Our main target species in the small nature reserve in Bedfont Lakes Country Park is the reed warbler. The ones that breed on our site have all left weeks ago, followed by the young birds who hatched in Bedfont this summer. To our surprise, we’re still catching reed warblers on migration from northern parts of the UK, later than ever before. Most of them have very little fat on, which may be what’s keeping them from moving on. If they attempted the long journey with no fat reserves, they would likely not make it.
There is a good number of blackcaps turning up in our nets. While UK blackcaps mostly leave for North Africa, some populations from central Europe choose UK to overwinter in. Below is a close-up of a female blackcap’s head.
And here is a photo of her wing:
We aged her as a bird born this year based on the moult limit in the greater coverts and narrow, pointy tail feathers. The moult limit may be hard to see depending on light and angle. In the photo only two outer greater coverts have distinctly more brownish edging, but if I remember correctly, there were more old greater coverts… I keep tilting the laptop screen backwards and forwards, trying to see it now to no avail. This is why it’s important to rely on more than one feature in ageing birds!
We also get a fair number of blue, great and long-tailed tits (below), which form flocks at this time of year.
Chiffchaffs have also been turning up in good numbers.
Last Wednesday we sat very close to the nets and had the opportunity to observe how birds reacted to seeing others in the net. While social birds like tits will hang around their trapped flock-mates, and especially long-tailed tits will repeat the flocking call, reluctant to leave, I didn’t expect to see a similar behaviour in chiffchaffs. One fell into the net and another kept flying up and hovering next to it, returning to a nearby branch, then repeating it again and again. It wasn’t trying to get across to the other side as it would only hover right by the other bird, looking at it. I know we shouldn’t project human emotions onto birds because they are likely to think in ways vastly different to ours, but it did seem like the chiffchaff was concerned about the other one and did not want to move on without it. The behaviour was too persistent to be just curiosity. Perhaps chiffchaffs bond with each other during migration?
We’ve been getting birds with ticks quite often towards the end of summer and beginning of autumn, mostly thrushes and blue or great tits. Ticks attach themselves to the nape or neck, where birds cannot reach them, and even little birds like blue tits may be carrying multiple ticks. A wren we netted had a tick the size you might find on a dog – imagine what a burden that must be! Our ringing group removes ticks, but not everyone does that. While I can understand the argument that we should not interfere, on the other hand we already affect the birds’ lives by netting them, causing them stress, preventing them from feeding for a short time, potentially leading to some birds becoming separated from their foraging flocks, so personally I think of removing ticks as a small favour we can do for them. Our impact on the tick population is negligible, and although we are not tick experts, the ticks we find do not seem to be host-specific. Of course, there will always be different opinions on the subject of when it is okay to try to help a wild animal.
The bat group who checks bat-boxes in the park kindly showed us a pipistrelle:
Gloves must be worn when handling bats, which may carry rabies. Bird ringing in city parks is a much less dangerous activity, as basic hygiene is all you need not to catch any disease or parasites: don’t reach for a biscuit with poop-stained hands. Although veteran ringers have been known to lose all fear of germs and parasites, or perhaps their biscuit cravings are too strong for hygiene concerns to stop them…