Much of my work requires intensive observations of wild birds and involves examining such questions as how frequent copulations may function in assuring male parentage, how relatedness can affect the evolution of begging intensity in nestling birds, and how males adjust the amount of paternal care they invest in offspring in relation to their certainty of paternity. Ultimately, a thorough understanding of how birds reproduce may give us a better insight into the way natural selection has shaped our own species. Sperm size and sperm competition in birds. Begging intensity of nestling birds varies with sibling relatedness. To answer this we focus on coevolutionary interactions between birds and various ectoparasites which range from feather- chewing lice, passing their entire life cycle on a single host, to mites which occur on a wide variety of birds and mammals.
Most species have a unique species of louse, but a few species share lice.
We are comparing the survival of lice transferred to foreign host taxa with that of lice moved to new individuals of the same host. We are measuring the reciprocal interactions between parasites and hosts, and the effects of parasites on host survival and reproduction. This unexplored possibility has the potential to explain a significant fraction of the earth's biodiversity. Such damage leads to a significant increase in metabolic rate to make up for heat loss. Experimental demonstration of the energetic cost of parasitism in free ranging hosts.