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Recovering from the brink of extinction


When Hurricane Iris hit Belize in 2001, primatologists could not have predicted the impact on the Black Howler Monkeys inhabiting the area. The damage to Monkey River, the site of a long-term anthropological study led by University of Calgary primatologist Mary Pavelka, led researchers to make a new discovery about the monkey’s primary food source.

“Howlers are the most folivorous (leaf eating) of all New World Monkeys, but when no fruit was produced in the area for eighteen months, we discovered that fruit had been the key to their diet,” says Pavelka. “Afterwards, their diet changed to leaves. They became less active and the population continued to fall for three years. We were predicting the extinction of this population.”

Pavelka began studying the monkeys in 1999 and has taught an annual spring semester field school to undergraduate students in Monkey River ever since. Anthropology students visit the area annually to follow the environmental impact and recovery on a small population of Black Howler Monkeys since the 2001 event.

The students, whose majors range from Veterinary Medicine, Nursing, Biology, Haskayne School of Business and Anthropology, monitor the monkeys’ behaviour and group composition and collect biological samples for analysis of parasites, hormones, and DNA. Each spring students observe an area of 90 hectares (100 sq meters), in which six distinct groups of 5 – 10 black howler monkeys live. They make observations and collect samples that are helping to uncover why the Howler Monkey population continued to fall and was heading for extinction.

“We make a true recording of everything each animal does for ten minute periods,” says Jordan Bryson, a third- year Anthropology and Natural Sciences major. “This includes sequence, frequency and duration of feeding times and all activities.”

After fifty percent of forest trees were destroyed in 2001, the social groups of the monkeys became fractured, causing social chaos among what had been eight separate clans of monkeys. Eventually, after three years, the monkeys increased their consumption of fruit as it returned to the trees and the population began to grow again.

“When habitat fragmentation is combined with natural disasters, it can be devastating,” says Pavelka. “The monkeys’ vulnerability is enhanced by any events that degrade their environment, including links to climate change.”

Interested in learning about Anthropology and non-human primates? The Anthropology Department and the Faculty of Arts have partnered with the Jane Goodall Institute of Canada to host a public lecture by Dr. Goodall titled 50 Years of Chimps and Change October 24 at the Jubilee Auditorium. For more information and tickets visit