Pages

Friday 8 July 2022

Babies everywhere!!

 The start of July heralds the start of the main season at Belvide and other sites we operate at, such as Witches Oak near East Midlands Airport. Although some birds may still be breeding with second or thirds broods, the majority of breeding is finishing and migration is about to start.

The birders at Belvide reported seeing lots of family parties in the netting area so we were optimistic as we started our season. As it turns out we have had three very good sessions already and ringed over 200 new bird--over 90% of which have been juveniles pointing to an excellent breeding season. Ben has had two sessions at Witches and he also has had lots of juveniles in his 100+ total. More of this in the near future.

For now, I'll carry on the theme of the last blog and show some pictures which I hope are of interest by illustrating some of the things we get to see and use as clues to identity.

First a very familiar bird, the Barn Swallow. Two things about this bird....first it is an adult ( more than 1 year old) as seen by the deep red on the throat and forehead ( creamy buff in juveniles)--and the extra long tail streamers show this to be a male. The streamers are much shorter in females and hardly any length in juveniles.
Next another very familiar bird--a robin. This is a juvenile as you can see from the brown speckled throat and head, as we have mentioned in previous notes. However, this bird is now moulting out these juvenile feathers and replacing them with the much more familiar red breast feathers. As soon as these grow fully through the bird will be 'encouraged' by it's parents to move out and set up it's own territory.
Here is a Goldfinch which many of you will have on feeders at home. This is a male as shown by two features......most obvious is the fact that the red patch extends beyond the eye both above and below the eye. Second and a bit less obvious is the very thin hair like feathers at the point where the beak joins the skull. These so-called nasal hairs are black in a male and cream in a female.
Now on to a couple of problems that birds have.....

This Goldfinch clearly has some kind of bacterial, fungal or viral infection in the skin of it's feet--resulting in these enlarged growths. What is less familiar to us is the extra long growth of the claws as a result of the infection. Kevin reports the bird to be otherwise in good health. It's prudent after handling such individuals to thoroughly clean hands to avoid passing on the infection.
This young warbler shows very obvious growth or fault bars in it's tail. Lots of birds show these and they are as a result of changes in diet at particular points--poor food quality, shortage of food during adverse weather are two classic examples. In this particular case it enables us to tell that this is a juvenile ( newly fledged) bird--but how? You can clearly see that the lines are parallel which shows that the problems occurred while all the tail feathers were f growing at the same time--ie as the feathers do during time in the nest. If this occurs during tail moult in adult birds there would be a step between each pair of feathers, because usually the outer feather on each side moults first followed by the next inner then the next and so on.

More soon........











No comments:

Post a Comment