How to become a success
In this project I study the migration performance, route choice, wintering movements and flight behavior of swifts from different populations across their European and Asian breeding range. In this endeavor I collaborate with local ringers and scientists in different parts of the swift range.
The aim is to understand how a bird species like the common swift has become so successful in exploring different types of habitat across large areas, and how they are able to explore ephemeral food resources in geographically distant sites. When the project begun in 2009, many open questions about the swift lifestyle were still open, even though David Lack covered the swifts life in depth in his book “Swifts in a Tower” first published in 1956.
10 months without landing
So far in my lab we have been able to answer some of the open questions, such as that common swifts spend up to ten months airborne without landing during the non-breeding period. It takes swifts less than a week to cross the Sahara desert in spring by continuous flight, but more than three weeks in autumn. Most of the north European swifts start the Sahara crossing from a restricted area in West Africa around Liberia, coinciding with good foraging conditions due to rainfall and supporting tailwinds in spring. European swifts have furthermore evolved an unusual chain migration pattern. There are, however, more to be investigated.
Tracking technology, genetic tools and analysis will give answers
Questions of interest are, for example: Which migration route do different populations follow? How do they explore food resources in their wintering range? How much variation do we find in migration performance and route choice in different individuals and populations of swifts? How are swifts adapted to sleep on the wing?
To answer these and other questions I use different types of tracking technology, genetic tools, and stable isotope analyses.