Behavioural Processes 57 (2002) 37–50
Maternal-care behavior and life-history traits in house mice
(Mus domesticus) artiﬁcially selected for high voluntary
I. Girard *, J.G. Swallow
, P.A. Carter
, P. Koteja
, J.S. Rhodes,
T. Garland Jr
Department of Zoology, Uni6ersity of Wisconsin-Madison,
Lincoln Dri6e, WI
Received 4 August 2000; received in revised form 30 October 2001; accepted 1 November 2001
To test the hypothesis that selective breeding for high voluntary wheel running negatively affects maternal
performance in house mice, we observed maternal behavior and compared litter size and mass, in replicate lines of
selected (N=4) and control (N =4) mice from generations 20 and 21 of an artiﬁcial selection experiment. At
generation 21, selected-line females ran 2.8-times more revolutions per day than females from random-bred control
lines, when tested at approximately 6 weeks of age as part of the normal selection protocol. After giving birth, dams
from selected and control lines exhibited similar frequencies of maternal behaviors and also spent similar amounts of
time in general locomotor activity at litter ages of both 9 and 16 days. Dams from selected lines also performed
equally well as controls in repeated pup-retrieval trials. At ﬁrst parturition, selected-line dams averaged 2.4 g smaller
in body mass as compared with dams from the control lines; however, neither litter size nor litter mass at birth
(generation 20) or at weaning (generation 21) differed signiﬁcantly between selected and control lines. We conclude
that, at least under the husbandry conditions employed, maternal behavior and reproductive output at ﬁrst
parturition are genetically independent of wheel-running behavior. © 2002 Elsevier Science B.V. All rights reserved.
Activity; Body size; Correlated response; Exercise; Reproduction
* Corresponding author. Tel.: +1-608-262-4437; fax: +1-608-265-6320.
email@example.com (I. Girard), firstname.lastname@example.org (J.G. Swallow), email@example.com (P.A. Carter),
firstname.lastname@example.org (P. Koteja), email@example.com (J.S. Rhodes), firstname.lastname@example.org (T. Garland, Jr).
Present address: Department of Biology, University of South Dakota, SD 57067, USA.
Present address: Department of Zoology, Washington State University, Pullman, WA 99164, USA.
Present address: Institute of Environmental Sciences, Jagiellonian University, ul. Ingardena 6, 30-060 Krako´w, Poland.
Present address: Department of Biology, University of California, Riverside, CA 92521, USA.
0376-6357/02/$ - see front matter © 2002 Elsevier Science B.V. All rights reserved.