Several social mammals, including elephants and some primates, whales and bats, live in multilevel societies that form temporary subgroups. Despite these fission–fusion dynamics, group members often maintain long-term bonds. However, it is unclear whether such individual links and the resulting stable social subunits continue to exist after a complete reorganisation of a society, e.g. following a population crash. Here, we employed a weighted network analysis on 7,109 individual roosting records collected over 4 years in a wild Bechstein’s bat colony. We show that, in response to a strong population decline, the colony’s two stable social subunits fused into a non-modular social network. Nevertheless, in the first year after the crash, long-term bonds were still detectable, suggesting that the bats remembered previous individual relationships. Our findings are important for understanding the flexibility of animal societies in the face of dramatic changes and for the conservation of social mammals with declining populations.
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Ancillotto L, Serangeli MT, Russo D (2012) Spatial proximity between newborns influences the development of social relationships in bats. Ethology 118:1–10
Blondel VD, Guillaume JL, Lambiotte R, Lefebvre E (2008) Fast unfolding of communities in large networks. J Stat Mech Theor Exp P10008
Boeckle M, Bugnyar T (2012) Long-term memory for affiliates in ravens. Curr Biol 22:801–806
Frère CH, Krützen M, Manna J, Connora RC, Bejdera L, Sherwin WB (2010) Social and genetic interactions drive fitness variation in a free-living dolphin population. Proc Natl Acad Sci U S A 107:19949–19954
Garnier S, Murphy T, Lutz M, Humre E, Leblanc S, Couzin ID (2013) Stability and responsiveness in a self-organized living architecture. PLoS Comput Biol 9:e1002984 EP
Kendrick KM, da Costa AP, Leigh AE, Hinton MR, Peirce JW (2001) Sheep don’t forget a face. Nature 414:165–166
Kerth G (2008) Animal sociality: bat colonies are founded by relatives. Curr Biol 18:R740–R742
Kerth G, Ebert C, Schmidtke C (2006) Group decision-making in fission–fusion societies: evidence from two-field experiments in Bechstein’s bats. Proc R Soc B 273:2785–2790
Kerth G, Perony N, Schweitzer F (2011) Bats are able to maintain long-term social relationships despite the high fission–fusion dynamics of their groups. Proc R Soc B 278:2761–2767
Parsons KM, Balcomb KC III, Ford JKB, Durban JW (2009) The social dynamics of southern resident killer whales and conservation implications for this endangered population. Anim Behav 77:963–971
Pretzlaff I, Kerth G, Dausmann K (2010) Communally breeding bats use physiological and behavioural adjustments to optimise daily energy expenditure. Naturwissenschaften 97:353–363
Safi K, Kerth G (2003) Secretions of the interaural gland contain information about individuality and colony membership in the Bechstein’s bat. Anim Behav 65:363–369
Schöner C, Schöner M, Kerth G (2010) Similar is not the same: social calls of conspecifics are more effective in attracting wild bats to day roosts than those of other bat species. Behav Ecol Sociobiol 64:2053–2063
Silk JB, Alberts SC, Altmann J (2003) Social bonds of female baboons enhance infant survival. Science 302:1231–1234
Wittemyer G, Douglas-Hamilton I, Getz WM (2005) The socioecology of elephants: analysis of the processes creating multitiered social structures. Anim Behav 69:1357–1371
We thank Sebastien Puechmaille and Danilo Russo for comments on the manuscript. This study was carried out under license from the nature conservancy department of Lower Franconia. The German Science Foundation (DFG, KE 746/4-1) provided financial support.
Communicated by: Sven Thatje
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Baigger, A., Perony, N., Reuter, M. et al. Bechstein’s bats maintain individual social links despite a complete reorganisation of their colony structure. Naturwissenschaften 100, 895–898 (2013). https://doi.org/10.1007/s00114-013-1090-x