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Culbert BM, Barnett JB, Ligocki IY, Salena MG, Wong MYL, Hamilton IM, Balshine S. Colorful facial markings are associated with foraging rates and affiliative relationships in a wild group-living cichlid fish. Curr Zool 2024; 70:70-78. [PMID: 38476131 PMCID: PMC10926260 DOI: 10.1093/cz/zoac100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Accepted: 12/11/2022] [Indexed: 03/14/2024] Open
Abstract
Many animals use color to signal their quality and/or behavioral motivations. Colorful signals have been well studied in the contexts of competition and mate choice; however, the role of these signals in nonsexual, affiliative relationships is not as well understood. Here, we used wild social groups of the cichlid fish Neolamprologus pulcher to investigate whether the size of a brightly colored facial patch was related to 1) individual quality, 2) social dominance, and/or 3) affiliative relationships. Individuals with larger patches spent more time foraging and tended to perform more aggressive acts against conspecific territory intruders. We did not find any evidence that the size of these yellow patches was related to social rank or body size, but dominant males tended to have larger patches than dominant females. Additionally, patch size had a rank-specific relationship with the number of affiliative interactions that individuals engaged in. Dominant males with large patches received fewer affiliative acts from their groupmates compared to dominant males with small patches. However, subordinates with large patches tended to receive more affiliative acts from their groupmates while performing fewer affiliative acts themselves. Taken together, our results suggest that patch size reflects interindividual variation in foraging effort in this cichlid fish and offer some of the first evidence that colorful signals may shape affiliative relationships within wild social groups.
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Affiliation(s)
- Brett M Culbert
- Department of Integrative Biology, University of Guelph, Guelph, Ontario, Canada
| | - James B Barnett
- Department of Psychology, Neuroscience & Behaviour, McMaster University, Hamilton, Ontario, Canada
| | - Isaac Y Ligocki
- Department of Evolution, Ecology, and Organismal Biology, The Ohio State University, Columbus, OH, USA
- Department of Biology, Millersville University, Millersville, PA, USA
| | - Matthew G Salena
- Department of Psychology, Neuroscience & Behaviour, McMaster University, Hamilton, Ontario, Canada
| | - Marian Y L Wong
- School of Earth, Atmospheric and Life Sciences, University of Wollongong, Wollongong, New South Wales, Australia
| | - Ian M Hamilton
- Department of Evolution, Ecology, and Organismal Biology, The Ohio State University, Columbus, OH, USA
- Department of Mathematics, The Ohio State University, Columbus, OH, USA
| | - Sigal Balshine
- Department of Psychology, Neuroscience & Behaviour, McMaster University, Hamilton, Ontario, Canada
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2
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Josi D, Taborsky M, Frommen JG. Investment of group members is contingent on helper number and the presence of young in a cooperative breeder. Anim Behav 2020. [DOI: 10.1016/j.anbehav.2019.11.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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3
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Braga Goncalves I, Radford AN. Experimental evidence that intruder and group member attributes affect outgroup defence and associated within-group interactions in a social fish. Proc Biol Sci 2019; 286:20191261. [PMID: 31594516 PMCID: PMC6790772 DOI: 10.1098/rspb.2019.1261] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
In many social species, individuals communally defend resources from conspecific outsiders. Participation in defence and in associated within-group interactions, both during and after contests with outgroup rivals, is expected to vary between group members because the threat presented by different outsiders is not the same to each individual. However, experimental tests examining both the contributions to, and the consequences of, outgroup conflict for all group members are lacking. Using groups of the cichlid Neolamprologus pulcher, we simulated territorial intrusions by different-sized female rivals and altered the potential contribution of subordinate females to defence. Dominant females and subordinate females defended significantly more against size- and rank-matched intruders, while males displayed lower and less variable levels of defence. Large and small, but not intermediate-sized, intruders induced increased levels of within-group aggression during intrusions, which was targeted at the subordinate females. Preventing subordinate females from helping in territorial defence led to significant decreases in post-contest within-group and female-specific submissive and affiliative displays. Together, these results show that the defensive contributions of group members vary greatly depending both on their own traits and on intruder identity, and this variation has significant consequences for within-group social dynamics both during and in the aftermath of outgroup contests.
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Affiliation(s)
- Ines Braga Goncalves
- School of Biological Sciences/Life Sciences, University of Bristol, 24 Tyndall Avenue, Bristol BS8 1TQ, UK
| | - Andrew N Radford
- School of Biological Sciences/Life Sciences, University of Bristol, 24 Tyndall Avenue, Bristol BS8 1TQ, UK
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4
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Hellmann JK, Ligocki IY, O'Connor CM, Reddon AR, Garvy KA, Marsh-Rollo SE, Gibbs HL, Balshine S, Hamilton IM. Reproductive sharing in relation to group and colony-level attributes in a cooperative breeding fish. Proc Biol Sci 2016; 282:rspb.2015.0954. [PMID: 26136450 DOI: 10.1098/rspb.2015.0954] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
The degree to which group members share reproduction is dictated by both within-group (e.g. group size and composition) and between-group(e.g. density and position of neighbours) characteristics. While many studies have investigated reproductive patterns within social groups, few have simultaneously explored how within-group and between-group social structure influence these patterns. Here, we investigated how group size and composition, along with territory density and location within the colony, influenced parentage in 36 wild groups of a colonial, cooperatively breeding fish Neolamprologus pulcher. Dominant males sired 76% of offspring in their group, whereas dominant females mothered 82% of offspring in their group. Subordinate reproduction was frequent, occurring in 47% of sampled groups. Subordinate males gained more paternity in groups located in high-density areas and in groups with many subordinate males. Dominant males and females in large groups and in groups with many reproductively mature subordinates had higher rates of parentage loss, but only at the colony edge. Our study provides, to our knowledge,the first comprehensive quantification of reproductive sharing among groups of wild N. pulcher, a model species for the study of cooperation and social behaviour. Further, we demonstrate that the frequency of extra-pair parentage differs across small social and spatial scales.
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Ligocki IY, Earley RL, Hellmann JK, Hamilton IM. Variation in glucocorticoid levels in relation to direct and third-party interactions in a social cichlid fish. Physiol Behav 2015; 151:386-94. [PMID: 26255122 DOI: 10.1016/j.physbeh.2015.08.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2014] [Revised: 07/30/2015] [Accepted: 08/01/2015] [Indexed: 11/30/2022]
Abstract
In complex animal societies, direct interactions between group members can influence the behavior and glucocorticoid levels of individuals involved. Recently, it has become apparent that third-party group members can influence dyadic interactions, and vice versa. Thus, glucocorticoid levels may vary depending on interactions of other members of the social group. Using the social cichlid fish Neolamprologus pulcher, we examined the relationship between levels of the glucocorticoid hormone cortisol in subordinate females and 1) direct interactions with dominant group members, as well as 2) dyadic interactions between the dominant male and female, in which the subordinate female was not directly involved. Subordinate females that frequently engaged in non-aggressive interactions with dominant females had lower cortisol levels. There was no relationship between subordinate female cortisol and agonistic interactions between the subordinate female and either dominant. Subordinate females had higher cortisol levels when in groups in which the dominant breeding pair behaved agonistically towards each other and performed fewer courtship behaviors. For subordinate females in this species, variation in cortisol levels is associated with their own affiliative behavior, but also can be explained by the broader social context of interactions between dominant members of the group.
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Affiliation(s)
- Isaac Y Ligocki
- Department of Evolution, Ecology, and Organismal Biology, The Ohio State University, Columbus, OH, USA.
| | - Ryan L Earley
- Department of Biological Sciences, University of Alabama, Tuscaloosa, AL, USA
| | - Jennifer K Hellmann
- Department of Evolution, Ecology, and Organismal Biology, The Ohio State University, Columbus, OH, USA
| | - Ian M Hamilton
- Department of Evolution, Ecology, and Organismal Biology, The Ohio State University, Columbus, OH, USA; Department of Mathematics, The Ohio State University, Columbus, OH, USA
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6
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Schaedelin FC, van Dongen WFD, Wagner RH. Mate choice and genetic monogamy in a biparental, colonial fish. Behav Ecol 2015; 26:782-788. [PMID: 26023276 PMCID: PMC4433329 DOI: 10.1093/beheco/arv011] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2014] [Revised: 01/05/2015] [Accepted: 01/17/2015] [Indexed: 11/22/2022] Open
Abstract
We report a rare case of genetic monogamy in a biparental fish species. Males and females paired assortatively by size, which is compatible with mutual mate choice. Mate choice in monogamous species is interesting because both sexes provide essential parental care, making males, as well as females, choosy. Social monogamy in the form of biparental care is well known from a variety of species, but uncommon in fish. In socially monogamous species, in which both sexes provide essential parental care, males as well as females are expected to be choosy. Whereas hundreds of studies have examined monogamy in biparental birds, only several such studies exist in fish. We examined mate choice in the biparental, colonial cichlid fish Neolamprologus caudopunctatus in Lake Tanganyika, Zambia. We genotyped more than 350 individuals at 11 microsatellite loci to investigate their mating system. We found no extrapair paternity, identifying this biparental fish as genetically monogamous. Breeders paired randomly according to their genetic similarity, suggesting a lack of selection against inbreeding avoidance. We further found that breeders paired assortatively by body size, a criterion of quality in fish, suggesting mutual mate choice. In a subsequent mate preference test in an aquarium setup, females showed a strong preference for male size by laying eggs near the larger of 2 males in 13 of 14 trials.
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Affiliation(s)
- Franziska C Schaedelin
- Konrad Lorenz Institute of Ethology, Department of Integrative Biology and Evolution, University of Veterinary Medicine Vienna , Savoyenstrasse 1a, 1160 Vienna , Austria
| | - Wouter F D van Dongen
- Konrad Lorenz Institute of Ethology, Department of Integrative Biology and Evolution, University of Veterinary Medicine Vienna , Savoyenstrasse 1a, 1160 Vienna , Austria
| | - Richard H Wagner
- Konrad Lorenz Institute of Ethology, Department of Integrative Biology and Evolution, University of Veterinary Medicine Vienna , Savoyenstrasse 1a, 1160 Vienna , Austria
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Pradhan DS, Solomon-Lane TK, Grober MS. Contextual modulation of social and endocrine correlates of fitness: insights from the life history of a sex changing fish. Front Neurosci 2015; 9:8. [PMID: 25691855 PMCID: PMC4315020 DOI: 10.3389/fnins.2015.00008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2014] [Accepted: 01/09/2015] [Indexed: 12/18/2022] Open
Abstract
Steroid hormones are critical regulators of reproductive life history, and the steroid sensitive traits (morphology, behavior, physiology) associated with particular life history stages can have substantial fitness consequences for an organism. Hormones, behavior and fitness are reciprocally associated and can be used in an integrative fashion to understand how the environment impacts organismal function. To address the fitness component, we highlight the importance of using reliable proxies of reproductive success when studying proximate regulation of reproductive phenotypes. To understand the mechanisms by which the endocrine system regulates phenotype, we discuss the use of particular endocrine proxies and the need for appropriate functional interpretation of each. Lastly, in any experimental paradigm, the responses of animals vary based on the subtle differences in environmental and social context and this must also be considered. We explore these different levels of analyses by focusing on the fascinating life history transitions exhibited by the bi-directionally hermaphroditic fish, Lythrypnus dalli. Sex changing fish are excellent models for providing a deeper understanding of the fitness consequences associated with behavioral and endocrine variation. We close by proposing that local regulation of steroids is one potential mechanism that allows for the expression of novel phenotypes that can be characteristic of specific life history stages. A comparative species approach will facilitate progress in understanding the diversity of mechanisms underlying the contextual regulation of phenotypes and their associated fitness correlates.
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Affiliation(s)
| | | | - Matthew S Grober
- Department of Biology, Georgia State University Atlanta, GA, USA ; Neuroscience Institute, Georgia State University Atlanta, GA, USA
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Zöttl M, Heg D, Chervet N, Taborsky M. Kinship reduces alloparental care in cooperative cichlids where helpers pay-to-stay. Nat Commun 2013; 4:1341. [DOI: 10.1038/ncomms2344] [Citation(s) in RCA: 91] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2012] [Accepted: 11/29/2012] [Indexed: 11/09/2022] Open
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9
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Riebli T, Taborsky M, Chervet N, Apolloni N, Zürcher Y, Heg D. Behavioural type, status and social context affect behaviour and resource allocation in cooperatively breeding cichlids. Anim Behav 2012. [DOI: 10.1016/j.anbehav.2012.07.017] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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10
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Bruintjes R, Bonfils D, Heg D, Taborsky M. Paternity of subordinates raises cooperative effort in cichlids. PLoS One 2011; 6:e25673. [PMID: 22022428 PMCID: PMC3192049 DOI: 10.1371/journal.pone.0025673] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2011] [Accepted: 09/09/2011] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND In cooperative breeders, subordinates generally help a dominant breeding pair to raise offspring. Parentage studies have shown that in several species subordinates can participate in reproduction. This suggests an important role of direct fitness benefits for cooperation, particularly where groups contain unrelated subordinates. In this situation parentage should influence levels of cooperation. Here we combine parentage analyses and detailed behavioural observations in the field to study whether in the highly social cichlid Neolamprologus pulcher subordinates participate in reproduction and if so, whether and how this affects their cooperative care, controlling for the effect of kinship. METHODOLOGY/PRINCIPAL FINDINGS We show that: (i) male subordinates gained paternity in 27.8% of all clutches and (ii) if they participated in reproduction, they sired on average 11.8% of young. Subordinate males sharing in reproduction showed more defence against experimentally presented egg predators compared to subordinates not participating in reproduction, and they tended to stay closer to the breeding shelter. No effects of relatedness between subordinates and dominants (to mid-parent, dominant female or dominant male) were detected on parentage and on helping behaviour. CONCLUSIONS/SIGNIFICANCE This is the first evidence in a cooperatively breeding fish species that the helping effort of male subordinates may depend on obtained paternity, which stresses the need to consider direct fitness benefits in evolutionary studies of helping behaviour.
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Affiliation(s)
- Rick Bruintjes
- Department of Behavioural Ecology, Institute of Ecology and Evolution, University of Bern, Hinterkappelen, Switzerland.
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11
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Sefc KM. Mating and Parental Care in Lake Tanganyika's Cichlids. INTERNATIONAL JOURNAL OF EVOLUTIONARY BIOLOGY 2011; 2011:470875. [PMID: 21822482 PMCID: PMC3142683 DOI: 10.4061/2011/470875] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 12/30/2010] [Revised: 03/22/2011] [Accepted: 05/02/2011] [Indexed: 11/20/2022]
Abstract
Cichlid fishes of Lake Tanganyika display a variety of mating and parental care behaviors, including polygamous and monogamous mouthbrooding and substrate breeding, cooperative breeding, as well as various alternative reproductive tactics such as sneaking and piracy. Moreover, reproductive behaviors sometimes vary within species both in space and in time. Here, I survey reports on mating and parenting behaviors of Lake Tanganyika cichlid species and address the evolution of mating and parental care patterns and sexual dimorphism. Notes on measures of sexual selection intensity and the difficulties of defining mating systems and estimating selection intensities at species level conclude the essay.
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Affiliation(s)
- Kristina M. Sefc
- Department of Zoology, Karl-Franzens University Graz, Universitätsplatz 2, 8010 Graz, Austria
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13
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Chervet N, Zöttl M, Schürch R, Taborsky M, Heg D. Repeatability and heritability of behavioural types in a social cichlid. INTERNATIONAL JOURNAL OF EVOLUTIONARY BIOLOGY 2011; 2011:321729. [PMID: 21716729 PMCID: PMC3119426 DOI: 10.4061/2011/321729] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/11/2010] [Accepted: 02/28/2011] [Indexed: 11/27/2022]
Abstract
Aim. The quantitative genetics underlying correlated behavioural traits (''animal personality") have hitherto been studied mainly in domesticated animals. Here we report the repeatability (R) and heritability (h(2)) of behavioural types in the highly social cichlid fish Neolamprologus pulcher. Methods. We tested 1779 individuals repeatedly and calculated the h(2) of behavioural types by variance components estimation (GLMM REML), using 1327 offspring from 162 broods from 74 pairs. Results. Repeatability of behavioural types was significant and considerable (0.546), but declined from 0.83 between tests conducted on the same day, to 0.19 on tests conducted up to 1201 days apart. All h(2) estimates were significant but low (e.g., pair identity h(2) = 0.15 ± 0.03 SE). Additionally, we found significant variation between broods nested within the parent(s), but these were not related to several environmental factors tested. Conclusions. We conclude that despite a considerable R, h(2) in this cichlid species is low, and variability in behavioural type appears to be strongly affected by other (non)genetic effects.
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Affiliation(s)
- Noémie Chervet
- Department of Behavioural Ecology, Institute of Ecology and Evolution, University of Bern, 3032 Hinterkappelen, Switzerland
| | - Markus Zöttl
- Department of Behavioural Ecology, Institute of Ecology and Evolution, University of Bern, 3032 Hinterkappelen, Switzerland
| | - Roger Schürch
- Department of Behavioural Ecology, Institute of Ecology and Evolution, University of Bern, 3032 Hinterkappelen, Switzerland
| | - Michael Taborsky
- Department of Behavioural Ecology, Institute of Ecology and Evolution, University of Bern, 3032 Hinterkappelen, Switzerland
| | - Dik Heg
- Department of Behavioural Ecology, Institute of Ecology and Evolution, University of Bern, 3032 Hinterkappelen, Switzerland
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Johnstone RA. Load lightening and negotiation over offspring care in cooperative breeders. Behav Ecol 2011. [DOI: 10.1093/beheco/arq190] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Schürch R, Rothenberger S, Heg D. The building-up of social relationships: behavioural types, social networks and cooperative breeding in a cichlid. Philos Trans R Soc Lond B Biol Sci 2010; 365:4089-98. [PMID: 21078660 PMCID: PMC2992742 DOI: 10.1098/rstb.2010.0177] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Consistent individual differences in behavioural types may not only cause variation in life-history decisions, but may also affect the choice of social partners and sociality in general. Here, we tested whether and how behavioural type influences the establishment of social ties using the cooperatively breeding cichlid, Neolamprologus pulcher. In a habitat saturation experiment with individuals pre-tested for behavioural type, we first analysed whether behavioural type affected the likelihood of settlement (i.e. social status), group sizes, and the types of dominant and subordinate individuals accepted as group members. Corrected for effects of body size and sex, the behavioural type did not affect settlement. However, bold dominant males only accepted smaller females, and grouped with bold subordinates, while shy dominant males accepted larger females than themselves, and grouped with shy subordinates. Second, we analysed the relationships between behavioural type and the aggressiveness or affiliation social network. Behavioural type significantly affected the number and quality of connections within the two networks. We show that behavioural types affect group composition, social networks and status achieved, in interaction with body size. Thus, the interactions within groups may depend not only on age, size and sex, but also on the behavioural type of the individuals involved.
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Affiliation(s)
- Roger Schürch
- Department of Behavioural Ecology, Institute of Ecology and Evolution, University of Bern, Wohlenstrasse 50a, CH-3032 Hinterkappelen, Switzerland
- Department of Evolution, Ecology and Organismal Biology, The Ohio State University, Columbus, OH 43210, USA
| | - Susan Rothenberger
- Department of Behavioural Ecology, Institute of Ecology and Evolution, University of Bern, Wohlenstrasse 50a, CH-3032 Hinterkappelen, Switzerland
| | - Dik Heg
- Department of Behavioural Ecology, Institute of Ecology and Evolution, University of Bern, Wohlenstrasse 50a, CH-3032 Hinterkappelen, Switzerland
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Heg D, Rothenberger S, Schürch R. Habitat saturation, benefits of philopatry, relatedness, and the extent of co-operative breeding in a cichlid. Behav Ecol 2010. [DOI: 10.1093/beheco/arq170] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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17
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Wong M, Balshine S. The evolution of cooperative breeding in the African cichlid fish, Neolamprologus pulcher. Biol Rev Camb Philos Soc 2010; 86:511-30. [DOI: 10.1111/j.1469-185x.2010.00158.x] [Citation(s) in RCA: 127] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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18
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Heg D, Taborsky M. Helper response to experimentally manipulated predation risk in the cooperatively breeding cichlid Neolamprologus pulcher. PLoS One 2010; 5:e10784. [PMID: 20520816 PMCID: PMC2877084 DOI: 10.1371/journal.pone.0010784] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2009] [Accepted: 03/09/2010] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND We manipulated predation risk in a field experiment with the cooperatively breeding cichlid Neolamprologus pulcher by releasing no predator, a medium- or a large-sized fish predator inside underwater cages enclosing two to three natural groups. We assessed whether helpers changed their helping behaviour, and whether within-group conflict changed, depending on these treatments, testing three hypotheses: 'pay-to-stay' PS, 'risk avoidance' RA, or (future) reproductive benefits RB. We also assessed whether helper food intake was reduced under risk, because this might reduce investments in other behaviours to save energy. METHODOLOGY/PRINCIPAL FINDINGS Medium and large helpers fed less under predation risk. Despite this effect helpers invested more in territory defence, but not territory maintenance, under the risk of predation (supporting PS). Experimentally covering only the breeding shelter with sand induced more helper digging under predation risk compared to the control treatment (supporting PS). Aggression towards the introduced predator did not differ between the two predator treatments and increased with group member size and group size (supporting PS and RA). Large helpers increased their help ratio (helping effort/breeder aggression received, 'punishment' by the dominant pair in the group) in the predation treatments compared to the control treatment, suggesting they were more willing to PS. Medium helpers did not show such effects. Large helpers also showed a higher submission ratio (submission/ breeder aggression received) in all treatments, compared to the medium helpers (supporting PS). CONCLUSIONS/SIGNIFICANCE We conclude that predation risk reduces helper food intake, but despite this effect, helpers were more willing to support the breeders, supporting PS. Effects of breeder punishment suggests that PS might be more important for large compared to the medium helpers. Evidence for RA was also detected. Finally, the results were inconsistent with RB.
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Affiliation(s)
- Dik Heg
- Department of Behavioural Ecology, Institute of Ecology and Evolution, University of Bern, Hinterkappelen, Switzerland.
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19
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Heg D. Status-dependent and strategic growth adjustments in female cooperative cichlids. Behav Ecol Sociobiol 2010. [DOI: 10.1007/s00265-010-0945-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Schürch R, Heg D. Life history and behavioral type in the highly social cichlid Neolamprologus pulcher. Behav Ecol 2010. [DOI: 10.1093/beheco/arq024] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Schürch R, Heg D. Variation in Helper Type Affects Group Stability and Reproductive Decisions in a Cooperative Breeder. Ethology 2010. [DOI: 10.1111/j.1439-0310.2009.01738.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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