40ca3a923c77565c8969129c397a5209 English series BTO Ilya M.D Maclean and Mark M. Rehfisch The Nunnery Thetford Norfolk IP24 2PU pointOfContact 2009-05-07 MEDIN Discovery Metadata Standard Version 2.3.5 urn:ogc:def:crs:EPSG::4326 OGP 2007, COWRIE, Further use of aerial surveys to detect bird displacement by offshore wind farms 2007-10-01 publication 2007-01-01 creation 3225 http://data.offshorewind.co.uk/ This report follows a previous report commissioned by COWRIE (Maclean et al. 2006), in which the extent to which BERR (formally DTI) aerial survey protocol allows changes in bird number to be detected, was examined using power analysis. Changes in bird numbers can be hard to detect due to natural fluctuations in bird numbers. Power analysis allows a statistical assessment to be made of the probability that such changes could be distinguished from background fluctuations. Similar conclusions are drawn in this report compared with the previous displacement report. The statistical power of being able to detect changes in bird numbers is lower than desirable. This is primarily because there are large inter-annual fluctuations in numbers. Ilya M.D Maclean and Mark M. Rehfisch British Trust for Ornithology +44 (0)1842 750050 +44 (0)1842 750030 The Nunnery, Thetford, ilya.maclean@bto.org bto.org originator The Crown Estate +44 020 7851 5000 16 New Burlington Place London W1S 2HX United Kingdom enquiries@thecrownestate.co.uk http://www.thecrownestate.co.uk custodian Henrik Skov DHI Water Environment Health Agern Alle 11 originator notPlanned pdf Marine Environmental Data and Information Network Metadata record availability 2012-01-11T07:46:54 revision Research Research and Development Activity The Crown Estate Renewable Energy Development Phases 2012-05-15T02:00:03 revision Bird counts Bird taxonomy-related abundance per unit area of surface Bird behaviour SeaDataNet Parameter Discovery Vocabulary 2017-10-18 revision 104 no conditions apply eng biota environment -9.33312855790775 2.68743327033997 49.0399981037863 60.7672028638749 2007-10 2007-10 Origin: BTO and DHI http://www.marinedataexchange.co.uk/search?q=#fq=fq%3DProject%253Amdecowrie1027 download https://www.marinedataexchange.co.uk/details/260/summary A link to the web service or dataset. https://www.marinedataexchange.co.uk A link to the general host site. dataset We selected four taxa for analysis: red-throated diver, common scoter, black-backed gulls and sandwich tern. As the majority of the divers are unidentifeid to species level during aerial surveys we added a proportion of positively identified red-throated diver relative to the other identified diver species. The vast majority of scoter species were recorded as common scoter, presumably because although this spcies can be difficult to distinguish from other scoter species from the air, the areas surveyed are known to contain only small numbers of velvet scoter (Melanitta fusca). Thus addition unidentified scoters were not added to common scoter count, although in relality the numbers of these are such that doing so would not have made any appreciable difference.