Parasites & immunecology
Parasite exposure is one of the strongest sorting factors in animal populations, due to its potentially damaging effect on survival and reproduction. The immune defence system is therefore essential in all animals. However, the immune system also carries costs, in terms of nutrient consumption and immunopathology. It has therefore been predicted that the activity of a host’s immune defence system should be adapted to the risk of infection. In addition, physiologically demanding behaviours such as movement in animals generally result in suppressed immunity making moving animals vulnerable to parasite infection.
It is therefore important to study the risk of exposure to parasites in different habitats and in different geographical regions. Such approach will make it possible to investigate adaptations to changes in risk of parasitism in hosts, host-parasite coevolution, the effect of parasites as a “cost of moving”, and global warming effects on parasite distribution and transmission. Currently ongoing research includes studies of avian malaria parasites and their bird hosts; geographical patterns of infection risk, transfer of parasites between regions and host immune response to malaria. We have made a database “MalAvi” containing distribution data of >850 parasite lineages found in birds. Other ongoing research focuses on seasonal adjustments of immune function and diversity in immune genes (e.g. Major Histocompatibility Complex genes) within and between species. We want to know if species have evolved to cope with different levels of parasite exposure in relation to migration distance and winter distribution.