New research from The University of Western Ontario leads investigators to believe that woolly mammoths living north of the Arctic Circle during the Pleistocene Epoch (approx. 150,000 to 40,000 years ago) began weaning infants up to three years later than modern day African elephants due to prolonged hours of darkness.
This adapted nursing pattern could have contributed to the prehistoric elephant's eventual extinction. The findings were published recently in the journal, Palaeogeography, Palaeoclimatology, Palaeoecology.
By studying the chemical composition of adult and infant mammoth teeth, Jessica Metcalfe, an Earth Sciences PhD student working with professor Fred Longstaffe, was able to determine woolly mammoths that once inhabited Old Crow, Yukon didn't begin eating plants and other solid foods before the age of two (and perhaps as late as three) and considers predatory mammals like saber-toothed cats and a lack of sufficient vegetation to be the secondary reasons for delayed weaning.
"In modern Africa, lions can hunt baby elephants but not adults. They can't kill adults. But they can kill babies and by and large, they tend to be successful when they hunt at night because they have adapted night vision," explains Metcalfe, who examined fossil specimens alongside Grant Zazula of the Yukon Paleontology Program. "In Old Crow, where you have long, long hours of darkness, the infants are going to be more vulnerable, so the mothers nursed longer to keep them close."
Metcalfe says delayed weaning by Old Crow mammoths may have further significance for understanding mammoth life histories and extinction.
"Today, a leading cause of infant elephant deaths in Myanmar is insufficient maternal milk production," offers Metcalfe. "Woolly mammoths may have been more vulnerable to the effects of climate change and human hunting than modern elephants not only because of their harsher environment, but also because of
|Contact: Jeff Renaud|
University of Western Ontario