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Bronstein JL, Sridhar H. Connecting and integrating cooperation within and between species. Philos Trans R Soc Lond B Biol Sci 2024; 379:20230203. [PMID: 39034697 PMCID: PMC11293865 DOI: 10.1098/rstb.2023.0203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Revised: 12/31/2023] [Accepted: 01/24/2024] [Indexed: 07/23/2024] Open
Abstract
There has long been a fundamental divide in the study of cooperation: researchers focus either on cooperation within species, including but not limited to sociality, or else on cooperation between species, commonly termed mutualism. Here, we explore the ecologically and evolutionarily significant ways in which within- and between-species cooperation interact. We highlight two primary cross-linkages. First, cooperation of one type can change the context in which cooperation of the other type functions, and thus potentially its outcome. We delineate three possibilities: (i) within-species cooperation modulates benefits for a heterospecific partner; (ii) between-species cooperation affects the dynamics of within-species cooperation; and (iii) both processes take place interactively. The second type of cross-linkage emerges when resources or services that cooperation makes available are obtainable either from members of the same species or from different species. This brings cooperation at the two levels into direct interaction, to some extent obscuring the distinction between them. We expand on these intersections between within- and between-species cooperation in a diversity of taxa and interaction types. These interactions have the potential to weave together social networks and trophic dynamics, contributing to the structure and functioning of ecological communities in ways that are just beginning to be explored. This article is part of the theme issue 'Connected interactions: enriching food web research by spatial and social interactions'.
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Affiliation(s)
- Judith L. Bronstein
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ85721, USA
| | - Hari Sridhar
- Konrad Lorenz Institute for Evolution and Cognition Research, KlosterneuburgA-3400, Austria
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2
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Kerr NZ, Morris WF, Walters JR. Inclusive Fitness May Explain Some but Not All Benefits Derived from Helping Behavior in a Cooperatively Breeding Bird. Am Nat 2024; 203:393-410. [PMID: 38358814 DOI: 10.1086/728670] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2024]
Abstract
AbstractIn cooperative breeding systems, inclusive fitness theory predicts that nonbreeding helpers more closely related to the breeders should be more willing to provide costly alloparental care and thus have more impact on breeder fitness. In the red-cockaded woodpecker (Dryobates borealis), most helpers are the breeders' earlier offspring, but helpers do vary within groups in both relatedness to the breeders (some even being unrelated) and sex, and it can be difficult to parse their separate impacts on breeder fitness. Moreover, most support for inclusive fitness theory has been positive associations between relatedness and behavior rather than actual fitness consequences. We used functional linear models to evaluate the per capita effects of helpers of different relatedness on eight breeder fitness components measured for up to 41 years at three sites. In support of inclusive fitness theory, helpers more related to the breeding pair made greater contributions to six fitness components. However, male helpers made equal contributions to increasing prefledging survival regardless of relatedness. These findings suggest that both inclusive fitness benefits and other direct benefits may underlie helping behaviors in the red-cockaded woodpecker. Our results also demonstrate the application of an underused statistical approach to disentangle a complex ecological phenomenon.
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Turner CR, Spike M, Magrath RD. The evolution of eavesdropping on heterospecific alarm calls: Relevance, reliability, and personal information. Ecol Evol 2023; 13:e10272. [PMID: 37449019 PMCID: PMC10337016 DOI: 10.1002/ece3.10272] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Accepted: 06/21/2023] [Indexed: 07/18/2023] Open
Abstract
Interceptive eavesdropping on the alarm calls of heterospecifics provides crucial information about predators. Previous research suggests predator discrimination, call relevance, reliability, and reception explain when eavesdropping will evolve. However, there has been no quantitative analysis to scrutinize these principles, or how they interact. We develop a mathematical framework that formalizes the study of the key principles thought to select for eavesdropping. Interceptive eavesdropping appears to be greatly affected by the threat faced by caller and eavesdropper, as well as presence of informational noise affecting the detection of calls and predators. Accordingly, our model uses signal detection theory to examine when selection will favor alarm calling by a sender species and fleeing by an eavesdropping receiver species. We find eavesdropping is most strongly selected when (1) the receiver faces substantial threats, (2) species are ecologically similar, (3) senders often correctly discriminate threats, (4) receivers often correctly perceive calls, and (5) the receiver's personal discrimination of threats is poor. Furthermore, we find (6) that very high predation levels can select against eavesdropping because prey cannot continuously flee and must conserve energy. Reliability of heterospecific calls for identifying threats is thought to be important in selecting for eavesdropping. Consequently, we formally define reliability, showing its connection to specificity and sensitivity, clarifying how these quantities can be measured. We find that high call relevance, due to similar vulnerability to predators between species, strongly favors eavesdropping. This is because senders trade-off false alarms and missed predator detections in a way that is also favorable for the eavesdropper, by producing less of the costlier error. Unexpectedly, highly relevant calls increase the total number of combined errors and so have lower reliability. Expectedly, when noise greatly affects personally gathered cues to threats, but not heterospecific calls or detection of predators, eavesdropping is favored.
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Affiliation(s)
- Cameron Rouse Turner
- Computational Cognitive Science Lab, Department of Computer SciencePrinceton UniversityPrincetonNew JerseyUSA
- Division of Ecology and Evolution, Research School of BiologyAustralian National UniversityCanberraAustralian Capital TerritoryAustralia
| | - Matt Spike
- Centre for Language Evolution, School of Philosophy, Psychology and Language SciencesThe University of EdinburghEdinburghUK
| | - Robert D. Magrath
- Division of Ecology and Evolution, Research School of BiologyAustralian National UniversityCanberraAustralian Capital TerritoryAustralia
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4
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Mangini GG, Rutt CL, Sridhar H, Buitron G, Muñoz J, Robinson SK, Montaño-Centellas F, Zarco A, Fanjul ME, Fernández-Arellano G, Xing S, Camerlenghi E. A classification scheme for mixed-species bird flocks. Philos Trans R Soc Lond B Biol Sci 2023; 378:20220100. [PMID: 37066650 PMCID: PMC10107246 DOI: 10.1098/rstb.2022.0100] [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: 09/16/2022] [Accepted: 01/17/2023] [Indexed: 04/18/2023] Open
Abstract
The literature on mixed-species flocks references a wide variety of bird associations. These studies, however, have used an array of unstructured characteristics to describe flocks, ranging from the temporal occurrence of flocking to the identity and behavioural features of constituent members, with little consensus on which key traits define and characterize a mixed-species flock. Moreover, although most studies report species-specific roles, there is no clear consensus about what these roles signify nor how to define them. This lack of consistency limits our ability to compare flocks from different habitats, regions and species pools. To unify this sizable body of literature, we reviewed and synthesized 538 studies on mixed-species flocks. We propose 13 categories to classify mixed-species flocks using behavioural and physical traits at the flock and participant level, as well as the habitat where the flock occurs. Lastly, we discuss the historical terminology for different species roles and propose definitions to clarify and distinguish among nuclear, leader, sentinel, and flock-following species. We envision that these guidelines will provide a universal language for mixed-species flock research, paving the way for future comparisons and new insight between different regions and systems. This article is part of the theme issue 'Mixed-species groups and aggregations: shaping ecological and behavioural patterns and processes'.
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Affiliation(s)
- G. Giselle Mangini
- Instituto de Ecologia Regional (IER) CONICET-UNT, 4107 Yerba Buena, Argentina
| | | | - Hari Sridhar
- Independent Researcher, Bengaluru, Karnataka 560003, India
- Konrad Lorenz Institute for Evolution and Cognition Research, 3400 Klosterneuburg, Austria
| | - Galo Buitron
- Universidad Estatal Amazónica-Sede Académica El Pangui, Zamora Chinchipe, 190401, Ecuador
| | - Jenny Muñoz
- University of British Columbia Biodiversity Research Center, Vancouver, Canada V6T 1Z4
| | - Scott K. Robinson
- Florida Museum of Natural History, University of Florida, Gainesville, FL 32611, USA
| | | | - Agustin Zarco
- Instituto Argentino de Investigación en las Zonas Áridas (IADIZA) CONICET, 5500 Mendoza, Argentina
- Fundación de Historia Natural Félix de Azara, 1405 Buenos Aires, Argentina
| | - M. Elisa Fanjul
- Instituto de Vertebrados, Zoología, Fundación Miguel Lillo, 4000 Tucumán, Argentina
- Facultad de Ciencias Naturales e IML – Universidad Nacional de Tucumán, 4000 Tucumán, Argentina
| | - Gilberto Fernández-Arellano
- Programa de Pós-Graduação em Ecologia e Conservação da Biodiversidade, Universidade Federal de Mato Grosso – UFMT, 78060-900 Cuiabá, Brazil
| | - Shuang Xing
- School of Ecology, Sun Yat-sen University, 518107 Guangdong, People's Republic of China
| | - Ettore Camerlenghi
- School of Biological Sciences, Monash University, Wellington Road, Clayton, Victoria 3800, Australia
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Zhao L, Qin Y, Wang J, Liang W. Avian Alarm Calls Do Not Induce Anti-Predator Response in Three Anuran Species. Animals (Basel) 2022; 12:3537. [PMID: 36552456 PMCID: PMC9774322 DOI: 10.3390/ani12243537] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2022] [Revised: 12/08/2022] [Accepted: 12/12/2022] [Indexed: 12/23/2022] Open
Abstract
Many species produce alarm calls in response to predators, and the anti-predator signals are often used by other species. Eavesdropping on heterospecific alarm calls has been widely found in bird and mammal species. Other taxa, such as reptiles and amphibians, however, receive limited attention at present. Here, we selected three types of alarm calls of Japanese Tits (Parus minor) that were evoked by the Siberian Chipmunk (Eutamias sibiricus), Eurasian Sparrow Hawk (Accipiter nisus), and model snake (Elaphe spp.), respectively, and then carried out playback experiments to test whether three frog species changed their behaviors in response to the three treatments of Japanese Tit calls while the tit's territory song was used as a control. The results showed that Little Torrent Frogs (Amolops torrentis), Ornamented Pygmy Frogs (Microhyla fissipes) and Spot-legged Treefrogs (Polypedates megacephalus) did not jump off their positions in response to the same four acoustic signals. They also did not change their calling behaviors in response to the alarm calls of Japanese Tits. This study found no evidence that these anuran species can eavesdrop on heterospecific tits' alarm signals.
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Affiliation(s)
| | | | - Jichao Wang
- Ministry of Education Key Laboratory for Ecology of Tropical Islands, Key Laboratory of Tropical Animal and Plant Ecology of Hainan Province, College of Life Sciences, Hainan Normal University, Haikou 571158, China
| | - Wei Liang
- Ministry of Education Key Laboratory for Ecology of Tropical Islands, Key Laboratory of Tropical Animal and Plant Ecology of Hainan Province, College of Life Sciences, Hainan Normal University, Haikou 571158, China
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6
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Beauchamp G, Bowman R. Visual Monitoring Strategies of Sentinels in a Cooperative Breeder. BIOLOGY 2022; 11:biology11121769. [PMID: 36552280 PMCID: PMC9775325 DOI: 10.3390/biology11121769] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Revised: 11/30/2022] [Accepted: 12/02/2022] [Indexed: 12/12/2022]
Abstract
Vigilance is important for early detection of threats. Previous studies have focused on the allocation of time to vigilance but neglected how animals monitor their surroundings during vigilance. Where animals look and how long each look lasts can affect the quality of visual monitoring and thus the ability to detect threats during vigilance. We examined visual monitoring strategies in the Florida scrub-jay (Aphelocoma coerulescens), a cooperative breeder with sentinel behaviour. Sentinels in this species make head turns from vantage points to detect the arrival of predators and intruding neighbours. We found that sentinels initiated head turns at regular intervals and also returned their gaze to areas previously monitored at regular intervals, which is predicted when predators and intruders rely on surprise rather than stealth to approach. Sentinels made head turns in several directions, but often more frequently on one side of the body than the other, which was not predicted for regular vigilance. Average look duration during sentinel bouts was shorter in smaller groups and in juveniles. We argue that shorter looks are beneficial to increase visual coverage in more threatening situations. Our study highlights how visual monitoring strategies during vigilance reflect the risk posed by predators and intruders.
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Affiliation(s)
- Guy Beauchamp
- Independent Researcher, Montreal, QC, Canada
- Correspondence:
| | - Reed Bowman
- Archbold Biological Station, 123 Main Dr., Venus, FL 33960, USA
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7
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Eavesdropping on conspecific alarm calls links birds across territory borders into a population-wide information network. Anim Behav 2022. [DOI: 10.1016/j.anbehav.2022.07.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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8
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Humphries DJ, Nelson‐Flower MJ, Bell MBV, Finch FM, Ridley AR. Kinship, dear enemies, and costly combat: The effects of relatedness on territorial overlap and aggression in a cooperative breeder. Ecol Evol 2021; 11:17031-17042. [PMID: 34938490 PMCID: PMC8668771 DOI: 10.1002/ece3.8342] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Revised: 08/29/2021] [Accepted: 10/13/2021] [Indexed: 11/30/2022] Open
Abstract
Many species maintain territories, but the degree of overlap between territories and the level of aggression displayed in territorial conflicts can vary widely, even within species. Greater territorial overlap may occur when neighboring territory holders are close relatives. Animals may also differentiate neighbors from strangers, with more familiar neighbors eliciting less-aggressive responses during territorial conflicts (the "dear enemy" effect). However, research is lacking in how both kinship and overlap affect territorial conflicts, especially in group-living species. Here, we investigate kinship, territorial overlap, and territorial conflict in a habituated wild population of group-living cooperatively breeding birds, the southern pied babbler Turdoides bicolor. We find that close kin neighbors are beneficial. Territories overlap more when neighboring groups are close kin, and these larger overlaps with kin confer larger territories (an effect not seen for overlaps with unrelated groups). Overall, territorial conflict is costly, causing significant decreases in body mass, but conflicts with kin are shorter than those conducted with nonkin. Conflicts with more familiar unrelated neighbors are also shorter, indicating these neighbors are "dear enemies." However, kinship modulates the "dear enemy" effect; even when kin are encountered less frequently, kin elicit less-aggressive responses, similar to the "dear enemy" effect. Kin selection appears to be a main influence on territorial behavior in this species. Groups derive kin-selected benefits from decreased conflicts and maintain larger territories when overlapping with kin, though not when overlapping with nonkin. More generally, it is possible that kinship extends the "dear enemy" effect in animal societies.
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Affiliation(s)
- David J. Humphries
- Department of Biological SciencesMacquarie UniversitySydneyNew South WalesAustralia
- Pied Babbler Research ProjectUniversity of Cape TownRondeboschWestern CapeSouth Africa
| | - Martha J. Nelson‐Flower
- Pied Babbler Research ProjectUniversity of Cape TownRondeboschWestern CapeSouth Africa
- Department of BiologyLangara CollegeVancouverBritish ColumbiaCanada
| | - Matthew B. V. Bell
- Pied Babbler Research ProjectUniversity of Cape TownRondeboschWestern CapeSouth Africa
- Institute of Evolutionary BiologySchool of Biological SciencesUniversity of EdinburghEdinburghUK
| | - Fiona M. Finch
- Pied Babbler Research ProjectUniversity of Cape TownRondeboschWestern CapeSouth Africa
| | - Amanda R. Ridley
- Pied Babbler Research ProjectUniversity of Cape TownRondeboschWestern CapeSouth Africa
- DST/NRF Centre of ExcellencePercy FitzPatrick Institute for African OrnithologyUniversity of Cape TownRondeboschSouth Africa
- School of Biological SciencesUniversity of Western AustraliaPerthWestern AustraliaAustralia
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9
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Catto S, Sumasgutner P, Amar A, Thomson RL, Cunningham SJ. Pulses of anthropogenic food availability appear to benefit parents, but compromise nestling growth in urban red-winged starlings. Oecologia 2021; 197:565-576. [PMID: 34536140 PMCID: PMC8585795 DOI: 10.1007/s00442-021-05033-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Accepted: 08/30/2021] [Indexed: 11/28/2022]
Abstract
The provision of anthropogenic food undoubtedly influences urban bird fitness. However, the nature of the impact is unclear, with both benefits and costs of urban diets documented. Moreover, the influence of short-term fluctuations in food availability, linked to urban weekday/weekend cycles of human presence, is largely unknown. We explored whether breeding red-winged starlings Onychognathus morio in Cape Town, South Africa, altered foraging and provisioning behaviour between days with high human presence (HHP) and days with low human presence (LHP)—i.e. weekdays versus weekends and vacation days. We investigated the relationship between starling diet, adult body mass and nestling development. Breeding adults consumed and provisioned the same quantity of food, but a significantly greater proportion of anthropogenic food on HHP compared to LHP days. Adults apparently benefited from the anthropogenic diet, experiencing significantly greater mass gain on HHP days. However, nestlings experienced a cost, with the number of HHP days during the nestling period associated negatively with nestling size. Adults may, therefore, benefit from the high calorie content of anthropogenic food, while nestlings may be negatively affected by nutrient limitation. The quantity of food available in urban environments may, therefore, benefit adult survival, while its quality imposes a cost to nestling growth.
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Affiliation(s)
- Sarah Catto
- FitzPatrick Institute of African Ornithology, DSI-NRF Centre of Excellence, University of Cape Town, Private Bag X3, Rondebosch, 7701, South Africa
| | - Petra Sumasgutner
- FitzPatrick Institute of African Ornithology, DSI-NRF Centre of Excellence, University of Cape Town, Private Bag X3, Rondebosch, 7701, South Africa. .,Konrad Lorenz Research Center, Core Facility for Behaviour and Cognition, Department of Behavioral and Cognitive Biology, University of Vienna, Grünau/Almtal, 4645, Austria.
| | - Arjun Amar
- FitzPatrick Institute of African Ornithology, DSI-NRF Centre of Excellence, University of Cape Town, Private Bag X3, Rondebosch, 7701, South Africa
| | - Robert L Thomson
- FitzPatrick Institute of African Ornithology, DSI-NRF Centre of Excellence, University of Cape Town, Private Bag X3, Rondebosch, 7701, South Africa
| | - Susan J Cunningham
- FitzPatrick Institute of African Ornithology, DSI-NRF Centre of Excellence, University of Cape Town, Private Bag X3, Rondebosch, 7701, South Africa
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10
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Rauber R, Manser MB. Effect of group size and experience on the ontogeny of sentinel calling behaviour in meerkats. Anim Behav 2021. [DOI: 10.1016/j.anbehav.2020.11.014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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11
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Ridley AR, Wiley EM, Bourne AR, Cunningham SJ, Nelson-Flower MJ. Understanding the potential impact of climate change on the behavior and demography of social species: The pied babbler (Turdoides bicolor) as a case study. ADVANCES IN THE STUDY OF BEHAVIOR 2021. [DOI: 10.1016/bs.asb.2021.03.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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12
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Arbon JJ, Kern JM, Morris-Drake A, Radford AN. Context-dependent contributions to sentinel behaviour: audience, satiation and danger effects. Anim Behav 2020. [DOI: 10.1016/j.anbehav.2020.04.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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13
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Guindre-Parker S, Rubenstein DR. Survival Benefits of Group Living in a Fluctuating Environment. Am Nat 2020; 195:1027-1036. [PMID: 32469654 DOI: 10.1086/708496] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Group living is predicted to arise only when the fitness benefits outweigh the costs of sociality. Group-living species-including cooperatively breeding and family-living birds and mammals-occur most frequently in environments where climatic conditions fluctuate unpredictably from year to year. The fitness consequences of group living are thus expected to vary with changing environmental conditions, though few studies have examined this possibility. We examined whether living in large social groups improves adult survivorship in cooperatively breeding superb starlings (Lamprotornis superbus). We also tested the hypothesis that larger groups buffer against harsh conditions by increasing survivorship most under periods of low rainfall. We found that group size was positively correlated with adult survival but in a sex-specific manner: female survival increased with group size across all environmental conditions, whereas male survival increased with group size only in wet years. Together with previous work in this system, our results suggest that larger groups confer survival benefits by reducing predation, rather than by improving access to food or buffering against physiological stress. Although group living does not appear to buffer against harsh conditions in adult starlings living in a fluctuating environment, living in larger groups does confer a survival advantage.
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14
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Goodale E, Sridhar H, Sieving KE, Bangal P, Colorado Z GJ, Farine DR, Heymann EW, Jones HH, Krams I, Martínez AE, Montaño-Centellas F, Muñoz J, Srinivasan U, Theo A, Shanker K. Mixed company: a framework for understanding the composition and organization of mixed-species animal groups. Biol Rev Camb Philos Soc 2020; 95:889-910. [PMID: 32097520 PMCID: PMC7383667 DOI: 10.1111/brv.12591] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Revised: 02/02/2020] [Accepted: 02/06/2020] [Indexed: 12/19/2022]
Abstract
Mixed-species animal groups (MSGs) are widely acknowledged to increase predator avoidance and foraging efficiency, among other benefits, and thereby increase participants' fitness. Diversity in MSG composition ranges from two to 70 species of very similar or completely different phenotypes. Yet consistency in organization is also observable in that one or a few species usually have disproportionate importance for MSG formation and/or maintenance. We propose a two-dimensional framework for understanding this diversity and consistency, concentrating on the types of interactions possible between two individuals, usually of different species. One axis represents the similarity of benefit types traded between the individuals, while the second axis expresses asymmetry in the relative amount of benefits/costs accrued. Considering benefit types, one extreme represents the case of single-species groups wherein all individuals obtain the same supplementary, group-size-related benefits, and the other extreme comprises associations of very different, but complementary species (e.g. one partner creates access to food while the other provides vigilance). The relevance of social information and the matching of activities (e.g. speed of movement) are highest for relationships on the supplementary side of this axis, but so is competition; relationships between species will occur at points along this gradient where the benefits outweigh the costs. Considering benefit amounts given or received, extreme asymmetry occurs when one species is exclusively a benefit provider and the other a benefit user. Within this parameter space, some MSG systems are constrained to one kind of interaction, such as shoals of fish of similar species or leader-follower interactions in fish and other taxa. Other MSGs, such as terrestrial bird flocks, can simultaneously include a variety of supplementary and complementary interactions. We review the benefits that species obtain across the diversity of MSG types, and argue that the degree and nature of asymmetry between benefit providers and users should be measured and not just assumed. We then discuss evolutionary shifts in MSG types, focusing on drivers towards similarity in group composition, and selection on benefit providers to enhance the benefits they can receive from other species. Finally, we conclude by considering how individual and collective behaviour in MSGs may influence both the structure and processes of communities.
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Affiliation(s)
- Eben Goodale
- Guangxi Key Laboratory for Forest Ecology and Conservation, College of Forestry, Guangxi University, Nanning, Guangxi, 530004, China
| | - Hari Sridhar
- Centre for Ecological Sciences, Indian Institute of Science, Bengaluru, Karnataka, 560012, India.,National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bangalore, Karnataka, 560012, India
| | - Kathryn E Sieving
- Department of Wildlife Ecology and Conservation, University of Florida, Gainesville, FL, 32611, U.S.A
| | - Priti Bangal
- Centre for Ecological Sciences, Indian Institute of Science, Bengaluru, Karnataka, 560012, India
| | - Gabriel J Colorado Z
- Departamento de Ciencias Forestales, Universidad Nacional de Colombia, Medellín, 050034, Colombia
| | - Damien R Farine
- Department of Collective Behavior, Max Planck Institute of Animal Behavior, Universitätsstrasse 10, D-78464, Konstanz, Germany.,Centre for the Advanced Study of Collective Behaviour, University of Konstanz, D-78464, Konstanz, Germany.,Department of Biology, University of Konstanz, D-78464, Konstanz, Germany
| | - Eckhard W Heymann
- Deutsches Primatenzentrum, Leibniz-Institut für Primatenforschung, D-37077, Göttingen, Germany
| | - Harrison H Jones
- Department of Biology, University of Florida, Gainesville, FL, 32611, U.S.A.,Florida Museum of Natural History, Gainesville, FL, 32611, U.S.A
| | - Indrikis Krams
- Institute of Ecology and Earth Sciences, University of Tartu, Tartu, 51410, Estonia.,Department of Zoology and Animal Ecology, Faculty of Biology, University of Latvia, Rīga, 1004, Latvia
| | - Ari E Martínez
- Department of Biological Sciences, California State University, Long Beach, CA, 90840, U.S.A
| | - Flavia Montaño-Centellas
- Department of Wildlife Ecology and Conservation, University of Florida, Gainesville, FL, 32611, U.S.A.,Instituto de Ecologia, Universidad Mayor de San Andres, La Paz, 10077, Bolivia
| | - Jenny Muñoz
- Zoology Department and Biodiversity Research Center, University of British Columbia, Vancouver, BC, V6T 1ZA, Canada
| | - Umesh Srinivasan
- Woodrow Wilson School of Public and International Affairs, Princeton University, Princeton, NJ, 08540, U.S.A
| | - Anne Theo
- Centre for Ecological Sciences, Indian Institute of Science, Bengaluru, Karnataka, 560012, India
| | - Kartik Shanker
- Centre for Ecological Sciences, Indian Institute of Science, Bengaluru, Karnataka, 560012, India.,Dakshin Foundation, Bengaluru, 560092, India
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15
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Jones HH, Sieving KE. Foraging ecology drives social information reliance in an avian eavesdropping community. Ecol Evol 2019; 9:11584-11597. [PMID: 31695870 PMCID: PMC6822049 DOI: 10.1002/ece3.5561] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2019] [Revised: 06/14/2019] [Accepted: 07/26/2019] [Indexed: 11/06/2022] Open
Abstract
Vertebrates obtain social information about predation risk by eavesdropping on the alarm calls of sympatric species. In the Holarctic, birds in the family Paridae function as sentinel species; however, factors shaping eavesdroppers' reliance on their alarm calls are unknown. We compared three hypothesized drivers of eavesdropper reliance: (a) foraging ecology, (b) degree of sociality, and (c) call relevance (caller-to-eavesdropper body-size difference). In a rigorous causal-comparative design, we presented Tufted Titmouse (Baeolophus bicolor) alarm calls to 242 individuals of 31 ecologically diverse bird species in Florida forests and recorded presence/absence and type (diving for cover or freezing in place) of response. Playback response was near universal, as individuals responded to 87% of presentations (N = 211). As an exception to this trend, the sit-and-wait flycatcher Eastern Phoebe (Sayornis phoebe) represented 48% of the nonresponses. We tested 12 predictor variables representing measures relevant to the three hypothesized drivers, distance to playback speaker, and vulnerability at time of playback (eavesdropper's microhabitat when alarm call is detected). Using model-averaged generalized linear models, we determined that foraging ecology best predicted playback response, with aerial foragers responding less often. Foraging ecology (distance from trunk) and microhabitat occupied during playback (distance to escape cover) best predicted escape behavior type. We encountered a sparsity of sit-and-wait flycatchers (3 spp.), yet their contrasting responses relative to other foraging behaviors clearly identified foraging ecology as a driver of species-specific antipredator escape behavior. Our findings align well with known links between the exceptional visual acuity and other phenotypic traits of flycatchers that allow them to rely more heavily on personal rather than social information while foraging. Our results suggest that foraging ecology drives species-specific antipredator behavior based on the availability and type of escape cover.
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Affiliation(s)
- Harrison H. Jones
- Department of Wildlife Ecology and ConservationUniversity of FloridaGainesvilleFLUSA
- Department of BiologyUniversity of FloridaGainesvilleFLUSA
| | - Kathryn E. Sieving
- Department of Wildlife Ecology and ConservationUniversity of FloridaGainesvilleFLUSA
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16
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Lilly MV, Lucore EC, Tarvin KA. Eavesdropping grey squirrels infer safety from bird chatter. PLoS One 2019; 14:e0221279. [PMID: 31483829 PMCID: PMC6726132 DOI: 10.1371/journal.pone.0221279] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2019] [Accepted: 08/02/2019] [Indexed: 11/19/2022] Open
Abstract
When multiple species are vulnerable to a common set of predators, it is advantageous for individuals to recognize information about the environment provided by other species. Eastern gray squirrels (Sciurus carolinensis) and other small mammals have been shown to exploit heterospecific alarm calls as indicators of danger. However, many species-especially birds-emit non-alarm auditory cues such as contact calls when perceived predator threat is low, and such public information may serve as cues of safety to eavesdroppers. We tested the hypothesis that eavesdropping gray squirrels respond to "bird chatter" (contact calls emitted by multiple individuals when not under threat of predation) as a measure of safety. We compared vigilance behavior of free-ranging squirrels in the presence of playbacks of bird chatter vs non-masking ambient background noise lacking chatter after priming them with a playback recording of a red-tailed hawk (Buteo jamaicensis) call. Squirrels responded to the hawk call playbacks by significantly increasing the proportion of time they spent engaged in vigilance behaviors and the number of times they looked up during otherwise non-vigilance behaviors, indicating that they perceived elevated predation threat prior to the playbacks of chatter or ambient noise. Following the hawk playback, squirrels exposed to the chatter treatment engaged in significantly lower levels of vigilance behavior (i.e., standing, freezing, fleeing, looking up) and the decay in vigilance behaviors was more rapid than in squirrels exposed to the ambient noise treatment, suggesting squirrels use information contained in bird chatter as a cue of safety. These findings suggest that eastern gray squirrels eavesdrop on non-alarm auditory cues as indicators of safety and adjust their vigilance level in accordance with the vigilance level of other species that share the same predators.
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Affiliation(s)
- Marie V. Lilly
- Department of Biology, Oberlin College, Oberlin, Ohio, United States of America
| | - Emma C. Lucore
- Department of Biology, Oberlin College, Oberlin, Ohio, United States of America
| | - Keith A. Tarvin
- Department of Biology, Oberlin College, Oberlin, Ohio, United States of America
- * E-mail:
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17
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Silvestri A, Morgan K, Ridley AR. The association between evidence of a predator threat and responsiveness to alarm calls in Western Australian magpies ( Cracticus tibicen dorsalis). PeerJ 2019; 7:e7572. [PMID: 31523516 PMCID: PMC6714966 DOI: 10.7717/peerj.7572] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Accepted: 07/29/2019] [Indexed: 11/26/2022] Open
Abstract
Alarm calls are a widespread form of antipredator defence and being alerted to the presence of predators by the alarm calls of conspecifics is considered one of the benefits of group living. However, while social information can allow an individual to gain additional information, it can also at times be inaccurate or irrelevant. Such variation in the accuracy of social information is predicted to select for receivers to discriminate between sources of social information. In this study, we used playback experiments to determine whether Western Australian magpies (Cracticus tibicen dorsalis) respond to the predator information associated with alarm calls. Magpies were exposed to the alarm calls of two group members that differed in the threat associated with the alarm call: one call was played in the presence of a predator model while the other was not—in order to establish differences in the predator information provided by each caller. We then played back the alarm calls of the same group members in the absence of the predator model to determine whether magpies responded differently to signallers in response to the previous association between the alarm call and a predator threat. We found that receivers showed significantly greater levels of responsiveness to signallers that previously gave alarm calls in the appropriate context. Thus, the accuracy of threat-based information influenced subsequent receiver response.
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Affiliation(s)
- Annabel Silvestri
- School of Biological Sciences, University of Western Australia, Perth, WA, Australia
| | - Kate Morgan
- School of Biological Sciences, University of Western Australia, Perth, WA, Australia
| | - Amanda R Ridley
- School of Biological Sciences, University of Western Australia, Perth, WA, Australia
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18
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Stofberg M, Cunningham S, Sumasgutner P, Amar A. Juggling a “junk-food” diet: responses of an urban bird to fluctuating anthropogenic-food availability. Urban Ecosyst 2019. [DOI: 10.1007/s11252-019-00885-3] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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19
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Komo L, Scanvion Q, Hedouin V, Charabidze D. Facing death together: heterospecific aggregations of blowfly larvae evince mutual benefits. Behav Ecol 2019. [DOI: 10.1093/beheco/arz059] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
AbstractHeterospecific aggregations and foraging associations have been observed between different species, from apes to birds to insects. Such associations are hypothesized to result in a mutually beneficial relationship entailing benefits that are not apparent in conspecific groupings. Therefore, the objectives of the present study were to investigate 1) how 3 blowfly species, namely, Calliphora vicina, Calliphora vomitoria, and Lucilia sericata, aggregate according to species, and 2) if developmental benefits are linked to heterospecific aggregation. For objective (1), larvae of 2 species were placed between 2 conspecific aggregates, each with a different species (i.e., a binary choice test). After 20 h, the positions of all larvae were determined. On average, 98% of the maggots added later settled together on one of the 2 pre-existing aggregations, demonstrating a collective choice. The aggregation spot with C. vicina was preferred against others, indicating different attractiveness of different species. To relate this behavior to its benefits (objective ii), C. vicina and L. sericata larvae were raised from first instar to adult in con- and heterospecific conditions, and their development time, mortality rates, and morphometrics were measured. Thereby, mutual and asymmetric consequences were observed: specifically, there were significant increases in size and survival for L. sericata and faster development for C. vicina in heterospecific groups. These results indicate that the predilection for heterospecific association leads to mutual developmental benefits. This heterospecific aggregation behavior may be a resource-management strategy of blowflies to face carrion-based selection pressure.
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Affiliation(s)
- Larissa Komo
- CHU Lille, EA 7367 - UTML - Unite de Taphonomie Medico-Legale, University of Lille, Lille, France
| | - Quentin Scanvion
- CHU Lille, EA 7367 - UTML - Unite de Taphonomie Medico-Legale, University of Lille, Lille, France
| | - Valéry Hedouin
- CHU Lille, EA 7367 - UTML - Unite de Taphonomie Medico-Legale, University of Lille, Lille, France
| | - Damien Charabidze
- CHU Lille, EA 7367 - UTML - Unite de Taphonomie Medico-Legale, University of Lille, Lille, France
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20
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Jepsen EM, Ganswindt A, Ngcamphalala CA, Bourne AR, Ridley AR, McKechnie AE. Non-invasive monitoring of physiological stress in an afrotropical arid-zone passerine bird, the southern pied babbler. Gen Comp Endocrinol 2019; 276:60-68. [PMID: 30836104 DOI: 10.1016/j.ygcen.2019.03.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/09/2018] [Revised: 02/01/2019] [Accepted: 03/01/2019] [Indexed: 11/27/2022]
Abstract
Using faecal matter to monitor stress levels in animals non-invasively is a powerful technique for elucidating the effects of biotic and abiotic stressors on free-living animals. To validate the use of droppings for measuring stress in southern pied babblers (Turdoides bicolor) we performed an ACTH challenge on captive individuals and determined the effect of temporary separation from their social group on their faecal glucocorticoid metabolite (fGCM) concentration. Additionally, we compared fGCM concentrations of captive babblers to those of wild conspecifics and examined the effects of dominance rank on fGCM concentration. We found droppings to be a suitable matrix for measuring physiological stress in babblers and that individual separation from the group caused an increase in fGCM levels. In addition, babblers temporarily held in captivity had substantially higher fGCM concentrations than wild individuals, indicating that babblers kept in captivity experience high levels of stress. In wild, free-living individuals, dominant males showed the highest levels of stress, suggesting that being the dominant male of a highly territorial social group is stressful. Non-invasive sampling allows field-based researchers to reduce disturbance related to monitoring adrenocortical function, thereby avoiding artificially increasing circulating corticosterone concentration as it is not necessary to physically restrain study animals.
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Affiliation(s)
- Emma M Jepsen
- South African Research Chair in Conservation Physiology, National Zoological Garden, South African National Biodiversity Institute, Pretoria, South Africa; DST-NRF Centre of Excellence at the FitzPatrick Institute, Department of Zoology and Entomology, University of Pretoria, Private Bag X20, Hatfield 0028, Pretoria, South Africa
| | - André Ganswindt
- Mammal Research Institute, University of Pretoria, Private Bag X20, Hatfield 0028, Pretoria, South Africa
| | - Celiwe A Ngcamphalala
- South African Research Chair in Conservation Physiology, National Zoological Garden, South African National Biodiversity Institute, Pretoria, South Africa; DST-NRF Centre of Excellence at the FitzPatrick Institute, Department of Zoology and Entomology, University of Pretoria, Private Bag X20, Hatfield 0028, Pretoria, South Africa
| | - Amanda R Bourne
- FitzPatrick Institute of African Ornithology, DST-NRF Centre of Excellence, University of Cape Town, Rondebosch, 7701, Cape Town, South Africa
| | - Amanda R Ridley
- FitzPatrick Institute of African Ornithology, DST-NRF Centre of Excellence, University of Cape Town, Rondebosch, 7701, Cape Town, South Africa; Centre for Evolutionary Biology, School of Biological Sciences, University of Western Australia, Crawley, Australia
| | - Andrew E McKechnie
- South African Research Chair in Conservation Physiology, National Zoological Garden, South African National Biodiversity Institute, Pretoria, South Africa; DST-NRF Centre of Excellence at the FitzPatrick Institute, Department of Zoology and Entomology, University of Pretoria, Private Bag X20, Hatfield 0028, Pretoria, South Africa.
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21
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Althouse MA, Cohen JB, Karpanty SM, Spendelow JA, Davis KL, Parsons KC, Luttazi CF. Evaluating response distances to develop buffer zones for staging terns. J Wildl Manage 2019. [DOI: 10.1002/jwmg.21594] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Melissa A. Althouse
- Department of Environmental and Forest BiologyState University of New York College of Environmental Science and Forestry1 Forestry DriveSyracuseNY13210USA
| | - Jonathan B. Cohen
- Department of Environmental and Forest BiologyState University of New York College of Environmental Science and Forestry1 Forestry DriveSyracuseNY13210USA
| | - Sarah M. Karpanty
- Department of Fish and Wildlife ConservationVirginia TechBlacksburgVA24061USA
| | - Jeffrey A. Spendelow
- U.S. Geological Survey Patuxent Wildlife Research Center12100 Beech Forest RoadLaurelMD20708USA
| | - Kayla L. Davis
- Department of Fish and Wildlife ConservationVirginia TechBlacksburgVA24061USA
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22
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Eavesdropping magpies respond to the number of heterospecifics giving alarm calls but not the number of species calling. Anim Behav 2019. [DOI: 10.1016/j.anbehav.2018.12.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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23
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Engesser S, Ridley AR, Manser MB, Manser A, Townsend SW. Internal acoustic structuring in pied babbler recruitment cries specifies the form of recruitment. Behav Ecol 2018. [DOI: 10.1093/beheco/ary088] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Sabrina Engesser
- Animal Behaviour, Department of Evolutionary Biology and Environmental Studies, University of Zurich, Winterthurerstrasse, Zurich, Switzerland
| | - Amanda R Ridley
- Centre for Evolutionary Biology, School of Animal Biology, The University of Western Australia, Stirling Highway, Crawley, Australia
- Percy FitzPatrick Institute, University of Cape Town, University Avenue, Rondebosch, South Africa
| | - Marta B Manser
- Animal Behaviour, Department of Evolutionary Biology and Environmental Studies, University of Zurich, Winterthurerstrasse, Zurich, Switzerland
| | - Andri Manser
- Institute of Integrative Biology, University of Liverpool, Crown Street, Liverpool, UK
| | - Simon W Townsend
- Animal Behaviour, Department of Evolutionary Biology and Environmental Studies, University of Zurich, Winterthurerstrasse, Zurich, Switzerland
- Department of Psychology, University of Warwick, University Road, Coventry, UK
- Comparative Communication and Cognition Group, Department of Comparative Linguistics, University of Zurich, Plattenstrasse, Zurich, Switzerland
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24
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Nelson-Flower MJ, Flower TP, Ridley AR. Sex differences in the drivers of reproductive skew in a cooperative breeder. Mol Ecol 2018; 27:2435-2446. [PMID: 29663552 DOI: 10.1111/mec.14587] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Revised: 03/25/2018] [Accepted: 03/26/2018] [Indexed: 01/08/2023]
Abstract
Many cooperatively breeding societies are characterized by high reproductive skew, such that some socially dominant individuals breed, while socially subordinate individuals provide help. Inbreeding avoidance serves as a source of reproductive skew in many high-skew societies, but few empirical studies have examined sources of skew operating alongside inbreeding avoidance or compared individual attempts to reproduce (reproductive competition) with individual reproductive success. Here, we use long-term genetic and observational data to examine factors affecting reproductive skew in the high-skew cooperatively breeding southern pied babbler (Turdoides bicolor). When subordinates can breed, skew remains high, suggesting factors additional to inbreeding avoidance drive skew. Subordinate females are more likely to compete to breed when older or when ecological constraints on dispersal are high, but heavy subordinate females are more likely to successfully breed. Subordinate males are more likely to compete when they are older, during high ecological constraints, or when they are related to the dominant male, but only the presence of within-group unrelated subordinate females predicts subordinate male breeding success. Reproductive skew is not driven by reproductive effort, but by forces such as intrinsic physical limitations and intrasexual conflict (for females) or female mate choice, male mate-guarding and potentially reproductive restraint (for males). Ecological conditions or "outside options" affect the occurrence of reproductive conflict, supporting predictions of recent synthetic skew models. Inbreeding avoidance together with competition for access to reproduction may generate high skew in animal societies, and disparate processes may be operating to maintain male vs. female reproductive skew in the same species.
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Affiliation(s)
- Martha J Nelson-Flower
- Department of Forest and Conservation Sciences, University of British Columbia, Vancouver, BC, Canada
| | - Tom P Flower
- Department of Biology, Capilano University, North Vancouver, BC, Canada.,Percy FitzPatrick Institute of African Ornithology, DST NRF Centre of Excellence, University of Cape Town, Rondebosch, South Africa
| | - Amanda R Ridley
- Percy FitzPatrick Institute of African Ornithology, DST NRF Centre of Excellence, University of Cape Town, Rondebosch, South Africa.,Centre for Evolutionary Biology, University of Western Australia, Crawley, WA, Australia
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25
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Nelson-Flower MJ, Wiley EM, Flower TP, Ridley AR. Individual dispersal delays in a cooperative breeder: Ecological constraints, the benefits of philopatry and the social queue for dominance. J Anim Ecol 2018; 87:1227-1238. [PMID: 29560614 DOI: 10.1111/1365-2656.12814] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Accepted: 01/31/2018] [Indexed: 11/27/2022]
Abstract
Delayed dispersal is a key step in the evolution of familial animal societies and cooperative breeding. However, no consensus has been reached on the ecological and social circumstances driving delayed dispersal. Here, we test predictions from the ecological constraints and benefits of philopatry hypotheses as well as the recently proposed dual benefits hypothesis to better understand the evolution of group-living and cooperative breeding. Furthermore, we consider how individual social circumstances within groups affect dispersal decisions. We examine 11 years of life-history information on a wild population of cooperatively breeding southern pied babblers Turdoides bicolor. We investigate the effects of ecological conditions, natal-group membership and individual social context on male and female dispersal delays, disperser survival and acquisition of dominance. Female dispersal decisions are generally unconstrained by ecological or social circumstances. In contrast, males disperse in response to relaxed ecological constraints, decreases in nepotistic tolerance or when low social rank in the queue for dominance decreases their likelihood of gaining a dominant breeding position. Early dispersal by end-of-queue males often leads to a head-of-queue subordinate position in a non-natal group, thereby increasing access to dominant breeding positions. However, males and females remaining in natal groups gain benefits of philopatry via increased survival and, for head-of-queue males, very high likelihood of acquisition of a breeding position. Overall, predictions from the dual benefits hypothesis best describe these results, while some predictions from each of the ecological constraints and benefits of philopatry hypotheses were supported. The benefits of living and working together (collective action benefits) in large stable groups are of central importance in shaping dispersal delays in southern pied babbler societies. In addition, position in the subordinate social queue for dominance is the key in determining access to reproduction, particularly for males. This research highlights the importance of considering the costs and benefits of individual social circumstances in dispersal decisions and illustrates how the dual benefits hypothesis offers new perspectives in understanding delayed dispersal.
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Affiliation(s)
- Martha J Nelson-Flower
- Department of Forest and Conservation Sciences, University of British Columbia, Vancouver, BC, Canada
| | - Elizabeth M Wiley
- Centre of Evolutionary Biology, School of Animal Biology, University of Western Australia, Crawley, WA, Australia
| | - Tom P Flower
- Department of Biology, Capilano University, North Vancouver, BC, Canada.,Centre for Wildlife Ecology, Simon Fraser University, Burnaby, BC, Canada.,Percy FitzPatrick Institute of African Ornithology, DST NRF Centre of Excellence, University of Cape Town, Rondebosch, South Africa
| | - Amanda R Ridley
- Centre of Evolutionary Biology, School of Animal Biology, University of Western Australia, Crawley, WA, Australia.,Percy FitzPatrick Institute of African Ornithology, DST NRF Centre of Excellence, University of Cape Town, Rondebosch, South Africa
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26
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Eavesdropping in an African large mammal community: antipredator responses vary according to signaller reliability. Anim Behav 2018. [DOI: 10.1016/j.anbehav.2017.12.018] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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27
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McQueen A, Naimo AC, Teunissen N, Magrath RD, Delhey K, Peters A. Bright birds are cautious: seasonally conspicuous plumage prompts risk avoidance by male superb fairy-wrens. Proc Biol Sci 2017; 284:rspb.2017.0446. [PMID: 28659448 DOI: 10.1098/rspb.2017.0446] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Accepted: 05/30/2017] [Indexed: 11/12/2022] Open
Abstract
Increased predation risk is considered a cost of having conspicuous colours, affecting the anti-predator behaviour of colourful animals. However, this is difficult to test, as individual factors often covary with colour and behaviour. We used alarm call playback and behavioural observations to assess whether individual birds adjust their response to risk according to their plumage colour. Male superb fairy-wrens (Malurus cyaneus) change from a dull brown to conspicuous blue plumage each year, allowing the behaviour of different coloured birds to be compared while controlling for within-individual effects. Because the timing of colour change varies among males, blue and brown birds can also be compared at the same time of year, controlling for seasonal effects on behaviour. While blue, fairy-wrens fled more often in response to alarm calls, and took longer to emerge from cover. Blue fairy-wrens also spent more time foraging in cover and being vigilant. Group members appeared to benefit from the presence of blue males, as they reduced their response to alarms, and allocated less time to sentinel behaviour when a blue male was close by. We suggest that fairy-wrens perceive themselves to be at a higher risk of predation while in conspicuous plumage and adjust their behaviour accordingly.
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Affiliation(s)
- Alexandra McQueen
- School of Biological Sciences, Monash University, Clayton Campus, Clayton, Victoria 3800, Australia
| | - Annalise C Naimo
- School of Biological Sciences, Monash University, Clayton Campus, Clayton, Victoria 3800, Australia
| | - Niki Teunissen
- School of Biological Sciences, Monash University, Clayton Campus, Clayton, Victoria 3800, Australia
| | - Robert D Magrath
- Division of Ecology and Evolution, Research School of Biology, Australian National University, Canberra 2601, Australia
| | - Kaspar Delhey
- School of Biological Sciences, Monash University, Clayton Campus, Clayton, Victoria 3800, Australia
| | - Anne Peters
- School of Biological Sciences, Monash University, Clayton Campus, Clayton, Victoria 3800, Australia
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28
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Humphries DJ, Finch FM, Bell MBV, Ridley AR. Vocal Cues to Identity: Pied Babblers Produce Individually Distinct But Not Stable Loud Calls. Ethology 2016. [DOI: 10.1111/eth.12508] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- David J. Humphries
- Department of Biological Sciences; Macquarie University; Sydney NSW Australia
- Pied Babbler Research Project, Kuruman River Reserve; Van Zylsrus South Africa
| | - Fiona M. Finch
- Pied Babbler Research Project, Kuruman River Reserve; Van Zylsrus South Africa
| | - Matthew B. V. Bell
- Pied Babbler Research Project, Kuruman River Reserve; Van Zylsrus South Africa
- Institute of Evolutionary Biology; School of Biological Sciences; University of Edinburgh; Edinburgh UK
| | - Amanda R. Ridley
- Department of Biological Sciences; Macquarie University; Sydney NSW Australia
- Pied Babbler Research Project, Kuruman River Reserve; Van Zylsrus South Africa
- DST/NRF Centre of Excellence at the Percy FitzPatrick Institute; University of Cape Town; Cape Town Western Cape South Africa
- Centre for Evolutionary Biology; School of Animal Biology; University of Western Australia; Perth WA Australia
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29
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Mirville MO, Kelley JL, Ridley AR. Group size and associative learning in the Australian magpie (Cracticus tibicen dorsalis). Behav Ecol Sociobiol 2016. [DOI: 10.1007/s00265-016-2062-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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30
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Baigrie BD, Thompson AM, Flower TP. Interspecific signalling between mutualists: food-thieving drongos use a cooperative sentinel call to manipulate foraging partners. Proc Biol Sci 2015; 281:20141232. [PMID: 25080343 DOI: 10.1098/rspb.2014.1232] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Interspecific communication is common in nature, particularly between mutualists. However, whether signals evolved for communication with other species, or are in fact conspecific signals eavesdropped upon by partners, is often unclear. Fork-tailed drongos (Dicrurus adsimilis) associate with mixed-species groups and often produce true alarms at predators, whereupon associating species flee to cover, but also false alarms to steal associating species' food (kleptoparasitism). Despite such deception, associating species respond to drongo non-alarm calls by increasing their foraging and decreasing vigilance. Yet, whether these calls represent interspecific sentinel signals remains unknown. We show that drongos produced a specific sentinel call when foraging with a common associate, the sociable weaver (Philetairus socius), but not when alone. Weavers increased their foraging and decreased vigilance when naturally associating with drongos, and in response to sentinel call playback. Further, drongos sentinel-called more often when weavers were moving, and weavers approached sentinel calls, suggesting a recruitment function. Finally, drongos sentinel-called when weavers fled following false alarms, thereby reducing disruption to weaver foraging time. Results therefore provide evidence of an 'all clear' signal that mitigates the cost of inaccurate communication. Our results suggest that drongos enhance exploitation of a foraging mutualist through coevolution of interspecific sentinel signals.
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Affiliation(s)
- Bruce D Baigrie
- DST/NRF Centre of Excellence, Percy FitzPatrick Institute, University of Cape Town, Rondebosch 7701, South Africa
| | - Alex M Thompson
- DST/NRF Centre of Excellence, Percy FitzPatrick Institute, University of Cape Town, Rondebosch 7701, South Africa
| | - Tom P Flower
- DST/NRF Centre of Excellence, Percy FitzPatrick Institute, University of Cape Town, Rondebosch 7701, South Africa
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31
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Humphries DJ, Finch FM, Bell MBV, Ridley AR. Calling Where It Counts: Subordinate Pied Babblers Target the Audience of Their Vocal Advertisements. PLoS One 2015; 10:e0130795. [PMID: 26177094 PMCID: PMC4503734 DOI: 10.1371/journal.pone.0130795] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Accepted: 05/26/2015] [Indexed: 12/01/2022] Open
Abstract
For territorial group-living species, opportunities to reproduce on the natal territory can be limited by a number of factors including the availability of resources within a territory, access to unrelated individuals, and monopolies on reproduction by dominant group members. Individuals looking to reproduce are therefore faced with the options of either waiting for a breeding opportunity to arise in the natal territory, or searching for reproductive opportunities in non-natal groups. In the cooperatively breeding Southern pied babbler, Turdoides bicolor, most individuals who achieve reproductive success do so through taking up dominant breeding positions within non-natal groups. For subordinate pied babblers therefore, searching for breeding opportunities in non-natal groups is of primary importance as this represents the major route to reproductive success. However, prospecting (where individuals leave the group to search for reproductive opportunities within other groups) is costly and individuals rapidly lose weight when not part of a group. Here we demonstrate that subordinate pied babblers adopt an alternative strategy for mate attraction by vocal advertisement from within their natal territories. We show that subordinates focus their calling efforts on the edges of their territory, and specifically near boundaries with neighbouring groups that have potential breeding partners (unrelated individuals of the opposite sex). In contrast to prospecting, calling individuals showed no body mass loss associated with this behaviour, suggesting that calling from within the group may provide a ‘cheap’ advertisement strategy. Additionally, we show that subordinates use information regarding the composition of neighbouring groups to target the greatest number of potential mating partners.
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Affiliation(s)
- David J. Humphries
- Department of Biological Sciences, Macquarie University, Sydney, NSW, Australia
- Pied Babbler Research Project, Kuruman River Reserve, Van Zylsrus, South Africa
- * E-mail:
| | - Fiona M. Finch
- Pied Babbler Research Project, Kuruman River Reserve, Van Zylsrus, South Africa
| | - Matthew B. V. Bell
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, EH9 3JT, United Kingdom
- Pied Babbler Research Project, Kuruman River Reserve, Van Zylsrus, South Africa
| | - Amanda R. Ridley
- Department of Biological Sciences, Macquarie University, Sydney, NSW, Australia
- DST/NRF Centre of Excellence at the Percy FitzPatrick Institute, University of Cape Town, Cape Town, Western Cape, South Africa
- Pied Babbler Research Project, Kuruman River Reserve, Van Zylsrus, South Africa
- Centre for Evolutionary Biology, School of Animal Biology, University of Western Australia, Perth, WA, Australia
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Slow development of foraging skills and parental costs of family-living in a semi-precocial, non-cooperatively breeding bird. Behav Ecol Sociobiol 2015. [DOI: 10.1007/s00265-015-1943-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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33
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Westrip JRS, Bell MBV. Breaking down the Species Boundaries: Selective Pressures behind Interspecific Communication in Vertebrates. Ethology 2015. [DOI: 10.1111/eth.12379] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- James R. S. Westrip
- Institute of Evolutionary Biology; School of Biological Sciences; University of Edinburgh; Ashworth Laboratories; Edinburgh UK
| | - Matthew B. V. Bell
- Institute of Evolutionary Biology; School of Biological Sciences; University of Edinburgh; Ashworth Laboratories; Edinburgh UK
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34
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Bednekoff PA. Sentinel Behavior: A Review and Prospectus. ADVANCES IN THE STUDY OF BEHAVIOR 2015. [DOI: 10.1016/bs.asb.2015.02.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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35
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Kern JM, Radford AN. Sentinel dwarf mongooses, Helogale parvula, exhibit flexible decision making in relation to predation risk. Anim Behav 2014. [DOI: 10.1016/j.anbehav.2014.10.012] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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36
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Abstract
Deception is common in nature, but victims of deception discriminate against and ultimately ignore deceptive signals when they are produced too frequently. Flexible variation of signals could allow evasion of such constraints. Fork-tailed drongos (Dicrurus adsimilis) use false alarm calls to scare other species away from food that they then steal. We show that drongos mimic the alarms of targeted species. Further, target species reduce their response to false alarm calls when they are repeated. However, the fear response is maintained when the call is varied. Drongos exploit this propensity by changing their alarm-call type when making repeated theft attempts on a particular species. Our results show that drongos can evade the frequency-dependent constraints that typically limit deception payoffs through flexible variation of their alarm calls.
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Affiliation(s)
- Tom P Flower
- Department of Science and Technology/National Research Foundation Centre of Excellence at the Percy FitzPatrick Institute, University of Cape Town, Rondebosch 7701, South Africa
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37
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Magrath RD, Haff TM, Fallow PM, Radford AN. Eavesdropping on heterospecific alarm calls: from mechanisms to consequences. Biol Rev Camb Philos Soc 2014; 90:560-86. [PMID: 24917385 DOI: 10.1111/brv.12122] [Citation(s) in RCA: 211] [Impact Index Per Article: 21.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Revised: 05/05/2014] [Accepted: 05/13/2014] [Indexed: 11/28/2022]
Abstract
Animals often gather information from other species by eavesdropping on signals intended for others. We review the extent, benefits, mechanisms, and ecological and evolutionary consequences of eavesdropping on other species' alarm calls. Eavesdropping has been shown experimentally in about 70 vertebrate species, and can entail closely or distantly related species. The benefits of eavesdropping include prompting immediate anti-predator responses, indirect enhancement of foraging or changed habitat use, and learning about predators. Eavesdropping on heterospecifics can provide more eyes looking for danger, complementary information to that from conspecifics, and potentially information at reduced cost. The response to heterospecific calls can be unlearned or learned. Unlearned responses occur when heterospecific calls have acoustic features similar to that used to recognize conspecific calls, or acoustic properties such as harsh sounds that prompt attention and may allow recognition or facilitate learning. Learning to recognize heterospecific alarm calls is probably essential to allow recognition of the diversity of alarm calls, but the evidence is largely indirect. The value of eavesdropping on different species is affected by problems of signal interception and the relevance of heterospecific alarm calls to the listener. These constraints on eavesdropping will affect how information flows among species and thus affect community function. Some species are 'keystone' information producers, while others largely seek information, and these differences probably affect the formation and function of mixed-species groups. Eavesdroppers might also integrate alarm calls from multiple species to extract relevant and reliable information. Eavesdropping appears to set the stage for the evolution of interspecific deception and communication, and potentially affects communication within species. Overall, we now know that eavesdropping on heterospecific alarm calls is an important source of information for many species across the globe, and there are ample opportunities for research on mechanisms, fitness consequences and implications for community function and signalling evolution.
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Affiliation(s)
- Robert D Magrath
- Division of Evolution, Ecology & Genetics, Research School of Biology, Australian National University, Canberra 0200, Australia
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38
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Golubski AJ, O'Connell NS, Schwartz JA, Ellermeyer SF. A 'crying wolf' game of interspecific kleptoparasitic mutualism. Biol Lett 2014; 10:20140073. [PMID: 24621556 DOI: 10.1098/rsbl.2014.0073] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
We model a potentially mutualistic interaction between a species making antipredator alarm calls and a species which eavesdrops on those calls. Callers may or may not make deceptive alarm calls in order to kleptoparasitize food from eavesdroppers, which in turn may either heed or ignore all alarm calls. The two most likely outcomes in our model are either maximally deceptive callers and maximally trusting eavesdroppers, or persistently cycling strategy frequencies. The latter is favoured by low predator density, low density of any alternative honest alarm-calling species, ability of eavesdroppers to preferentially heed calls when costs of doing so are low and, in some cases, low food availability.
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Affiliation(s)
- Antonio J Golubski
- Department of Biology and Physics, Kennesaw State University, , 1000 Chastain Road, Kennesaw, GA 30144, USA
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39
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Ghoul M, Griffin AS, West SA. Toward an evolutionary definition of cheating. Evolution 2013; 68:318-31. [PMID: 24131102 DOI: 10.1111/evo.12266] [Citation(s) in RCA: 117] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2013] [Accepted: 08/27/2013] [Indexed: 12/17/2022]
Abstract
The term "cheating" is used in the evolutionary and ecological literature to describe a wide range of exploitative or deceitful traits. Although many find this a useful short hand, others have suggested that it implies cognitive intent in a misleading way, and is used inconsistently. We provide a formal justification of the use of the term "cheat" from the perspective of an individual as a maximizing agent. We provide a definition for cheating that can be applied widely, and show that cheats can be broadly classified on the basis of four distinctions: (i) whether cooperation is an option; (ii) whether deception is involved; (iii) whether members of the same or different species are cheated; and (iv) whether the cheat is facultative or obligate. Our formal definition and classification provide a framework that allow us to resolve and clarify a number of issues, regarding the detection and evolutionary consequences of cheating, as well as illuminating common principles and similarities in the underlying selection pressures.
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Affiliation(s)
- Melanie Ghoul
- Department of Zoology, Oxford University, Oxford, OX1 3PS, United Kingdom.
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40
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Thompson AM, Ridley AR, Hockey PA, Finch FM, Britton A, Raihani NJ. The influence of siblings on begging behaviour. Anim Behav 2013. [DOI: 10.1016/j.anbehav.2013.07.021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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41
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Zaccaroni M, Binazzi R, Massolo A, Dessì-Fulgheri F. Audience effect on aerial alarm calls in the monogamous red-legged partridge. ETHOL ECOL EVOL 2013. [DOI: 10.1080/03949370.2013.798352] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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42
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Using intra-flock association patterns to understand why birds participate in mixed-species foraging flocks in terrestrial habitats. Behav Ecol Sociobiol 2013. [DOI: 10.1007/s00265-013-1633-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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43
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Affiliation(s)
- Amanda R. Ridley
- Percy FitzPatrick Institute of African Ornithology; University of Cape Town; Rondebosch 7701 South Africa
- School of Animal Biology; University of Western Australia; Perth 6009 Western Australia Australia
| | - Elizabeth M. Wiley
- Percy FitzPatrick Institute of African Ornithology; University of Cape Town; Rondebosch 7701 South Africa
- School of Animal Biology; University of Western Australia; Perth 6009 Western Australia Australia
| | - Alex M. Thompson
- Percy FitzPatrick Institute of African Ornithology; University of Cape Town; Rondebosch 7701 South Africa
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44
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Nelson-Flower MJ, Hockey PAR, O'Ryan C, English S, Thompson AM, Bradley K, Rose R, Ridley AR. Costly reproductive competition between females in a monogamous cooperatively breeding bird. Proc Biol Sci 2013; 280:20130728. [PMID: 23677348 DOI: 10.1098/rspb.2013.0728] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
In many cooperatively breeding societies, only a few socially dominant individuals in a group breed, reproductive skew is high, and reproductive conflict is common. Surprisingly, the effects of this conflict on dominant reproductive success in vertebrate societies have rarely been investigated, especially in high-skew societies. We examine how subordinate female competition for breeding opportunities affects the reproductive success of dominant females in a monogamous cooperatively breeding bird, the Southern pied babbler (Turdoides bicolor). In this species, successful subordinate reproduction is very rare, despite the fact that groups commonly contain sexually mature female subordinates that could mate with unrelated group males. However, we show that subordinate females compete with dominant females to breed, and do so far more often than expected, based on the infrequency of their success. Attempts by subordinates to obtain a share of breeding impose significant costs on dominant females: chicks fledge from fewer nests, more nests are abandoned before incubation begins, and more eggs are lost. Dominant females appear to attempt to reduce these costs by aggressively suppressing potentially competitive subordinate females. This empirical evidence provides rare insight into the nature of the conflicts between females and the resultant costs to reproductive success in cooperatively breeding societies.
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Affiliation(s)
- Martha J Nelson-Flower
- Percy FitzPatrick Institute of African Ornithology, DST/NRF Centre of Excellence, University of Cape Town, Rondebosch 7701, South Africa.
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45
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Call of duty? Variation in use of the watchman's song by sentinel dwarf mongooses, Helogale parvula. Anim Behav 2013. [DOI: 10.1016/j.anbehav.2013.02.020] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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46
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Thompson AM, Raihani NJ, Hockey PAR, Britton A, Finch FM, Ridley AR. The influence of fledgling location on adult provisioning: a test of the blackmail hypothesis. Proc Biol Sci 2013; 280:20130558. [PMID: 23576792 DOI: 10.1098/rspb.2013.0558] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
One theory to explain the existence of conspicuous solicitation is that it is a way for young to 'blackmail' carers into provisioning them, by threatening their own destruction. Fledgling birds offer a unique opportunity to investigate the 'blackmail theory', as their mobility enables them to influence the predation risk they face. We investigated a novel solicitation behaviour in fledgling pied babblers (Turdoides bicolor), where fledglings use their location to influence provisioning rates. We show that fledglings face a trade-off: the ground is a much more profitable location in terms of provisioning rate from adult carers, but they are at greater risk from predators owing to their limited flying ability and slow response to alarm calls. Young babbler fledglings move to the ground when hungry, signalling their state, and this stimulates adults to increase their provisioning rates. Once satiated, fledglings return to the safety of cover. By experimentally increasing terrestrial predation risk, we found that adults increased their provisioning rate to terrestrial but not arboreal fledglings. Thus, by moving to a riskier location, fledglings revealed their need and were able to manipulate adults to achieve higher provisioning rates. These results provide support for the 'blackmail theory'.
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Affiliation(s)
- A M Thompson
- Percy FitzPatrick Institute of African Ornithology, University of Cape Town, Western Cape, South Africa.
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47
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Ridley AR, Nelson-Flower MJ, Thompson AM. Is sentinel behaviour safe? An experimental investigation. Anim Behav 2013. [DOI: 10.1016/j.anbehav.2012.10.017] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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48
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Do fledglings choose wisely? An experimental investigation into social foraging behaviour. Behav Ecol Sociobiol 2012. [DOI: 10.1007/s00265-012-1426-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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49
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du Plessis KL, Martin RO, Hockey PAR, Cunningham SJ, Ridley AR. The costs of keeping cool in a warming world: implications of high temperatures for foraging, thermoregulation and body condition of an arid-zone bird. GLOBAL CHANGE BIOLOGY 2012; 18:3063-3070. [PMID: 28741828 DOI: 10.1111/j.1365-2486.2012.02778.x] [Citation(s) in RCA: 166] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2012] [Accepted: 06/11/2012] [Indexed: 05/21/2023]
Abstract
Recent mass mortalities of bats, birds and even humans highlight the substantial threats that rising global temperatures pose for endotherms. Although less dramatic, sublethal fitness costs of high temperatures may be considerable and result in changing population demographics. Endothermic animals exposed to high environmental temperatures can adjust their behaviour (e.g. reducing activity) or physiology (e.g. elevating rates of evaporative water loss) to maintain body temperatures within tolerable limits. The fitness consequences of these adjustments, in terms of the ability to balance water and energy budgets and therefore maintain body condition, are poorly known. We investigated the effects of daily maximum temperature on foraging and thermoregulatory behaviour as well as maintenance of body condition in a wild, habituated population of Southern Pied Babblers Turdoides bicolor. These birds inhabit a hot, arid area of southern Africa where they commonly experience environmental temperatures exceeding optimal body temperatures. Repeated measurements of individual behaviour and body mass were taken across days varying in maximum air temperature. Contrary to expectations, foraging effort was unaffected by daily maximum temperature. Foraging efficiency, however, was lower on hotter days and this was reflected in a drop in body mass on hotter days. When maximum air temperatures exceeded 35.5 °C, individuals no longer gained sufficient weight to counter typical overnight weight loss. This reduction in foraging efficiency is likely driven, in part, by a trade-off with the need to engage in heat-dissipation behaviours. When we controlled for temperature, individuals that actively dissipated heat while continuing to forage experienced a dramatic decrease in their foraging efficiency. This study demonstrates the value of investigations of temperature-dependent behaviour in the context of impacts on body condition, and suggests that increasingly high temperatures will have negative implications for the fitness of these arid-zone birds.
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Affiliation(s)
- Katherine L du Plessis
- Percy FitzPatrick Institute of African Ornithology, DST/NRF Centre of Excellence, University of Cape Town, Rondebosch, 7701, Cape Town, South Africa
| | - Rowan O Martin
- Percy FitzPatrick Institute of African Ornithology, DST/NRF Centre of Excellence, University of Cape Town, Rondebosch, 7701, Cape Town, South Africa
| | - Philip A R Hockey
- Percy FitzPatrick Institute of African Ornithology, DST/NRF Centre of Excellence, University of Cape Town, Rondebosch, 7701, Cape Town, South Africa
| | - Susan J Cunningham
- Percy FitzPatrick Institute of African Ornithology, DST/NRF Centre of Excellence, University of Cape Town, Rondebosch, 7701, Cape Town, South Africa
| | - Amanda R Ridley
- Percy FitzPatrick Institute of African Ornithology, DST/NRF Centre of Excellence, University of Cape Town, Rondebosch, 7701, Cape Town, South Africa
- Department of Biological Sciences, Macquarie University, Marsfield, 2122, Sydney, NSW, Australia
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50
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Child MF, Flower TP, Ridley AR. Investigating a link between bill morphology, foraging ecology and kleptoparasitic behaviour in the fork-tailed drongo. Anim Behav 2012. [DOI: 10.1016/j.anbehav.2012.07.027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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