I may be biased by a forty-year love-affair with waders but I reckon that the plight of the Curlew is one of the big stories in Bird Atlas 2007-11. Within Britain there has been little change in the overall number of 10-km squares in which breeding or potentially-breeding birds have been recorded but there are clear warning signs in Ireland, where the contraction and decline in numbers combine to create a disturbing story. Across the World, many of the members of the Curlew family are fast disappearing, with Slender-billed Curlew on the verge of, if not already, joining Eskimo Curlew in the history books. Are losses of our Curlew in Ireland a warning of things to come?
If you are English or Scottish, the modelled map showing patterns of breeding Curlew relative abundance does not look too surprising, with lots of dark red in the uplands, much as in the map that was published for the 1988-91 Atlas. However, Irish and Welsh birdwatchers will see corroboration of an emerging story of a much reduced population. Over the four summers of the latest Atlas, probable and confirmed evidence of breeding was only reported from 111 Irish 10-km squares (as opposed to 265 in 1988-91 and 697 in 1968-72). It could be argued that less effort went into upgrading evidence from “possible” to “probable” or “confirmed”, but the total number of squares with any breeding evidence tells the same tale: 836 decreasing to 671, further decreasing to 201.
In the second map, showing specific gains and losses in the last twenty years, there are some areas in which Curlews have recently become established or re-established. Essentially the English records are focused upon an inland belt running from Lincolnshire through to Salisbury Plain, and there are some additional inland 10-km squares in Scotland. The losses are largely in the west, as suggested earlier. Outside the breeding season, the story of retrenchment and decline is less clear. As summer comes to a close, large numbers of Curlew arrive from Scandinavia and particularly Finland, mostly settling in coastal sites. The WeBS trend for the species, as revealed in the annual report, shows a slight decline in the last few years, which is likely to be due to both a drop in the British & Irish population and a redistribution of wintering birds across Europe. In the winter of 2009/10 the Wash and Morecambe Bay each held more than 10,000 birds, far more than any other estuary.
A map showing the recoveries of ringed Curlews that link these islands with mainland Europe and Scandinavia shows the close association with Finland, but also that some British nestlings are found wintering in Iberia. The species map is a new feature of the annual ringing report.
Winter records of Curlews, as displayed in the Atlas map showing winter changes, are probably more wide-spread than many birdwatchers would expect, with a growing number of inland flocks in areas such as the northwest and west of England, well away from the coast. Upland records of winter gains since the 1980s are largely February reports of birds returning early to breeding areas, as shown in the fourth map (see below).
The observations of birdwatchers who contributed to Bird Atlas 2007-11 and the maps that they have helped to produce will together act as a focus for conservation scientists and NGOs for the next twenty years. There are already strong signals of areas for study and one of them must certainly be to ask why species that rely on western grasslands – such as Curlew and Lapwing – are in so much trouble? To learn more, please join us at the annual conference at Swanwick in Derbyshire over the weekend 7 to 9 December, when Alan Lauder from BirdWatch Ireland will deliver a talk entitled, “Low lie the fields where Curlews cry”: How the Atlas helps to set Ireland’s conservation priorities.
by Graham Appleton