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Sexual dimorphism, activity budget and synchrony in groups of sheep

  • Behavioural Ecology
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Abstract

The activity budget hypothesis has been proposed to explain the social segregation commonly observed in ungulate populations. This hypothesis suggests that differences in body size – i.e. between dimorphic males and females – may account for differences in activity budget. In particular, if females spend more time grazing and less time resting than males, activity synchrony would be reduced. Increased costs of maintaining synchrony despite differences in activity budget would facilitate group fragmentation and instability of mixed-sex groups. In this paper two prerequisites of the activity budget hypothesis were tested: (1) that males should spend less time feeding and more time resting than females in single-sex groups and (2) that lower activity synchrony should be observed in mixed-sex compared to single-sex groups. The activity budget and synchrony in mixed and single-sex groups of merino sheep (Ovis aries) of different sizes (2, 4, 6, 8 individuals) were measured in three contiguous 491-m2 arenas located in a natural pasture. Three same-size groups, one of each category, were observed simultaneously. We found no sexual differences in the time spent inactive and active (i.e. grazing, standing, moving, interacting). Males spent significantly more time grazing and less time standing than females. These differences disappeared when yearling males were omitted from the group. Males and females had similar bite and step rates. Sheep of both sexes spent less time resting and more time grazing and moving and had lower bite rates when in mixed-sex groups than when in single-sex groups. The synchrony among visually isolated groups was near zero, indicating that they changed activities independently. On the contrary, within-group synchrony was high; however it was higher in single-sex groups, in particular for males, than in mixed-sex groups. Our results suggest that differences in activity budget and synchrony alone are insufficient to explain social segregation.

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References

  • Barthram GT (1986) Experimental techniques, the HFRO sward stick. In: Biennial Report 1984–1985, Hill Farming Research Organisation, Penicuik

  • Blanc F, Thériez M, Brelurut A (1999) Effects of mixed-species stocking and space allowance on the behaviour and growth of red deer hinds and ewes at pasture. Appl Anim Behav Sci 63:41–43

    Article  Google Scholar 

  • Bleich VC, Bowyer RT, Wehausen JD (1997) Sexual segregation in mountain sheep: resources or predation? Wildl Monogr 134:1–10

    Google Scholar 

  • Bon R (1991) Social and spatial segregation of males and females in polygamous ungulates: proximate factors. In: Spitz F, Janeau G, Gonzalez G, Aulagnier S (eds) Ongulés/Ungulates. SFEPM-IRGM, Paris-Toulouse, pp 195–198

  • Bon R, Campan R (1996) Unexplained sexual segregation in polygamous ungulates: a defense of an ontogenetic approach. Behav Process 38:131–154

    Article  Google Scholar 

  • Bon R, Rideau C, Villaret J-C, Joachim J (2001) Segregation is not only a matter of sex in Alpine ibex, Capra ibex ibex. Anim Behav 62:495–504

    Article  Google Scholar 

  • Bon R, Deneubourg J-L, Gerard J-F, Michelena P (2005) Sexual segregation in ungulates: from individual mechanisms to collective patterns. In: Ruckstuhl K, Neuhaus P (eds) Sexual segregation in vertebrates. Cambridge University Press, Cambridge

    Google Scholar 

  • Bonenfant C, Loe LE, Mysterud A, Langvatn R, Stenseth NC, Gaillard JM, Klein F (2004) Multiple causes of sexual segregation in European red deer: enlightenments from varying breeding phenology at high and low latitude. Proc R Soc London Ser B Biol Sci 271:883–892

    Article  Google Scholar 

  • Bosc P, Fabre P, Hubert D, Molénat G (1999) Influence de l’époque de pâturage des regrains de prés de Crau sur quelques paramètres de production de la prairie. Fourrages 157:33–45

    Google Scholar 

  • Bowyer RT (2004) Sexual segregation in ruminants: definitions, hypotheses, and implications for conservation and management. J Mammal 85:1039–1052

    Article  Google Scholar 

  • Bowyer RT, Kie JG (2004) Effects of foraging activity on sexual segregation in mule deer. J Mammal 85:498–504

    Article  Google Scholar 

  • Champion RA, Orr RJ, Penning PD, Rutter SM (2004) The effect of the spatial scale of heterogeneity of two herbage species on the grazing behaviour of lactating sheep. Appl Anim Behav Sci 88:61–76

    Article  Google Scholar 

  • Clayton DA (1978) Socially facilitated behavior. Q Rev Biol 53:373–392

    Article  Google Scholar 

  • Conradt L (1998a) Measuring the degree of sexual segregation in group-living animals. J Anim Ecol 67:217–226

    Article  Google Scholar 

  • Conradt L (1998b) Could asynchrony in activity between the sexes cause intersexual social segregation in ruminants? Proc R Soc London Ser B Biol Sci 265:1359–1363

    Article  CAS  Google Scholar 

  • Conradt L (1999) Social segregation is not a consequence of habitat segregation in red deer and feral soay sheep. Anim Behav 57:1151–1157

    Article  PubMed  Google Scholar 

  • Conradt L, Roper TJ (2000) Activity synchrony and social cohesion: a fission–fusion model. Proc R Soc London Ser B Biol Sci 267:2213–2218

    Article  CAS  Google Scholar 

  • Conradt L, Roper TJ (2003) Group decision-making in animals. Nature 421:155–158

    Article  PubMed  CAS  Google Scholar 

  • Corti P, Shackleton DM (2002) Relationship between predation risk factors and sexual segregation in Dall’s sheep (Ovis dalli dalli). Can J Zool 80:2108–2117

    Article  Google Scholar 

  • Côté SD, Schaefer JA, Messier F (1997) Time budgets and synchrony in activity in muskoxen: the influence of sex, age and season. Can J Zool 75:1628–1635

    Article  Google Scholar 

  • Cransac N, Gerard J-F, Maublanc ML, Pépin D (1998) An example of segregation between age and sex classes only weakly related to habitat use in mouflon sheep (Ovis gmelini). J Zool 244:371–378

    Article  Google Scholar 

  • Deneubourg J-L, Goss S (1989) Collective patterns and decision making. Ethol Ecol Evol 1:295–311

    Google Scholar 

  • Dubois M, Quenette PY, Bideau E, Magnac MP (1993) Seasonal range use by European mouflon rams in medium altitude mountains. Acta Theriol 38:185–198

    Google Scholar 

  • Dumont B, Boissy A (2000) Gazing behaviour of sheep in situation of conflict between feeding and social motivations. Behav Process 49:131–138

    Article  Google Scholar 

  • Ginnett TF, Demment MW (1997) Sex differences in giraffe foraging behavior at two spatial scales. Oecologia 110:291–300

    Article  Google Scholar 

  • Kie JG, Bowyer RT (1999) Sexual segregation in white-tailed deer: density-dependent changes in use of space, habitat selection, and dietary niche. J Mammal 80:1004–1020

    Article  Google Scholar 

  • Kohlmann SG, Müller DM, Alkon PU (1996) Antipredator constraints on lactating nubian ibexes. J Mammal 77:1122–1131

    Article  Google Scholar 

  • Maier JAK, White RG (1998) Timing and synchrony of activity in caribou. Can J Zool 76:1999–2009

    Article  Google Scholar 

  • Main MB, Weckerly FW, Bleich VC (1996) Sexual segregation in ungulates: new directions for research. J Mammal 77:449–461

    Article  Google Scholar 

  • Michelena P, Bouquet PM, Dissac A, Fourcassie V, Lauga J, Gerard JF, Bon R (2004) An experimental test of hypotheses explaining social segregation in dimorphic ungulates. Anim Behav 68:1371–1380

    Google Scholar 

  • Mooring MS, Fitzpatrick TA, Benjamin JE, Fraser IC, Nishihira TT, Reisig DD, Rominger EM (2003) Sexual segregation in desert bighorn sheep (Ovis canadensis mexicana). Behaviour 140:183–207

    Article  Google Scholar 

  • Mysterud A (1998) The relative roles of body size and feeding type on activity time of temperate ruminants. Oecologia 113:442–446

    Article  Google Scholar 

  • Mysterud A (2000) The relationship between ecological segregation and sexual body size dimorphism in large herbivores. Oecologia 124:40–54

    Article  Google Scholar 

  • Neuhaus P, Ruckstuhl KE (2002) Foraging behaviour in Alpine ibex (Capra ibex): consequences of reproductive status, body size, age and sex. Ethol Ecol Evol 14:373–381

    Google Scholar 

  • Orr RJ, Penning PD, Harvey A, Champion RA (1997) Diurnal patterns of intake rate by sheep grazing monocultures of ryegrass or white clover. Appl Anim Behav Sci 52:65–77

    Article  Google Scholar 

  • Penning PD, Parsons AJ, Newman JA, Orr RJ, Harvey A (1993) The effect of group size on grazing time in sheep. Appl Anim Behav Sci 37:101–109

    Article  Google Scholar 

  • Pérez-Barbería FJ, Gordon IJ (1998) The influence of sexual dimorphism in body size and mouth morphology on diet selection and sexual segregation in cervids. Acta Vet Hung 46:357–367

    PubMed  Google Scholar 

  • Pérez-Barbería FJ, Gordon IJ (1999a) Body size dimorphism and sexual segregation in polygynous ungulates: an experimental test with Soay sheep. Oecologia 120:258–267

    Article  Google Scholar 

  • Pérez-Barbería FJ, Gordon IJ (1999b) The relative roles of phylogeny, body size and feeding style on the activity time of temperate ruminants: a reanalysis. Oecologia 120:193–197

    Article  Google Scholar 

  • Ramirez Avila GM, Guisset JL, Deneubourg JL (2003) Synchronization in light-controlled oscillators. Physica D 182:254–273

    Article  Google Scholar 

  • Rook AJ, Penning PD (1991) Synchronisation of eating, ruminating and idling activity by grazing sheep. Appl Anim Behav Sci 32:157–166

    Article  Google Scholar 

  • Ruckstuhl KE (1998) Foraging behaviour and sexual segregation in bighorn sheep. Anim Behav 56:99–106

    Article  PubMed  Google Scholar 

  • Ruckstuhl KE, Neuhaus P (2000) Sexual segregation in ungulates: a new approach. Behaviour 137:361–377

    Article  Google Scholar 

  • Ruckstuhl KE, Neuhaus P (2001) Behavioral synchrony in ibex groups: effects of age, sex and habitat. Behaviour 138:1033–1046

    Article  Google Scholar 

  • Ruckstuhl KE, Neuhaus P (2002) Sexual segregation in ungulates: a comparative test of three hypotheses. Biol Rev Cambridge Philos Soc 77:77–96

    PubMed  CAS  Google Scholar 

  • Ruckstuhl KE, Neuhaus P (2005) Sexual segregation in vertebrates: ecology of the two sexes. Cambridge University Press, Cambridge

    Google Scholar 

  • Ruckstuhl KE, Festa-Bianchet M, Jorgenson JT (2003) Bites rates in Rocky Mountain bighorn sheep (Ovis canadensis): effects of season, age, sex and reproductive status. Behav Ecol Sociobiol 54:167–173

    Google Scholar 

  • Siegel S, Castellan NJ (1988) Nonparametric statistics for the behavioral sciences, 2nd edn. McGraw-Hill, New-York

    Google Scholar 

  • Weckerly FW (1993) Intersexual resource partitioning in black-tailed deer: a test of the body size hypothesis. J Wildl Manag 57:475–494

    Article  Google Scholar 

  • Weckerly FW, Ricca MA, Meyer KP (2001) Sexual segregation in Roosevelt elk: Cropping rates and aggression in mixed-sex groups. J Mammal 82:825–835

    Article  Google Scholar 

  • Yearsley JM, Javier Perez-Barberia F (2005) Does the activity budget hypothesis explain sexual segregation in ungulates? Anim Behav 69:257–267

    Article  Google Scholar 

Download references

Acknowledgements

We thank Hervé Monod, Michel Goulard and Alain Baccini for statistical assistance and Jean-Pierre Theau for help with the grass measurements. We acknowledge the participation of Cathy Boléat and Virginia Colom in data collection and that of the staff of the Domaine du Merle for technical assistance. Vincent Fourcassié and the two anonymous referees provided valuable comments on the manuscript. Special thanks are addressed to Richard H. Porter for English revision. Pablo Michelena and Jacques Gautrais were supported by the LEURRE project sponsored by the Future and Emerging Technologies program of the European Community (IST-2001-35506). Animal care and experimental manipulations were in accordance with the rules of the French committee of animal experimentation ethics.

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Authors and Affiliations

  1. Centre de Recherches sur la Cognition Animale, Université Paul Sabatier, 118 route de Narbonne, 31062, Toulouse cedex 04, France

    Pablo Michelena, Sarah Noël, Jacques Gautrais & Richard Bon

  2. Laboratoire de Comportement et d’Ecologie de la Faune Sauvage, Institut National de la Recherche Agronomique, BP 27, 31326, Castanet Tolosan cedex, France

    Jean-François Gerard

  3. Service d’Ecologie Sociale, CP 231, Université Libre de Bruxelles, Boulevard du Triomphe, 1050, Brussels, Belgium

    Jean-Louis Deneubourg

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  1. Pablo Michelena
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  2. Sarah Noël
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  3. Jacques Gautrais
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  4. Jean-François Gerard
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  5. Jean-Louis Deneubourg
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  6. Richard Bon
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Correspondence to Pablo Michelena.

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Communicated by Hannu Ylonen

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Michelena, P., Noël, S., Gautrais, J. et al. Sexual dimorphism, activity budget and synchrony in groups of sheep. Oecologia 148, 170–180 (2006). https://doi.org/10.1007/s00442-005-0347-2

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