Title: Waterways Breeding Bird Survey: progress and population trends: 1998
Author: J.H. Marchant
Author: A.C. Joys
Author: D.G. Noble
Author: R.H. Coombes
Author: Environment Agency
Document Type: Monograph
Annotation: Environment Agency Project ID:EAPRJOUT_1190, Representation ID: 371, Object ID: 2410
Abstract:
The Waterways Breeding Bird Survey (WBBS) was set up in 1998 by the British Trust for Ornithology (BTO), with funding from the Environment Agency. It was designed initially to complement the long-running Waterways Bird Survey (WBS), with a potential for replacing it in the long term. Development of the WBBS has been in three phases. Phases 1 and 2, during 1998-2000, established its value as a monitoring tool for breeding birds along waterways. This report concerns Phase 3, 2001-2004. It aims to demonstrate that the BTO can maintain a sample of WBBS surveys sufficient for long-term population monitoring. It also aims to evaluate WBBS data for this purpose and decide how best to analyse them. Comparisons of trends between the WBBS and WBS were generally favourable but revealed major discrepancies for some species. These may be due to the short and interrupted run of years available for this comparison, or in some cases to differences in the units of counting. A longer run of years, and alternative treatment of large flocks on WBBS counts, might improve the agreement between WBS and WBBS trends. Including non-random WBBS sites conducted by WBS observers increases both monitoring precision and the range of species that can be monitored, and has relatively little effect on the resulting population trends. The entire sample provides enough data to monitor more than 70 bird species, including at least 25 waterbird species. The report concludes that where linear waterways are the major habitat of a species, the WBBS is likely to give a more reliable indicator of UK population change than the BBS, because the quantity of appropriate habitat being sampled is larger. The BTO proposes that the WBBS and WBS continue in parallel for at least a further two breeding seasons, 2005 and 2006, to allow the calibration of WBBS and WBS trends to be improved, and to consolidate the WBBS sample. This may pave the way for the WBBS eventually to replace the WBS as the way of monitoring breeding birds of linear waterways.
Publisher: Environment Agency
Subject Keywords: Rivers; Surveys; Monitoring; Birds; Aquatic animals; Breeding; Biological surveys; Freshwater ecology
Geographic Keywords: United Kingdom
Extent: 84
Permalink: http://www.environmentdata.org/archive/ealit:4618
Total file downloads: 60
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