Study

Rehabilitation and relocation of young Hawaiian monk seals (Monachus schauinslandi)

  • Published source details Gilmartin W.G., Sloan A.C., Harting A.L., Johanos T.C., Baker J.D., Breese M. & Ragen T.J. (2011) Rehabilitation and relocation of young Hawaiian monk seals (Monachus schauinslandi). Aquatic Mammals, 37, 332-341.

Actions

This study is summarised as evidence for the following.

Action Category

Translocate marine and freshwater mammals to re-establish or boost native populations

Action Link
Marine and Freshwater Mammal Conservation

Rehabilitate and release injured, sick or weak marine and freshwater mammals

Action Link
Marine and Freshwater Mammal Conservation
  1. Translocate marine and freshwater mammals to re-establish or boost native populations

    A replicated study in 1984–2005 of multiple sites on islands in the North Pacific Ocean, Hawaii, USA (Gilmartin et al. 2011) found that nearly all translocated Hawaiian monk seal Monachus schauinslandi young, and approximately half of rehabilitated and translocated monk seal young, survived for at least one year after release and some reproduced. Five of six translocated monk seal young (83%) were known to survive for at least one year. Thirty-five of 68 rehabilitated and translocated monk seal young (52%) were known to survive for at least one year after release, 18 of which reproduced in the wild (at least 68 pups in 1984–2005). Thirty other rescued monk seal young died in captivity (17 seals) or were kept permanently in captivity for health or behavioural reasons (13 seals). In 1984–1995, a total of 104 weaned, female seals (aged <3 years old) that were underweight, ill or threatened (by human disturbance, shark predation or aggressive adult male seals) were translocated directly to new sites (six seals) or brought into captivity for 3–14 months before release at new sites (98 seals). Captive seals were given medical treatment and fed milk formula or fish with multivitamins. The seals were transported between islands by plane or ship, and either released immediately or held in beach enclosures before release. All released seals were tagged and observed annually in 1984–2005.

    (Summarised by: Anna Berthinussen)

  2. Rehabilitate and release injured, sick or weak marine and freshwater mammals

    A replicated study in 1984–2005 of multiple sites on islands in the North Pacific Ocean, Hawaii, USA (Gilmartin et al. 2011) found that approximately half of Hawaiian monk seal Monachus schauinslandi young that were rehabilitated, translocated, and released back into the wild survived for at least one year, and half of those produced offspring. The study did not distinguish between the effects of rehabilitation and translocation. Thirty-five of 68 monk seal young (52%) that were rehabilitated, translocated, and released back into the wild survived for at least one year after release. By 2005, eighteen of the 35 surviving seals (51%) had produced offspring in the wild (at least 68 pups). Thirty other monk seal young captured for rehabilitation either died in captivity (17 seals) or were kept permanently in captivity for health or behavioural reasons (13 seals). In 1984–1985, a total of 98 weaned, female seals (aged <3 years old) that were underweight, sick or threatened (by human disturbance, shark predation or aggressive adult male seals) were collected from islands (the French Frigate Shoals) and brought into captivity. The seals were transported by plane or ship and kept at care facilities or in beach enclosures. Captive seals were given medical treatment and fed milk formula or fish with multivitamins. After 3–14 months of rehabilitation, the 68 seals were fitted with tags, released at different islands (Kure Atoll and Midway Islands), and observed annually in 1984–2005.

    (Summarised by: Anna Berthinussen)

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