Ta. Oksanen et al., Optimal allocation of reproductive effort: manipulation of offspring number and size in the bank vole, P ROY SOC B, 268(1467), 2001, pp. 661-666
Citations number
28
Categorie Soggetti
Experimental Biology
Journal title
PROCEEDINGS OF THE ROYAL SOCIETY OF LONDON SERIES B-BIOLOGICAL SCIENCES
The number of offspring attaining reproductive age is an important measure
of an individual's fitness. However, reproductive success is generally cons
trained by a trade-off between offspring number and quality. We conducted a
factorial experiment in order to study the effects of an artificial enlarg
ement of offspring number and size on the reproductive success of female ba
nk voles (Clethrionomys glareolus). We also studied the effects of the mani
pulations on growth, survival and reproductive success of the offspring. Po
tentially confounding effects of varying maternal quality were avoided by c
ross-fostering. Our results showed that the number of offspring alive in th
e next breeding season was higher in offspring number manipulation groups,
despite their smaller body size at weaning. Offspring size manipulation had
no effect on offspring growth or survival. Further, the first litter size
of female offspring did not differ between treatments. In conclusion, femal
es may be able to increase the number of offspring reaching reproductive ag
e by producing larger litters, whereas increasing offspring size benefits n
either the mother nor the offspring.