07 December 2012
Migrants delayed by drought in Africa
A recent paper in Science: “Drought in Africa caused extreme delayed arrival of European songbirds”, by the CMEC researchers Anders P. Tøttrup, Mikkel Willemoes Kristensen, Carsten Rahbek and Kasper Thorup, explains the exceptional late arrival of many European songbirds in 2011.
Using 1-g light-level geolocators to track red-backed shrikes and thrush nightingales during their entire annual cycle, the authors pinpoint the delay to coincide with the catastrophic Horn of Africa drought. This documents so-called carry-over effects between the unusual drought conditions on the Horn of Africa and the late arrival in northern Europe.
Given that arrival in migratory songbirds has advanced by more than a week due to climate change during the last decades, the delay in 2011 was unexpected and current research models linking arrival to breeding area conditions failed to explain the delay.
Tøttrup, A.P., Klaassen, R.H.G., Kristensen, M.W., Strandberg, R., Vardanis, Y., Lindström, Å., Rahbek, C., Alerstam, T. and Thorup, K. (2012). Drought in Africa caused delayed arrival of European songbirds. SCIENCE 338: 1307