Saturday 13 April 2013

Yellow-fronted and Cross-billed Blue Tits - April 2013

It was almost back to normality this week in that I dusted off my ringing kit and was able to have three ringing sessions. For the first I headed back down to Manor Farm Country Park, whereas the two latter sessions were in my back garden. 

Sunday 7th April was the first session and having not got up very early for a while, it was tough extracting myself from the warmth of my bed at 05:15, and when I ventured outside, the heavy frost covering my car didn't help to fill me with enthusiasm. But it wasn't long before I was at Manor Farm the nets were up and and the sun was breaking through.

As with the last session I was going to be assisted by a handful of trainees only and so limited the number of nets I put up to four. The first net round yielded an adult redwing as the highlight, a couple of blue tits and a re-trap blackbird. The next round was slightly better with more blue tits and blackbirds, a few robins, on re-trap from two and a half years ago, and a couple of new house sparrows. The latter is still one of the target birds at this site, since it is where I run my BTO RAS project, alas we did not catch or see a re-trap. It is difficult to understand what is going on at this site, since the sparrow population seems to be declining, yet superficially the site looks the same. Hopefully I will have more time available this year to investigate.

The session was steady with 25 birds captured of 11 species, 16 new and nine re-traps, so a nice mix for the trainees. The highlight for all was a Eurasian treecreeper, not a species I catch many of each year, but always a delight.

The second session was on Monday 8th April, an evening session in the garden after work, oh how I love these light evenings!! Recent windy conditions have made ringing difficult, so I have to take every opportunity that I can. There have still been quite a few siskins in the garden, and this was the main motivation for opening the nets. I did catch one new one, and a new Eurasian goldfinch, but the bulk of the bird caught were blue tits. In fact it was the blue tits that proved to be the most interesting, because one had a yellow forehead and the other had a crossed over bill (hence the title to this blog post).


Yellow-fronted Blue Tit

Sometimes at this time you year birds will have yellow foreheads where they have been feeding either on pollen or the insects that are on it. Typically I have seen this in migrant birds, such as chiffchaffs just after arrival from their wintering grounds. But this blue tit has probably been feeding on willow catkins, since these are the only trees with pollen on in the field behind my house at present. I have seen several blue tits with deformed bills in the past, one of which had a ridiculously long lower mandible, which I have to admit I did trim back for it. The bird below though had a badly deformed and crossed bill, which overlapped in a similar style to a crossbill. The bird was obviously feeding OK though since it was an adult bird, and when on the feeder was happily feeding on sunflower hearts. Hopefully I will catch it again a be able to see how it's doing. This session ended with 13 birds ringed, which was a fair result for one and a quarter hours ringing.


Cross-billed Blue Tit

The third session of the week was today, Saturday 13th April, and another garden session. This session was carried out to the back drop of chiffchaff song and the threat of imminent rain, fortunately the latter held off long enough to allow a couple of hours ringing. The day began with a male blackcap on the peanut feeder, right next to the net, but not going in, but there were enough other birds to keep me occupied. Several siskins were still present in the garden, the most I counted was five, with only one having been already ringed. Blue tits were again the commonest birds, but it was worth opening the net since I also caught two  new goldfinches, two new greenfinches, two new siskins and one re-trap and a female blackcap. 

Female Blackcap (one of two in the garden)

Finally, the spring bird migration seems to have arrived, as yesterday I saw my first swallows and house martins and today caught my first balckcaps. I ended the session having caught 18 birds of six species, but have now caught 39 siskin in the garden since February.

2 comments:

  1. Presume you're near Botley, Trevor. Ringed/retrapped 32 Blackcaps this week in garden (W. Somerset). You should be catching these and other migrants next week. ATB.

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    Replies
    1. Hi Errol, 32 in your garden that is probably as many as ring on all my sites in a year, excepting that is Titchfield Haven, but we don't tend to do that in the spring. None caught this week but then it has been very windy!

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