology, are already becoming the next major challenge. We are moving towards a holistic picture in which Tinbergen's four levels of explanation: evolution, function, development, and mechanism, are being used to explain variation and convergence in nest design—and, in turn, could shed light on the question of how birds know how to build ‘good’ nests.Publisher PDFPeer reviewe

From a sequential pattern, temporal adjustments emerge in hummingbird traplining

Animals that feed from resources that are constant in space and that refill may benefit from repeating the order in which they visit locations. This is a behavior known as traplining, a spatial phenomenon. Hummingbirds, like other central‐place foragers, use short traplines when moving between several rewarding sites. Here we investigated whether traplining hummingbirds also use relevant temporal information when choosing which flowers to visit. Wild rufous hummingbirds that were allowed to visit 3 artificial flower patches in which flowers were refilled 20 min after they had been depleted repeated the order in which they visited the 3 patches. Although they tended to visit the first 2 patches sooner than 20 min, they visited the third patch at approximately 20‐min intervals. The time between visits to the patches increased across the experiment, suggesting that the birds learned to wait longer before visiting a patch. The birds appeared to couple the sequential pattern of a trapline with temporal regularity, to some degree. This suggests that there is a temporal component to the repeated spatial movements flown by foraging wild hummingbirds.PostprintPeer reviewe