Elephantine Obesity?

Somewhat counter-intuitively, it has been claimed by the RSPCA that captive elephants do badly (http://www.guardian.co.uk/science/2008/dec/12/elephants-animal-welfare) in comparison to 'wild' counterparts. Comparisons were made of almost 800 Asian and African elephant born and raised in European zoos with 'free' counterparts. Asian elephant were compared with subjects of the same species employed by a Burmese logging company. Zoo-based African elephant were contrasted with animals in Kenya's Amboseli National Park. The study appeared to show that zoo-born Asian elephant lived an average of 18.9 years compared with 41.7 years in their logging counterparts. In the case of the African elephant, the figures were 16.9 years and 35.9 years (56 years if culled animals were omitted from the study). The reduced longevity of the zoo animals were linked to obesity, lack of exercise (some captive animals were apparently unable to walk properly) and 'stress' (always a difficult thing to define but being limited to small groups might be problem). Unremarkably, elephant enclosures in zoos are dramatically smaller than the "smallest wild territories" but it would be very difficult to do much about this in a zoo context. I think that this is certainly an area of concern but the study does have some limitations. I suspect that the figures for longevity in the zoo animals are more trust-worthy than their comparisons. Logging Asian elephant are hardly 'wild' and these working animals are certainly selected for their physical prowess. Elephant in Amboseli also live a rather protected existence compared to animals outside National Parks. I also suspect that cases of infanticide and other forms of infant death are more likely to be recorded in European zoos than in these animals. Having said all that, the study does hint at some of the complex issues in zoo versus wild animal comparisons. Perhaps not all captive species (especially wide-ranging and long-lived species) benefit from a 'protected' existence in a zoo.