Essay On Bird Migration

This thesis tries to summarize relevant literature on the influence of climate change on bird migration. The research on bird migration, and especially timing, started around the 1950s (Kramer 1950), and recent climate changes have made this field of research even more interesting and necessary. Here, the two major subjects of climate change and migration are brought together to answer two main questions: 1. Will birds delay or advance their migration timing in response to climate change? 2. Will birds change their migration route and/or goal in response to climate change? The answer reveals many unanswered questions and fields still to be studied.

Birds use many different strategies to time their migration and to orientate and navigate during

Cultural changes like forest clearings, hunting, but also loss of habitat and food resources may cause birds to change their breeding or wintering area or advance or delay their migration (Böhning-Gaese and Lemoine 2004, Coppack and Pulido 2004). For instance, hunting on geese species showed to delay migration timing, due to high hunting pressures on geese in Europe (Kruckenberg 2003). Furthermore, the timing and migratory restlessness of urban birds and rural birds might differ. Urban birds seem to show less migratoriness than rural birds and are more prone to stay in the urban habitat year-round (Coppack and Pulido 2004). This may be the result of the warmer habitat in urban areas and more artificial light, but also winter feeding by humans. Finally, human activities might also enable species to winter at or closer to the breeding grounds or shift their distribution. For instance winter feeding of blackcaps in Britain, herring gulls that feed on open garbage dumps or coots that are able to winter on ice-free water near a power plant (Fiedler et al. 2004 and references therein). It is important to implement these human induced changes to the environment into research on timing and distribution of migratory