Aquila pennata

Temesvary, Peter, Heinz, Dr. Walter & Gundert, Martin, 2013, Additional Assessment Report - Crucea North Wind Farm 99 MW, Constanta County, Romania: European Bank for Reconstruction and Development (EBRD) : 171-172

6.3.7 Booted Eagle ( Aquila pennata / Hieraaetus pennatus)

Booted eagle is a qualifying interest feature of Allah Bair – Capidava SPA, Cheile Dobrogei SPA, Stepa Saraiu-Horea SPA, and Stepa Casimcea SPA. The populations for each are shown in Table 6.13 below.

A single possible booted eagle nest was recorded during breeding surveys undertaken in 2013 within the Allah Bair-Capidava SPA. During the VP surveys booted eagles were only recorded on three occasions, with individual birds recorded on each occasion.

The CRM calculated at the most conservative avoidance rate of 95% that one booted eagle would be killed every 28.08 years and at a more realistic avoidance rate of 99% that one booted eagle would be killed every 140.41 years (see Annex C).

Average adult survival has not been estimated for booted eagle. The Romanian breeding population is relatively small and has been estimated at 80-120 pairs, with a declining population trend (14). During migration far greater numbers pass through Romania from breeding areas to the north.

Although the breeding population for Cheile Dobrogei SPA is small (and the species may also breed in low numbers in Allah-Bair-Capidava SPA) given the very low collision mortality calculated by the CRM, it is predicted that there will not be any significant effects on the SPA breeding populations of booted eagle as a result of collision mortality.

Given the very low numbers of flights recorded within the windfarm site it is not predicted to be likely that loss of habitat or disturbance during construction or operation will affect the booted eagle population such that there will be an effect on the integrity of any SPAs.

There is the potential for barrier effects on migrating booted eagle, however as stated for other species the Crucea North Wind Farm site has not been reported to support any important migratory routes in the context of the wider area and is not know to generate important thermals for migratory birds (Wildlife Management 2012). This conclusion is supported by the results of the 2013 VP surveys. As a result no barrier effects are predicted. Overall no effects to the integrity of any of the SPAs are predicted as a result of effects on the qualifying interest feature booted eagle populations.

During the 2013 surveys of Crucea North a total of 3 booted eagles were recorded. During the 2008/2009 surveys of the wider Crucea area a total of 4 booted eagles were recorded during autumn surveys, with none recorded during the spring, summer or winter. No booted eagles were recorded during surveys of the Crucea East Wind Farm (Generacion Eolica Dacia SRL 2011). The collision rate for booted eagle for Crucea North was calculated at 0.01 birds per year based on 99% avoidance.

The overall boted eagle flight activity was 1.84 x 10 -7 hrs/ha/hr, amounting to 7.19 x 10 -4 hr/hr over the whole site.

Booted eagles were present on the site throughout the observation period, amounting to 153 days and they were presumed to be able to fly for an average of 14.1 hours daylight per day, a total of 2157.3 hours

Booted eagle occupancy ( n) of the wind farm area is, therefore, estimated to be 1.55 hours per year for the observation period (7.19 x 10 -4 x 2157.3).

5.1.2 Number of Transits of Booted eagles Through the Rotors

The size of the flight risk volume (Vw) is 4,682,040,000m 3. The combined volume swept out by the turbine rotors (Vr) is 1,516,627.92m 3 using a body length for booted eagle of 0.49m.

The bird occupancy of the volume swept by the rotors in seconds ( b) is:

( n x 3,600) x (Vr/Vw)

= ( 1.55 x 3600) x (1,516,627.92/4,682,040,000)

= 1.81 bird-secs.

The time taken for a bird to make transit through the rotor and completely clear the rotors ( t) is (d + l)/v, where d is the depth of the rotor blade from front to back (4), l is the body length for booted eagle (0.49m) and v is the speed of the bird through the rotor (11 ms-1) (35), = 0.41secs.

The number of bird transits through the rotors per season is b / t = 4.43

5.1. 3 Estimating Collision Likelihood

Using the SNH spreadsheet, and assuming a booted eagle flight speed of 11 m/s, the model predicts that an average of 20.1% of booted eagle flights through the rotor swept area would result in collisions. This was reduced to 16.08% to allow for non operating time.

The number of birds predicted to collide with the operating rotors over the season is 0.71 birds per year during the observation period (4.43 x 16.08%). This assumes no avoiding action is taken by the birds.

Avoidance rates were calculated as for kestrel. Mortalities were calculated using avoidance rates of 90%, 95%, 98% and 99% to provide an indication of potential risk (see Table 1.4 below).

This equates to a loss of a bird every 28.08 years during the observation period at 95% avoidance or a bird every 140.41 years at 99% avoidance.

Common name: Booted Eagle.

Compiled from data in Table 4 , Table 4 , and Table 4 .

2 ex.; Romania, Constanta County, Crucea , lat: 44.533, long: 28.233; 2013-03-15 - 2013-05-31; ( Table 4 ) • 1 ex.; Romania, Constanta County, Crucea , lat: 44.533, long: 28.233; 2013-06-01 - 2013-07-31; ( Table 4 ) • 7 ex.; Romania, Constanta County, Crucea , lat: 44.533, long: 28.233; 2009-03-15 - 2009-05-31; ( Table 4 ) .