Ringng at Woolston Eyes - summer 2013 Michael Miles

In the period from April through September the team at Woolston ringed 3,772 new birds compared with 3,064 in the corresponding period of 2012, an increase of 23%. Although this appears to be a marked improvement it should be remembered that 2012 was a very poor season. This summer’s total is still 10% lower than the very good summer of 2011.Ringing effort year on year was broadly constant although a few sessions were lost to rain or high winds and the access to No.1 bed became impassable for a short period. The early part of the season was cold and wet and the “spring” was very late arriving. Early nests of species such as Blackbird and Robin suffered high levels of predation because there was little leaf cover to hide them. The entire season appears to have been delayed with some juvenile birds still going through their post-juvenile moult in October.

A large amount of management work took place last winter on No.3 bed under the terms of the grant for Higher Level Stewardship. Invasive scrub has been removed and channels of open water created to reconnect the pools on the bed. This work did not encroach on the areas where nets are set so ringing was not impacted. As I write this the contractors are returning to complete the work on the bed. This will include construction of a pool with an island suitable for a decent sized duck trap. This is the most exciting development in ringing on the bed for many years.

The work on the bed paid immediate dividends in the form of the best wader passage through the bed for many years. In ringing terms this was evidenced by the catching of Woolston’s first Ringed Plover and third Common Sandpiper.

The increase of 708 in new birds ringed is spread across a number of groups. We ringed 291 more hirundines, returning to the catching levels of 2011. This reflects improved weather conditions in the late summer/early autumn period and the formation of an accessible roost on No.1 bed, an event that did not happen in 2012. There were no significant Hobby events this year although there were the usual “bouncing Sparrowhawks” on several occasions.

In general, warblers had a better season and 269 more were ringed than in 2012. (1,693 vs. 1,424). Acrocephalus Warblers returned in good numbers. On No.3 bed we recaptured 37 of our own returning adult Reed Warblers. They also enjoyed a good breeding season and any early losses seem to have been replaced with later broods in the warm weather of July and August. As a result we ringed 89 more Sedge Warblers and 114 more Reed Warblers when compared with 2012. In contrast only two Grasshopper Warblers were ringed, down from four in 2012 with no evidence of successful breeding. The other warbler that had a particularly good season was Chiffchaff with 397 new birds ringed compared to 298 in 2012. This represents a recovery to the “norm” as the 10 year average for Chiffchaff is 399. Just a single Lesser Whitethroat was ringed. Never common at Woolston, only two were ringed in 2012 and this represents a particularly poor run of catches. The resident insectivores enjoyed mixed fortunes. What might be called “exposed nesters” particularly if the trees had no leaves, suffered high levels of predation and catches reflect this with Robins down 28%, Blackbirds 36% and Song Thrushes 54%.

In the case of Song Thrushes 2012 was an exceptional year and several new birds have been ringed in October so the outcome at the end of the year may be less unfavourable than currently appears to be the case. In contrast Wrens and Dunnocks, maybe nesting in better cover, did not suffer in the same way. Dunnock catches were up 40% against a poor year in 2012 and Wrens were caught in similar numbers.

The resident tit species had a fair breeding season in line with the last two years and do not seem to be subject to the fluctuations seen in the wider countryside. Year-round feeding must contribute to their winter survival but fledging success is also consistently good. Long-tailed Tits recovered from a very poor 2012 and some large family parties have been seen on the beds but catches are still below the 10 year average up to 2010 of 169 new birds ringed.

Amongst the seedeaters, 381 new Greenfinches were ringed; an increase of 128% on 167 in 2012 and Chaffinches were up 61 from 72 to 133. As ever these numbers must be treated with caution because many of these finches come onto the beds to the feeders or to feed on the ground in the sacrificial crop and timing of movements can have a big impact on numbers. Bramblings are irruptive. Last year was not much of a Brambling year with a movement starting in the second winter period. We ended with 30 birds ringed. The birds stayed until April and this year we have caught 96 to date. This is the highest annual total ever at Woolston and the century beckons.

Bullfinches have enjoyed an exceptional few years with the average of newly ringed birds in the four years to 2012 being over 200. There has been a decline this year with 123 new birds ringed in the summer period compared to 149 in 2012. However this still represents a good population at Woolston. Catches of Reed Buntings are in long term decline. The ten year average up to 2007 is 255 and in the five years to 2012 this declines to 160. This year shows this decline accelerating with just 50 new birds ringed to the end of September. The steepest decline has occurred on No.3 bed and the reason is unclear. It may be that some of the resident adults were displaced by the work over the winter.

Away from the core species, the winter weather was not conducive to trapping and no ducks or rails have been ringed so far this year. Sightings of Sparrowhawks at Woolston seem to be fewer than in past years and just one new bird has been ringed. A handsome male Redstart was a pleasant surprise on No.3 bed and the only kingfisher of the summer was the first caught on that bed since 2010. On No.1 bed a Nuthatch visited from the golf course on the south side of the ship canal and two Tree Sparrows were the first at Woolston since 2004.