A bit more ageing and sexing!!

 We have been catching quite a lot of Brambling and Siskin recently, and here are a few pictures to illustrate a couple of clues that we look for.

First, I have talked about a feature of fiches whereby the colours are muted during the winter because the coloured feathers are 'hidden' by them having pale tips, which break or wear off just before the breeding season to reveal the breeding colours. Team member Jenni took this stunning and unusual picture of the mantle ( upper back) feathers of a male Brambling recently.....

Here you can clearly see the pale tips to the black feathers on the mantle. In the next couple of weeks these will wear off and the black feathers will show at just the right time for breeding.

This next picture is of the wing of another Brambling showing how we can tell that it's a juvenile, born last year....

The arrow points to the outermost greater covert, and you can see that it is both shorter than the other greater coverts as you move towards the body of the bird--and this one is white tipped rather than orange. This is a feather left from when this bird fledged which ( unlike the others in that row) it hasn't yet moulted and replaced with an adult type feather.

These next two pictures are of Siskins ( although you wouldn't know it.......!! Now Siskins are easy to sex in the field because males and females have very different plumage. But some birds eg Dunnocks have no sexual plumage difference. However, in the breeding season we can often separate males from females by closely examining their belly--and gently blowing apart the feathers. Females develop a brood patch whereby the belly feathers drop out to leave bare skin with which to keep the eggs warm

You can clearly see that here. The skin also gets well supplied with blood vessels, and wrinkles to increase its surface area. In contrast males usually develop a 'bump' on their vent, called a cloacal protuberance, ( white arrow) with a tuft of feathers, ( yellow arrow), as shown in this picture......

Lastly, I've mentioned a few times our member Pat, who moved to a village west of Welshpool a couple of years ago. In that time his garden has developed a reputation within the group as a great place to ring Siskins, and we take our trainees out there to benefit from the exposure to a large number of birds in order to learn as much about them as possible. Last year we took (then trainee but now qualified) member Liz an she had a wonderful time handling around 60 Siskins in the day! Pat's place became known as 'Siskin City'--and yesterday we tool advanced trainee Tom out. Even we were surprised and impressed by the number of Siskin in his garden--we caught 147, in just one medium net during our 3.5 hour visit!!! Remarkable. Here's a picture of us extracting birds from the net. No sooner had we emptied it than it filled up again-and again-and again. Thanks Pat, and well done Tom.