Saturday, 26 July 2014

24th to 26th July

The weather has been favourable for ringing over the past few days and the fine conditions with light winds at either end of the day have helped produce some very good catches. I have managed to fit in 2 evening and 2 morning sessions over the past 3 days and was tempted to put in that amount of effort because of the good weather and number of birds that have been about.

There appears to have been a bit of an influx of Willow Warblers which has supplemented the locally bred birds and resulted in a good number being caught. This influx of Willow Warblers has coincided with arrivals on Bardsey Island over the same period and suggests there has been a large scale movement down the west coast. Willow Warblers have declined markedly in recent years and have been outnumbered by Chiffchaffs in the ringing totals for quite a few years now so it is good to see them show some signs of a resurgence. Evidence of migration also came in the form of a Reed Warbler which was well away from the nearest breeding habitat along with 2 adult Garden Warblers which were similarly on the move.

A freshly moulted adult Willow Warbler (left) and juvenile right showing the difference in the colour of the underparts. Adults are generally much whiter below whereas juveniles have extensive lemon yellow underparts.

Juvenile Reed Warbler 26/07/14

Adult Garden Warbler 26/07/14. 

Garden Warblers don't breed at any of my ringing sites and only occur as a
scarce and less than annual passage migrant.
Goldfinch family parties are starting to merge into flocks and although most of the birds caught have been juveniles there have been a few adults which I have photographed to add to my sexing guide update or may even result in a new post. Being able to confirm the sex of the birds from the presence of a good brood patch or the shape of the cloaca has been really useful; I now have some photographs that show how much overlap there is in the plumage features of the sexes especially with regard to the extent of the red on the face.

Female left and male right. The slight difference in colour cast was caused by the lighting conditions with the female caught on a dull evening and the male caught in bright morning sunshine. The female clearly has an extensive red face mask that extends well behind the eye and bit further than that of the male. There is not a lot of difference in the lesser coverts although the fringes of the male's lesser coverts were golden (brownish-yellow) and the fringes of the female's were brown and a bit more extensive. In terms of plumage features the nasal hairs stand out as being the most different with the female's being white and the males being black.
There were roughly between 100 and 300 Swallows using the roost but some birds only dropped in late and from some height making numbers hard to gauge. These late arrivals were presumably birds that had been on the move and were looking for a roost to join.  At the other end of the scale in terms of numbers I am still catching the odd wandering juvenile Willow Tit with another ringed this morning. All in all it has been a very interesting and productive few days especially when you consider that I only used 2 nets for each session.

Ringing Totals 24th to 26th July (retraps in brackets).
Willow Warbler 32 (3)
Chiffchaff 10 (1)
Blackcap 10
Whitethroat 5
Garden Warbler 2
Reed Warbler 1
Goldcrest 3
Goldfinch 24
Linnet 8 (1)
Chaffinch 5
Reed Bunting 2
Yellowhammer 1
Swallow 41
Blackbird 3
Long-tailed Tit 2
Great Tit 1
Willow Tit 1
Total 151 (5)

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