Elephant Mortality Doubles Due To Low Rainfall And High Temperatures
February 5, 2013

Working Elephants Experience Soaring Death Rates In Face Of Climate Change

April Flowers for redOrbit.com - Your Universe Online

Climate change models are predicting higher temperatures and months without rainfall, which could negatively impact populations of already endangered Asian elephants.

Led by scientists from the University of Sheffield, the research team, matched monthly climate records with birth and death data to track how climate variation affects the survival rate of elephants.

The results of this study were recently published in the journal Ecology. The team, which included members from the Berlin College of Science and the Leibniz Institute for Zoo and Wildlife Research in Germany, hopes their findings will highlight the importance of protecting vulnerable elephant calves in captivity from the effects of climate change.

Researchers collected data from rare birth and death records of more than 8,000 Myanmar elephants, spanning three generations and almost a century. The animals described in this database are semi-captive, working in the timber industry to push and drag logs.

PhD student Hannah Mumby from the University of Sheffield said, “Our results show that the optimal conditions for elephant survival correspond to high rainfall and a moderate temperature of 23ºC (73 F), but that further from those optimal conditions, elephant survival was lower.

“Overall, switching from good to bad climatic conditions within an average year significantly increases mortality rates of elephants of all ages. The most dramatic example comes from baby elephants, whose risk of death before the age of five approximately doubles in the hottest weather in comparison to the optimal moderate temperature for elephant survival,” she explained.

The Sheffield team also found heat stroke and infectious diseases account for the larger number of deaths during the hot months. Because of their large size and the fact they do not sweat like humans or pant like dogs to cool down, elephants are particularly vulnerable to heat stress.

“These results could have important implications for Asian elephant populations both in western zoos, where they may experience unfamiliar climate, and in range countries where climate may be changing faster than elephants can adapt to it,” added Mumby. “It also highlights the importance of protecting vulnerable calves from extremes of temperature because more calves will be needed to maintain the dwindling population of endangered Asian elephants.”