Drought in the Horn of Africa delays migrating birds

University of Copenhagen News: The catastrophic drought last year in the Horn of Africa affected millions of people but also caused the extremely late arrival into northern Europe of several migratory songbird species, a study published today in Science shows. Details of the migration route was revealed by data collected from small backpacks fitted on birds showing that the delay resulted from an extended stay in the Horn of Africa.

The extensive 2011 drought in the Horn of Africa had significant consequences for European songbirds such as thrush nightingale and red-backed shrike. These birds visit northern Europe every spring to mate and take advantage of ample summer food resources.

However, their spring migrating route from southern Africa to northern latitudes passes directly through the Horn of Africa, where the birds stop to feed and refuel for the next stage of their migration.

"Our research was able to couple the birds’ delayed arrival in Europe with that stopover in the Horn of Africa. Here they stayed about a week longer in 2011 than in the years before and after 2011. Because of the drought, the birds would have needed longer to feed and gain energy for their onward travel, causing delayed arrival and breeding in Europe. This supports our theory that migrating animals in general are dependent on a series of areas to reach their destination," says Associate Professor Anders Tøttrup from the Center for Macroecology, Evolution and Climate at the University of Copenhagen....

Nestlings of red-backed shrike, an 1887 painting by Bruno Liljefors