Saturday, 21 September 2013

Going for Gold

The number of Goldfinches feeding in the garden has increased since last Saturday's successful catch and I have had to put out additional feeders as a result. I am now using 10 feeders: 2 with nyjer seed and 8 with sunflower hearts or a mixture of sunflower seeds and hearts. Even with the extra feeders most have still been getting emptied each day.

The forecast for this morning of calm and overcast conditions was perfect for a ringing session in the garden. I didn't manage to get up early as planned and only put up an 18ft net at about 8am. The first check of the net produced 9 birds including 5 new Goldfinches. The catching rate continued to be very good for the rest of the morning with Goldfinches dominating the catch as expected.
Many of the birds caught were still in full juvenile plumage like this bird.
I took the net down at lunchtime having caught 48 new Goldfinches (a new record catch) all of which were juveniles. Only 1 retrap was caught and that was an adult that I had originally ringed in the garden on 20th October last year. I had expected there to be a few retraps from the 36 Goldfinches ringed last Saturday but none of those birds were caught.

If today's catch of Goldfinches turns out to be the peak for the garden this autumn, as seems likely, it fits in well with previous years in terms of timing. On checking the data for the previous 2 years the peak catch was 18th September in 2011 and 22nd September in 2012. The fit is even tighter when you consider last year was a leap year. This is remarkably consistent given the very different weather and breeding seasons in each of those years and came as a bit of a surprise. The main variable between the years being the proportion of juveniles and adults in the catch.

The two photos above show birds in various stages of post juvenile moult.
I took a few photographs after taking the net down and only about half the Goldfinches visiting the feeders were ringed. The total number of birds visiting the garden is likely to be well over the 100 mark given that 84 new birds and 2 retraps have been caught in just over a week and many unringed birds were seen this afternoon. This is an exceptional number of Goldfinches for the garden and the high proportion in full juvenile indicates that later broods have been particularly successful.


Ringing totals for the garden with retraps in brackets:
Goldfinch 48 (1)
Greenfinch 5
Chaffinch 2
Robin 1
Dunnock 1
Great Ti 1
Coal Tit 1
Blue Tit 1
Total 60 (1)

This evening I went to the reed bed site with John G to see if there were any Swallows passing through or roosting. The MP3 lures attracted a flock of about 120 Swallows and we managed to catch and ring 57 of them. We also ringed a Sand Martin, 2 Reed Warblers, a Chiffchaff and a Wren.

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