TABLE 4.
Mean distance of the drone from birds
| No. | Species | Mean distance | Mean dist. of reaction #0 | Mean dist. of reaction #1 | Mean dist. of reaction #2 | Mean dist. of reaction #3 | Mean dist. of reaction #4 | Mean dist. of reaction #5 |
|---|---|---|---|---|---|---|---|---|
| 1 | Cygnus olor | 13 | 13 | NA | NA | NA | NA | NA |
| 2 | Cygnus cygnus | 18 | 12 | 8 | NA | 28 | 43 | NA |
| 3 | Anser albifrons | 44 | 35 | NA | NA | NA | 49 | NA |
| 4 | Anser fabalis/serrirostris a | 32 | 23 | 30 | NA | NA | 41 | NA |
| 5 | Anser anser | 26 | 15 | 13 | NA | 29 | 44 | NA |
| 6 | Anas platyrhynchos | 16 | 11 | 13 | NA | 30 | 43 | NA |
| 7 | Anas acuta | 15 | NA | 15 | NA | NA | NA | NA |
| 8 | Anas crecca | 15 | NA | NA | NA | 15 | NA | NA |
| 9 | Mareca penelope | 15 | NA | 15 | NA | NA | NA | NA |
| 10 | Mareca strepera | 10 | 11 | 10 | NA | NA | NA | NA |
| 11 | Aythya ferina | 31 | 35 | 26 | NA | NA | NA | NA |
| 12 | Aythya marila | 23 | 32 | 19 | 24 | NA | 20 | NA |
| 13 | Aythya fuligula | 25 | 30 | 20 | 25 | NA | 29 | NA |
| 14 | Melanitta nigra | 31 | 35 | 25 | NA | NA | NA | NA |
| 15 | Clangula hyemalis | 30 | 35 | 25 | NA | NA | NA | NA |
| 16 | Bucephala clangula | 24 | 33 | 24 | 23 | 20 | 21 | NA |
| 17 | Mergus merganser | 20 | 25 | 18 | 18 | NA | NA | NA |
| 18 | Mergus serrator | 35 | NA | 35 | NA | NA | NA | NA |
| 19 | Podiceps cristatus | 14 | 14 | NA | NA | NA | NA | NA |
| 20 | Phalacrocorax carbo | 14 | 11 | 20 | NA | 13 | NA | NA |
| 21 | Ardea cinerea | 29 | 32 | NA | NA | 26 | NA | NA |
| 22 | Ardea alba | 25 | NA | NA | NA | 25 | NA | NA |
| 23 | Fulica atra | 14 | 10 | 30 | NA | NA | NA | NA |
| 24 | Grus grus | 25 | 10 | 20 | NA | 25 | 50 | NA |
| 25 | Chroicocephalus ridibundus | 15 | 12 | NA | NA | 40 | NA | NA |
| 26 | Larus canus | 13 | 13 | NA | NA | NA | NA | NA |
| 27 | Ichthyaetus melanocephalus | 15 | 15 | NA | NA | NA | NA | NA |
| 28 | Larus argentatus sensu lato b | 9 | 9 | 10 | NA | 10 | NA | NA |
| 29 | Larus marinus | 15 | 13 | 20 | NA | NA | NA | NA |
| 30 | Sternula albifrons | 15 | 15 | NA | NA | NA | NA | NA |
| 31 | Sterna hirundo | 13 | 13 | 15 | NA | 10 | NA | NA |
| 32 | Chlidonias niger | 24 | 15 | NA | NA | 25 | NA | 37 |
| 33 | Chlidonias hybrida | 9 | 9 | NA | NA | NA | NA | NA |
The mean distances of the initial reaction to the drone approach and type of reaction. Type of reaction – a bird: #1 – moved slowly away; #2 – dived; #3 – was flushed over a short distance but remained in the sample plot, or quickly returned; #4 – was scared away, exhibited a panic reaction, left the sample plot, and did not return; #5 – attacked the drone; #0 – displayed no reaction; NA – no reaction of any type was recorded.
a
Bean Goose complex (two species Tundra and Taiga Bean Goose Anser fabalis/serrirostris).
b
The group of closely related large gulls in the study area is Herring Gull Larus argentatus and Caspian Gull Larus cachinnans.