| Nederlands

Individual fitness correlates in the Black-tailed Godwit

(2010) Schröder, Julia

The world we live in is constantly changing due to human activities. This affects selection pressures, especially for species living in human-made habitats. Such changes in selection pressures are imprinted in the natural history of a species. In my thesis I set out to find such patterns and discuss how human-induced changes such as agricultural intensification, changing landscape use and climate warming, could have affected, and probably still do affect, black-tailed godwit breeding and migratory biology. I present data on timing of breeding and reproductive investment, and discuss the historically changing patterns in the light of advancing changes in agricultural practice and climate. Correlations between fitness correlates and plumage ornamentation are presented. Historical data on the same traits gathered from museum skins, revealed a change over the last century. I also compare data of the Icelandic godwit subspecies and find, with respect to plumage ornamentation, a contrasting pattern, possibly due to differences in timing of historical and recent developments of agricultural advancements in Iceland vs. the Netherlands. This suggestion is supported by additional findings related to breeding density. I also analytically predict the future population development of breeding black-tailed godwits breeding in the Netherlands. The results are disheartening and they suggest that if no decisive and deliberate measures are taken immediately, the black-tailed godwit will soon be a rare breeding bird in the Netherlands.