How an insectivorous migrant shorebird may mitigate the negative effects of a warming Arctic by prey and patch selection
The short Arctic summer is characterized by a spectacular outburst of arthropods. Birds migrate to the Arctic, specifically to capitalize on this rich and reliable source of arthropods to raise young. Ongoing climate change has resulted in an earlier outburst of arthropods, while birds have not adjusted their timing of egg laying. The resulting phenological asynchrony between avian predators and their prey can result in hampered growth and fledging success of the predators’ offspring if they do not adapt.
However, the tundra is not homogenous, and the availability of arthropods can vary on a small spatial scale. Parents might thus be able to guide their chicks to patches with a later arthropod phenology. In addition, different species of arthropods vary in their phenology. This might allow chicks to change their diet throughout the Arctic summer to match local changes in arthropod availability. During this PhD project, we aim to assess whether such behavioral adjustments might buffer the consequences of a phenological mismatch in Sanderlings (Calidris alba), a migratory shorebird that breeds on the high Arctic tundra of Zackenberg in northeast Greenland (74º28’ N, 20º34’ W).
We will thereby radio-track Sanderling families with varying degrees of phenological mismatch to provide detailed measurements on growth, survival and habitat use of chicks. Also, we will monitor the spatiotemporal heterogeneity of arthropod abundance on the tundra and assess chick diet using DNA barcoding of faecal samples.
Photo's by Jeroen Reneerkens, Peter Spierenburg and Gavin Ballantyne