Welsh Curlew in south Devon

The RSPB’s major Trial Management Project involves studies of breeding Curlews at six upland sites in Northern Ireland, Scotland, England and Wales. The Welsh study site is at Ysbyty Ifan near Bettws-y-Coed; for background details on the Welsh work see (on this website) the reports presented by David Smith and Fiona Walker to the Welsh Curlew Conference at Builth Wells in January 2018. As the Welsh project advances, ever greater efforts are made by Rachel Taylor and her BTO Cymru team to mark the birds (nearby to Ysbyty Ifan, but 3km further east), with colour rings, GPS tags and geolocators: (geolocators record light levels and allow the estimation of latitude and longitude; but  – small inconvenience – you have to recapture the bird to retrieve these data). The colour rings and GPS tags (remote download) make it possible to follow a bird’s movements around its territory, while the geolocator can record its movements from its breeding grounds to the winter quarters. The birds are caught using cannon-nets within their breeding territory, a technique requiring huge patience and dedication. Thus, these are adult birds, ringed on a known breeding territory, and not (as in many other Curlew ringing projects) birds caught on their wintering grounds and of unknown origin.

One of the birds caught was an adult female, ringed on 18 April 2019 at Ysbyty. It was marked with a white ring on its left tibia (i.e. above the ‘knee’), and an orange ring over a white ring on the left tarsus (i.e. below the ’knee’) – all Ysbyty birds have this orange over white marker, to help field observers identify the place of ringing. On its right tibia two rings were placed, by coincidence orange over white again, while a metal ring FJ23427 was placed on the right tarsus (see illustration). The white ring on the left tibia looks larger than usual, as it incorporates a geolocator,

The bird was sighted on the Axe Estuary at Seaton in Devonshire, a favourite wader-watching and wader-ringing site, by Ian McLean on 12 August 2019. Ian reported this sighting to the WWT Curlew email address curlew@wwt.org.uk (though he clearly realised that it was not one of the Slimbridge head-started Curlews). What was clearly the same bird was seen at Seaton on 21 August by Dave Smith, a bird-watcher visiting the site. Interestingly, and herein lies a cautionary tale, both observers recorded the ring slightly differently:

  • Ian noted: “Left leg: one white ring above the joint orange above white below the joint
    Right leg: two rings below the joint orange above white”.

Almost perfect, except that the two colour rings on the right leg were above, not below the joint.

  • Dave noted: “Right leg orange on top with yellow underneath. Left leg white above knee and orange over yellow below knee.”

Again, almost perfect, except there is a confusion between white and yellow (a frequent problem), and it doesn’t actually specify whether the rings on the right leg were above or below the ‘knee’.

So, to make sure of the reading, local Seaton bird-watchers were requested to look out for the bird, and within a few hours of the request, the doyen of wader studies in the International Wader Study Group, Humphrey Sitters, took the attached picture, which confirms that it was indeed FJ23427 from Ysbyty. Once again, a result achieved by the combined efforts of several cooperating bird watchers, and a warning of how important it is to record colour rings with the greatest precision possible, wherever feasible with a photograph! Experience of other colour-ringed Curlews suggests that this bird, once it has reached the Axe estuary Seaton and stayed from August until October, is likely to remain there all winter; we look forward to more observations and photographs to confirm this.

This recovery is actually of special interest: firstly because it is of a bird whose breeding ground is known, and for which a life history can be built up over future years (especially if the geolocator can be retrieved). Secondly because it shows a distinctly different migratory direction from other birds marked at Ysbyty; of the Curlews marked there, most have moved in winter in the expected westerly direction, three to the Welsh coast and three to southern Ireland. But this bird has moved south-south east and ended up on the English Channel, the first Ysbyty bird to do so. How many more Ysbyty birds will take this bearing?

Leave a comment