1
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Anahi R, Ramiro F. Annual changes of Neohelice granulata cognitive abilities indicate opposition between short- and long-term memory retention. iScience 2023; 26:108161. [PMID: 38026154 PMCID: PMC10660089 DOI: 10.1016/j.isci.2023.108161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2023] [Revised: 08/11/2023] [Accepted: 10/05/2023] [Indexed: 12/01/2023] Open
Abstract
Neohelice is a long-standing model for memory studies for its strong retention of a reduced escape response when trained to iterative presentations of a visual danger stimulus (VDS). Here we present year-round changes that are related to the memory acquisition, storage, and expression. First, we evaluated exploratory activity and response to the VDS, as necessary for memory acquisition and expression. Both parameters change year-round. Second, short-term memory (STM) and two types of long-term memory (LTM) were assessed throughout the year. STM and long-term context-dependent signal memory (CSM) change between periods of the year, whereas signal memory (SM) does not, indicating that the cognitive abilities of the crab display circannual rhythms. Third, during the reproductive period, STM retention is higher than both CSM and SM, indicating a trade-off between STM and LTM. This is the first report of memory retention abilities changing seasonally as a trade-off between short- and long-term memories.
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Affiliation(s)
- Rosso Anahi
- Laboratory of Synaptic Plasticity and Memory, Institute of Biosciences, Biotechnology, and translational Biology (iB3), Department of Physiology Molecular and Cellular Biology, University of Buenos Aires/CONICET, Ciudad autónoma de Buenos Aires 1428, Argentina
| | - Freudenthal Ramiro
- Laboratory of Synaptic Plasticity and Memory, Institute of Biosciences, Biotechnology, and translational Biology (iB3), Department of Physiology Molecular and Cellular Biology, University of Buenos Aires/CONICET, Ciudad autónoma de Buenos Aires 1428, Argentina
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2
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Wojczulanis-Jakubas K, Araya-Salas M. Foraging, Fear and Behavioral Variation in a Traplining Hummingbird. Animals (Basel) 2023; 13:1997. [PMID: 37370506 DOI: 10.3390/ani13121997] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2023] [Revised: 06/11/2023] [Accepted: 06/13/2023] [Indexed: 06/29/2023] Open
Abstract
Traditionally, foraging behavior has been explained as the response to a trade-off between energetic gain from feeding resources and potential costs from concomitant risks. However, an increasing number of studies has shown that this view fails to explain an important fraction of the variation in foraging across a variety of taxa. One potential mechanism that may account for this variation is that various behavioral traits associated with foraging may have different fitness consequences, which may depend on the environmental context. Here, we explored this mechanism by evaluating the foraging efficiency of long-billed hermit hummingbirds (Phaethornis longirostris) with regard to three behavioral traits: (a) exploration (number of feeders used during the foraging visit), (b) risk avoidance (latency to start feeding) and (c) arousal (amount of movements during the foraging visit) in conditions at two different levels of perceived risk (low-control and high-experimental, with a threatening bullet ant model). Foraging efficiency decreased in response to threatening conditions. However, behavioral traits explained additional variation in foraging efficiency in a condition-dependent manner. More exploration was associated with a higher foraging efficiency under control conditions, but this was reversed when exposed to a threat. Regardless of the conditions, arousal was positively associated with foraging efficiency, while risk avoidance was negatively related. Importantly, exploratory behavior and risk avoidance were quite repeatable behaviors, suggesting that they may be related to the intrinsic traits of individuals. Our findings highlight the importance of taking into account additional behavioral dimensions to better understand the foraging strategies of individuals.
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Affiliation(s)
| | - Marcelo Araya-Salas
- Centro de Investigación en Neurociencias, University of Costa Rica, San José 11501-2060, Costa Rica
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3
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Jude MB, Strand CR. Sex and Season Affect Cortical Volumes in Free-Living Western Fence Lizards, Sceloporus occidentalis. BRAIN, BEHAVIOR AND EVOLUTION 2023; 98:160-170. [PMID: 36796337 DOI: 10.1159/000529692] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Accepted: 02/06/2023] [Indexed: 02/18/2023]
Abstract
The hippocampus plays an important role in spatial navigation and spatial learning across a variety of vertebrate species. Sex and seasonal differences in space use and behavior are known to affect hippocampal volume. Similarly, territoriality and differences in home range size are known to affect the volume of the reptile hippocampal homologues, the medial and dorsal cortices (MC, DC). However, studies have almost exclusively investigated males and little is known about sex or seasonal differences in MC and/or DC volumes in lizards. Here, we are the first to simultaneously examine sex and seasonal differences in MC and DC volumes in a wild lizard population. In Sceloporus occidentalis, males display territorial behaviors that are more pronounced during the breeding season. Given this sex difference in behavioral ecology, we expected males to have larger MC and/or DC volumes than females and for this difference to be most pronounced during the breeding season when territorial behavior is increased. Male and female S. occidentalis were captured from the wild during the breeding season and the post-breeding season and were sacrificed within 2 days of capture. Brains were collected and processed for histology. Cresyl-violet-stained sections were used to quantify brain region volumes. In these lizards, breeding females had larger DC volumes than breeding males and nonbreeding females. There was no sex or seasonal difference in MC volumes. Differences in spatial navigation in these lizards may involve aspects of spatial memory related to breeding other than territoriality that affect plasticity of the DC. This study highlights the importance of investigating sex differences and including females in studies of spatial ecology and neuroplasticity.
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Affiliation(s)
- Morgan B Jude
- Department of Biological Sciences, California Polytechnic State University, San Luis Obispo, California, USA,
- School of Medicine, University of California Davis Medical Center, Sacramento, California, USA,
| | - Christine R Strand
- Department of Biological Sciences, California Polytechnic State University, San Luis Obispo, California, USA
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4
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Joshi S, Williams CL, Kapur J. Limbic progesterone receptors regulate spatial memory. Sci Rep 2023; 13:2164. [PMID: 36750584 PMCID: PMC9905062 DOI: 10.1038/s41598-023-29100-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Accepted: 01/30/2023] [Indexed: 02/09/2023] Open
Abstract
Progesterone and its receptors (PRs) participate in mating and reproduction, but their role in spatial declarative memory is not understood. Male mice expressed PRs, predominately in excitatory neurons, in brain regions that support spatial memory, such as the hippocampus and entorhinal cortex (EC). Furthermore, segesterone, a specific PR agonist, activates neurons in both the EC and hippocampus. We assessed the contribution of PRs in promoting spatial and non-spatial cognitive learning in male mice by examining the performance of mice lacking this receptor (PRKO), in novel object recognition, object placement, Y-maze alternation, and Morris-Water Maze (MWM) tasks. In the recognition test, the PRKO mice preferred the familiar object over the novel object. A similar preference for the familiar object was also seen following the EC-specific deletion of PRs. PRKO mice were also unable to recognize the change in object position. We confirmed deficits in spatial memory of PRKO mice by testing them on the Y-maze forced alternation and MWM tasks; PR deletion affected animal's performance in both these tasks. In contrast to spatial tasks, PR removal did not alter the response to fear conditioning. These studies provide novel insights into the role of PRs in facilitating spatial, declarative memory in males, which may help with finding reproductive partners.
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Affiliation(s)
- Suchitra Joshi
- Department of Neurology, University of Virginia, Health Sciences Center, P.O. Box 801330, Charlottesville, VA, 22908, USA.
| | - Cedric L Williams
- Department of Psychology, University of Virginia, Charlottesville, VA, 22908, USA
| | - Jaideep Kapur
- Department of Neurology, University of Virginia, Health Sciences Center, P.O. Box 801330, Charlottesville, VA, 22908, USA.,Department of Neuroscience, University of Virginia, Charlottesville, VA, 22908, USA.,UVA Brain Institute, University of Virginia, Charlottesville, VA, 22908, USA
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5
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Beltrán DF, Araya-Salas M, Parra JL, Stiles FG, Rico-Guevara A. The evolution of sexually dimorphic traits in ecological gradients: an interplay between natural and sexual selection in hummingbirds. Proc Biol Sci 2022; 289:20221783. [PMID: 36515116 PMCID: PMC9748779 DOI: 10.1098/rspb.2022.1783] [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: 09/08/2022] [Accepted: 11/22/2022] [Indexed: 12/15/2022] Open
Abstract
Traits that exhibit differences between the sexes have been of special interest in the study of phenotypic evolution. Classic hypotheses explain sexually dimorphic traits via intra-sexual competition and mate selection, yet natural selection may also act differentially on the sexes to produce dimorphism. Natural selection can act either through physiological and ecological constraints on one of the sexes, or by modulating the strength of sexual/social selection. This predicts an association between the degree of dimorphism and variation in ecological environments. Here, we characterize the variation in hummingbird dimorphism across ecological gradients using rich databases of morphology, colouration and song. We show that morphological dimorphism decreases with elevation in the understorey and increases with elevation in mixed habitats, that dichromatism increases at high altitudes in open and mixed habitats, and that song is less complex in mixed habitats. Our results are consistent with flight constraints, lower predation pressure at high elevations and with habitat effects on song transmission. We also show that dichromatism and song complexity are positively associated, while tail dimorphism and song complexity are negatively associated. Our results suggest that key ecological factors shape sexually dimorphic traits, and that different communication modalities do not always evolve in tandem.
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Affiliation(s)
- Diego F. Beltrán
- Department of Biology, University of Washington, Seattle, WA 98195, USA
| | - Marcelo Araya-Salas
- Centro de Investigación en Neurociencias, Universidad de Costa Rica, San José, Costa Rica
- Escuela de Biología, Universidad de Costa Rica, San José, Costa Rica
| | - Juan L. Parra
- Grupo de Ecología y Evolución de Vertebrados, Instituto de Biología, Universidad de Antioquia, Medellín, Colombia
| | - F. Gary Stiles
- Instituto de Ciencias Naturales, Universidad Nacional de Colombia, Bogotá D.C., Colombia
| | - Alejandro Rico-Guevara
- Department of Biology, University of Washington, Seattle, WA 98195, USA
- Burke Museum of Natural History and Culture, University of Washington, Seattle, WA 98105, USA
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6
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De Meester G, Van Linden L, Torfs J, Pafilis P, Šunje E, Steenssens D, Zulčić T, Sassalos A, Van Damme R. Learning with lacertids: Studying the link between ecology and cognition within a comparative framework. Evolution 2022; 76:2531-2552. [PMID: 36111365 DOI: 10.1111/evo.14618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2022] [Revised: 08/10/2022] [Accepted: 08/21/2022] [Indexed: 01/22/2023]
Abstract
Cognition is an essential tool for animals to deal with environmental challenges. Nonetheless, the ecological forces driving the evolution of cognition throughout the animal kingdom remain enigmatic. Large-scale comparative studies on multiple species and cognitive traits have been advanced as the best way to facilitate our understanding of cognitive evolution, but such studies are rare. Here, we tested 13 species of lacertid lizards (Reptilia: Lacertidae) using a battery of cognitive tests measuring inhibitory control, problem-solving, and spatial and reversal learning. Next, we tested the relationship between species' performance and (a) resource availability (temperature and precipitation), habitat complexity (Normalized Difference Vegetation Index), and habitat variability (seasonality) in their natural habitat and (b) their life history (size at hatching and maturity, clutch size, and frequency). Although species differed markedly in their cognitive abilities, such variation was mostly unrelated to their ecology and life history. Yet, species living in more variable environments exhibited lower behavioral flexibility, likely due to energetic constrains in such habitats. Our standardized protocols provide opportunities for collaborative research, allowing increased sample sizes and replication, essential for moving forward in the field of comparative cognition. Follow-up studies could include more detailed measures of habitat structure and look at other potential selective drivers such as predation.
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Affiliation(s)
- Gilles De Meester
- Functional Morphology Lab, Department of Biology, University of Antwerp, Wilrijk, 2610, Belgium.,Section of Zoology and Marine Biology, Department of Biology, National and Kapodistrian University of Athens, Athens, 157 84, Greece
| | - Lisa Van Linden
- Functional Morphology Lab, Department of Biology, University of Antwerp, Wilrijk, 2610, Belgium
| | - Jonas Torfs
- Functional Morphology Lab, Department of Biology, University of Antwerp, Wilrijk, 2610, Belgium
| | - Panayiotis Pafilis
- Section of Zoology and Marine Biology, Department of Biology, National and Kapodistrian University of Athens, Athens, 157 84, Greece
| | - Emina Šunje
- Functional Morphology Lab, Department of Biology, University of Antwerp, Wilrijk, 2610, Belgium.,Department of Biology, Faculty of Natural Sciences, University of Sarajevo, Sarajevo, 71000, Bosnia and Herzegovina.,Herpetological Association in Bosnia and Herzegovina: BHHU: ATRA, Sarajevo, 71000, Bosnia and Herzegovina
| | - Dries Steenssens
- Functional Morphology Lab, Department of Biology, University of Antwerp, Wilrijk, 2610, Belgium
| | - Tea Zulčić
- Herpetological Association in Bosnia and Herzegovina: BHHU: ATRA, Sarajevo, 71000, Bosnia and Herzegovina
| | - Athanasios Sassalos
- Section of Zoology and Marine Biology, Department of Biology, National and Kapodistrian University of Athens, Athens, 157 84, Greece
| | - Raoul Van Damme
- Functional Morphology Lab, Department of Biology, University of Antwerp, Wilrijk, 2610, Belgium
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7
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Claudino RM, Antonini Y, Martins C, Beirão MV, Braga EM, Azevedo CS. Is bigger always better? Neither body size nor aggressive behavior predicts specialization of hummingbirds in a rocky outcrop. J Zool (1987) 2022. [DOI: 10.1111/jzo.12961] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Affiliation(s)
- R. M. Claudino
- Programa de Pós‐Graduação em Ecologia Conservação e Manejo de Vida Silvestre Universidade Federal de Minas Gerais Belo Horizonte Brazil
| | - Y. Antonini
- Departamento de Biodiversidade Evolução e Meio Ambiente Universidade Federal de Ouro Preto Ouro Preto Brazil
| | - C. Martins
- Departamento de Biodiversidade Evolução e Meio Ambiente Universidade Federal de Ouro Preto Ouro Preto Brazil
| | - M. V. Beirão
- Departamento de Biodiversidade Evolução e Meio Ambiente Universidade Federal de Ouro Preto Ouro Preto Brazil
| | - E. M. Braga
- Programa de Pós‐Graduação em Ecologia Conservação e Manejo de Vida Silvestre Universidade Federal de Minas Gerais Belo Horizonte Brazil
| | - C. S. Azevedo
- Departamento de Biodiversidade Evolução e Meio Ambiente Universidade Federal de Ouro Preto Ouro Preto Brazil
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8
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Fuss T. Mate Choice, Sex Roles and Sexual Cognition in Vertebrates: Mate Choice Turns Cognition or Cognition Turns Mate Choice? Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.749495] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The idea of “smart is sexy,” meaning superior cognition provides competitive benefits in mate choice and, therefore, evolutionary advantages in terms of reproductive fitness, is both exciting and captivating. Cognitively flexible individuals perceive and adapt more dynamically to (unpredictable) environmental changes. The sex roles that females and males adopt within their populations can vary greatly in response to the prevalent mating system. Based on how cognition determines these grossly divergent sex roles, different selection pressures could possibly shape the (progressive) evolution of cognitive abilities, suggesting the potential to induce sexual dimorphisms in superior cognitive abilities. Associations between an individual’s mating success, sexual traits and its cognitive abilities have been found consistently across vertebrate species and taxa, providing evidence that sexual selection may well shape the supporting cognitive prerequisites. Yet, while superior cognitive abilities provide benefits such as higher feeding success, improved antipredator behavior, or more favorable mate choice, they also claim costs such as higher energy levels and metabolic rates, which in turn may reduce fecundity, growth, or immune response. There is compelling evidence in a variety of vertebrate taxa that females appear to prefer skilled problem-solver males, i.e., they prefer those that appear to have better cognitive abilities. Consequently, cognition is also likely to have substantial effects on sexual selection processes. How the choosing sex assesses the cognitive abilities of potential mates has not been explored conclusively yet. Do cognitive skills guide an individual’s mate choice and does learning change an individual’s mate choice decisions? How and to which extent do individuals use their own cognitive skills to assess those of their conspecifics when choosing a mate? How does an individual’s role within a mating system influence the choice of the choosing sex in this context? Drawing on several examples from the vertebrate world, this review aims to elucidate various aspects associated with cognitive sex differences, the different roles of males and females in social and sexual interactions, and the potential influence of cognition on mate choice decisions. Finally, future perspectives aim to identify ways to answer the central question of how the triad of sex, cognition, and mate choice interacts.
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9
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Green PA, McHenry MJ, Rico-Guevara A. Mechanoethology: The Physical Mechanisms of Behavior. Integr Comp Biol 2021; 61:613-623. [PMID: 34124767 PMCID: PMC8427180 DOI: 10.1093/icb/icab133] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 03/31/2021] [Accepted: 06/11/2021] [Indexed: 11/14/2022] Open
Abstract
Research that integrates animal behavior theory with mechanics-including biomechanics, physiology, and functional morphology-can reveal how organisms accomplish tasks crucial to their fitness. Despite the insights that can be gained from this interdisciplinary approach, biomechanics commonly neglects a behavioral context and behavioral research generally does not consider mechanics. Here, we aim to encourage the study of "mechanoethology," an area of investigation intended to encompass integrative studies of mechanics and behavior. Using examples from the literature, including papers in this issue, we show how these fields can influence each other in three ways: (1) the energy required to execute behaviors is driven by the kinematics of movement, and mechanistic studies of movement can benefit from consideration of its behavioral context; (2) mechanics sets physical limits on what behaviors organisms execute, while behavior influences ecological and evolutionary limits on mechanical systems; and (3) sensory behavior is underlain by the mechanics of sensory structures, and sensory systems guide whole-organism movement. These core concepts offer a foundation for mechanoethology research. However, future studies focused on merging behavior and mechanics may reveal other ways by which these fields are linked, leading to further insights in integrative organismal biology.
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Affiliation(s)
- P A Green
- Centre for Ecology and Conservation, College of Life and Environmental Sciences, University of Exeter, Penryn TR10 9FE, UK
| | - M J McHenry
- Department of Ecology and Evolutionary Biology, University of California, Irvine, CA 92697, USA
| | - A Rico-Guevara
- Department of Biology, University of Washington, Seattle, WA 98105, USA
- Burke Museum of Natural History and Culture, University of Washington, Seattle, WA 98105, USA
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10
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Sargent AJ, Groom DJE, Rico-Guevara A. Locomotion and Energetics of Divergent Foraging Strategies in Hummingbirds: A Review. Integr Comp Biol 2021; 61:736-748. [PMID: 34113992 DOI: 10.1093/icb/icab124] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 06/02/2021] [Accepted: 06/08/2021] [Indexed: 11/13/2022] Open
Abstract
Hummingbirds have two main foraging strategies: territoriality (defending a patch of flowers) and traplining (foraging over routine circuits of isolated patches). Species are often classified as employing one or the other. Not only have these strategies been inconsistently defined within the behavioral literature, but this simple framework also neglects the substantial evidence for flexible foraging behavior displayed by hummingbirds. Despite these limitations, research on hummingbird foraging has explored the distinct avenues of selection that proponents of either strategy presumably face: trapliners maximizing foraging efficiency, and territorialists favoring speed and maneuverability for resource defense. In earlier studies, these functions were primarily examined through wing disc loading (ratio of body weight to the circular area swept out by the wings, WDL) and predicted hovering costs, with trapliners expected to exhibit lower WDL than territorialists and thus lower hovering costs. While these pioneering models continue to play a role in current research, early studies were constrained by modest technology, and the original expectations regarding WDL have not held up when applied across complex hummingbird assemblages. Current technological advances have allowed for innovative research on the biomechanics/energetics of hummingbird flight, such as allometric scaling relationships (e.g., wing area-flight performance) and the link between high burst lifting performance and territoriality. Providing a predictive framework based on these relationships will allow us to reexamine previous hypotheses, and explore the biomechanical trade-offs to different foraging strategies, which may yield divergent routes of selection for quintessential territoriality and traplining. With a biomechanical and morphofunctional lens, here we examine the locomotor and energetic facets that dictate hummingbird foraging, and provide (a) predictions regarding the behavioral, biomechanical, and morphofunctional associations with territoriality and traplining; and (b) proposed methods of testing them. By pursuing these knowledge gaps, future research could use a variety of traits to help clarify the operational definitions of territoriality and traplining, to better apply them in the field.
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Affiliation(s)
- A J Sargent
- Department of Biology, University of Washington, 24 Kincaid Hall, Seattle, WA 98105, USA.,Burke Museum of Natural History and Culture, 4300 15th Ave NE, Seattle, WA 98105, USA
| | - D J E Groom
- Department of Biology, University of Washington, 24 Kincaid Hall, Seattle, WA 98105, USA.,Burke Museum of Natural History and Culture, 4300 15th Ave NE, Seattle, WA 98105, USA.,Department of Biology, San Francisco State University, 1600 Holloway Avenue, San Francisco, CA 94132, USA
| | - A Rico-Guevara
- Department of Biology, University of Washington, 24 Kincaid Hall, Seattle, WA 98105, USA.,Burke Museum of Natural History and Culture, 4300 15th Ave NE, Seattle, WA 98105, USA
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11
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Korzan WJ, Summers CH. Evolution of stress responses refine mechanisms of social rank. Neurobiol Stress 2021; 14:100328. [PMID: 33997153 PMCID: PMC8105687 DOI: 10.1016/j.ynstr.2021.100328] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 04/07/2021] [Accepted: 04/09/2021] [Indexed: 02/08/2023] Open
Abstract
Social rank functions to facilitate coping responses to socially stressful situations and conditions. The evolution of social status appears to be inseparably connected to the evolution of stress. Stress, aggression, reward, and decision-making neurocircuitries overlap and interact to produce status-linked relationships, which are common among both male and female populations. Behavioral consequences stemming from social status and rank relationships are molded by aggressive interactions, which are inherently stressful. It seems likely that the balance of regulatory elements in pro- and anti-stress neurocircuitries results in rapid but brief stress responses that are advantageous to social dominance. These systems further produce, in coordination with reward and aggression circuitries, rapid adaptive responding during opportunities that arise to acquire food, mates, perch sites, territorial space, shelter and other resources. Rapid acquisition of resources and aggressive postures produces dominant individuals, who temporarily have distinct fitness advantages. For these reasons also, change in social status can occur rapidly. Social subordination results in slower and more chronic neural and endocrine reactions, a suite of unique defensive behaviors, and an increased propensity for anxious and depressive behavior and affect. These two behavioral phenotypes are but distinct ends of a spectrum, however, they may give us insights into the troubling mechanisms underlying the myriad of stress-related disorders to which they appear to be evolutionarily linked.
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Affiliation(s)
| | - Cliff H Summers
- Department of Biology, University of South Dakota, Vermillion, SD 57069 USA.,Neuroscience Group, Division of Basic Biomedical Sciences, Sanford School of Medicine, University of South Dakota, Vermillion, SD 57069, USA.,Veterans Affairs Research Service, Sioux Falls VA Health Care System, Sioux Falls, SD 57105 USA
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12
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Arroyo MTK, Robles V, Tamburrino Í, Martínez-Harms J, Garreaud RD, Jara-Arancio P, Pliscoff P, Copier A, Arenas J, Keymer J, Castro K. Extreme Drought Affects Visitation and Seed Set in a Plant Species in the Central Chilean Andes Heavily Dependent on Hummingbird Pollination. PLANTS (BASEL, SWITZERLAND) 2020; 9:E1553. [PMID: 33198222 PMCID: PMC7697181 DOI: 10.3390/plants9111553] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 11/07/2020] [Accepted: 11/09/2020] [Indexed: 01/19/2023]
Abstract
Rising temperatures and increasing drought in Mediterranean-type climate areas are expected to affect plant-pollinator interactions, especially in plant species with specialised pollination. Central Chile experienced a mega drought between 2010 and 2020 which reached an extreme in the austral summer of 2019-2020. Based on intensive pollinator sampling and floral studies we show that the subalpine form of Mutisia subulata (Asteraceae) is a specialised hummingbird-pollinated species. In a two-year study which included the severest drought year, we quantified visitation frequency, flower-head density, flower-head visitation rates, two measures of floral longevity, nectar characteristics and seed set and monitored climatic variables to detect direct and indirect climate-related effects on pollinator visitation. Flower-head density, nectar standing crop and seed set were significantly reduced in the severest drought year while nectar concentration increased. The best model to explain visitation frequency included flower-head density, relative humidity, temperature, and nectar standing crop with highly significant effects of the first three variables. Results for flower-head density suggest hummingbirds were able to associate visual signals with reduced resource availability and/or were less abundant. The negative effect of lower relative humidity suggests the birds were able to perceive differences in nectar concentration. Reduced seed set per flower-head together with the availability of far fewer ovules in the 2019-2020 austral summer would have resulted in a major reduction in seed set. Longer and more intense droughts in this century could threaten local population persistence in M. subulata.
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Affiliation(s)
- Mary T. K. Arroyo
- Facultad de Ciencias, Universidad de Chile, Las Palmeras 3425, 7800003 Ñuñoa, Santiago, Chile; (V.R.); (Í.T.); (A.C.); (J.A.); (J.K.); (K.C.)
- Instituto de Ecología y Biodiversidad (IEB), Las Palmeras 3425, 7800003 Ñuñoa, Santiago, Chile;
| | - Valeria Robles
- Facultad de Ciencias, Universidad de Chile, Las Palmeras 3425, 7800003 Ñuñoa, Santiago, Chile; (V.R.); (Í.T.); (A.C.); (J.A.); (J.K.); (K.C.)
- Instituto de Ecología y Biodiversidad (IEB), Las Palmeras 3425, 7800003 Ñuñoa, Santiago, Chile;
| | - Ítalo Tamburrino
- Facultad de Ciencias, Universidad de Chile, Las Palmeras 3425, 7800003 Ñuñoa, Santiago, Chile; (V.R.); (Í.T.); (A.C.); (J.A.); (J.K.); (K.C.)
- Instituto de Ecología y Biodiversidad (IEB), Las Palmeras 3425, 7800003 Ñuñoa, Santiago, Chile;
| | - Jaime Martínez-Harms
- INIA, La Cruz, Instituto de Investigaciones Agropecuarias, Chorrillos 86, 2280454 La Cruz, Chile;
| | - René D. Garreaud
- Departamento de Geofísica, Universidad de Chile, Avenida Blanco Encalada 2002, 8370449 Santiago, Chile;
- Centro de Ciencia del Clima y la Resiliencia (CR2), Avenida Blanco Encalada 2002, Universidad de Chile, 8370449 Santiago, Chile
| | - Paola Jara-Arancio
- Instituto de Ecología y Biodiversidad (IEB), Las Palmeras 3425, 7800003 Ñuñoa, Santiago, Chile;
- Departamento de Ciencias Biológicas y Departamento de Ecología y Biodiversidad, Facultad de Ciencias de la Vida, Universidad Andrés Bello, Republica 252, 8370134 Santiago, Chile
| | - Patricio Pliscoff
- Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Alameda 340, 8331150 Santiago, Chile;
- Instituto de Geografía, Facultad de Historia, Geografía y Ciencia Política, Pontificia Universidad Católica de Chile, Avenida Vicuña Mackenna 4860, 7820436 Macul, Santiago, Chile
| | - Ana Copier
- Facultad de Ciencias, Universidad de Chile, Las Palmeras 3425, 7800003 Ñuñoa, Santiago, Chile; (V.R.); (Í.T.); (A.C.); (J.A.); (J.K.); (K.C.)
| | - Jonás Arenas
- Facultad de Ciencias, Universidad de Chile, Las Palmeras 3425, 7800003 Ñuñoa, Santiago, Chile; (V.R.); (Í.T.); (A.C.); (J.A.); (J.K.); (K.C.)
| | - Joaquín Keymer
- Facultad de Ciencias, Universidad de Chile, Las Palmeras 3425, 7800003 Ñuñoa, Santiago, Chile; (V.R.); (Í.T.); (A.C.); (J.A.); (J.K.); (K.C.)
| | - Kiara Castro
- Facultad de Ciencias, Universidad de Chile, Las Palmeras 3425, 7800003 Ñuñoa, Santiago, Chile; (V.R.); (Í.T.); (A.C.); (J.A.); (J.K.); (K.C.)
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13
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Langley EJG, Adams G, Beardsworth CE, Dawson DA, Laker PR, van Horik JO, Whiteside MA, Wilson AJ, Madden JR. Heritability and correlations among learning and inhibitory control traits. Behav Ecol 2020; 31:798-806. [PMID: 32821079 PMCID: PMC7428062 DOI: 10.1093/beheco/araa029] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Revised: 02/19/2020] [Accepted: 03/13/2020] [Indexed: 12/22/2022] Open
Abstract
To understand the evolution of cognitive abilities, we need to understand both how selection acts upon them and their genetic (co)variance structure. Recent work suggests that there are fitness consequences for free-living individuals with particular cognitive abilities. However, our current understanding of the heritability of these abilities is restricted to domesticated species subjected to artificial selection. We investigated genetic variance for, and genetic correlations among four cognitive abilities: inhibitory control, visual and spatial discrimination, and spatial ability, measured on >450 pheasants, Phasianus colchicus, over four generations. Pheasants were reared in captivity but bred from adults that lived in the wild and hence, were subject to selection on survival. Pheasant chicks are precocial and were reared without parents, enabling us to standardize environmental and parental care effects. We constructed a pedigree based on 15 microsatellite loci and implemented animal models to estimate heritability. We found moderate heritabilities for discrimination learning and inhibitory control (h2 = 0.17-0.23) but heritability for spatial ability was low (h2 = 0.09). Genetic correlations among-traits were largely positive but characterized by high uncertainty and were not statistically significant. Principle component analysis of the genetic correlation matrix estimate revealed a leading component that explained 69% of the variation, broadly in line with expectations under a general intelligence model of cognition. However, this pattern was not apparent in the phenotypic correlation structure which was more consistent with a modular view of animal cognition. Our findings highlight that the expression of cognitive traits is influenced by environmental factors which masks the underlying genetic structure.
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Affiliation(s)
- Ellis J G Langley
- Centre for Research in Animal Behaviour, College of Life and Environmental Sciences, Washington Singer Labs, University of Exeter, Exeter, UK
| | - Gracie Adams
- Department of Animal and Plant Sciences, Alfred Denny Building, University of Sheffield, Western Bank, Sheffield, UK
| | - Christine E Beardsworth
- Centre for Research in Animal Behaviour, College of Life and Environmental Sciences, Washington Singer Labs, University of Exeter, Exeter, UK
| | - Deborah A Dawson
- Department of Animal and Plant Sciences, Alfred Denny Building, University of Sheffield, Western Bank, Sheffield, UK
| | - Philippa R Laker
- Centre for Research in Animal Behaviour, College of Life and Environmental Sciences, Washington Singer Labs, University of Exeter, Exeter, UK
| | - Jayden O van Horik
- Centre for Research in Animal Behaviour, College of Life and Environmental Sciences, Washington Singer Labs, University of Exeter, Exeter, UK
| | - Mark A Whiteside
- Centre for Research in Animal Behaviour, College of Life and Environmental Sciences, Washington Singer Labs, University of Exeter, Exeter, UK
| | - Alastair J Wilson
- Centre for Ecology and Conservation, University of Exeter, Penryn Campus, Penryn, UK
| | - Joah R Madden
- Centre for Research in Animal Behaviour, College of Life and Environmental Sciences, Washington Singer Labs, University of Exeter, Exeter, UK
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14
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Araya-Salas M, Smith-Vidaurre G, Mennill DJ, González-Gómez PL, Cahill J, Wright TF. Social group signatures in hummingbird displays provide evidence of co-occurrence of vocal and visual learning. Proc Biol Sci 2019; 286:20190666. [PMID: 31138067 DOI: 10.1098/rspb.2019.0666] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Vocal learning, in which animals modify their vocalizations based on social experience, has evolved in several lineages of mammals and birds, including humans. Despite much attention, the question of how this key cognitive trait has evolved remains unanswered. The motor theory for the origin of vocal learning posits that neural centres specialized for vocal learning arose from adjacent areas in the brain devoted to general motor learning. One prediction of this hypothesis is that visual displays that rely on complex motor patterns may also be learned in taxa with vocal learning. While learning of both spoken and gestural languages is well documented in humans, the occurrence of learned visual displays has rarely been examined in non-human animals. We tested for geographical variation consistent with learning of visual displays in long-billed hermits ( Phaethornis longirostris), a lek-mating hummingbird that, like humans, has both learned vocalizations and elaborate visual displays. We found lek-level signatures in both vocal parameters and visual display features, including display element proportions, sequence syntax and fine-scale parameters of elements. This variation was not associated with genetic differentiation between leks. In the absence of genetic differences, geographical variation in vocal signals at small scales is most parsimoniously attributed to learning, suggesting a significant role of social learning in visual display ontogeny. The co-occurrence of learning in vocal and visual displays would be consistent with a parallel evolution of these two signal modalities in this species.
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Affiliation(s)
- Marcelo Araya-Salas
- 1 Department of Biology, New Mexico State University , Las Cruces, NM , USA.,2 Laboratory of Ornithology, Cornell University , Ithaca, NY , USA.,3 Escuela de Biología, Universidad de Costa Rica , San Pedro, San José , Costa Rica
| | | | - Daniel J Mennill
- 4 Department of Biological Sciences, University of Windsor , Windsor, Ontario , Canada
| | - Paulina L González-Gómez
- 5 Department of Neurobiology, Physiology and Behavior, University of California Davis , Davis, CA , USA.,6 Universidad Autónoma de Chile , Santiago , Chile
| | - James Cahill
- 7 Laboratory of the Neurogenetics of Language, Rockefeller University , New York, NY , USA
| | - Timothy F Wright
- 1 Department of Biology, New Mexico State University , Las Cruces, NM , USA
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15
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De Meester G, Huyghe K, Van Damme R. Brain size, ecology and sociality: a reptilian perspective. Biol J Linn Soc Lond 2019. [DOI: 10.1093/biolinnean/bly206] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Gilles De Meester
- Functional Morphology Group, Department of Biology, University of Antwerp, Wilrijk, Belgium
| | - Katleen Huyghe
- Functional Morphology Group, Department of Biology, University of Antwerp, Wilrijk, Belgium
| | - Raoul Van Damme
- Functional Morphology Group, Department of Biology, University of Antwerp, Wilrijk, Belgium
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16
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Rico-Guevara A, Rubega MA, Hurme KJ, Dudley R. Shifting Paradigms in the Mechanics of Nectar Extraction and Hummingbird Bill Morphology. Integr Org Biol 2019; 1:oby006. [PMID: 33791513 PMCID: PMC7671138 DOI: 10.1093/iob/oby006] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
As functional morphologists, we aim to connect structures, mechanisms, and emergent higher-scale phenomena (e.g., behavior), with the ulterior motive of addressing evolutionary patterns. The fit between flowers and hummingbird bills has long been used as an example of impressive co-evolution, and hence hummingbirds' foraging behavior and ecological associations have been the subject of intense study. To date, models of hummingbird foraging have been based on the almost two-centuries-old assumption that capillary rise loads nectar into hummingbird tongue grooves. Furthermore, the role of the bill in the drinking process has been overlooked, instead considering it as the mere vehicle with which to traverse the corolla and access the nectar chamber. As a scientific community, we have been making incorrect assumptions about the basic aspects of how hummingbirds extract nectar from flowers. In this article, we summarize recent advances on drinking biomechanics, morphological and ecological patterns, and selective forces involved in the shaping of the hummingbird feeding apparatus, and also address its modifications in a previously unexpected context, namely conspecific and heterospecific fighting. We explore questions such as: how do the mechanics of feeding define the limits and adaptive consequences of foraging behaviors? Which are the selective forces that drive bill and tongue shape, and associated sexually dimorphic traits? And finally, what are the proximate and ultimate causes of their foraging strategies, including exploitative and interference competition? Increasing our knowledge of morphology, mechanics, and diversity of hummingbird feeding structures will have implications for understanding the ecology and evolution of these remarkable animals.
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Affiliation(s)
- A Rico-Guevara
- Department of Integrative Biology, University of California, Berkeley, 3040 Valley Life Sciences Building, Berkeley, CA 94720, USA.,Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs, CT 06269, USA.,Instituto de Ciencias Naturales, Universidad Nacional de Colombia, Código Postal 11001, Bogotá DC, Colombia
| | - M A Rubega
- Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs, CT 06269, USA
| | - K J Hurme
- Department of Integrative Biology, University of California, Berkeley, 3040 Valley Life Sciences Building, Berkeley, CA 94720, USA.,Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs, CT 06269, USA
| | - R Dudley
- Department of Integrative Biology, University of California, Berkeley, 3040 Valley Life Sciences Building, Berkeley, CA 94720, USA
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