Sex/age differences in foraging, vigilance and alertness in a social herbivore
Antipredator strategies and social factors may influence vigilance behaviour in herbivores. Vigilance can differ between sex/age classes, but information is contradictory in the existing literature. We investigated sex/age differences of vigilance in fallow deer Dama dama, in a Mediterranean area. Females (> 1 year old) showed a lower proportion of time foraging and a greater alertness rate than males (≥ 1 years old). Decrease of vigilance with increasing group size was observed for females and adult males, but not for young and subadult males, suggesting that group-size effects on vigilance were not consistent across individuals of different sex/age classes. Most likely, females tended to reduce the predation risk for their offspring through a comparatively greater duration and frequency of vigilance. Young/subadult males showed a greater alertness than adult males, which may depend on intraspecific competition in larger groups. Both antipredator and social factors could explain sex/age differences of vigilance in fallow deer.
KeywordsVigilance Head lift Antipredator behaviour Group-size effect Intraspecific competition Ungulates
We thank the MRP Agency and A. Vivarelli Colonna, who authorised us to carry out observations on their lands. We are indebted to S. Lovari, who supported and gave feedback to F.F. throughout the study, to A. Sforzi for suggestions and backing in the initial stages of this work, and to the MRP staff for logistical support and backing. We are grateful to two anonymous reviewers for their helpful comments on an early draft of this manuscript.
F.F. planned this study, collected data in 2006-2008, performed statistical analyses, supervised all stage of this study and participated in writing up all drafts. I.P. collected data in 2012–2013 and participated in writing up all drafts. N.F. performed statistical analyses and participated in writing up. E.M. participated in data discussion and in writing up.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
This article does not contain any studies with human participants performed by any of the authors.
This article does not contain any studies with human participants.
- Apollonio M (2003) Dama dama (Linnaeus, 1758) In: Boitani L, Lovari S, Vigna Taglianti A (eds) Fauna d’Italia. Mammalia III Carnivora - Artiodactyla. Calderini, Bologna, pp 295–304Google Scholar
- Bartoń K (2012) MuMIn: multi-model inference. R Foundation for Statistical Computing, ViennaGoogle Scholar
- Beauchamp G (2015) Animal vigilance. In: Monitoring predators and competitors. Elsevier, BostonGoogle Scholar
- Bolker BM, Skaug H, Magnusson A, Nielsen A (2012) Getting started with the glmm ADMB package. http://glmmadmb.r-forge.r-project.org. Accessed 15 November 2017
- Bunnell FL, Gillingham MP (1985) Foraging behavior: dynamics of dining out. In: Hudson RJ, White RG (eds) Bioenergetics of wild herbivores. CRC, Boca Raton, pp 53–79Google Scholar
- Burnham KP, Anderson DR (2002) Model selection and multimodel inference: a practical information-theoretic approach. Springer-Verlag, New YorkGoogle Scholar
- Favreau FR, Goldizen AW, Pays O (2010) Interactions among social monitoring, anti-predator vigilance and group size in eastern grey kangaroos. P Roy Soc Lond B Bio rspb20092337Google Scholar
- Ferretti F, Costa A, Corazza M, Pietrocini V, Cesaretti G, Lovari S (2014a) Males are faster foragers than females: intersexual differences of foraging behaviour in the Apennine chamois. Behav Ecol Sociobiol 68:1335–1344Google Scholar
- Ferretti F, Sforzi A, Coats J, Massei G (2014b) The BOS™ as a species-specific method to deliver baits to wild boar in a Mediterranean area. Eur J Wildl Res 60(3):555–558Google Scholar
- Lehner PN (1996) Handbook of ethological methods. Cambridge University Press, CambridgeGoogle Scholar
- Lovari S, Rosto G (1985) Feeding rate and social stress of female chamois foraging in groups. In: Lovari S (ed) The biology and management of mountain ungulates. Croom Helm, London, pp 102–105Google Scholar
- Manghi L, Boitani L (2012) Indagine sull’ecologia alimentare di Canis lupus e sviluppo di un'applicazione con il software Cyber Traker per il monitoraggio della biodiversità. Relazione sulle attività svolte: Giugno-Dicembre 2011. Fondazione Grosseto Cultura, GrossetoGoogle Scholar
- Sforzi A, Machetti A, Boldrini U, Tonini L, Ferretti F (2014) Programma annuale per la gestione delle popolazioni di ungulati selvatici del Parco Regionale della Maremma. Ente Parco Regionale della Maremma, AlbereseGoogle Scholar