Comparative ecology of wild Columbiformes native to Europe - An analysis of movement behaviour, diet composition and haemosporidian infections
Behaviour encompasses all interactions of an animal with other organisms and with its environment. Studying animal behaviour can provide important information for species conservation and management. In this thesis, I aimed at closing fundamental knowledge gaps on different behavioural-ecological aspects of the three migratory species of ... Columbiformes (order of doves and pigeons) native to Europe. The species studied include one of the most rapidly declining breeding birds in Europe, the European Turtle Dove (Streptopelia turtur). As a Palearctic-African migratory species, it is the only long-distance migrant among the European native wild Columbiformes. On the contrary, Common Woodpigeons (Columba palumbus) and Stock Doves (Columba oenas) are both short-distance migrants. They belong to the most common European breeding birds or have a stable population trend, respectively. All three species are regularly hunted in several European countries. In my thesis, I examined the wintering areas, migration flyways and phenology of European Turtle Doves by means of analysing feather-isotope values (chapter 1) and satellite tracking data (chapter 2). My findings highlight the use of several migration flyways and suggest that individuals breeding in different parts of Europe may occupy separate African wintering grounds. Tracking of Common Woodpigeons with GPS-GSM transmitters (chapter 3) showed that individuals breeding in Germany are facultative partial migrants, which can switch their migratory strategy (resident vs. migrant) between years. Tracking data evaluated along with land cover data indicated that both European Turtle Doves and Common Woodpigeons adapt their foraging areas and distances to the availability of food resources (chapters 2 and 3). A comparative assessment of diet components, analysed from faecal samples through DNA metabarcoding (chapter 4), revealed a variation in the presence and frequency of occurrence of diet items between the three species. Identified diet components were mainly seed-bearing plants (Spermatopsida). Furthermore, comparisons with previous studies suggest distinct regional intraspecific differences in diet composition. An evaluation of haemosporidian parasite infections (Plasmodium sp., Haemoproteus sp. and Leucocytozoon sp.) from avian blood samples (chapter 5) demonstrated interspecific differences in lineage diversity, overall and genus-specific prevalence. The observed infection pattern supported the assumption that long-distance migrants harbour a higher parasite prevalence and diversity compared to resident or short-distance migratory species. Summarising, the findings of this thesis (i) enable a better interpretation of different behaviours observed in the Columbiformes, (ii) help to comprehend how behavioural habits are influenced by ecological causation and (iii) emphasize the distinct behavioural diversity and plasticity present among species as well as individuals. Furthermore, the results contribute to a greater understanding of the general and specific ecological requirements of the species of Columbiformes. This can help to optimise present or to plan effective future management and conservation strategies that reconcile the challenges of game bird management on the one hand and species conservation on the other hand.