Table 1. Mean ± SD of parameters extracted from calls of type E (Eistla), C (calf), F (Freya), and T (Thora).
| Call Type | n | Duration (s) | Pulse Repetition Rate (PRR) (pulses/s) | Peak Frequency (kHz) | Inter-signal Interval (ISI) (s)a | # of Overlapping Elementsb | Dominant Tonal Frequency (kHz) | Minimum Contour Frequency (kHz) | Maximum Contour Frequency (kHz) | Start Contour Frequency (kHz) | End Contour Frequency (kHz) |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Type E | 33 | 1.26 ± 0.33 | 127.82 ± 12.04 | * | 3.62 ± 1.99 | 2 | - | - | - | - | - |
| *Peak Frequency Before Release | 5 | - | - | 30.25 ± 6.30 | - | - | - | - | - | - | - |
| *Peak Frequency After Release | 28 | - | - | 12.43 ± 9.93 | - | - | - | - | - | - | - |
| Type C | 7 | 1.39 ± 0.30 | 38.96 ± 6.95 | 15.04 ± 10.58 | 2.58 ± 2.19 | 5 | 8.94 ± 1.43 | 5.23 ± 1.23 | 13.83 ± 2.70 | 8.34 ± 4.21 | 5.66 ± 1.13 |
| Type F c | 3 | 1.01 ± 0.16 | 182.42 ± 11.72 | 2.02 ± 0.35 | - | 0 | - | - | - | - | - |
| Type T | 33 | 0.65 ± 0.07 | 245.69 ± 32.81 | 19.68 ± 6.78 | 3.68 ± 1.90 | 0 | - | - | - | - | - |
a The mean inter-signal interval (ISI) represents the ISI between signals in series only (n = 28 ISIs for type E, n = 40 ISIs for type C, n = 200 ISIs for type T, type F never appeared in a series).
b Represents the median number of overlapping elements.
c Depth restrictions for parameter extraction were not applied to the few calls available in Freya’s HF record.