Behavior, movements, and apparent survival of rehabilitated and free-ranging harbor seal pups

  • Published source details Lander M.E., James T., Harvey K.D.H. & Lance E.M. (2002) Behavior, movements, and apparent survival of rehabilitated and free-ranging harbor seal pups. Journal of Wildlife Management, 66, 19-28.


This study is summarised as evidence for the following.

Action Category

Hand-rear orphaned or abandoned marine and freshwater mammal young

Action Link
Marine and Freshwater Mammal Conservation
  1. Hand-rear orphaned or abandoned marine and freshwater mammal young

    A controlled study in 1995–1996 and 1998 at a beach in the North Pacific Ocean, California, USA (Lander et al. 2002) found that Pacific harbour seal Phoca vitulina richardsi pups reared in captivity and released back into the wild had similar survival estimates and diving behaviour to wild pups. Overall, survival estimates did not differ significantly between captive-reared seal pups and wild seal pups during the first 15 weeks after release for (data reported as statistical model results). Captive-reared and wild pups also dived for similar durations (average 1.2 vs 1.3 minutes respectively) and surfaced at similar intervals (average 0.4 minutes for both). Twenty-nine stranded seal pups were taken to a rehabilitation facility during March–May 1995, 1996 and 1998. They were treated with antibiotics, fed milk formula, and weaned onto herring Clupea spp. The 29 pups were radio-tagged and released in pairs/groups of three at a beach in 1995, 1996 and 1998 once they had reached a weight of at least 20 kg and had suitable behaviour. Twenty-four newly weaned, wild Pacific harbour seal pups were captured in 1995, 1996 and 1998 at three locations along the same coast and fitted with radio-tags. Each of 53 pups was radio-tracked for 3–5 months and dive behaviour monitored for 9–24 h (captive-reared pups) or 15–22 h (wild pups) after release during 1995, 1996 or 1998.

    (Summarised by: Anna Berthinussen)

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