Story written by Kathleen Berger in collaboration with Washington University in St. Louis.
There’s a mystery surrounding colobus monkeys that scientists in St. Louis hope to resolve through DNA analysis.
In the ‘80s, a group of Peters’ Angolan colobus monkeys (Colobus angolensis palliatus) were brought to the United States from East Africa. They became the first generation of their species to inhabit U.S. zoos. But where exactly did the captive species come from?
“The best records weren’t always kept in terms of where they actually originated from,” said Emily Wroblewski, Assistant Professor of Biological Anthropology at Washington University in St. Louis. “In thinking about these animals that are quite diverse and wanting to manage their breeding and genetic diversity, it’s helpful to understand their origins.”
The Saint Louis Zoo has resources to help the conservation and preservation efforts.
“An interesting fact about colobus monkeys is that the word ‘colobus’ comes from the Greek word ‘mutilated’ because colobus monkeys don’t have a thumb. That lack of thumb is helpful in their locomotion,” explained Monica McDonald, program coordinator for the Association of Zoos and Aquarium’s Reproductive Management Center at the Saint Louis Zoo.
In order to better understand the needs of Peters’ Angolan colobus monkeys and to protect them in the wild, scientific research is required.
Thanks to a seed grant from the Living Earth Collaborative — a center for biodiversity supporting a collaboration among Washington University in St. Louis, the Saint Louis Zoo, and Colobus Conservation — these monkey mysteries may soon be resolved.
“Currently, we are unable to answer simple questions about the colobus we are protecting,” said Pamela Cunneyworth, director of Colobus Conservation, an organization dedicated to promoting the conservation, preservation and protection of the Angolan colobus monkey and its associated habitat. “Without that basic information it is impossible to do conservation using a landscape approach.”
Cunneyworth approached McDonald to collaborate, as this study would help conservationists understand and more precisely identify areas of greater extinction risk. And — if there are in fact several distinct subspecies — zoo management programs could be tailored according to their different requirements.
“I traveled to the remote areas of Tanzania collecting colobus fecal samples for the study and sent them to Monica and Emily,” she said.
McDonald coordinated the effort with the zoos, requesting and collecting fecal samples from their monkeys. Determining how the founder monkeys fit into the larger family tree required Wroblewski’s lab for the DNA comparison of zoo samples to fecal samples from the animals in the wild.
“This allows us to access wild populations without dramatically interfering with them,” said Wroblewski.
Scientists want to know how genetically different Peters’ Angolan colobus are across their range. The range can be from the southernmost corner of Kenya south into Tanzania.
Wroblewski and her team are isolating mitochondrial DNA from fecal samples. It’s a type of DNA inherited from the mother.
“What’s useful about this DNA, mitochondrial DNA are present in multiple, multiple copies. Thousands of copies,” said Wroblewski. “So when we’re trying to get DNA out of feces, that’s an advantage.”
The mitochondrial DNA holds genetic information that can help scientists answer key questions.
“Genetically, it’s very helpful because it mutates at a pretty high, steady rate. So that mutation rate allows us to look at differences between populations, species, subspecies and estimate how different or similar, how related those populations are,” said Wroblewski. “Potentially if there are two different subspecies, zoos may make breeding decisions based on who to reproduce with to best replicate what we would observe in the wild.”
“The results should help zoos determine how representative their monkeys are of the wild population,” said McDonald.
Understanding genetic diversity would help conservationists protect the wild colobus monkeys threatened by hunting, habitat loss, disease and climate change.
“We know the Kenyan population is more threatened than the Tanzanian population,” Wroblewski said. “If they are a distinct subspecies and we understand their range, we can target efforts for conserving those particular habitats that the animals live within. But if different subspecies are lumped together in conservation planning, we could lose important genetic diversity that is under threat.”