Marine mammals live longer in captivity

Embargoed until: Publicly released: 2023-10-18 10:01

International

Photo by Shane Rounce on Unsplash

Some governments have banned marine mammals from zoos, under the assumption that their survival in captivity is inferior to the wild. Researchers looked at data for almost 9000 animals from four species (harbour seal, California sea lion, polar bear, and common bottlenose dolphin) held in zoos between 1829 to 2020. Over that time life expectancy increased up to 3.4 times, and the life expectancy of sea mammals in zoos is currently 1.65-3.55 times longer than their wild counterparts. The authors acknowledge that there may be other reasons not to keep these animals in captivity, for instance different ethical viewpoints and concerns about welfare conditions. However they say that banning species from zoos may represent missed opportunities, such as serving as a temporary home for rescued animals, or maintaining populations to help prevent species extinction and preserve their genetic diversity.

Media release

From: The Royal Society

Intense public debate has led to governmental bans on marine mammals in zoos, fueled by the belief that their survival in captivity is inferior to the wild. However, using statistical methods applied to data from zoo-held and wild populations of four marine mammal species (harbour seal, California sea lion, polar bear, common bottlenose dolphin) reveals significant improvements. Over the last century, life expectancy in zoos increased by up to 3.40 times for these species, and first-year mortality decreased by up to 31%. Currently, zoo animals benefit from life expectancies 1.65 to 3.55 times longer than their wild counterparts. These gains are attributed to improved management practices, paralleling advancements in human healthcare. Embracing science-based decisions can guide effective legislative changes and enhance animal welfare in captivity.

Attachments

Note: Not all attachments are visible to the general public. Research URLs will go live after the embargo ends.

Research The Royal Society, Web page The URL will go live after the embargo ends.

Journal/
conference: Proceedings of the Royal Society B

Research:Paper

Organisation/s: University of Southern Denmark, Denmark

Funder: M.T. is funded by the National Institutes of Health (NIH) grant no. P01-AG031719 (primary investigator: JW Vaupel; supporting PIs: F.C. and D.A.C.).

Media Contact/s

Contact details are only visible to registered journalists.