Llanelli Naturalists Newsletter - Winter 1990/1991
Barry Stewart

Ringing efforts were carried out at several sites during the period, principally in the south of the county by Steve Ormerod, Richard Jenkins and myself. This report covers my own efforts only which were concentrated at Ffrwd Fen, Trostre and the Tywi valley. A little garden trapping was also carried out at Tir Morfa Farm at Penclacwydd and Kidwelly.

4,414 new birds have been trapped and ringed, of which over 650 were recaptured by myself in the study areas and there were 28 recoveries including a French-ringed Sand Martin for which I am still awaiting details. These totals include 50 species which are listed below with totals of new birds trapped and ringed for each year. Nestlings ringed and numbers of recoveries for the two years combined.

Ffrwd Fen

(Reed bed with encroaching willow) SN420027 etc.

Generally mist netting in the eastern corner at the site has been carried out during both years between April and October, and this year the site was registered with the BTO's Constant Effort Site (CES) Scheme, which makes the information gained more valuable for monitering the bird population over numbers of years on a national scale.

One of the most interesting finds has been the proof of breeding Cetti's warblers in both years. It is likely that this species is benefitting from the recent mild winters and hopefully they will establish a good population in the area. However, it is Reed and Sedge Warblers which form the bulk of the catches with large numbers of young birds occuring at the site during August. Often associated are smaller numbers of other warblers and chats. Lesser and common Whitethroat, Garden Warbler, Blackcap, Redstart and Pied Flycatcher have all been trapped in the reed bed during this period.

The Hirundine roost is quite a feature in late summer and consists mainly of swallows with smaller numbers of Sand Martins - as with the Llangennech roost (Ormerod, 1988) it seems there is a virtual 100% turnover of birds each night. It is therefore clear that the site is not only important for its own breeding populations, but is vitally important for thousands of passage migrants that stop to feed and roost during their journey south.

Trostre SS530993

A large roost of up to 600 Pied Wagtails forms during the winter months in the highest part of the tinplate works roof. Eight visits were made between November '89 and April '90 resulting in 292 new birds being ringed.

The species is straightforward to age and sex and results show 32% were adult males; 23% were young males; 15% were adult females and 32% were young females. Of these it was the adult males which showed the highest fidelity to the roost site with over half of recaptures belonging to this group. Presumably females and immatures are more likely to make winter movements. The only recovery was of an immature female ringed in Sussex on the 10th January 1990 and recaptured at Trostre on the 6th April 1990. Birds with rings were sighted at many local sites (including Llangennech, Llanelli Town Centre and Swiss Valley) after ringing commenced and as no other wagtails are ringed nearby it seems probable that the roost attracts birds from a large area; any records of pied wagtails bearing rings are worth noting. D.K. Thomas also intensively. ringed Pied Wagtails at this site in the early 1980's; as well as several local recoveries, one bird was recovered in Scotland during the breeding season.

Tywi Valley

Sand Martin colonies were trapped at during the two summers resulting in 958 new birds being ringed and 15 recoveries from other sites notably 6 from Icklesham in Sussex (a reed bed roost), and a bird ringed as a juvenile on 24th June 1989 and recaptured at Loir-et-cher, France 20 days later. A large number of colonies are only 1-2 foot above the low summer water levels. Therefore the releasing of water from the Llyn Brianne Resv. in summer must pose a serious threat.

In 1990 a permit was obtained to ring Little Ringed Plovers. 27 pairs were found from which 11 adults and 35 chicks were ringed. Despite problems such as disturbance from fishing activities, risk of flooding, predation of eggs and young from crows, gulls, foxes etc., trampling by sheep and cattle the species still continues to increase along the Tywi and is spreading onto the Cothi. Twice as many pairs were found in 1990 compared to the previous year although it is likely that the increase may be limited by the availability of suitable nesting sites.

Other Ringing

The only other significant effort was on Greenfinches during the summer of '89 which revealled a high turnover of mainly young (presumably 1st brood) birds at Tyr Morfa Farm SS532983, Penclacwydd. Over 200 were ringed in June and July yet flocks of no more than 30 birds were ever seen.

I would like to thank Steve Ormerod and Richard Jenkins for their help with the Sand Martins and Pied Wagtails, and also Julian Friese . without whose help and knowledge of the Tywi a lot less would have been achieved.

Reference

Ormerod, S.J. (1988). Ringing around Llanelli. Llanelli Nats. Newsl. Winter 1988-89., 18-23.