The effect of eroded ecological networks on the movement of harvest mice (Micromys minutus)

Abstract

Habitat fragmentation and degradation of ecological networks have been identified as an influencing factor of M. minutus population viability, although, this has yet to be fully quantified. Within a specially designed release enclosure located in semi-improved grassland, various sized gaps were created in cross sections of ‘hard’ (artificial road surface 4.8m) and ‘soft’ (mown, with low vegetative cover 1m, 2m and 4.8m). Movements of a reintroduced population of M. minutus (Soft ♂N=5, ♀N=9; Hard ♂N=8, ♀ N=13) over these gaps were recorded. Whilst both genders crossed narrower fragments that have ground vegetation, as gap width increased willingness to cross decreased significantly (P < 0.001). The implications here suggest that gaps over just 2m will impede movement and dispersal of both sexes, with potential genetic implications on M. minutus populations