Survival improvements of marine mammals in zoological institutions mirror historical advances in human longevity
Publication Type: |
Journal Article |
Year of Publication: |
2023 |
Authors: |
Morgane Tidière, Fernando Colchero, Johanna Staerk, Michael J. Adkesson, Ditte H. Andersen, Lucie Bland, Martin Böye, Sabrina Brando, Isabella Clegg, Sarah Cubaynes, Amy Cutting, Danny De Man, Andrew E. Derocher, Candice Dorsey, William Elgar, Eric Gaglione, Kirstin Anderson Hansen, Allison Jungheim, José Kok, Gail Laule, Agustín Lopez Goya, Lance Miller, Tania Monreal-Pawlowsky, Katelyn Mucha, Megan A. Owen, Stephen D. Petersen, Nicholas Pilfold, Douglas Richardson, Evan S. Richardson, Devon Sabo, Nobutaka Sato, Wynona Shellabarger, Cecilie R. Skovlund, Kanako Tomisawa, Sandra E. Trautwein, William Van Bonn, Cornelis Van Elk, Lorenzo Von Fersen, Magnus Wahlberg, Peijun Zhang, Xianfeng Zhang, Dalia A. Conde |
Publication/Journal: |
Proceedings of the Royal Society B: Biological Sciences |
Publisher: |
Royal Society |
Keywords: |
adult mortality, first-year mortality, life expectancy, lifespan equality, population welfare |
Abstract:
An intense public debate has fuelled governmental bans on marine mammals held in zoological institutions. The debate rests on the assumption that survival in zoological institutions has been and remains lower than in the wild, albeit the scientific evidence in support of this notion is equivocal. Here, we used statistical methods previously applied to assess historical improvements in human lifespan and data on 8864 individuals of four marine mammal species (harbour seal, Phoca vitulina; California sea lion, Zalophus californianus; polar bear, Ursus maritimus; common bottlenose dolphin, Tursiops truncatus) held in zoos from 1829 to 2020. We found that life expectancy increased up to 3.40 times, and first-year mortality declined up to 31%, during the last century in zoos. Moreover, the life expectancy of animals in zoos is currently 1.65–3.55 times longer than their wild counterparts. Like humans, these improvements have occurred concurrently with advances in management practices, crucial for population welfare. Science-based decisions will help effective legislative changes and ensure better implementation of animal care.