Behavioural developmental studies on four genera and several strains of mice

Abstract

The present study deals with the development and behaviour of the young of several genera and strains of mice. The animals studied were Microtus ochrogaster, Peromyscus maniculatus Bairdii, Onychomys leucogaster and three strains of Mus, Mus musculus ‘Mo.’ (a wild type), Mus musculus CF-I, and Mus musculus C57BL 6J . The first 20 days of life were investigated in regard to changes in maternal defence, weight gain, the appearance of fur and teeth, the ability to walk and right themselves, the behaviour of the neonate on a balancing wheel apparatus, and the maternal interest shown by the mother when the litter was returned to her. The results are discussed with particular attention to the emerging behavioural profiles of the adults. The order of occurrence of various traits was relatively constant across the genera with a few exceptions. The differences between the herbivorous genera and Onychomys and the importance of a longer period of interaction within the nest for the carnivorous and omnivorous commensals were noted with regard to the behavioural profiles of the adults.