During this week the windy weather interspersed with heavy showers has continued. Not very conducive to our autumn ringing program but I have managed to get out on three occasions.
On the 29th our trainee Carol and I visited Holton Lee, the private estate on the south side of Lytchett Bay. I was keen to see how many of the birds I had ringed last winter were still coming to the feeders. The answer seemed to be not many, as only one Blue Tit and one Nuthatch out of the 142 birds we ringed last winter were re-trapped. Of course more of last years bird might be in the vicinity, just not coming to the feeders that morning, but it does show what a rapid turn over occurs, even among sedentary birds like tits, woodpeckers and Dunnocks from year to year due to natural mortality.
We trapped three Great Spotted Woodpeckers, all young males, a new Nuthatch, several Goldcrests and two Marsh Tits. There also seemed to be a new influx of Robins, as seven were ringed. Being highly territorial in the winter, it seems unlikely that they had been around for long as you would expect a resident bird to chose and defend a territory against all comers. Although a local breeder there is definitely an influx of migrant Robins every autumn.
There has been a significant decline in Marsh Tit numbers in recent years. This has been variously attributed to competition with increasing numbers of Blue and Great Tits for food and nesting sites and to the destruction of their favoured understory by a burgeoning deer population.
On visit a Durlston on the 30th we saw a good number of finches, Redwings and even a few Swallows on migration. We ringed 35 birds, predominately Goldfinches. It would seem that the large numbers of migrant warblers we experienced since we commenced autumn ringing at the start of August is now over.
On the 2nd, Mick was joined by his friend and former trainer Mick Netherwood who was visiting from London. I have known both of them for many years since we used to ring at Chapman’s Pool, the annual visit for a week or so by the ‘two Micks’ was a firm fixture in the ringing calender. As I haven’t seen Mick N for several years, I joined them, although I have to admit the conditions weren’t promising. Increasing wind and showers meant we had to pack up by 0930 but although we only trapped 21 birds, we had a couple of corkers.
This was the first Firecrest we have trapped at Durlston this autumn. Numbers of this, our smallest bird (along with Goldcrest), seem to be increasing with more breeding pairs being discovered. It is not yet known if the Firecrests that breed in the UK are represented among the migrants encountered on the coast but ringing recoveries have indicated that many of the migrant birds come from the near continent.
The real surprise was the capture of this Yellow-browed Warbler. No longer a rarity, this species is best considered a scarce migrant. From 1968-84, 0-5 were recorded annually in Dorset, from 1985-99 up to 29, but these days over 40 are seen, with Portland taking the lion’s share. Probably a couple of thousand pass through the whole of the UK each autumn. Whilst the vast majority of the population breed in Siberia and winter in SE Asia, it may be that the most westerly breeding population is establishing a separate wintering ground in western Europe.
Today was the first date since the start of August where we haven’t trapped either a Willow Warbler or a Chiffchaff at Durlston. However in world terms YBW is perhaps the most numerous of the genus Phylloscopus, breeding across vast swathes of the Siberian taiga. This species needs to be distinguished from the very similar, but considerably rarer, Hume’s Leaf Warbler (with which it was once considered conspecific) but Hume’s is greyer, has a reduced median covert bar, all dark bill, darker legs and paler centres to the tertials and coverts. They also differ considerably in vocalisations, but that would have been of no use in this circumstance. Photo by Simon Breeze.
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