Contrasting habitat use between and within Bar-tailed Godwit and Eurasian Curlew wintering on the Wash, England

Near Threatened Bar-tailed Godwit Limosa lapponica lapponica and Eurasian Curlew Numenius arquata winter on the Wash in eastern England in internationally and nationally important numbers respectively. For both species we confirm that there is an excess of males in the wintering population on the Wash; there are different sex ratios on other estuaries. In addition, we found that in winter on the Wash, Curlew, but not Bar-tailed Godwit, use inland areas to feed, with increasing numbers feeding inland through the winter as prey on the intertidal become fewer and less available. Male Curlew are more likely to feed inland on the Wash than females. Although the Wash is protected by various international and national designations and both species are listed features of the Wash Special Protection Area and Ramsar Site, land away from the shore is not protected. However, we demonstrate that these inland fields are functionally linked for Curlew. Should the opportunity for inland feeding on the Wash be lost, this is likely to affect males (particularly the individuals with the shortest bills) disproportionately, which may have implications for the population as a whole (including birds wintering on other estuaries). We recommend consideration of an extension to the protected area to include the field-feeding sites. Furthermore, the phenotypic-related distribution of both species across their wintering range reinforces the need for coordinated range-wide (international) protection to avoid any issues affecting one sex disproportionately.