Sunday, 22 January 2017

Garden ringing and a big bill.

I haven't posted anything about my ringing activities so far this year but that doesn't mean I have been sitting on my hands. Much of my effort has been focused on the garden and Starlings in particular. The fat cakes have been attracting far more Starlings than I usually get in winter (despite the generally mild conditions) which has allowed me to get a lot of resightings of birds that were colour-ringed as part of my RAS project and also ring a good number of new birds. Yesterday was no exception with 9 colour-ringed Starlings recorded and another 4 new birds ringed.

D61 is a frequent visitor to the fat cakes at the moment and was ringed as a juvenile last summer.
Most Starlings can now be sexed from their bill colour with males having a blue base to their bill and females having a pink pink base to an otherwise similarly yellow bill. Some birds, all probably 2cy+, were showing these breeding season colours before the end of December but the rest are catching up now. There are other differences between the sexes with the colour of the eye being another useful feature and one that works for most individuals throughout the year. Males generally have an evenly coloured brown iris whilst females usually show a pale orbital ring within the brown iris.

Male Starling 21/01/2017

Female Starling 21/01/2017
Whilst watching the Starlings yesterday I noticed one with a deformed bill that I hadn't seen before. The lower mandible was much longer than normal while the upper mandible was quite a bit shorter than usual. It had a unique way of feeding on the fat cakes and slid the lower mandible along the side of the fat cake which allowed it to nip bits off when the upper mandible made contact with the fat cake.

Luckily it went into the bird table trap and I was able to catch it. The upper mandible looked like it had suffered some sort of damage which had allowed the lower mandible to over-grow. Normally the upper mandible overlaps the lower at the tip and, along with normal wear from feeding, helps to prevent this sort of deformity.

Male Starling with deformed bill 21/01/2017.

Male Starling with deformed bill 21/01/2017.

Male Starling with deformed bill 21/01/2017. It was an adult (2cy+), in very good condition and had clearly learned to cope with its deformity. However, it may struggle if the lower mandible continues to grow and it is likely to have difficulty feeding young if it manages to find a mate and breed.
It's not just Starlings that I have been watching and ringing as the other feeders have been attracting large numbers of birds and Goldfinches in particular. There are 7 seed feeders around the garden and the birds are currently getting through over a kilo of sunflower hearts each day.  

The scene around one of the 7 sunflower heart feeders yesterday.

 Male Goldfinch 21/01/2017

Adult male Siskin 21/02/2017
This morning I took advantage of the calm and overcast conditions and a short session with the usual 6m net resulted in a catch of 33 birds (18 new birds and 15 retraps). This was made up as follows (retraps in brackets): Goldcrest 1; Blue Tit (1); Great Tit 1;  Long-tailed Tit 1 (4); Robin 1; Goldfinch 11 (9); Siskin 3 (1).

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