Lifespan, longevity, and ageing
Observations: The total gestation time, of about 11.5 months, includes a 3 to 4 months period of delayed implantation (Ronald Nowak 2003). Males are typically much bigger than females. In the wild, males have been reported to live more than 23 years (http://www.demogr.mpg.de/longevityrecords), and there are anecdotal reports of animals living over 25 years. Their longevity in captivity has not been studied in detail, but one specimen lived 23.7 years (Richard Weigl 2005).