Diving behaviour of narwhals (Monodon monceros) at two coastal localaties in the Canadian High Arctic
Abstract: In August 1999 and 2000, four suction-cup-attached time–depth recorders (TDRs) were deployed and re-trieved from narwhals (Monodon monoceros) in Tremblay Sound, Baffin Island, and Creswell Bay, Somerset Island, Nunavut, Canada. The TDRs remained on the whales for between 12 and 33 h and co...
| Main Authors: | , , |
|---|---|
| Other Authors: | |
| Format: | Text |
| Language: | English |
| Published: |
2002
|
| Subjects: | |
| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.459.1264 http://www.neri.dk/1_Om_DMU/2_Afdelinger/3_AM/4_Expertise/5_Research/6_marine_mammals/Litterature_pdf/narhval.pdf |
| Summary: | Abstract: In August 1999 and 2000, four suction-cup-attached time–depth recorders (TDRs) were deployed and re-trieved from narwhals (Monodon monoceros) in Tremblay Sound, Baffin Island, and Creswell Bay, Somerset Island, Nunavut, Canada. The TDRs remained on the whales for between 12 and 33 h and collected 64.5 h of dive data. Mean dive depths ranged from 20.8 m (SD = 14.8 m) to 50.8 m (SD = 43.8 m) and mean dive durations ranged from 3.4 min (SD = 1.6 min) to 4.9 min (SD = 4.5 min). There appeared to be individual differences in dive parameters both within a region and between regions. Three of the whales made short, shallow dives, while another whale made dives twice as deep and twice as long. One whale had maximum dive durations (>20 min) that exceeded predicted aerobic dive limits for narwhals. There was a strong relationship between maximum dive depth and duration for all whales (p < 0.0001). Narwhals spent between 30.3 and 52.9 % of their time at depths <5 m and the range of correction factors for availability bias was 1.9–3.3. Satellite-linked TDRs were simultaneously deployed on the whales at both localities. Dive data collected using the two methods were compared and good agreement between the methods was obtained. |
|---|