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Part B - Technical instructions 
Table 3.2.2.: Visual observations/recording of flight calls. 
Baseline study 
Construction 
phase 
Operation phase 
Objectives 
Recording of bird movements 
(migration, foraging, flights bet 
ween feeding and resting 
grounds etc.). 
Recording of 
impact due to 
built structures 
(evasion move 
ment, events of 
attraction etc.). 
Recording of impact due to 
operation (evasive behaviour, 
attraction etc.). 
Scope 
Survey frequency in the main migration periods 7 days/month (not in a single block). 
Main migration periods: March to May and mid-July to November. 
In total, at least 50 survey days are required. During these periods, at least 900 survey 
hours must be suitable for evaluation. 
A survey day comprises 24 hours. The surveys should cover full, uninterrupted 
24-hour cycles. The aim is to record bird migration and migration behaviour as evenly 
as possible in the course of a day (day- and night-time). 
Timing 
At least two consecutive com 
plete seasonal cycles prior to the 
start of construction. 
Throughout the 
entire construc 
tion phase. 
At least three years, up to five 
years if required, after commissio 
ning. 
Method 
To determine the species spectrum, parallel day-time visual observations and recor 
ding of flight calls at night have to be carried out (day/night according to civil twilight). 
Survey frequency: 2 observation units of 15 min. each per hour. 
Location: If a platform is available that is suitable with regards to location and equip 
ment (e. g. FINO, USPW), surveys should be carried out from the platform; otherwise, 
ship based surveys exclusively at fixed positions (e. g. anchoring buoy). A fixed posi 
tion is obligatory for cluster studies. The location for ship based surveys should be 
chosen relative to the wind farm in the direction from where most of the birds come to 
ensure optimal detection of the evasive movements of flying birds. 
Survey conditions: Depending on the ship’s configuration, the surveys can be usually 
carried out in stronger winds of up to 7 Bft and at wave heights of up to 2.5 m. 
Platform based surveys can be carried out at even higher wave heights. 
Moreover, the following information should be recorded at 30 min. intervals: Meteoro 
logical data as well as, in the event of ship based survey, GPS position and heading, if 
need be. During construction and operation phase, the number of ships in the area 
that are associated with the wind farm must be recorded. 
Visual observations: 
• Communication by voice between the observer watching the radar display and the 
visual observer may be useful. The registrations have to be made independently, 
however. 
• Registration of the species spectrum and number of birds counted in an angular 
field of view extending from the horizon to 45° (Binoculars with 10 x magnification) 
up to 1.5 km distance. Also undetermined birds have to be recorded (e. g. as “pipit 
spec.” or “grey geese”). In addition, birds in > 1.5 km distance should be recorded 
in a separate class. 
• Distance of the bird/birds to the observer, flight height and association as well as, 
as far as possible, age, gender and plumage should be recorded for each observa 
tion. 
• Observations are recorded on the basis of quarter-hour intervals; individual events 
within a quarter-hour interval are separately recorded (different parameter data).