Search for dissertations about: "migration of bird"
Showing result 1 - 5 of 39 swedish dissertations containing the words migration of bird.
-
1. Flight Behaviour of Passerines on Nocturnal Migration
Abstract : Many passerines migrate during the night and at high altitudes, making their migration difficult to observe. By using tracking radars we have been able to make exact observations of the flight behaviour of passerines on nocturnal migration, which has enabled us to test several hypotheses about adaptive values and constraints regarding migratory behaviour in different ecological contexts. READ MORE
-
2. On the role of migration for the distribution of arctic birds - a circumpolar perspective
Abstract : Flexibility as well as constraints to the evolution of migration routes has the possibility of affecting large-scale patterns of geographical ranges of animals both by facilitating, but sometimes restricting, accessibility to and colonization of new regions. This dissertation concerns the broad-scale effects migration has on the distributional patterns of birds in the Arctic. READ MORE
-
3. The Problem of Partial Migration - the Case of the Blue Tit
Abstract : In the evolution of bird migration, partial migration is assumed to be an important intermediate step between migration and residency. Partial migration is characterised by the existence of both migratory and resident individuals in a given population. READ MORE
-
4. Individual consistency in bird migration
Abstract : Slight differences, which appear in the individual animals of the same species and population have been recognised and appreciated ever since Darwin. These consistent intra-specific differences in animals have been considered very important because they are often inherited, and thus, provide the basic material for evolution to act on. READ MORE
-
5. Ecology and evolution of large-scale bird migration patterns : A natural history and comparative study of the migration in common and little ringed plovers
Abstract : Migration distance and seasonal redistribution patterns may vary between and within bird populations. A common pattern is leap-frog migration, in which northerly breeding populations migrate farther and winter south of more southerly breeding populations. READ MORE