The effect of behavioural interactions on the transfer of fleas (Siphonaptera) between two rodent species.

The transfer of fleas between the house mouse, Mus musculus, and the midday jird, Meriones meridianus, through social contacts was studied by performing interspecific dyadic encounters on a neutral arena. M. meridianus and M. musculus exchanged parasites through social contacts. The intensity of this exchange was higher between mice and adult male and young jirds than between mice and adult female jirds. The pattern of behavioural interactions was the main determinant of the intensity of flea exchange. Adult female jirds were highly aggressive towards mice. In contrast, interactions between male and young jirds and mice were mainly cohesive and resulted in higher frequency of flea transfer. The proportion of fleas transferred was positively correlated with the number and cumulative duration of tactile contacts between opponents in dyads.