Study

Eighteen years of Antillean manatee Trichechus manatus manatus releases in Brazil: lessons learnt

  • Published source details Normande I.C., Luna F.D.O., Malhado A.C.M., Borges J.C.G., Viana Junior P.C., Attademo F.L.N. & Ladle R.J. (2015) Eighteen years of Antillean manatee Trichechus manatus manatus releases in Brazil: lessons learnt. Oryx, 49, 338-344.

Actions

This study is summarised as evidence for the following.

Action Category

Release captive-bred marine and freshwater mammals to re-establish or boost native populations

Action Link
Marine and Freshwater Mammal Conservation

Hand-rear orphaned or abandoned marine and freshwater mammal young

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

    A study in 1994–2012 in an estuary near Porto de Pedras, northeast Brazil (Normande et al. 2015) found that two of three captive-born Antillean manatees Trichechus manatus manatus released into the wild survived for at least one year. Two of three captive-born manatees (a male and a female) survived for at least one year after release into the wild and did not need to be rescued. The other male manatee died in the first year after release. Three manatees born in captivity (two males, one female) were released (aged 3–5 years old) in an estuary within a marine protected area between 1994 and 2012. Manatees were kept in enclosures at release sites for 15 days or 3–12 months prior to release. Manatees were fitted with satellite tags and tracked for an average of 972 days after release.

    (Summarised by: Anna Berthinussen)

  2. Hand-rear orphaned or abandoned marine and freshwater mammal young

    A replicated study in 1994–2012 at three coastal sites in the South Atlantic Ocean, northeast Brazil (Normande et al. 2015) found that more than three-quarters of orphaned Antillean manatees Trichechus manatus manatus reared in captivity and released back into the wild survived for at least one year, and most manatees monitored for longer periods reproduced. Twenty-one of 26 orphaned, captive-reared manatees (81%) survived for at least one year in the wild, although five had to be rescued and re-released. Four males and two of three females monitored for an average of seven years bred with wild or released manatees. The other five captive-reared manatees died in the first year after release or had to be returned permanently to captivity. One captive-reared manatee died before release. Twenty-seven stranded manatee calves (16 males, 11 females) were rescued and reared in captivity.  They were kept in pools and fed soya milk compound, algae and sea grass, supplemented with vegetables and vitamins. After 1–17 years, 26 manatees were fitted with satellite tags and released at three sites within marine protected areas between 1994 and 2012. Manatees were kept in enclosures at release sites for 15 days or 3–12 months prior to release. Released manatees were tracked for an average of 972 days. Seven of the 26 released manatees (four males, three females) were tracked and observed for an average of seven years.

    (Summarised by: Anna Berthinussen)

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