ageing and sexing Spotted Redshank
On 21 June Gijsbert Twigt and I trapped a Spotted Redshank in Meijendel, Wassenaar - the first one ever to be ringed at the site, where ringing started back in 1927.
This bird is obviously in sum plum and given the time of year, it's never gonna be a juvenile of course.
Note the fairly fresh primaries. 2nd calendar year (cy) birds have very worn primaries, so this bird must be older.
It has of course a lot of white fringes on the underparts, but an interesting feature to sex birds are the central undertail coverts.
In spring males these are blackish, whereas they are white in females. So this is a female! This must be nearly impossible to see (well) in the field.
So this bird is an adult (> 2cy) female. Not surprising given the time of year: this female was already on autumn migration at the end of June. The females lay eggs on the Scandinavian and Russian tundra, but leave before the eggs hatch. The males stay behind to take care of the brood.