Thursday, 31 October 2013

Titchfield Haven - Late October 2013 Bird Ringing Update

With the bird ringing season at Titchfield Haven rapidly approaching it's close, the number of birds ringed is dropping off dramatically. Migration is of course still in full swing, but it is the arrival of winter thrushes and finches that predominate now, and these species do not venture into our ringing area very much. That said there is still the chance of the odd rarity, as was demonstrated on Saturday when we ringed our first Radde's warbler, so we will keep going for a few weeks yet. weather permitting.

Up to the 26th October we had ringed 4037 new birds of 39 species, and had re-trapped/recovered a further 253 birds, bringing the grand total to 4290 birds. Barry Duffin has been keeping a tally of birds ringed since 1973, and this years total represents the fourth highest total of all time. I know I have referred to 2011 many times, but it was an exceptional year with 5194 new birds ringed.  In 2002 a total of 4923 new birds were ringed, but that year is skewed since we ringed a two different locations on the reserve. The third best year is 2004 when 4276 new birds were ringed. The grand total of birds ringed since 1973 now stands at 77,724 of 118 species. This total includes all birds that have ever been ringed, and in the early years the ringing effort was more random. Since 1998 we have ringed with a more structured effort, only doing three sessions a week, and where possible opening the same number of nets. This therefore enables us to draw some comparison between different years in that period.

Total ringing captures at Titchfield Haven for 2013

Looking again at the nine sample species that we have chosen for comparison over the last four years, it would appear that there has been some good productivity for most species. Sedge warbler numbers have been excellent with the total of 1431, only five birds short of the best ever total. Reed warbler numbers also seem to have recovered from last years low; the 608 birds ringed is the second highest total ever. Willow warbler numbers recovered from what looked like was going to be a bad year; 138 birds is the sixth highest total.

We tend to judge grasshopper warbler numbers on that stunning total of 950 birds in 2011, but that was clearly an exceptional year for the species. The 318 birds ringed this year although the lowest for the last five years, is still the sixth highest total. This total may indicate a more difficult breeding season for this species, it will be interesting to see what the national trend is. The three species of Sylvia warbler, Garden, Blackcap and Whitethroat, all appear to have had a good year too, with the third, fifth and second highest totals, respectively. The whitethroat total was only the third time we have captured more than 100 birds in a season.

This year the chiffchaff number were boosted in the early season by a good breeding population in the ringing area. In the mid season the numbers dropped, but as is typical of this late migrant the numbers picked up again in the late season. The total of 377 is the third highest total. And finally Cetti's warbler, a species which has a stronghold at the Haven and after a couple of hard winters, which resulted in a reduced population, this year has seen the third highest number of birds ringed ever.

A couple of other species that seem to have had a good year are robin and song thrush. But these totals have been boosted in the last couple of weeks by an influx of birds from the continent. This is something which hasn't yet happened for goldcrest and firecrest as we have so far ringed only 7 goldcrests and no firecrests, compared with 56 and seven, respectively last year.

No comments:

Post a Comment

Related Posts Plugin for WordPress, Blogger...