Short-term and long-term consequences of avian malaria-like infection
Final Report Abstract
Parasites pose a major threat to wild organisms as they drain energy and resources, and may exhaust their hosts at times when physical competence is of vital importance. The costs potentially caused by parasites, however, have to be measured rather than presumed, as they can be modified or even negated by some traits and states as well as through long co-evolutionary adaptations on both sides. Longitudinal studies are vital to understand the actual health costs and the defence mechanisms used by hosts to cope and potentially tame their symbionts. In a population of common buzzards Buteo buteo, more than half of all nestlings are infected with the malaria-related blood parasite Leucocytozoon. This research project explored at which points of the infection course, symptoms and costs are measurable, whether these effects last and what physiological tools are used by both specialized partners to achieve coexistence. Neither condition of nestlings, nor survival in their later life were affected in the long term by infection with Leucocytozoon. Short periods of condition loss during peak infection were swiftly compensated. This rebound appeared to be independent of food abundance or individual colour morph of the nestlings. A number of genes were identified belonging both to immune cascades and tolerance mechanisms, which describe the specific ways how nestlings limit the costs of the parasites, while leaving scope for their transmission. Additionally, we characterised a number of specific immune loci and alleles expressed by individuals as well as new clades of parasites which were discovered and described. The results obtained in this research project document the complex coevolution between host and parasite life histories and the ways in which both individuals and populations manage to thrive while engaging in potentially detrimental symbiosis.
Publications
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The prevalence of Leucocytozoon spp. in nestlings of three wild raptor species including implications on haematological and blood chemistry values. International Journal for Parasitology: Parasites and Wildlife, 16, 236-243.
Wiegmann, Anja; Springer, Andrea; Rinaud, Tony; Ottensmann, Meinolf; Legler, Marko; Krüger, Oliver; Fehr, Michael; Chakarov, Nayden & Strube, Christina
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Tolerability of Atovaquone—Proguanil Application in Common Buzzard Nestlings. Veterinary Sciences, 9(8), 397.
Wiegmann, Anja; Rinaud, Tony; Ottensmann, Meinolf; Krüger, Oliver; Springer, Andrea; Legler, Marko; Fehr, Michael; Strube, Christina & Chakarov, Nayden
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High functional allelic diversity and copy number in both MHC classes in the common buzzard. BMC Ecology and Evolution, 23(1).
Winternitz, Jamie; Chakarov, Nayden; Rinaud, Tony; Ottensmann, Meinolf & Krüger, Oliver
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Novel phylogenetic clade of avian Haemoproteus parasites (Haemosporida, Haemoproteidae) from Accipitridae raptors, with description of a new Haemoproteus species. Parasite, 31, 5.
Harl, Josef; Fauchois, Anaïs; Puech, Marie-Pierre; Gey, Delphine; Ariey, Frédéric; Izac, Brigitte; Weissenböck, Herbert; Chakarov, Nayden; Iezhova, Tatjana; Valkiūnas, Gediminas & Duval, Linda
