3.1.2 Abundances
A total of 47,777 birds were recorded in distance bands A-D during the 2020-2021 boat-based surveys, comprising 40 identified species. The five key species accounted for 86.83% of all records: kittiwake (23.67%); gannet (16.12%); guillemot (32.09%); razorbill (9.68%); and puffin (7.26%). The majority of birds were recorded within the western survey sites 3 and 4 of the Berwick Bank project area (61.12%) compared to eastern survey sites 1 and 2 (38.88%). This is likely due to sites 3 and 4 within Berwick Bank being in closer proximity to coastal breeding colonies. Table 3.6 shows the total monthly records of each species at each survey site; for individual monthly breakdowns, see Appendix 2.
A large portion of Arctic tern were present during the August surveys (see Appendix 2, Table 4.1), specifically in site 3 of the Berwick Bank project area. High abundances are likely the result of post-breeding dispersal movements from their breeding colonies along the east coast.
Table 3.6 Total observations of all bird species in Distance Bands A-D with repeat sightings excluded
Species | Site 1 | Site 2 | Site 3 | Site 4 | Total |
|---|---|---|---|---|---|
Arctic Skua | 2 | 0 | 1 | 0 | 3 |
Arctic Tern | 114 | 361 | 489 | 2565 | 3529 |
Unidentified Auk species | 8 | 14 | 94 | 70 | 186 |
Black-headed Gull | 0 | 0 | 1 | 0 | 1 |
Collared Dove | 0 | 1 | 1 | 0 | 2 |
Common Gull | 10 | 2 | 3 | 2 | 17 |
Common Scoter | 0 | 0 | 0 | 1 | 1 |
Common Tern | 0 | 1 | 0 | 0 | 1 |
Curlew | 0 | 0 | 5 | 5 | 10 |
Fulmar | 144 | 160 | 128 | 141 | 573 |
Gannet | 1570 | 1484 | 2146 | 2504 | 7704 |
Golden Plover | 1 | 0 | 0 | 0 | 1 |
Great Black-backed Gull | 10 | 23 | 10 | 6 | 49 |
Great Skua | 3 | 1 | 6 | 2 | 12 |
Guillemot | 2601 | 4560 | 3333 | 4839 | 15333 |
Herring Gull | 103 | 204 | 192 | 197 | 696 |
Kittiwake | 1234 | 3220 | 3741 | 3113 | 11308 |
Large Gull species | 0 | 0 | 1 | 0 | 1 |
Lesser Black-backed Gull | 43 | 38 | 57 | 41 | 179 |
Little Gull | 0 | 0 | 0 | 1 | 1 |
Manx Shearwater | 3 | 4 | 7 | 8 | 22 |
Meadow Pipit | 0 | 0 | 0 | 2 | 2 |
Pink-footed Goose | 0 | 0 | 0 | 2 | 2 |
Puffin | 606 | 835 | 1276 | 752 | 3469 |
Razorbill | 632 | 573 | 1067 | 2353 | 4625 |
Redshank | 0 | 0 | 11 | 0 | 11 |
Red-breasted Merganser | 0 | 0 | 1 | 1 | 2 |
Sabine's Gull | 0 | 0 | 1 | 0 | 1 |
Sandwich Tern | 1 | 0 | 0 | 0 | 1 |
Sooty Shearwater | 0 | 0 | 1 | 1 | 2 |
Sedge Warbler | 0 | 0 | 0 | 1 | 1 |
Skylark | 0 | 1 | 0 | 0 | 1 |
Storm Petrel | 4 | 0 | 1 | 0 | 5 |
Swallow | 1 | 0 | 0 | 0 | 1 |
Swift | 2 | 1 | 1 | 0 | 4 |
Teal | 0 | 0 | 14 | 0 | 14 |
Tern species | 0 | 0 | 1 | 0 | 1 |
Tree Pipit | 0 | 0 | 1 | 0 | 1 |
Turnstone | 0 | 2 | 1 | 1 | 4 |
Whimbrel | 0 | 0 | 0 | 1 | 1 |
To estimate the densities for each key species within each survey area ( Figure 2.1 Open ▸ ), adjusted counts from Distance analysis were apportioned down to cell size estimates, with cell sizes derived from all snapshots considered in any month. Table 3.7 shows the number of cells covered by each survey run.
Table 3.7 Number of cells each month taken from the number of snapshots surveys at each site.
Survey Site / Transect Run | Survey Month | ||||
|---|---|---|---|---|---|
July 2020 | August 2020 | April 2021 | May 2021 | June 2021 | |
Site 1 |
|
|
|
|
|
1 | 58 | 60 | 0 | 0 | 44 |
2 | 60 | 58 | 0 | 0 | 40 |
3 | 56 | 58 | 34 | 52 | 50 |
4 | 60 | 60 | 24 | 44 | 50 |
5 | 56 | 0 | 0 | 0 | 0 |
Site 2 |
|
|
|
|
|
1 | 60 | 60 | 42 | 50 | 54 |
2 | 60 | 58 | 44 | 44 | 58 |
3 | 60 | 60 | 36 | 54 | 60 |
4 | 60 | 58 | 0 | 60 | 56 |
Site 3 |
|
|
|
|
|
1 | 54 | 60 | 46 | 52 | 42 |
2 | 60 | 60 | 46 | 48 | 48 |
3 | 60 | 60 | 20 | 52 | 40 |
4 | 56 | 60 | 32 | 38 | 50 |
Site 4 |
|
|
|
|
|
1 | 54 | 60 | 36 | 48 | 40 |
2 | 60 | 60 | 36 | 38 | 48 |
3 | 56 | 60 | 48 | 0 | 52 |
4 | 58 | 60 | 44 | 0 | 50 |
Figure 3.1 to Figure 3.5 below, shows the densities across each survey region for each of the five key seabird species, highlighting the differing densities dependent on the time of day. Time of day was derived from site survey times shown in Table 3.1 to Table 3.5.
The above results show that the highest abundances of all five key species were observed in July and August. Overall there were greater abundances of each species in the western half of the Berwick Bank wind farm area (sites 3 and 4) than in the eastern half (sites 1 and 2), likely due to the closer proximity to coastal breeding colonies. There was no clear pattern between time of day and seabird abundances.