Go fly the kites
Who’s going to snag the best mate and dominate the territory? We look at how red kites choose their wintering grounds.
Almost all young kites fly south for the winter, whereas the older birds often stay put. | Image: Halfdark / Getty Images
Not every red kite migrates south for the winter. Researchers at the Swiss Ornithological Institute in Sempach have been investigating how they choose their wintering grounds, tracking almost 500 individual birds for a good ten years using GPS. Almost all young birds flew south for their first winter. But the older they got, the more likely they were to remain in Switzerland. Their size and sex also influence their migration behaviour.
“The social system of red kites presumably plays a role in this”, says Martin Grüebler, the lead researcher on the project. “The males are highly competitive and occupy territory, while the females choose their future territory when they choose their mate. This means that large females acquire a territory earlier in their lives”. Individual birds without their own territory, however, tend to move south in the winter.
