The following morning as I was sitting at home looking out of the patio window I saw a male Blackcap hop out of the conifers and onto a bird feeder containing sunflower hearts. I was a little surprised as the spring arrivals had certainly not made it to these parts yet. Later that morning when the sun was out the bird was in full song.
It was then seen regularly each day on the same feeder, I surmised that this was probably an overwintering bird that was putting on weight before heading towards central Europe for the summer. I do very little ringing in the garden but when I do I usually use traps rather than mist nets. I usually keep a couple of chardonnerets out and baited with mixed seed, almost like supplementary feeders - but not set for trapping. On Wednesday I added sunflower hearts to the feed tray in one of the traps and within a few minutes the Blackcap was in the trap feeding!
This morning the bird was still coming in to feed so I set the traps and soon caught it. As I picked the bird out of the trap I could feel it was no lightweight and when I weighed it topped the scales at 25.7g and on inspection it had a fat score of 5. I had a quick look at Blackcap weights on our IPMR system and of the 3518 weight records we have for Blackcaps in Nott’s this was the equal second highest weight recorded, the highest being 26.1g. This weight and the other 25.7g weight we have on our database were both recorded in the Autumn period, as have all weight records we have over 24g. So a nice capture and as I suspected it probably is an overwintering bird that is about to head into central Europe.
(photo: Christine Hemsley)