Compromised survivorship in zoo elephants

Area of Science:

• Veterinary Science
• Zoology
• Animal Welfare Science

Background:

• Elephants in zoological institutions often face different environmental and health challenges compared to wild populations.
• Understanding factors affecting elephant longevity is crucial for conservation and welfare efforts.

Purpose of the Study:

• To compare the median lifespan of elephants in European zoos with conspecifics in protected populations in range countries.
• To identify specific risk factors contributing to reduced survivorship in zoo-housed elephants, particularly Asian elephants.

Main Methods:

• Analysis of data from over 4500 elephants.
• Comparison of survival rates between zoo-housed elephants and those in protected wild populations.
• Identification of demographic and management-related factors influencing elephant mortality.

Main Results:

• Elephants in European zoos exhibit approximately half the median lifespan of elephants in protected wild populations.
• Asian elephants in zoos show very high infant mortality and stagnant adult survivorship, unlike African elephants.
• Moving elephants between institutions and early maternal separation negatively impact survival, especially in Asian elephants.
• Zoo-born Asian elephants have poor adult survivorship, suggesting prenatal or early infancy influences.

Conclusions:

• Zoo environments pose significant risks to elephant survivorship, with Asian elephants being particularly vulnerable.
• Management practices such as inter-institutional transfers and early life experiences are critical risk factors.
• Stress and/or obesity are proposed as likely contributors to the compromised survivorship observed in zoo elephants.