Table 3 Foraging trip and dive characteristic means and standard deviations per tag type
From: Acute impacts of biologging devices on the diving behaviour of Manx shearwaters
Variables | Pathtrack nanoFix Geo | CatLog genII+ | Pathtrack nanoFix Geo & Edic microphone | CatLog genII+ & Cefas G5 | ||||
|---|---|---|---|---|---|---|---|---|
Number of foraging trips | 43 | 34 | 3 | 16 | ||||
Mean | ± SD | Mean | ± SD | Mean | ± SD | Mean | ± SD | |
Foraging trip characteristics | ||||||||
Maximum trip range (km) | 75 | 71.8 | 59.4 | 60.5 | 34.7 | 26.4 | 49.6 | 30 |
Speed (km.h−1) | 8.5 | 3.3 | 7 | 2.8 | 5.8 | 1 | 7.8 | 2.8 |
Trip duration (h) | 41.2 | 35.6 | 44.2 | 41 | 24.5 | 17.7 | 24.4 | 11.2 |
% Time spent resting per foraging trip | 36.2 | 11 | 38.4 | 10.7 | 43.2 | 2.8 | 33.2 | 9.4 |
% Time spent in ARS per foraging trip | 48.2 | 9.7 | 49.8 | 7.6 | 47.2 | 0.4 | 53.4 | 10.9 |
% Time spent in transit per foraging trip | 15.2 | 6.7 | 12.1 | 8.6 | 5.1 | 4.5 | 13.8 | 7.9 |
Number of dives per hour of foraging trip | 3.8 | 1.9 | – | – | 3.01 | 1.2 | 4.1 | 1.8 |
Total dive duration per hour of foraging trip (min) | 50.4 | 28.3 | – | – | 55.6 | 19.8 | 58.4 | 34.5 |
Dives characteristics | ||||||||
Number of dives | 8046 | – | 224 | 1739 | ||||
% of U-shaped dives | 6.56 | – | 10.7 | 7.4 | ||||
Dive duration (s) | 12.54 | 9.04 | – | – | 18.4 | 11.7 | 14 | 10 |
Dive depth (m) | 5.9 | 5.2 | – | – | 9 | 7.2 | 6.4 | 5.8 |
Time interval between dives (s) | 1.03 | 1.1 | – | – | 1.3 | 1.3 | 1.1 | 1.0 |
Descent rate (m.s−1) | 0.95 | 0.37 | – | – | 1 | 0.38 | 0.94 | 0.37 |
Ascent rate (m.s−1) | 1 | 0.36 | – | – | 1.04 | 0.36 | 0.94 | 0.33 |
Bottom time * (s) | 9 | 4.1 | – | – | 10 | 4.2 | 8.8 | 3.4 |