Two good birds save the day.

The silence that greeted me at dawn this morning did not bode well for a ringing session in the top willows at Billinge and pointed to another poor showing by Goldcrests in particular. In previous autumns, when Goldcrests have passed through in large numbers, they have usually been the first species to call at daybreak and early net rounds nearly always produced the bulk of the birds. This morning the first Goldcrest wasn't heard until well after after sunrise and there wasn't much happening at the nets either.

To say it was quiet and slow going is an understatement and I thought I would end up cutting my losses by packing up early. However, the first Chiffchaff caught was really quite striking and wasn't your typical September green and mustard-yellow 'collybita'.  It was distinctly paler having much greyer tones to the upperparts, was much whiter underneath and the flanks were washed with pale brown and I immediately thought this must be a Scandinavian 'abietinus' Chiffchaff. It was certainly very different to any 'collybita' I have ever seen and I have ringed well over a thousand at Billinge and many more elsewhere.

A very grey and white looking Chiffchaff compared to your typical autumn 'collybita'. It was aged as a first-year from the shape and wear of the tail feathers.

A typical autumn 'collybita' photographed the same day in similar lighting conditions and also aged as a first-year.

The different races of Chiffchaffs present all manner of problems when it comes to identification as shown by the DNA analysis of birds caught in Holland that were identified as 'abietinus' on appearance and proved to be 'tristis' from their DNA. This and other studies have thrown the status of abietinus in western Europe into question and it now appears to be much rarer than its more easterly Siberian (tristis) counterpart. 

There are a couple of other factors that make today's bird even more interesting: one is the date, it is quite early for seeing a dodgy looking Chiffchaff which are usually associated with late autumn or winter; the other is lack of easterly winds so far this autumn which are generally needed to drift birds of such origin to the UK. Had I caught this bird in late October or early November I may have thought it to be a bird with more easterly credentials and possibly from the intergrade zone between abietinus and tristis. It has certainly got some of that look about it.

A collage of both birds. Whatever it is, and potentially proves to be in due course from its DNA, is going to be interesting.

Had I not caught that Chiffchaff I may have packed up by 9:00 but I decided to stick it out and I am glad I did as the second bird that helped 'save the day' was a 1cy female Redstart. This species is a regular but scarce passage migrant at the site and this one was only my second of the autumn and my latest by some margin. Redstarts are usually a bird of late August and early September at this site and my previous latest was caught on 14th September 2017 with all the others recorded between 23rd August and 7th September.

1cy female Redstart

The are not called Redstarts for nothing.

The final total of 30 new birds wasn't too bad but was below the average for the time of year, largely due to the continued lack of Goldcrests. Only 5 Goldcrests were caught compared to 25 on the same date in 2016 and 14 on the same date last year. One minor point of interest about today's Goldcrests is that they were all first-year females, not that anything significant should be read into that as the sex ratios usually even out over time. So while the catching rate was slow from start to finish a couple of interesting birds really did 'save the day' and made staying the course worthwhile.

Ringing totals for 23/09/2018 were: Coal Tit 1; Blue Tit 4; Great Tit 2;  Chiffchaff 6; Blackcap 2; Goldcrest 5; Wren 3; Robin 2; Redstart 1; Chaffinch 1; Linnet 1; Reed Bunting 2.