| Summary: | A multi-scale approach was taken in describing patterns of abundance of five species of breeding waders, oystercatcher. <i>Haematopus ostralegus,</i> lapwing <i>Vanellus vanellus,</i> snipe <i>Gallinago gallinago, </i>curlew<i> Numenius arquata</i> and redshank <i>Tringa totanus,</i> onupland enclosed grassland in northern Britain. Data from one region, in Wales, compared changes in wader numbers with changes in habitat at both site and field scales. This highlighted the importance of habitat and predation as factors affecting wader abundance. Data from a further eight regions in northern Britain enabled two sets of comparisons to be made. These were between a), wader abundance and habitat and b), changes in lapwing numbers with the present habitat and predator numbers. All five species were positively associated with wet habitats although each species was related to a unique pattern of habitat mosaics. Lapwings and oystercatchers avoided heathland and blanket bog and used short vegetation within grassland. Oystercatchers were also associated with arable fields. Curlews were positively associated with blanket bog in addition to wet habitats and fields with a mid-range of vegetation heights. Redshanks avoided heathland habitats, and preferred short vegetation. Snipe were associated with fields with a mid-range of vegetation heights. The habitat models were able to predict wader numbers well, indicating repeatability across regions. There was little variation in wader habitat associations at the scales considered. This was probably due to the limited and simplistic structure of upland enclosed grassland. Sites with declining lapwing numbers tended to have significantly fewer lapwings than predicted by the lapwing habitat models. This suggests that reasons other than loss of habitat were reducing lapwing numbers on these sites.
|
|---|
