A genetic analysis of group movement in an isolated population of tree-roosting bats

Abstract

Group fission is an important dispersal mechanism for philopatric adults. In Cypress Hills Interprovincial Park, Saskatchewan, tree-roosting big brown bats (Eptesicus fuscus) exhibit fission-fusion roosting behaviour. During 2004During -2007, the majority of females previously resident to roosting area 1 (RA1) moved to a new roosting area (RA4). We examined how genetic relationships, inferred from data for microsatellite loci and mitochondrial DNA, influenced new roost area (RA) selection during 2006 when colony members were split between the RAs. We found that females who moved to RA4 had higher average relatedness than those that remained in RA1. We found that nearly all females belonging to matrilines with high average relatedness moved to RA4 while females from matrilines with low average relatedness were split between the two RAs. These results suggest that closely related maternal kin preferentially move to new RAs. However, daily roosting preferences within a RA are not based on genetic relationships probably because daily roosting associations between kin and non-kin are used to ensure adequate roost group size. Studying the effects of kinship on the fission and movements of groups not only enhances our understanding of social behaviour and population genetics but also informs conservation decisions.

Dispersal and group formation dynamics in a rare and endangered temperate forest bat (Nyctalus lasiopterus, Chiroptera: Vespertilionidae)

“…Group fission along matrilineal lines documented for E. fuscus by Metheny et al. (2008) is probably not the norm, even within the same species, as suggested by the lack of genetic structure among the populations of big brown bats studied by Vonhof et al. (2008).…”

“…(2008). The studied colony fissioned, one group moving to a previously uninhabited area 7 km away from the original colony (Metheny et al.…”

“…The latter has also been documented for big brown bats, Eptesicus fuscus , in which average pairwise relatedness was higher than expected among individuals of three of five matrilines following the formation of a new group (Metheny et al. 2008). Previous studies had found little or no correlation between the degree of association and relatedness levels among members of bat maternity colonies, including in this particular species (Kerth and König 1999; Metheny et al.…”

“…2008). As part of a long‐term study of giant noctule populations in southwestern Andalusia, Spain, we examined the influence of genetic relatedness on the formation of a new colony in Doñana National Park prior to 2007 and after 2010, following a temporary, unexplained 3‐year abandonment.…”

Rabies Prevalence in Migratory Tree-Bats in Alberta and the Influence of Roosting Ecology and Sampling Method on Reported Prevalence of Rabies in Bats

“…In large colonies, bats roost in close proximity to one another, increasing the opportunity for a rabies-infected individual to bite and infect conspecifics. Fission-fusion societies, in which individuals move among roosting groups, have been described in several bat species (Willis and Brigham, 2004;Garroway and Broders, 2007;Metheny et al, 2008) and may provide a mechanism for transmission between roosts in colonial species. In addition, multiple bat species have been found roosting together (Schowalter, 1980;Constantine, 2009), and geographic range overlap has been shown to be an important predictor of cross-species rabies transmission (Streicker et al, 2010).…”