Effects of supplementary food on the winter inhibition of reproduction in male and female four-striped field mice (Rhabdomys pumilio)
C. Jackson A B and R. T. F. Bernard A CA Department of Zoology and Entomology, Rhodes University, Grahamstown 6139, South Africa.
B Present address: Department of Zoology, Sub-Department of Animal Behaviour, University of Cambridge, Madingley, Cambridge CB3 8AA, United Kingdom.
C Corresponding author. Email: r.bernard@ru.ac.za
Reproduction, Fertility and Development 17(4) 393-400 https://doi.org/10.1071/RD04134
Submitted: 12 November 2004 Accepted: 1 February 2005 Published: 7 March 2005
Abstract
The effects of winter food supplementation on reproduction in the seasonally breeding four-striped field mouse Rhabdomys pumilio were investigated at Mountain Zebra National Park in the Eastern Cape Province of South Africa. On both control and supplemented grids, reproductive activity in females was inhibited; no pregnant females were collected and juveniles were only present in the first winter month. The provision of additional food resulted in an increase in body mass and mass of the male and female reproductive organs. However, all males, from both grids, were spermatogenically active. Ovarian activity was not stimulated by the provision of additional food, but the development of the uterus was and the endometrium was thicker and more vascularised in mice from the supplemented grid than from the control grid. We conclude that seasonal reproduction in R. pumilio is controlled by the females, in which reproductive activity is inhibited in winter. However, the provision of supplementary food was not sufficient to override the reproductive inhibition.
Extra keywords: climatic variability, opportunistic reproduction, rodent, South Africa.
Acknowledgments
The authors are grateful for the financial support of Rhodes University and the National Research Foundation, for permission from the South African National Parks Board to work in MZNP and to numerous students and friends who helped with the field work. The comments of two referees have added considerably to the precision of the manuscript.
Briggs, J. M. (1986). Supplemental food and two island populations of Peromyscus leucopus. J. Mammal. 67, 474–480.
Bronson, F. H. , and Perrigo, G. (1987). Seasonal regulation of reproduction in muroid rodents. Am. Zool. 27, 929–940.
Brooks, P. M. (1982). Aspects of the reproduction, growth and development of the four-striped field mouse, Rhabdomys pumilio (Sparrman, 1784). Mammalia 46, 53–63.
Christensen, J. T. (1993). The seasonal variation in breeding and growth of Mastomys natalensis (Rodentia, Muridae): evidence for resource limitation. Afr. J. Ecol. 31, 1–9.
Cole, F. R. , and Batzli, G. O. (1978). Influence of supplemental feeding on a vole population. J. Mammal. 59, 809–819.
Demas, G. E. , and Nelson, R. J. (1998). Social, but not photoperiodic, influences on reproductive function in male Peromyscus aztecus. Biol. Reprod. 58, 385–389.
| PubMed |
McAdam, A. G. , and Millar, J. S. (1999). Dietary protein constraint on age at maturity: an experimental test with wild deer mice. J. Anim. Ecol. 68, 733–740.
| Crossref | GoogleScholarGoogle Scholar |
Monadjem, A. , and Perrin, M. R. (1996). The effects of additional food on the demography of rodents in subtropical grassland in Swaziland. Mammalia 60, 785–789.
Neal, B. R. (1996). Reproductive response of Tatera leucogaster (Rodentia) to supplemental food, water, and 6-methoxybenzoxazolinone. Mammalia 60, 651–666.
Nunes, S. , Muecke, E. , Ross, H. E. , Bartholomew, P. A. , and Holekamp, K. E. (2000). Food availability affects behavior but not circulating gonadal hormones in maternal Belding’s ground squirrels. Physiol. Behav. 71, 447–455.
| Crossref | GoogleScholarGoogle Scholar | PubMed |
O’Donoghue, M. , and Krebs, C. J. (1992). Effects of supplemental food on snowshoe hare reproduction and juvenile growth at a cyclic population peak. J. Anim. Ecol. 61, 631–641.
Perrin, M. R. (1980). Ecological strategies of two co-existing rodents. S. Afr. J. Sci. 76, 487–491.
Perrin, M. R. , and Johnson, S. J. (1999). The effect of supplemental food and cover availability on a population of the striped mouse. S. Afr. J. Wildl. Res. 29, 15–19.
Saitoh, T. (1989). Effects of added food on some attributes of an enclosed vole population. J. Mammal. 70, 772–782.
Smithers, R. H. N. (1971). The mammals of Botswana. Trustees of the national museums and monuments of Zimbabwe, Harare. Mus. Mem. 4, 1–340.
Sullivan, T. P. (1990). Responses of red squirrel (Tamiasciurus hudsonicus) populations to supplemental food. J. Mammal. 71, 579–590.
Sullivan, T. P. , Sullivan, D. S. , and Krebs, C. J. (1983). Demographic responses of a chipmunk (Eutamias townsendii) population to supplemental food. J. Anim. Ecol. 52, 743–755.
Swanepoel, C. M. (1980). Some factors influencing the breeding season of Praomys natalensis. S. Afr. J. Zool. 15, 95–98.
Taitt, M. J. , and Krebs, C. J. (1983). Predation, cover and food manipulations during a spring decline of Microtus townsendii. J. Anim. Ecol. 52, 837–848.
Taylor, K. D. , and Green, M. G. (1976). The influence of rainfall on diet and reproduction in four African rodent species. J. Zool. 180, 367–389.
| PubMed |
Vaughan, M. R. , and Keith, L. B. (1981). Demographic responses of experimental snowshoe hare populations to overwinter food shortage. J. Wildl. Manage. 45, 354–380.
Yom-Tov, Y. (1993). Size variation in Rhabdomys pumilio: a case of character release? Z. Saugetierkd. 58, 48–53.
