Secondary sex ratios do not support maternal manipulation: extensive data from laboratory colonies of spiny mice (Muridae: Acomys)
2010
Abstract
Spiny mice of the genus Acomys (Muridae) represent a very suitable mammalian model for studying factors influencing the secondary sex ratio (SSR). The maternal effort in these rodents is extremely biased in favour of the prenatal period and, therefore, maternal manipulation of the SSR is potentially more advantageous.
We studied the SSR in four populations/species of spiny mice. The groups were established from founding animals aged about 3 months (maturing age) and were allowed to breed freely for several months.
Each litter was sexed after birth, and relevant data were thoroughly recorded. The overall sex ratio was close to 1:1 (49.2%).
Our evaluation of a large dataset revealed that the sex ratio in spiny mice is surprisingly stable.