Forthbank Wind Energy Development - Partnerships for Renewables

Forthbank Wind Energy Development
12.2.20 The surveys, which used the vantage point methodology advocated by SNH 2 , extended from
September 2009 and to August 2010 inclusive and aimed to record the flights of all target
species of conservation concern within 500m of the proposed turbine array. Only one vantage
point was necessary to cover the site. This was situated on the western flood embankment of
the River Black Devon (NS 8959 9128), located due north of the proposed wind energy
development site (see Figure 12.1).
12.2.21 The flight activity surveys covered three seasons which included the autumn migration (July to
October), overwintering (November to February) and spring migration periods (March to June).
These represent the periods when bird numbers, and hence flight activity, are highest around
the estuary. A minimum of 36 hours survey effort was conducted for each season as
recommended in the guidance 2 . In addition, the survey time was split between dawn, day and
dusk and covered all stages of the 12 hour tidal cycle in order to collect data which fully
represented bird flight activity at the site.
12.2.22 In total, 141 hours of flight activity surveys were carried between 18 September 2009 and 15
August 2010, thus covering each month within a full calendar year. For the purposes of data
collection, the year was divided into three periods of four months covering the autumn
migration or passage period (July to October), the winter (November to February) and the
spring migration period (March to June), and between 45 and 51 hours of effort were
conducted in each period (see Table 12.1.7, Appendix 12.1). The amount of fight activity
survey effort conducted each month is presented in Table 12.1.4, Appendix 12.1 along with
details of the distribution of effort in relation to the tide and period of the day (Tables 12.1.5 and
12.1.6, Appendix 12.1).
12.2.23 A map showing the flight lines for each target species was compiled in a Geographic
Information System (ArcView v.9.3 GIS), with each flight line linked to its associated flight
duration and height information which was held in a Microsoft Access database.
12.2.24 The information collected on key target species flying over the proposed wind energy
development site and the adjacent airspace was used to estimate the number of individuals
per species predicted to collide with the turbine rotors. These figures were obtained by
estimating from the survey data, the number of flights of each of these species during a
particular period of interest (such as breeding season, non-breeding season, or whole year)
and entering these estimates into an appropriate collision risk model. The collision risk
modelling methods used were in accordance with the Band Model recommended by SNH.
Table 12.3 Schedule of bird survey timings for Forthbank
Survey
Month
Winter
Walkover
Estuary Zone
Counts
Breeding
Birds
Barn Owl
surveys
Flight Activity
(Vantage Point
September 2009
October 2009
November 2009
December 2009
January 2010
February 2010
March 2010
April 2010
May 2010
June 2010
July 2010
August 2010
November 2010 Chapter 12 Page 7
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