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Variation in dive behavior of Cuvier’s beaked whales with seafloor depth, time-of-day, and lunar illumination

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  • Journal Title:
    Marine Ecology Progress Series
  • Personal Author:
  • NOAA Program & Office:
  • Description:
    Depth distributions were analyzed from a study of 19 Cuvier’s beaked whales Ziphius cavirostris that were tagged with satellite transmitting instruments off southern California, USA. Over 113000 depth measurements were made over the equivalent of ~200 sampling days. The mean foraging depth was 1182 m (SD = 305 m), and the mean of the maximum depth of all foraging dives was 1427 m (SD = 298 m). Mean foraging depths increased with seafloor depths up to a maximum of ~1300 m at a seafloor depth of 1900 m, but decreased slightly to a mean of ~1200 m at seafloor depths of 2000-4000 m. Near-bottom habitat appears to be important for foraging; whales spent ~30% of their foraging time within 200 m of the bottom at seafloor depths of 1000-2000 m. However, little foraging time was spent near the bottom at seafloor depths greater than 2000 m. The percentage of time spent at near-surface depths (<50 m) was more than twice as high at night (25%) than during the day (12%). Lunar light also appears to affect diving, with 28% of dark nights and only 17% of brightly moonlit nights spent at these near-surface depths. The apparent avoidance of surface waters during daytime and on brightly moonlit nights is consistent with avoidance of visual predators. A considerably greater fraction of time was spent foraging at night (24.8%) than during the day (15.7%), possibly due to energetic constraints imposed by predator avoidance during the day.
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  • Source:
    Marine Ecology Progress Series, 644, 199-214
  • DOI:
  • ISSN:
    0171-8630 ; 1616-1599
  • Format:
    PDF
  • Publisher:
    Inter-Research Science Center
  • Document Type:
    Journal Article
  • Rights Information:
    Other
  • Compliance:
    Library
  • Main Document Checksum:
    urn:sha256:4ed5e61bd8e9c2784f0b91bc5b356ea68ada922de3eec664e76cf2e10d7a8e91
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  • File Type:
    Filetype[PDF - 1.56 MB ]
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