Hauling-out

"Haulout" redirects here. For the short documentary, see Haulout (film).
Sea lion group at haulout
Harbor seals at haulout

Hauling out is a behaviour associated with pinnipeds (true seals, sea lions, fur seals and walruses) temporarily leaving the water.[1][2] Hauling-out typically occurs between periods of foraging activity.[1][3][4] Rather than remain in the water, pinnipeds haul out onto land or sea ice for reasons such as reproduction and rest.[4][2] Hauling out is necessary in seals for mating (with the exception of the Baikal seal[1]) and giving birth (although a distinction is generally made between reproductive aggregations, termed "rookeries", and non-reproductive aggregations, termed "haul-outs").[4][5] Other benefits of hauling out may include predator avoidance, thermoregulation, social activity, parasite reduction and rest.[4][2][5][6]

There is much variation in haul-out patterns among different seal species.[1] Haul-out sites may be segregated by age and sex within the same species.[3] Many species of pinniped have only a few localized rookeries where they breed, but periodically occupy hundreds of haul-out sites throughout the range.[5] For example, the Australian fur seals breed on only nine islands in Bass Strait but also occupy up to 50 haul-out sites in south-east Australian waters,[4] and Steller sea lions have around 50 rookeries throughout their range, but several hundred haul-out sites.[5] Hauling-out behaviour provides numerous benefits to pinnipeds besides reproduction. This behaviour has been shown to be used for activities such as thermoregulation, predator avoidance, moulting, nursing, and resting.[2] Haul-out frequency, duration, and site location (i.e. sea-ice, floating-ice, and terrestrial) are all influenced by physical constraints (i.e. air temperature, wind speed, and time of day) and biological constraints (i.e. moulting, age, and sex).[2][7][6][8][9] Variations in hauling-out behaviour exist among pinnipeds for reasons such as geographical location.[7]

  1. ^ a b c d Hoelzel, A. Rus. (2002). Marine Mammal Biology: An Evolutionary Approach. Blackwell Publishing. ISBN 978-0-632-05232-5. p. 197.
  2. ^ a b c d e London, Josh M.; Ver Hoef, Jay M.; Jefferies, Steven J.; Lance, Monique M.; Boveng, Peter L. (June 18, 2012). "Haul-Out Behavior of Harbor Seals (Phoca vitulina) in Hood Canal, Washington". PLOS ONE. 7 (6): e38180. Bibcode:2012PLoSO...738180L. doi:10.1371/journal.pone.0038180. PMC 3377645. PMID 22723851.
  3. ^ a b Kovacs, Kit M.; Jonas, Krista M.; Welke, Sylvia E. (1990). "Sex and age segregation by Phoca vitulina concolor at haul-out sites during the breeding season in the Passamaquoddy Bay region, New Brunswick". Marine Mammal Science. 6 (3): 204–214. Bibcode:1990MMamS...6..204K. doi:10.1111/j.1748-7692.1990.tb00244.x.
  4. ^ a b c d e Gales, Nick; Gales, Nicholas; Hindell, Mark; & Kirkwood, Roger. (2003). Marine Mammals: Fisheries, Tourism and Management Issues. CSIRO Publishing. ISBN 978-0-643-06953-4. p. 259.
  5. ^ a b c d Loughlin, Thomas R.; Rugh, David J.; Fiscus, Clifford H. (1984). "Northern Sea Lion Distribution and Abundance: 1956-80". The Journal of Wildlife Management. 48 (3): 729–740. doi:10.2307/3801420. JSTOR 3801420.
  6. ^ a b Cite error: The named reference :3 was invoked but never defined (see the help page).
  7. ^ a b Cite error: The named reference :1 was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference :4 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference :7 was invoked but never defined (see the help page).