Many feral house mouse populations have low recapture rates (0-20%) in
live-trapping studies carried out at 2-4-week intervals. We consider
six hypotheses to explain low recapture rates. We radio-collared 155 h
ouse mice between September 1992 and May 1993 in agricultural fields o
n the Darling Downs of south-eastern Queensland during a phase of popu
lation increase. Low recapture rates during the breeding season were d
ue to low trappability and during the non-breeding period to nomadic m
ovements. During the breeding season radio-collared mice of both sexes
survived well and moved mostly small distances (<11 m). Low trappabil
ity has consequences for the precision of population indices that rely
on catch per unit effort. Capture-recapture models robust to heteroge
neity of trap responses should be used to census feral Mus populations
.