29 Feb 2016

Siskins galore................

Wow. It's proving to be a god year for Siskins locally. I've now ringed 51 since the middle of January with a best day total of 24 new birds. I'm sure I could catch more if the weather had been better but wind and rain has limited my mist netting activities. To put this year into perspective I've only caught Siskins in one other year since 2011 and that was 2013 when I caught 20 birds.

The trees are alive with them early morning and they seem to arrive about an hour after sunrise, feed up and then go off to digest their food before hitting the feeders again. So far I've only re-trapped 3 birds.

Using the DuFeu formula that allows you to calculate the population of a species by logging the number of new recaptures (24) and the same day recaptures (1) the estimated population of Siskins using the garden to feed up before migrating north is an incredible 269 birds. At anyone time there is a flock of 20-30 in the trees surrounding the pond adjacent to the house and the noise is incredible.

Its been interesting to study the moult in these birds with many 2nd calendar year birds having undergone an extensive full post juvenile moult, having all new greater coverts and some having a limited post juvenile moult with no new greater coverts. Some have moult limits in their median coverts and some have moulted greater coverts and median coverts out of sequence:

 Above: 2nd calendar year Siskin (Euring 5) with all old juvenile greater coverts but showing a moult contrast (symmetrical in both wings!) in the median coverts. The median coverts have been moulted out of sequence.

Below: 2nd calendar year Siskin (Euring 5) showing moult contrast in greater (6 old) and median coverts (3 old).

As well as Siskins I've been catching a few other finches although Goldfinches are quite scarce. Its been nice to see a few more Chaffinches around and they're probably being attracted to the food source by following the Siskins.

This female (below) is a 2nd calendar year bird showing a moult contrast in the greater coverts and a typical juvenile type tail with worn and pointed tail feathers.

Its not all been about the birds though and I've been lucky enough to find a local colony of Bee orchids numbering 18 plants - the rosettes are just coming through. This is about 50 m from where there used to be a thriving colony a few years ago and in the same spot where I found a single flowering plant last year.

Its hard work keeping motivated to walk my local patch regularly this time of year. There are no new birds and being a predominantly improved pasture area with a few small ponds and copses there isn't a wide variety of birds to be found. The joys of an inland north patch!

No comments :