Effect of social environment on the proctodaeal glands of Microtus agrestis L.

The effect of social environment on the proctodaeal glands of male Microtus agrestis L. was assessed by examining a number of physical parameters of the glands, as well as of the testes and of the blood, following a range of socialisation treatments. Social isolation depresses glandular development; vole odour from the stock room does not restore gland size. Socialisation with members of the opposite sex restores gland size, but replacement of females twice a week is less effective than constancy of partner. The glands respond to the level of blood testosterone, but glandular development appears to be heavily influenced by other factors.