Social structure of the mound‐building mouse Mus spicilegus revealed by genetic analysis with microsatellites

Abstract

The Mound-building mouse Mus spicilegus possesses a unique behaviour amongst mice. It constructs large earthen mounds and associated nesting chambers which serve to store food for immature individuals during the winter nesting period. We have used genetic analysis of four autosomal and four X-linked microsatellite loci to determine relationships between individuals inhabiting 40 mounds in Bulgaria. We show that, in almost all cases, individuals in a mound are the product of multiple parentage. We estimate the minimum number of males and female parents contributing offspring to each mound and demonstrate that at least two male and two female parents contribute offspring to a minimum of seven mounds. Analyses of relatedness coefficients and allele sharing values demonstrate that parents of different sibships within mounds are more related than if they had been chosen at random from the population and suggest that it is the female parents that contribute this excess relatedness. These results suggest that the mechanism by which individuals congregate to build mounds is kin-based and that the evolution of mound building and communal nesting in M. spicilegus is due in part to kin selection. This study represents a novel approach to the study of mammalian behavioural ecology. We have used a genetic dataset to construct an outline of social structure in the absence of behavioural data. These inferences can now be used to direct further work on this species.

A review of the evolutionary causes of rodent group-living

“…This is puzzling given the evidence showing that burrowing may convey a relatively high energetic cost to individual diggers (Lovegrove 1989, Ebensperger andBozinovic 2000a). The hillock mouse Mus spicilegus builds earthen mounds in autumn, which are then used communally by more than two parents to deposit and provision their immature offspring with grain (Muntyanu 1990, Garza et al 1997. These mounds are large, take several days to build, and are provisioned with 3 to 5 kg of grain, and thus they are energetically costly (Muntyanu 1990).…”

“…These mounds are large, take several days to build, and are provisioned with 3 to 5 kg of grain, and thus they are energetically costly (Muntyanu 1990). The observation of multiple individuals participating in mound building (Garza et al 1997) suggests that hillock mice might live in groups to share the cost of constructing a burrow. Other social rodents in which group members communally dig their burrows include the semifossorial plains vizcachas Lagostomus maximus (Chinchillidae, Branch 1993).…”

Estimating gene flow across hybrid zones: how reliable are microsatellites?

“…These properties have allowed population genetics studies at a much more detailed scale than was possible with the less polymorphic allozymes {eg Amos etal. 1993, Garza et al 1997, Balloux et al 1998.…”

Comparison of Urinary Scents of Two Related Mouse Species, Mus spicilegus and Mus domesticus

“…Unlike M. domesticus, M. spicilegus are monogamous (Patris and Baudoin, 1998;Dobson and Baudoin, 2002;Baudoin et al, 2005;Gouat and Féron, 2005) and build co-operatively colonial mounds for overwintering (Orsini et al, 1983;Garza et al, 1997;Poteaux et al, 2008). Moreover, M. spicilegus males display intense paternal care (Patris and Baudoin, 2000;Féron and Gouat, 2007).…”