Table 2 Frequency of occurrence, total time allocation, and average duration of activities, separated for surface and subsurface observations
|  | Activity | Frequency of occurrence (%) (n = ind. where behaviour was observed) | Total time spent (%) | Average duration ± SD (s) |
|---|---|---|---|---|
Surface survey (total n = 443) | Invisible | 62.5 (n = 417) | 86.9 | 276 ± 62 |
Surface inactivity | 6.4 (n = 43) | 3.9 | 119 ± 91 | |
Surface crawl | 10.2 (n = 68) | 6.6 | 128 ± 81 | |
Swim | 1.3 (n = 9) | 0.8 | 120 ± 141 | |
Scrape | 16.0 (n = 107) | 1.3 | 16 ± 15 | |
Flush | 3.4 (n = 23) | 0.6 | 22 ± 21 | |
Subsurface survey (total n = 152) | Subsurface inactivity | 37.4 (n = 108) | 51.4 | 217 ± 105 |
Ventilate and filter feed | 33.6 (n = 97) | 43.8 | 206 ± 103 | |
Subsurface walk | 27 (n = 78) | 4.4 | 26 ± 25 | |
Bulldoze | 2.1 (n = 6) | 0.4 | 34 ± 22 |