Ringing and Results

A review of ringing in 2022

In 2022 the group ringed a total of 2,957 new birds, which is an increase of just over 1,100 birds from 2021 and just over 70% of the long-term average of 4,112 birds (based on data from 1960 to 2022). A total of 60 species were ringed, which is up six species from 2021 and 91% of the long-term average. Of course, our objective in ringing is not just to ring as many birds as possible (although as small birds have a very low reporting rate, more birds means more likelihood of getting data about their movements), but to glean as much information as possible on how they are faring and what locations we share our birds with.

These low totals are largely the result of further access restrictions to areas of the site. A few months after being granted access to the Thames Water South Lagoons again (although not yet the Works), a ban on general ringing by RSPB on their reserves was put in place in the summer; this was their response to increasing cases of Avian Flu in the country. Thankfully the RSPB granted an exemption for project ringing, and our application to complete our official CES visits on the reserve was accepted, so that valuable data from that project at least could continue to contribute to the national scheme. This on-going ringing ban has meant normally productive sites on the reserve for autumn and winter migrants sadly went unused in the second half of the year.

New record totals were set for three species. Firstly Jack Snipe, with 25 –  an increase of ten birds on the previous best. As well as the traditional drag-netting method which has served the group very well in the past, we have, since November, started using thermal imaging equipment to help locate Jack Snipe in the meadows, with very encouraging results. Secondly, our seven Tawny Owls, thanks to unusually two pairs on site, rearing six young. Thirdly, we ringed a total of 73 Cettis Warblers, and finally we equalled our best year for Treecreepers with a total of 14 birds ringed – a total we’ve reached in four other years!

Chiffchaff took over top spot from Reed Warbler’s four-year run as the most-ringed species on our site; the number of warblers ringed in general was up.

However, there were disappointments too. Despite a record 301 pairs of Black-headed Gulls and 19 of Common Terns, those nests on the rafts (and later those on the scrape too) were subject to night time predation of the chicks. No young survived on the rafts and only 40 or so gull chicks fledged from the scrape and south lagoons rafts. Rather surprisingly the finger of blame points to Otters, who have been regularly picked up on the reserve’s trail cameras this summer. Consequently, the number of Black-headed Gulls ringed was very low, and we missed out on Common Tern altogether, which is our first blank year for this species since 1970.

Thanks to regaining access to the Thames Water south lagoons and the ringing ban exemption on the RSPB reserve for project ringing, we managed all twelve official visits of both South and North CES sites. Both of these sites yielded numbers of captures well above the long term averages.

In terms of recoveries (birds we ringed that were subsequently reported from elsewhere), records of note include our 43rd Tufted Duck recovery, this time to Russia; and from the chicks ringed at nests on the rafts we had Black-headed Gulls to Shropshire, Gloucestershire and Cornwall and a Common Tern to France. A Tawny Owl chick ringed in April 2022 sadly didn’t get very far; the partly eaten corpse was found in the meadows. We’ve had Blackcaps to Kent, the usual Sedge Warbler to East Sussex, and Reed Warblers to Hertfordshire, Greater London, East Sussex, and Portugal.

As for controls (birds ringed elsewhere that we subsequently capture), as well as the usual Black-headed Gulls from Essex and Hertfordshire, we also had one from Croatia, which was our second ever bird to or from that country. We also had our second ever Chiffchaff from Denmark, our second ever control from Derbyshire in the form of a Blackcap, and a Chaffinch from Norway.

With contributions from Roger Emmens, Alan Harris and Jan Swan

The table below shows the totals ringed in 2022 with the previous year’s for comparison, and the grand totals for the Group.