Submitted to: Behavioral Ecology and Sociobiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/6/1998
Publication Date: N/A
Interpretive Summary: Parasite infection alters host metabolism and causes disease, but may also alter host behavior. Changes in behavior often benefit the parasite by improving the success for transmission to another host. Host needs are generally in opposition to needs of the parasite and generally benefit by reducing the likelihood of parasite transmission to another host. In the present study, scientists from the Agricultural Research Service and Johns Hopkins University studied the effect of infection with the parasite Trichinella spiralis on mating behavior of two species of voles. Female voles were able to discriminate against parasitized males, reducing their reproductive success. These results suggest that parasite transmission is negatively affected by mating behavior.
Technical Abstract: Females may choose mates based on secondary sex traits that reflect disease resistance. Accordingly, females should be able to distinguish between unparasitized and parasitized males, and should prefer to mate with unparasitized individuals. Mate and odor preference for uninfected males or males infected with the nematode, Trichinella spiralis, was examined among prairie voles (Microtus ochrogaster) and meadow voles (M. pennsylvanicus). In a 15 min odor preference test, only female meadow voles distinguished between bedding from parasitized and unparasitized conspecific males, and preferred to spend time with bedding from unparasitized males. Although T. spiralis infections influenced odor preference in female meadow voles, there was no effect of infection status on mate preference among either species. Testosterone and corticosterone concentrations were not different between parasitized and unparasitized males. However, among prairie voles, males that spent an increased amount of time with females during the mate preference test had higher testosterone concentrations. Taken together, these data suggest that: (1) female meadow voles can discriminate between unparasitized and parasitized males, (2) the effects of infection on steroid hormone concentrations may be masked by the effects of social interactions, and (3) transmissibility of a parasite may influence female preference of mates and should be considered in studies of female preference.