2010-2011, APEM Ltd., London Array, Aerial Bird Surveys series https://portal.medin.org.uk/portal/start.php?tpc=015_c3e87ec731f82faa50718ba5cde96eec This report summarises the findings of the winter 2010/11 pre-construction aerial surveys of the proposed London Array Ltd. offshore wind farm site, and associated control zones, for birds and marine mammals. The aerial surveys are designed to meet the requirements of the Food and Environment Protection Act (FEPA) 1985 licence granted in respect of the wind farm, and to satisfy the wider Ornithological Review Panel (ORP) process. Pre-construction monitoring for Phase I development in order to satisfy FEPA licence conditions constitutes aerial survey of the London Array Offshore Wind Farm (OWF) site, plus survey of a control zone. Surveys designed to fulfil the ORP process cover further control zones. The aim of this project was to provide information about the response of and risks to bird species (predominantly but not exclusively red-throated diver Gavia stellata), arising from the construction and operation of the wind farm. The red-throated diver is listed under Annex I of the EU Birds Directive (79/409/EEC) as being a rare or vulnerable species, meaning that EU member states are obligated to identify and designate key areas of habitat used by the species as Special Protection Areas (SPAs). Sites supporting 1% or more of the Great Britain population of an Annex I species are automatically considered for SPA designation (Stroud et al., 2001). The defined objectives of the project were to: 1. Provide pre-construction baseline surveys of the London Array Offshore Wind Farm (OWF) site before wind farm construction commences; 2. Provide pre-construction baseline surveys of control zones for the OWF site; 3. Describe temporal and spatial variation in bird numbers across the OWF and control sites; 4. Produce population estimates, with a given level of precision, for birds across the OWF and control sites; 5. Produce updated estimates of red-throated diver abundance and distribution within the OWF and control sites, with respect to the Special Protection Area (SPA) in the Outer Thames Estuary; 6. Report on flight heights and direction of birds recorded in flight within the OWF site. 20111007 20111007