Unexpected Blackcaps

I had a bit of a lie in today because the forecast was for heavily overcast conditions and little or no breeze that would last throughout morning. Luckily the forecast looked like it was going to hold true and I headed off to the baited site at Crawford at 8:00am under a completely grey sky and with little or no breeze to speak of. I didn't go earlier as there doesn't seem to be any advantage in setting up at dawn at this site now the days are much longer and had I thought the conditions would have remained the same throughout the day I would have opted for another afternoon visit.

First job was topping up the feeders and judging by how much the food had gone down since they were filled on Friday they were still being well used. I quickly set up the usual 18m net and I didn't have long to wait before the first bird was caught. There were a few Goldfinches and Tree Sparrows around but the first bird caught turned out to be a Blackcap. One had been singing while I was setting up and I assumed it was the bird I had first heard a few days ago (on the 3rd). A pair normally breed at the site so a singing Blackcap wasn't unexpected and nor was catching it. However, I didn't expect that 5 of the total of 20 birds caught over the next 3 hours would be Blackcaps (4 males and 1 female).

Male Blackcap

Female Blackcap

Looking at other blogs and sightings reports there appears to have been a bit of an influx of Blackcaps into the region overnight and it is likely that some of the Crawford birds fall into that category. The glut of ivy berries in the hedge by the feeders probably helped by providing a good refuelling point for recently arrived migrants.

The rest of the catch was pretty much as expected in terms of species but wasn't without interest. Two of the Goldfinches were fat with the heaviest weighing 19.7g which was 5.3g heavier than the lightest Goldfinch caught. The retrap Tree Sparrow was interesting as it was the first one from a previous year and was originally ringed as a breeding female on 9th June 2016. It was also interesting because of the state of its plumage. It basically looked like it had been attacked by a mad hairdresser for want of a better description. Many of the barbs of the feathers of the underparts appeared to have broken off and other feathers were similarly affected to a lesser degree. As to the cause I have no idea but I have caught Blue Tits that were similarly affected in the past.

Female Tree Sparrow S144976

A close up of the junction between the affected and the seemingly unaffected feathers.

Many of the wing feathers had a ragged edge.

The tail was in a poor state, the breakages didn't follow any fault lines and appeared to be quite random. It is as if the feathers have become brittle and the breakages happened during preening and that is perhaps why the head and neck appear to be the least affected.

Ringing totals (retraps in brackets) for 07/04/2019 were: Blue Tit 1; Great Tit 1; Blackcap 5; Blackbird 1; Tree Sparrow 3 (1); Robin 1; Chaffinch 1; Goldfinch 4(2).