Sökning: "ecology"
Visar resultat 26 - 30 av 1824 avhandlingar innehållade ordet ecology.
26. Population dynamics of tundra-living grey-sided voles
Sammanfattning : This thesis deals with the dynamics of tundra living voles with emphasis on the most common one, the grey-sided vole (Clethrionomys rufocanus). The tundra area chosen for the study was Finnmarksvidda, a vast flatland in northernmost Norway. LÄS MER
27. Reproduction and moult in pied and collared flycatchers (Ficedula hypoleuca and F. albicollis) : A life-history approach
Sammanfattning : This thesis examines the trade-offs between investments in reproduction and self-maintenance (moult) in pied and collared flycatchers (Ficedula hypoleuca and F. albicollis). These two long-distance migratory passerine bird species were studied on the breeding grounds in Fennoscandia and in England. LÄS MER
28. Rarity in boreal stream: patterns, causes and consequences
Sammanfattning : Patterns of site occupancy among boreal stream insects were studied in central Sweden with focus on sparsely distributed species and the role of dispersal and niche limitations.In the study of dispersal limitation, I found that effects of an extraordinarily harsh winter in small to medium-sized streams were strongest in sites located in small streams and far from lake outlets. LÄS MER
29. Cryptic coloration, microhabitat choice and polymorphism in Idotea baltica (Isopoda)
Sammanfattning : In this thesis I have studied cryptic coloration, microhabitat use and colour polymorphism in the marine isopod Idotea baltica. In the Baltic Sea it lives and feeds mainly on the seaweed Fucus vesiculosus, which in sheltered sites usually is whitespotted on its lower parts due to epizoites. The white-spotted morph of I. LÄS MER
30. Trade-offs between life history traits and immune defence in the collared flycatcher Ficedula albicollis
Sammanfattning : This thesis examines the effects of reproductive effort on immune function and parasite resistance in breeding collared flycatchers, Ficedula albicollis. It also focuses on the role of the immune function in the trade-off between number and fitness of offspring. LÄS MER