When two legs are better than one: the spring migration of Black-tailed Godwits.
The winter range of Icelandic Black-tailed Godwits covers a relatively wide latitudinal spread, from southern Spain to Scotland. Even though not at the extremes of this distribution, a flock of birds in Lisbon experiences very different mid-winter conditions to a flock of birds in Liverpool. December days never get shorter than 9hr 27min in Lisbon, which is 2 hours more than in Liverpool, and the average maximum daytime temperature is 14⁰C, as opposed to 6⁰C. On the negative side, it’s a lot further from Iceland to Portugal than it is to northern England.
José Alves enjoying warm winter conditions in Portugal
In other studies (of Avocets and Cormorants, for instance) it has been shown that individual birds that winter close to their breeding areas are able to arrive back earlier in the spring than ones that winter…
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