From high-resolution to low-resolution dive datasets: a new index to quantify the foraging effort of marine predators

Table 1 Correlations between hunting times of high- and low-resolution dives according to different vertical velocity threshold values

Hunting time_lowres for different threshold values (m s⁻¹)	Hunting time_highres
Hunting time_lowres for different threshold values (m s⁻¹)	Weddell seal	SES 1	SES 2	Both SES
0.1	0.73	0.40	0.25	0.33
0.2	0.89	0.62	0.36	0.50
0.3	0.94	0.66	0.46	0.56
0.4	0.94	0.62	0.61	0.61
0.5	0.93	0.62	0.62	0.61
0.6	0.92	0.61	0.63	0.60
0.7	0.91	0.59	0.62	0.58
0.8	NA	0.57	0.63	0.55
0.9	NA	0.54	0.58	0.52

R ² of Spearman correlations between hunting time_highres and hunting time_lowres. Hunting_highres time is the total time spent in “hunting_highres” mode (highly sinuous phases of the dive) per high-resolution dive (see “Fine scale analysis of foraging behaviour”, [21]). Hunting time_lowres is the sum of the total time spent per low-resolution dive in segments associated with vertical velocity inferior to a defined threshold. The set of thresholds tested was chosen to encompass the first mode of the distribution of the vertical velocity associated with each segment in low-resolution dives (see Fig. 2)

ISSN: 2050-3385