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Schwab JA, Figueirido B, Martín-Serra A, van der Hoek J, Flink T, Kort A, Esteban Núñez JM, Jones KE. Evolutionary ecomorphology for the twenty-first century: examples from mammalian carnivores. Proc Biol Sci 2023; 290:20231400. [PMID: 38018109 PMCID: PMC10685142 DOI: 10.1098/rspb.2023.1400] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Accepted: 11/06/2023] [Indexed: 11/30/2023] Open
Abstract
Carnivores (cats, dogs and kin) are a diverse group of mammals that inhabit a remarkable range of ecological niches. While the relationship between ecology and morphology has long been of interest in carnivorans, the application of quantitative techniques has resulted in a recent explosion of work in the field. Therefore, they provide a case study of how quantitative techniques, such as geometric morphometrics (GMM), have impacted our ability to tease apart complex ecological signals from skeletal anatomy, and the implications for our understanding of the relationships between form, function and ecological specialization. This review provides a synthesis of current research on carnivoran ecomorphology, with the goal of illustrating the complex interaction between ecology and morphology in the skeleton. We explore the ecomorphological diversity across major carnivoran lineages and anatomical systems. We examine cranial elements (skull, sensory systems) and postcranial elements (limbs, vertebral column) to reveal mosaic patterns of adaptation related to feeding and hunting strategies, locomotion and habitat preference. We highlight the crucial role that new approaches have played in advancing our understanding of carnivoran ecomorphology, while addressing challenges that remain in the field, such as ecological classifications, form-function relationships and multi-element analysis, offering new avenues for future research.
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Affiliation(s)
- Julia A. Schwab
- Department of Earth and Environmental Sciences, University of Manchester, M13 9PL Manchester, UK
| | - Borja Figueirido
- Departamento de Ecología y Geología, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain
| | - Alberto Martín-Serra
- Departamento de Ecología y Geología, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain
| | - Julien van der Hoek
- Department of Earth and Environmental Sciences, University of Manchester, M13 9PL Manchester, UK
| | - Therese Flink
- Department of Palaeobiology, Swedish Museum of Natural History, PO Box 50007, 10405 Stockholm, Sweden
| | - Anne Kort
- Department of Earth and Atmospheric Sciences, Indiana University Bloomington, 1001 E 10th St, Bloomington, IN, USA
- Department of Earth and Environmental Sciences, University of Michigan, 1100 N University Ave, Ann Arbor, MI 48109, USA
| | | | - Katrina E. Jones
- Department of Earth and Environmental Sciences, University of Manchester, M13 9PL Manchester, UK
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2
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Montgomery TM, Lehmann KDS, Gregg S, Keyser K, McTigue LE, Beehner JC, Holekamp KE. Determinants of hyena participation in risky collective action. Proc Biol Sci 2023; 290:20231390. [PMID: 38018101 PMCID: PMC10685128 DOI: 10.1098/rspb.2023.1390] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Accepted: 11/03/2023] [Indexed: 11/30/2023] Open
Abstract
Collective action problems arise when cooperating individuals suffer costs of cooperation, while the benefits of cooperation are received by both cooperators and defectors. We address this problem using data from spotted hyenas fighting with lions. Lions are much larger and kill many hyenas, so these fights require cooperative mobbing by hyenas for them to succeed. We identify factors that predict when hyena groups engage in cooperative fights with lions, which individuals choose to participate and how the benefits of victory are distributed among cooperators and non-cooperators. We find that cooperative mobbing is better predicted by lower costs (no male lions, more hyenas) than higher benefits (need for food). Individual participation is facilitated by social factors, both over the long term (close kin, social bond strength) and the short term (greeting interactions prior to cooperation). Finally, we find some direct benefits of participation: after cooperation, participants were more likely to feed at contested carcasses than non-participants. Overall, these results are consistent with the hypothesis that, when animals face dangerous cooperative dilemmas, selection favours flexible strategies that are sensitive to dynamic factors emerging over multiple time scales.
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Affiliation(s)
- Tracy M. Montgomery
- Department of Integrative Biology and Program in Ecology, Evolution, and behavior, Michigan State University, 288 Farm Lane, East Lansing, MI 48824, USA
- Mara Hyena Project, PO Box 164-00502, Karen, Nairobi, Kenya
- Department for the Ecology of Animal Societies, Max Planck Institute for Animal Behavior, Bücklestraße 5a, 78467 Konstanz, Germany
- Center for the Advanced Study of Collective Behavior, University of Konstanz, Universitätsstraße 10, 78464 Konstanz, Germany
| | - Kenna D. S. Lehmann
- Department of Integrative Biology and Program in Ecology, Evolution, and behavior, Michigan State University, 288 Farm Lane, East Lansing, MI 48824, USA
- Human Biology Program, Michigan State University, 288 Farm Lane, East Lansing, MI 48824, USA
- Mara Hyena Project, PO Box 164-00502, Karen, Nairobi, Kenya
| | - Samantha Gregg
- Department of Integrative Biology and Program in Ecology, Evolution, and behavior, Michigan State University, 288 Farm Lane, East Lansing, MI 48824, USA
| | - Kathleen Keyser
- Department of Integrative Biology and Program in Ecology, Evolution, and behavior, Michigan State University, 288 Farm Lane, East Lansing, MI 48824, USA
| | - Leah E. McTigue
- Department of Integrative Biology and Program in Ecology, Evolution, and behavior, Michigan State University, 288 Farm Lane, East Lansing, MI 48824, USA
- Rocky Mountain Research Station, Colorado State University, 240 W Prospect St, Fort Collins, CO 80525, USA
| | - Jacinta C. Beehner
- Department of Psychology, University of Michigan, 530 Church Street, Ann Arbor, MI 48109, USA
- Department of Anthropology, University of Michigan, 1085 South University Avenue, Ann Arbor, MI 48109, USA
| | - Kay E. Holekamp
- Department of Integrative Biology and Program in Ecology, Evolution, and behavior, Michigan State University, 288 Farm Lane, East Lansing, MI 48824, USA
- Mara Hyena Project, PO Box 164-00502, Karen, Nairobi, Kenya
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3
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The current state of carnivore cognition. Anim Cogn 2023; 26:37-58. [PMID: 36333496 DOI: 10.1007/s10071-022-01709-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Revised: 10/10/2022] [Accepted: 10/20/2022] [Indexed: 11/06/2022]
Abstract
The field of animal cognition has advanced rapidly in the last 25 years. Through careful and creative studies of animals in captivity and in the wild, we have gained critical insights into the evolution of intelligence, the cognitive capacities of a diverse array of taxa, and the importance of ecological and social environments, as well as individual variation, in the expression of cognitive abilities. The field of animal cognition, however, is still being influenced by some historical tendencies. For example, primates and birds are still the majority of study species in the field of animal cognition. Studies of diverse taxa improve the generalizability of our results, are critical for testing evolutionary hypotheses, and open new paths for understanding cognition in species with vastly different morphologies. In this paper, we review the current state of knowledge of cognition in mammalian carnivores. We discuss the advantages of studying cognition in Carnivorans and the immense progress that has been made across many cognitive domains in both lab and field studies of carnivores. We also discuss the current constraints that are associated with studying carnivores. Finally, we explore new directions for future research in studies of carnivore cognition.
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4
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Miller R, Garcia-Pelegrin E, Danby E. Neophobia and innovation in Critically Endangered Bali myna, Leucopsar rothschildi. ROYAL SOCIETY OPEN SCIENCE 2022; 9:211781. [PMID: 35875473 PMCID: PMC9297014 DOI: 10.1098/rsos.211781] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Accepted: 06/30/2022] [Indexed: 06/15/2023]
Abstract
Behavioural flexibility can impact on adaptability and survival, particularly in today's changing world, and encompasses associated components like neophobia, e.g. responses to novelty, and innovation, e.g. problem-solving. Bali myna (Leucopsar rothschildi) are a Critically Endangered endemic species, which are a focus of active conservation efforts, including reintroductions. Gathering behavioural data can aid in improving and developing conservation strategies, like pre-release training and individual selection for release. In 22 captive Bali myna, we tested neophobia (novel object, novel food, control conditions), innovation (bark, cup, lid conditions) and individual repeatability of latency responses in both experiments. We found effects of condition and presence of heterospecifics, including longer latencies to touch familiar food in presence than absence of novel items, and between problem-solving tasks, as well as in the presence of non-competing heterospecifics than competing heterospecifics. Age influenced neophobia, with adults showing longer latencies than juveniles. Individuals were repeatable in latency responses: (1) temporally in both experiments; (2) contextually within the innovation experiment and between experiments, as well as being consistent in approach order across experiments, suggesting stable behaviour traits. These findings are an important starting point for developing conservation behaviour related strategies in Bali myna and other similarly threatened species.
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Affiliation(s)
- Rachael Miller
- Department of Psychology, University of Cambridge, Cambridge, UK
- School of Life Sciences, Anglia Ruskin University, Cambridge, UK
| | - Elias Garcia-Pelegrin
- Department of Psychology, University of Cambridge, Cambridge, UK
- Department of Psychology, National University of Singapore, Singapore
| | - Emily Danby
- Department of Psychology, University of Cambridge, Cambridge, UK
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Heldstab SA, Isler K, Graber SM, Schuppli C, van Schaik CP. The economics of brain size evolution in vertebrates. Curr Biol 2022; 32:R697-R708. [PMID: 35728555 DOI: 10.1016/j.cub.2022.04.096] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Across the animal kingdom, we see remarkable variation in brain size. This variation has even increased over evolutionary time. Traditionally, studies aiming to explain brain size evolution have looked at the fitness benefits of increased brain size in relation to its increased cognitive performance in the social and/or ecological domain. However, brains are among the most energetically expensive tissues in the body and also require an uninterrupted energy supply. If not compensated, these energetic demands inevitably lead to a reduction in energy allocation to other vital functions. In this review, we summarize how an increasing number of studies show that to fully comprehend brain size evolution and the large variation in brain size across lineages, it is important to look at the economics of brains, including the different pathways through which the high energetic costs of brains can be offset. We further show how numerous studies converge on the conclusion that cognitive abilities can only drive brain size evolution in vertebrate lineages where they result in an improved energy balance through favourable ecological preconditions. Cognitive benefits that do not directly improve the organism's energy balance can only be selectively favoured when they produce such large improvements in reproduction or survival that they outweigh the negative energetic effects of the large brain.
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Affiliation(s)
- Sandra A Heldstab
- Department of Anthropology, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland; Development and Evolution of Cognition Research Group, Max Planck Institute of Animal Behavior, Bücklestrasse 5a, 78467 Konstanz, Germany.
| | - Karin Isler
- Department of Anthropology, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Sereina M Graber
- Department of Anthropology, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Caroline Schuppli
- Department of Anthropology, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland; Development and Evolution of Cognition Research Group, Max Planck Institute of Animal Behavior, Bücklestrasse 5a, 78467 Konstanz, Germany
| | - Carel P van Schaik
- Department of Anthropology, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland; Comparative Socioecology Group, Max Planck Institute of Animal Behavior, Bücklestrasse 5a, 78467 Konstanz, Germany; Department of Evolutionary Biology and Environmental Science, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
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6
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Johnson-Ulrich L, Johnson-Ulrich Z, Holekamp KE. Natural conditions and adaptive functions of problem-solving in the Carnivora. Curr Opin Behav Sci 2022. [DOI: 10.1016/j.cobeha.2022.101111] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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7
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Chambers HR, Heldstab SA, O’Hara SJ. Why big brains? A comparison of models for both primate and carnivore brain size evolution. PLoS One 2021; 16:e0261185. [PMID: 34932586 PMCID: PMC8691615 DOI: 10.1371/journal.pone.0261185] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 11/24/2021] [Indexed: 11/19/2022] Open
Abstract
Despite decades of research, much uncertainty remains regarding the selection pressures responsible for brain size variation. Whilst the influential social brain hypothesis once garnered extensive support, more recent studies have failed to find support for a link between brain size and sociality. Instead, it appears there is now substantial evidence suggesting ecology better predicts brain size in both primates and carnivores. Here, different models of brain evolution were tested, and the relative importance of social, ecological, and life-history traits were assessed on both overall encephalisation and specific brain regions. In primates, evidence is found for consistent associations between brain size and ecological factors, particularly diet; however, evidence was also found advocating sociality as a selection pressure driving brain size. In carnivores, evidence suggests ecological variables, most notably home range size, are influencing brain size; whereas, no support is found for the social brain hypothesis, perhaps reflecting the fact sociality appears to be limited to a select few taxa. Life-history associations reveal complex selection mechanisms to be counterbalancing the costs associated with expensive brain tissue through extended developmental periods, reduced fertility, and extended maximum lifespan. Future studies should give careful consideration of the methods chosen for measuring brain size, investigate both whole brain and specific brain regions where possible, and look to integrate multiple variables, thus fully capturing all of the potential factors influencing brain size.
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Affiliation(s)
- Helen Rebecca Chambers
- School of Science, Engineering & Environment, University of Salford, Salford, Greater Manchester, United Kingdom
| | | | - Sean J. O’Hara
- School of Science, Engineering & Environment, University of Salford, Salford, Greater Manchester, United Kingdom
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8
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Problem Solving in Animals: Proposal for an Ontogenetic Perspective. Animals (Basel) 2021; 11:ani11030866. [PMID: 33803609 PMCID: PMC8002912 DOI: 10.3390/ani11030866] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 03/15/2021] [Accepted: 03/16/2021] [Indexed: 12/16/2022] Open
Abstract
Simple Summary Animals must be able to solve problems to access food and avoid predators. Problem solving is not a complicated process, often relying only on animals exploring their surroundings, and being able to learn and remember information. However, not all species, populations, or even individuals, can solve problems, or can solve problems in the same way. Differences in problem-solving ability could be due to differences in how animals develop and grow, including differences in their genetics, hormones, age, and/or environmental conditions. Here, we consider how an animal’s problem-solving ability could be impacted by its development, and what future work needs to be done to understand the development of problem solving. We argue that, considering how many different factors are involved, focusing on individual animals, and individual variation, is the best way to study the development of problem solving. Abstract Problem solving, the act of overcoming an obstacle to obtain an incentive, has been studied in a wide variety of taxa, and is often based on simple strategies such as trial-and-error learning, instead of higher-order cognitive processes, such as insight. There are large variations in problem solving abilities between species, populations and individuals, and this variation could arise due to differences in development, and other intrinsic (genetic, neuroendocrine and aging) and extrinsic (environmental) factors. However, experimental studies investigating the ontogeny of problem solving are lacking. Here, we provide a comprehensive review of problem solving from an ontogenetic perspective. The focus is to highlight aspects of problem solving that have been overlooked in the current literature, and highlight why developmental influences of problem-solving ability are particularly important avenues for future investigation. We argue that the ultimate outcome of solving a problem is underpinned by interacting cognitive, physiological and behavioural components, all of which are affected by ontogenetic factors. We emphasise that, due to the large number of confounding ontogenetic influences, an individual-centric approach is important for a full understanding of the development of problem solving.
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9
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Johnson-Ulrich L, Yirga G, Strong RL, Holekamp KE. The effect of urbanization on innovation in spotted hyenas. Anim Cogn 2021; 24:1027-1038. [PMID: 33687598 DOI: 10.1007/s10071-021-01494-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 02/12/2021] [Accepted: 02/16/2021] [Indexed: 02/07/2023]
Abstract
Urbanization represents a dramatic form of evolutionary novelty in the landscapes inhabited by many extant animals. The Cognitive Buffer Hypothesis suggests that innovation, the process by which animals solve novel problems or use novel behaviors, may be key for many animals when adapting to novel environments. If innovation is especially beneficial in urban environments, then we would expect urban animals to be more innovative than their non-urban counterparts. However, studies comparing innovative problem-solving between urban and rural habitats have produced mixed results. Here, we hypothesized that these findings result from comparing only two levels of urbanization when related research suggests that the stage of invasion of urban habitats likely has a strong effect on demand for innovation, with demand being highest during early establishment in a novel environment. To test this hypothesis, we assessed innovation in three locations where spotted hyenas experienced varying degrees of urbanization. Spotted hyenas are relatively innovative compared to other carnivores and, although many large carnivores in Africa are endangered, spotted hyenas remain abundant both inside and outside protected areas. We measured innovation with a multi-access puzzle box with four different doors through which hyenas could obtain a food reward. We predicted that hyenas in a transitional, rapidly urbanizing habitat would be more innovative, measured by the number of unique doors opened, than those in rural or fully urban habitats. Contrary to our predictions, hyenas in the rural habitat were the most innovative. These results challenge the idea that the evolutionary novelty associated with urbanization favors greater innovativeness.
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Affiliation(s)
- Lily Johnson-Ulrich
- Department of Integrative Biology, Michigan State University, 288 Farm Lane, Rm 203, Natural Sciences Bldg, East Lansing, MI, 48823, USA. .,Ecology, Evolutionary Biology, & Behavior Program, Michigan State University, East Lansing, MI, 48824, USA. .,Mara Hyena Project, Michigan State University, Maasai Mara National Reserve, Talek, Kenya.
| | - Gidey Yirga
- Department of Biology, Mekelle University, P.O. Box 231, Mek'ele, Ethiopia.,Theoretical and Applied Biodiversity Research, Ruhr Universität Bochum, 44780, Bochum, Germany
| | - Robyn L Strong
- Mara Hyena Project, Michigan State University, Maasai Mara National Reserve, Talek, Kenya
| | - Kay E Holekamp
- Department of Integrative Biology, Michigan State University, 288 Farm Lane, Rm 203, Natural Sciences Bldg, East Lansing, MI, 48823, USA.,Ecology, Evolutionary Biology, & Behavior Program, Michigan State University, East Lansing, MI, 48824, USA.,Mara Hyena Project, Michigan State University, Maasai Mara National Reserve, Talek, Kenya
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10
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Castiglione S, Serio C, Piccolo M, Mondanaro A, Melchionna M, Di Febbraro M, Sansalone G, Wroe S, Raia P. The influence of domestication, insularity and sociality on the tempo and mode of brain size evolution in mammals. Biol J Linn Soc Lond 2020. [DOI: 10.1093/biolinnean/blaa186] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Abstract
The ability to develop complex social bonds and an increased capacity for behavioural flexibility in novel environments have both been forwarded as selective forces favouring the evolution of a large brain in mammals. However, large brains are energetically expensive, and in circumstances in which selective pressures are relaxed, e.g. on islands, smaller brains are selected for. Similar reasoning has been offered to explain the reduction of brain size in domestic species relative to their wild relatives. Herein, we assess the effect of domestication, insularity and sociality on brain size evolution at the macroevolutionary scale. Our results are based on analyses of a 426-taxon tree, including both wild species and domestic breeds. We further develop the phylogenetic ridge regression comparative method (RRphylo) to work with discrete variables and compare the rates (tempo) and direction (mode) of brain size evolution among categories within each of three factors (sociality, insularity and domestication). The common assertion that domestication increases the rate of brain size evolution holds true. The same does not apply to insularity. We also find support for the suggested but previously untested hypothesis that species living in medium-sized groups exhibit faster rates of brain size evolution than either solitary or herding taxa.
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Affiliation(s)
- Silvia Castiglione
- Department of Earth Sciences, Environment and Resources, University of Naples Federico II, Napoli, Italy
| | - Carmela Serio
- Research Centre in Evolutionary Anthropology and Palaeoecology, School of Biological and Environmental Sciences, Liverpool John Moores University, Liverpool, UK
| | - Martina Piccolo
- Department of Earth Sciences, Environment and Resources, University of Naples Federico II, Napoli, Italy
| | - Alessandro Mondanaro
- Department of Earth Sciences, Environment and Resources, University of Naples Federico II, Napoli, Italy
- Department of Earth Sciences, University of Florence, Firenze, Italy
| | - Marina Melchionna
- Department of Earth Sciences, Environment and Resources, University of Naples Federico II, Napoli, Italy
| | - Mirko Di Febbraro
- Department of Biosciences and Territory, University of Molise, C. da Fonte Lappone, 15, Pesche, IS, Italy
| | - Gabriele Sansalone
- Function, Evolution & Anatomy Research Lab, Zoology Division, School of Environmental and Rural Science, University of New England, Armidale, NSW, Australia
| | - Stephen Wroe
- Function, Evolution & Anatomy Research Lab, Zoology Division, School of Environmental and Rural Science, University of New England, Armidale, NSW, Australia
| | - Pasquale Raia
- Department of Earth Sciences, Environment and Resources, University of Naples Federico II, Napoli, Italy
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11
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Johnson-Ulrich L, Holekamp KE. Group size and social rank predict inhibitory control in spotted hyaenas. Anim Behav 2020. [DOI: 10.1016/j.anbehav.2019.11.020] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
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12
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Arold ST. Intrinsic negative feedback as a limiting factor for the evolution of higher forms of intelligence. F1000Res 2020; 9:34. [PMID: 34504689 PMCID: PMC8408545 DOI: 10.12688/f1000research.22039.3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 09/21/2021] [Indexed: 11/20/2022] Open
Abstract
Longstanding scientific efforts have been dedicated to answer why and how our particular intelligence is generated by our brain but not by the brain of other species. However, surprisingly little effort has been made to ask why no other species ever developed an intelligence similar to ours. Here, I explore this question based on genetic and paleontologic evidence. Contrary to the established view, this review suggests that the developmental hurdles alone are not high enough to explain the uniqueness of human intelligence (HI). As an additional explanation I propose that HI is normally not retained by natural selection, because it is, under most conditions, an intrinsically unfavourable trait. This unfavourableness, however, cannot be explained by physical constraints alone; rather, it may also be rooted in the same emotional and social complexity that is necessary for the development of HI. Thus, a major obstacle towards HI may not be solely the development of the required physical assets, but also to cope with harmful individual, social and environmental feedback intrinsically associated with this trait.
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Affiliation(s)
- Stefan T Arold
- Division of Biological and Environmental Sciences and Engineering, King Abdullah University of Science and Technology, Thuwal, MK, 23955-6900, Saudi Arabia.,Centre de Biologie Structurale, CNRS, INSERM, Université de Montpellier, 34090 Montpellier, France
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13
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Innovation in a native Australian rodent, the fawn-footed mosaic-tailed rat (Melomys cervinipes). Anim Cogn 2019; 23:301-310. [PMID: 31797112 DOI: 10.1007/s10071-019-01334-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 11/20/2019] [Accepted: 11/26/2019] [Indexed: 12/30/2022]
Abstract
Innovation is the ability to use a new behaviour, or use an existing behaviour in a new context. Innovation, as an aspect of behavioural flexibility, could be important for allowing animals to cope with rapid environmental changes. Surprisingly, few studies have focused on how innovation ability is affected by task complexity. We investigated innovation ability across multiple tasks of varying complexity in a native Australian rodent, the fawn-footed mosaic-tailed rat (Melomys cervinipes). We predicted that mosaic-tailed rats would be capable of innovating because they live in complex habitats and can exploit disturbed and changing environments. However, we also predicted that the success rate of innovating would decrease as task complexity increased. Mosaic-tailed rats were exposed to six novel problems: cylinder, matchbox, obstruction test, pillar, tile and lever (the last three presented in a Trixie dog activity board), which represented increasing complexity. We counted the number of individuals that could solve at least one task, compared individuals for solving efficiency and latency to solve, and compared the solving success of each task. All mosaic-tailed rats could innovate. However, solving success differed between individuals, with some solving every task and others only solving one. Solving success rate was significantly higher in the simplest task (pillar) compared to the most complicated task (lever). There was no effect of sex or sampling condition on innovation. This study is the first to demonstrate innovation ability across task complexity in an Australian rodent and provides promising avenues for future studies of innovation.
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14
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Simons M, Tibbetts E. Insects as models for studying the evolution of animal cognition. CURRENT OPINION IN INSECT SCIENCE 2019; 34:117-122. [PMID: 31271948 DOI: 10.1016/j.cois.2019.05.009] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Revised: 05/23/2019] [Accepted: 05/28/2019] [Indexed: 06/09/2023]
Abstract
Research on the evolution of cognition has long centered on vertebrates. Current research indicates that both complex social behavior and ecology influence the evolution of vertebrate cognition. Insects provide a powerful and underappreciated model system for research on cognitive evolution because they are a large group with multiple evolutionary transitions to complex social behavior as well as extensive ecological variation. Here, we integrate current research on cognitive evolution in vertebrates and insects. We specifically highlight recent advances in vertebrate research that are applicable to insects. We focus on two key topics: 1) The challenges of quantifying cognition 2) What factors contribute to the evolution of cognition? Applying methods like comparative analysis and behavioral cognition measurement to insects are likely to provide key insight into the evolution of animal minds.
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Affiliation(s)
- Meagan Simons
- University of Michigan, 1105 N. University Ave., Ann Arbor, MI 48104, United States
| | - Elizabeth Tibbetts
- University of Michigan, 1105 N. University Ave., Ann Arbor, MI 48104, United States.
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15
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Holekamp KE, Sawdy MA. The evolution of matrilineal social systems in fissiped carnivores. Philos Trans R Soc Lond B Biol Sci 2019; 374:20180065. [PMID: 31303158 DOI: 10.1098/rstb.2018.0065] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
We review matrilineal relationships in the societies of fissiped mammalian carnivores, focusing on how the most complex of these may have evolved from simpler systems. Although competition for food is very intense at the trophic level occupied by most carnivores, and although most species of extant fissiped carnivores therefore lead solitary lives, some species show at least rudimentary clustering of maternal kin and matrilineal resource-sharing or transmission of critical resources between generations. The resources shared or transmitted range from individual food items and territories to entire networks of potential allies. The greatest elaboration of matrilineal relationships has occurred in two large carnivores, lions and spotted hyenas, which occur sympatrically throughout much of Africa. The societies of both these species apparently evolved in response to a shared suite of ecological conditions. The highly matrilineal societies of spotted hyenas are unique among carnivores and closely resemble the societies of many cercopithecine primates. The conditions favouring the evolution of matrilineal societies in carnivores include male-biased dispersal, female philopatry, the need for assistance in protecting or provisioning offspring, reliance on large or abundant prey, particularly in open habitat, high population density and kin-structured cooperative interactions that have strong positive effects on fitness. This article is part of the theme issue 'The evolution of female-biased kinship in humans and other mammals'.
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Affiliation(s)
- Kay E Holekamp
- 1 Department of Integrative Biology, Michigan State University , East Lansing, MI , USA.,2 Program in Ecology, Evolutionary Biology and Behavior, Michigan State University , East Lansing, MI , USA
| | - Maggie A Sawdy
- 1 Department of Integrative Biology, Michigan State University , East Lansing, MI , USA.,2 Program in Ecology, Evolutionary Biology and Behavior, Michigan State University , East Lansing, MI , USA
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Janson CH. Foraging Benefits of Ecological Cognition in Fruit-Eating Primates: Results From Field Experiments and Computer Simulations. Front Ecol Evol 2019. [DOI: 10.3389/fevo.2019.00125] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
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17
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Abstract
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.
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Affiliation(s)
- Susan D Healy
- School of Biology, University of St Andrews, St Andrews, UK
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18
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Raihani NJ, Bell V. An evolutionary perspective on paranoia. Nat Hum Behav 2019; 3:114-121. [PMID: 30886903 PMCID: PMC6420131 DOI: 10.1038/s41562-018-0495-0] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Accepted: 11/15/2018] [Indexed: 12/29/2022]
Abstract
Paranoia is the most common symptom of psychosis but paranoid concerns occur throughout the general population. Here, we argue for an evolutionary approach to paranoia across the spectrum of severity that accounts for its complex social phenomenology - including the perception of conspiracy and selective identification of perceived persecutors - and considers how it can be understood in light of our evolved social cognition. We argue that the presence of coalitions and coordination between groups in competitive situations could favour psychological mechanisms that detect, anticipate and avoid social threats. Our hypothesis makes testable predictions about the environments in which paranoia should be most common as well as the developmental trajectory of paranoia across the lifespan. We suggest that paranoia should not solely be viewed as a pathological symptom of a mental disorder but also as a part of a normally-functioning human psychology.
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Affiliation(s)
- Nichola J Raihani
- Department of Experimental Psychology, University College London, London, UK.
| | - Vaughan Bell
- Division of Psychiatry, University College London, London, UK
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Powell LE, Isler K, Barton RA. Re-evaluating the link between brain size and behavioural ecology in primates. Proc Biol Sci 2018; 284:rspb.2017.1765. [PMID: 29046380 DOI: 10.1098/rspb.2017.1765] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Accepted: 09/25/2017] [Indexed: 12/15/2022] Open
Abstract
Comparative studies have identified a wide range of behavioural and ecological correlates of relative brain size, with results differing between taxonomic groups, and even within them. In primates for example, recent studies contradict one another over whether social or ecological factors are critical. A basic assumption of such studies is that with sufficiently large samples and appropriate analysis, robust correlations indicative of selection pressures on cognition will emerge. We carried out a comprehensive re-examination of correlates of primate brain size using two large comparative datasets and phylogenetic comparative methods. We found evidence in both datasets for associations between brain size and ecological variables (home range size, diet and activity period), but little evidence for an effect of social group size, a correlation which has previously formed the empirical basis of the Social Brain Hypothesis. However, reflecting divergent results in the literature, our results exhibited instability across datasets, even when they were matched for species composition and predictor variables. We identify several potential empirical and theoretical difficulties underlying this instability and suggest that these issues raise doubts about inferring cognitive selection pressures from behavioural correlates of brain size.
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Affiliation(s)
- Lauren E Powell
- Evolutionary Anthropology Research Group, Department of Anthropology, University of Durham, South Road, Durham DH1 3LE, UK
| | - Karin Isler
- Department of Anthropology, University of Zürich-Irchel, Winterthurerstr. 190, Zürich 8057, Switzerland
| | - Robert A Barton
- Evolutionary Anthropology Research Group, Department of Anthropology, University of Durham, South Road, Durham DH1 3LE, UK
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20
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Turner JW, Bills PS, Holekamp KE. Ontogenetic change in determinants of social network position in the spotted hyena. Behav Ecol Sociobiol 2017. [DOI: 10.1007/s00265-017-2426-x] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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21
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Abstract
AbstractThe goal of our target article was to lay out current evidence relevant to the question of whether general intelligence can be found in nonhuman animals in order to better understand its evolution in humans. The topic is a controversial one, as evident from the broad range of partly incompatible comments it has elicited. The main goal of our response is to translate these issues into testable empirical predictions, which together can provide the basis for a broad research agenda.
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Mikhalevich I, Powell R, Logan C. Is behavioural flexibility evidence of cognitive complexity? How evolution can inform comparative cognition. Interface Focus 2017; 7:20160121. [PMID: 28479981 PMCID: PMC5413892 DOI: 10.1098/rsfs.2016.0121] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Behavioural flexibility is often treated as the gold standard of evidence for more sophisticated or complex forms of animal cognition, such as planning, metacognition and mindreading. However, the evidential link between behavioural flexibility and complex cognition has not been explicitly or systematically defended. Such a defence is particularly pressing because observed flexible behaviours can frequently be explained by putatively simpler cognitive mechanisms. This leaves complex cognition hypotheses open to 'deflationary' challenges that are accorded greater evidential weight precisely because they offer putatively simpler explanations of equal explanatory power. This paper challenges the blanket preference for simpler explanations, and shows that once this preference is dispensed with, and the full spectrum of evidence-including evolutionary, ecological and phylogenetic data-is accorded its proper weight, an argument in support of the prevailing assumption that behavioural flexibility can serve as evidence for complex cognitive mechanisms may begin to take shape. An adaptive model of cognitive-behavioural evolution is proposed, according to which the existence of convergent trait-environment clusters in phylogenetically disparate lineages may serve as evidence for the same trait-environment clusters in other lineages. This, in turn, could permit inferences of cognitive complexity in cases of experimental underdetermination, thereby placing the common view that behavioural flexibility can serve as evidence for complex cognition on firmer grounds.
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Affiliation(s)
- Irina Mikhalevich
- School of Mind and Brain, Humboldt-Universitat zu Berlin, Berlin, Germany
| | - Russell Powell
- Department of Philosophy, Boston University, Boston, MA 02215, USA
| | - Corina Logan
- Department of Zoology, University of Cambridge, Cambridge, UK
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23
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Holekamp KE, Benson-Amram S. The evolution of intelligence in mammalian carnivores. Interface Focus 2017; 7:20160108. [PMID: 28479979 DOI: 10.1098/rsfs.2016.0108] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Although intelligence should theoretically evolve to help animals solve specific types of problems posed by the environment, it is unclear which environmental challenges favour enhanced cognition, or how general intelligence evolves along with domain-specific cognitive abilities. The social intelligence hypothesis posits that big brains and great intelligence have evolved to cope with the labile behaviour of group mates. We have exploited the remarkable convergence in social complexity between cercopithecine primates and spotted hyaenas to test predictions of the social intelligence hypothesis in regard to both cognition and brain size. Behavioural data indicate that there has been considerable convergence between primates and hyaenas with respect to their social cognitive abilities. Moreover, compared with other hyaena species, spotted hyaenas have larger brains and expanded frontal cortex, as predicted by the social intelligence hypothesis. However, broader comparative study suggests that domain-general intelligence in carnivores probably did not evolve in response to selection pressures imposed specifically in the social domain. The cognitive buffer hypothesis, which suggests that general intelligence evolves to help animals cope with novel or changing environments, appears to offer a more robust explanation for general intelligence in carnivores than any hypothesis invoking selection pressures imposed strictly by sociality or foraging demands.
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Affiliation(s)
- Kay E Holekamp
- Department of Integrative Biology, Michigan State University, 288 Farm Lane, Room 203, East Lansing, MI 48824-1115, USA.,Ecology, Evolutionary Biology and Behavior, Michigan State University, 103 Giltner Hall, East Lansing, MI 48824, USA
| | - Sarah Benson-Amram
- Department of Zoology and Physiology, University of Wyoming, 1000 E. University Ave, Biological Science Building, Laramie, WY 82071, USA.,Program in Ecology, Berry Center, University of Wyoming, Laramie, WY 82071, USA
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24
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Borrego N. Big cats as a model system for the study of the evolution of intelligence. Behav Processes 2017; 141:261-266. [PMID: 28336301 DOI: 10.1016/j.beproc.2017.03.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2016] [Revised: 02/11/2017] [Accepted: 03/15/2017] [Indexed: 11/24/2022]
Abstract
Currently, carnivores, and felids in particular, are vastly underrepresented in cognitive literature, despite being an ideal model system for tests of social and ecological intelligence hypotheses. Within Felidae, big cats (Panthera) are uniquely suited to studies investigating the evolutionary links between social, ecological, and cognitive complexity. Intelligence likely did not evolve in a unitary way but instead evolved as the result of mutually reinforcing feedback loops within the physical and social environments. The domain-specific social intelligence hypothesis proposes that social complexity drives only the evolution of cognitive abilities adapted only to social domains. The domain-general hypothesis proposes that the unique demands of social life serve as a bootstrap for the evolution of superior general cognition. Big cats are one of the few systems in which we can directly address conflicting predictions of the domain-general and domain-specific hypothesis by comparing cognition among closely related species that face roughly equivalent ecological complexity but vary considerably in social complexity.
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Affiliation(s)
- Natalia Borrego
- Department of Life Sciences, University of Kwazulu-Natal, South Africa; Lion Research Center, Department of Ecology, Evolution and Behavior, University of Minnesota, South Africa.
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25
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Abstract
The presence of general intelligence poses a major evolutionary puzzle, which has led to increased interest in its presence in nonhuman animals. The aim of this review is to critically evaluate this question and to explore the implications for current theories about the evolution of cognition. We first review domain-general and domain-specific accounts of human cognition in order to situate attempts to identify general intelligence in nonhuman animals. Recent studies are consistent with the presence of general intelligence in mammals (rodents and primates). However, the interpretation of a psychometric g factor as general intelligence needs to be validated, in particular in primates, and we propose a range of such tests. We then evaluate the implications of general intelligence in nonhuman animals for current theories about its evolution and find support for the cultural intelligence approach, which stresses the critical importance of social inputs during the ontogenetic construction of survival-relevant skills. The presence of general intelligence in nonhumans implies that modular abilities can arise in two ways, primarily through automatic development with fixed content and secondarily through learning and automatization with more variable content. The currently best-supported model, for humans and nonhuman vertebrates alike, thus construes the mind as a mix of skills based on primary and secondary modules. The relative importance of these two components is expected to vary widely among species, and we formulate tests to quantify their strength.
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26
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Lehmann KDS, Montgomery TM, MacLachlan SM, Parker JM, Spagnuolo OS, VandeWetering KJ, Bills PS, Holekamp KE. Lions, hyenas and mobs (oh my!). Curr Zool 2016; 63:313-322. [PMID: 29491990 PMCID: PMC5804176 DOI: 10.1093/cz/zow073] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2016] [Accepted: 06/20/2016] [Indexed: 11/12/2022] Open
Abstract
Understanding the factors that facilitate the emergence of cooperation among organisms is central to the study of social evolution. Spotted hyenas Crocuta crocuta frequently cooperate to mob lions Panthera leo, approaching the lions as a tightknit group while vocalizing loudly in an attempt to overwhelm them and drive them away. Whereas cooperative mobbing behavior has been well documented in birds and some mammals, to our knowledge it has never been described during interactions between 2 apex predators. Using a 27-year dataset, we characterize lion-hyena encounters, assess rates of mobbing behavior observed during these interactions, and inquire whether mobbing results in successful acquisition of food. Lions and hyenas interacted most often at fresh kills, especially as prey size and the number of hyenas present increased. Possession of food at the beginning of an interaction positively affected retention of that food by each predator species. The presence of male lions increased the probability of an interspecific interaction but decreased the likelihood of hyenas obtaining or retaining possession of the food. Hyena mobbing rates were highest at fresh kills, but lower when adult male lions were present. The occurrence of mobbing was predicted by an increase in the number of hyenas present. Whether or not mobbing resulted in acquisition of food from lions was predicted by an increase in the number of mobs formed by the hyenas present, suggesting that cooperation among hyenas enhances their fitness.
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Affiliation(s)
- Kenna D S Lehmann
- Department of Integrative Biology, Michigan State University, 288 Farm Lane, Room 203 East Lansing, MI 48824, USA.,Ecology, Evolutionary Biology and Behavior, Michigan State University, 293 Farm Lane, Room 103 East Lansing, MI 48824, USA
| | - Tracy M Montgomery
- Department of Integrative Biology, Michigan State University, 288 Farm Lane, Room 203 East Lansing, MI 48824, USA.,Ecology, Evolutionary Biology and Behavior, Michigan State University, 293 Farm Lane, Room 103 East Lansing, MI 48824, USA
| | - Sarah M MacLachlan
- Department of Integrative Biology, Michigan State University, 288 Farm Lane, Room 203 East Lansing, MI 48824, USA
| | - Jenna M Parker
- Department of Fish, Wildlife and Conservation Biology, Colorado State University, 1474 Campus Delivery Fort Collins, CO 80523, USA
| | - Olivia S Spagnuolo
- Conservation Ecology and Environmental Informatics, School of Natural Resources and Environment, University of Michigan, 440 Church St. Ann Arbor, MI 48109, USA, and
| | - Kelsey J VandeWetering
- Department of Integrative Biology, Michigan State University, 288 Farm Lane, Room 203 East Lansing, MI 48824, USA
| | - Patrick S Bills
- Institute for Cyber Enabled Research, Michigan State University, Biomedical & Physical Sciences Building 567 Wilson Road, Room 1440 East Lansing, MI 48824, USA
| | - Kay E Holekamp
- Department of Integrative Biology, Michigan State University, 288 Farm Lane, Room 203 East Lansing, MI 48824, USA.,Ecology, Evolutionary Biology and Behavior, Michigan State University, 293 Farm Lane, Room 103 East Lansing, MI 48824, USA
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27
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Flies AS, Mansfield LS, Flies EJ, Grant CK, Holekamp KE. Socioecological predictors of immune defences in wild spotted hyenas. Funct Ecol 2016; 30:1549-1557. [PMID: 27833242 DOI: 10.1111/1365-2435.12638] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Social rank can profoundly affect many aspects of mammalian reproduction and stress physiology, but little is known about how immune function is affected by rank and other socio-ecological factors in free-living animals.In this study we examine the effects of sex, social rank, and reproductive status on immune function in long-lived carnivores that are routinely exposed to a plethora of pathogens, yet rarely show signs of disease.Here we show that two types of immune defenses, complement-mediated bacterial killing capacity (BKC) and total IgM, are positively correlated with social rank in wild hyenas, but that a third type, total IgG, does not vary with rank.Female spotted hyenas, which are socially dominant to males in this species, have higher BKC, and higher IgG and IgM concentrations, than do males.Immune defenses are lower in lactating than pregnant females, suggesting the immune defenses may be energetically costly.Serum cortisol and testosterone concentrations are not reliable predictors of basic immune defenses in wild female spotted hyenas.These results suggest that immune defenses are costly and multiple socioecological variables are important determinants of basic immune defenses among wild hyenas. Effects of these variables should be accounted for when attempting to understand disease ecology and immune function.
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Affiliation(s)
- Andrew S Flies
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, 7000, Australia; School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, SA, 5000, Australia; Department of Zoology, Michigan State University, East Lansing, MI 48824, U.S.A; Interdisciplinary program in Ecology, Evolutionary Biology and Behavior, Michigan State University, East Lansing, MI 48824, USA
| | - Linda S Mansfield
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI 48824, USA
| | - Emily J Flies
- School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, SA, 5000, Australia
| | - Chris K Grant
- Custom Monoclonals International Corp, West Sacramento, CA 95691, USA
| | - Kay E Holekamp
- Department of Zoology, Michigan State University, East Lansing, MI 48824, U.S.A; Interdisciplinary program in Ecology, Evolutionary Biology and Behavior, Michigan State University, East Lansing, MI 48824, USA
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Affiliation(s)
- J. M. Burkart
- Anthropological Institute and Museum; University of Zurich; Zurich Switzerland
| | - C. P. van Schaik
- Anthropological Institute and Museum; University of Zurich; Zurich Switzerland
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Abstract
Despite considerable interest in the forces shaping the relationship between brain size and cognitive abilities, it remains controversial whether larger-brained animals are, indeed, better problem-solvers. Recently, several comparative studies have revealed correlations between brain size and traits thought to require advanced cognitive abilities, such as innovation, behavioral flexibility, invasion success, and self-control. However, the general assumption that animals with larger brains have superior cognitive abilities has been heavily criticized, primarily because of the lack of experimental support for it. Here, we designed an experiment to inquire whether specific neuroanatomical or socioecological measures predict success at solving a novel technical problem among species in the mammalian order Carnivora. We presented puzzle boxes, baited with food and scaled to accommodate body size, to members of 39 carnivore species from nine families housed in multiple North American zoos. We found that species with larger brains relative to their body mass were more successful at opening the boxes. In a subset of species, we also used virtual brain endocasts to measure volumes of four gross brain regions and show that some of these regions improve model prediction of success at opening the boxes when included with total brain size and body mass. Socioecological variables, including measures of social complexity and manual dexterity, failed to predict success at opening the boxes. Our results, thus, fail to support the social brain hypothesis but provide important empirical support for the relationship between relative brain size and the ability to solve this novel technical problem.
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30
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Yoshida KCS, Van Meter PE, Holekamp KE. Variation among free-living spotted hyenas in three personality traits. BEHAVIOUR 2016. [DOI: 10.1163/1568539x-00003367] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Inter-individual differences in behaviour, termed ‘animal personality’, are often consistent over time and across contexts and can be significantly related to fitness. However, most studies of animal personality are conducted in the laboratory or involve experimental protocols. Here, we used longitudinal scan and all-occurrence data collected under naturalistic conditions over 21 years to study boldness, aggressiveness, and sociability in a wild population of spotted hyenas (Crocuta crocuta). We found significant variation among individual hyenas in all three traits; however, whereas both sexes exhibited consistent inter-individual differences in aggressiveness and sociability, males were less consistent than females in their boldness. Heritability and maternal effects were small but significant for both boldness and sociability. A large proportion of the variation in aggressiveness could be attributed to genetic and maternal effects, supporting previous research linking hormone exposure in utero to aggressive behaviour later in life. All three traits were correlated with at least one measure of fitness. Particularly aggressive females were more successful in raising their offspring to reproductive maturity than less aggressive females. Interestingly, the reproductive benefits of sociability depended on social rank; for low-ranking hyenas, gaining feeding tolerance via sociability may significantly enhance reproductive success. Both boldness and sociability were linked to survival, but these traits affected longevity in different ways; highly social hyenas lived longer than those that were less social, but selection on boldness was stabilizing, favoring hyenas with intermediate boldness values that balance the benefits of risky behaviour against risks of injury and death.
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Affiliation(s)
- Kathryn C. Shaw Yoshida
- Las Vegas Natural History Museum, 900 Las Vegas Boulevard N, Las Vegas, NV 89101, USA
- Ecology, Evolutionary Biology & Behavior Program, Michigan State University, 293 Farm Lane, Room 103, East Lansing, MI 48824, USA
- Department of Integrative Biology, Michigan State University, 288 Farm Lane, Room 203, East Lansing, MI 48824, USA
| | - Page E. Van Meter
- Department of Integrative Biology, Michigan State University, 288 Farm Lane, Room 203, East Lansing, MI 48824, USA
- Division of Clinical Therapeutics, New York State Psychiatric Institute, 1051 Riverside Drive, New York, NY 10032, USA
| | - Kay E. Holekamp
- Ecology, Evolutionary Biology & Behavior Program, Michigan State University, 293 Farm Lane, Room 103, East Lansing, MI 48824, USA
- Department of Integrative Biology, Michigan State University, 288 Farm Lane, Room 203, East Lansing, MI 48824, USA
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31
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The Evolution of Brains and Cognitive Abilities. Evol Biol 2016. [DOI: 10.1007/978-3-319-41324-2_5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Flies AS, Mansfield LS, Grant CK, Weldele ML, Holekamp KE. Markedly Elevated Antibody Responses in Wild versus Captive Spotted Hyenas Show that Environmental and Ecological Factors Are Important Modulators of Immunity. PLoS One 2015; 10:e0137679. [PMID: 26444876 PMCID: PMC4621877 DOI: 10.1371/journal.pone.0137679] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Accepted: 08/19/2015] [Indexed: 12/20/2022] Open
Abstract
Evolutionary processes have shaped the vertebrate immune system over time, but proximal mechanisms control the onset, duration, and intensity of immune responses. Based on testing of the hygiene hypothesis, it is now well known that microbial exposure is important for proper development and regulation of the immune system. However, few studies have examined the differences between wild animals in their natural environments, in which they are typically exposed to a wide array of potential pathogens, and their conspecifics living in captivity. Wild spotted hyenas (Crocuta crocuta) are regularly exposed to myriad pathogens, but there is little evidence of disease-induced mortality in wild hyena populations, suggesting that immune defenses are robust in this species. Here we assessed differences in immune defenses between wild spotted hyenas that inhabit their natural savanna environment and captive hyenas that inhabit a captive environment where pathogen control programs are implemented. Importantly, the captive population of spotted hyenas was derived directly from the wild population and has been in captivity for less than four generations. Our results show that wild hyenas have significantly higher serum antibody concentrations, including total IgG and IgM, natural antibodies, and autoantibodies than do captive hyenas; there was no difference in the bacterial killing capacity of sera collected from captive and wild hyenas. The striking differences in serum antibody concentrations observed here suggest that complementing traditional immunology studies, with comparative studies of wild animals in their natural environment may help to uncover links between environment and immune function, and facilitate progress towards answering immunological questions associated with the hygiene hypothesis.
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Affiliation(s)
- Andrew S. Flies
- Menzies Research Institute Tasmania, University of Tasmania, Hobart, TAS, Australia
- Department of Zoology, Michigan State University, East Lansing, MI, United States of America
- Interdisciplinary program in Ecology, Evolutionary Biology and Behavior, Michigan State University, East Lansing, MI, United States of America
- Department of Pharmacy and Medical Sciences, University of South Australia, Adelaide, South Australia, Australia
- * E-mail:
| | - Linda S. Mansfield
- Department of Microbiology and Molecular Genetics, National Food Safety and Toxicology Center, Michigan State University, East Lansing, MI, United States of America
| | - Chris K. Grant
- Custom Monoclonals International Corp, West Sacramento, CA, United States of America
| | - Mary L. Weldele
- Department of Psychology, University of California, Berkeley, CA, United States of America
| | - Kay E. Holekamp
- Department of Zoology, Michigan State University, East Lansing, MI, United States of America
- Interdisciplinary program in Ecology, Evolutionary Biology and Behavior, Michigan State University, East Lansing, MI, United States of America
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Carter G, Leffer L. Social Grooming in Bats: Are Vampire Bats Exceptional? PLoS One 2015; 10:e0138430. [PMID: 26445502 PMCID: PMC4596566 DOI: 10.1371/journal.pone.0138430] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2015] [Accepted: 08/30/2015] [Indexed: 11/18/2022] Open
Abstract
Evidence for long-term cooperative relationships comes from several social birds and mammals. Vampire bats demonstrate cooperative social bonds, and like primates, they maintain these bonds through social grooming. It is unclear, however, to what extent vampires are special among bats in this regard. We compared social grooming rates of common vampire bats Desmodus rotundus and four other group-living bats, Artibeus jamaicensis, Carollia perspicillata, Eidolon helvum and Rousettus aegyptiacus, under the same captive conditions of fixed association and no ectoparasites. We conducted 13 focal sampling sessions for each combination of sex and species, for a total of 1560 presence/absence observations per species. We observed evidence for social grooming in all species, but social grooming rates were on average 14 times higher in vampire bats than in other species. Self-grooming rates did not differ. Vampire bats spent 3.7% of their awake time social grooming (95% CI = 1.5-6.3%), whereas bats of the other species spent 0.1-0.5% of their awake time social grooming. Together with past data, this result supports the hypothesis that the elevated social grooming rate in the vampire bat is an adaptive trait, linked to their social bonding and unique regurgitated food sharing behavior.
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Affiliation(s)
- Gerald Carter
- Department of Biology, University of Maryland, College Park, Maryland, United States of America
| | - Lauren Leffer
- Department of Biology, University of Maryland, College Park, Maryland, United States of America
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