The development of bird indicators for British fresh waters and wetlands. (Special Issue: Recent developments in classification, assessment and management strategies for freshwater habitats in Britain and Europe.)

摘要

Population trends of breeding birds in freshwater habitats generated from long-term monitoring in the UK provide biodiversity indicators for some wetland habitats. Bird species were assigned to target wetland habitats based on evidence of their association and data availability. Species trends for each habitat were then modelled using a range of survey data from BTO schemes including the Common Bird Census, Breeding Bird Survey, Waterways Bird Survey and Waterways Breeding Bird Survey. Smoothed population trends for the selected species were combined to produce a composite indicator for birds of selected waterways and wetland habitats for England. This forms one of the three strands of a new aggregate bird indicator in the UK. These indicators show generally that breeding bird species associated with slow-moving waterways and standing waters have increased over the past 30 years. Over the same period, species associated with fast-flowing waters show modest declines, species associated with reed habitats have declined and recovered, while species associated with wet grasslands, including marshes, have declined. Further monitoring and exploration of the relationship between these indicators is needed to improve confidence in species trends and identifying potential drivers of change in freshwater and wetland habitats.