In the 1980s, a group of Peters’ Angolan colobus monkeys (Colobus angolensis palliatus) were brought to the United States from East Africa. This “founding population” became the first generation of their species to inhabit zoos in the United States.
Little is known about these founders, and questions remain about their wild relatives. “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.”
In order to better understand the needs of captive populations, and to protect wild monkeys threatened by hunting, habitat loss, and climate change, scientists needed to resolve two questions: How genetically different were populations of Peters’ Angolan colobus monkeys across their range, and where exactly did the captive founders come from?
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.
The range of Peter’s Angolan colobus monkeys stretches mainly from the southernmost corner of Kenya, south into Tanzania. It’s not exactly clear, however, where along this stretch of habitat the founder monkeys called home. “When animals were taken from the wild, that long ago, their origins were not always documented in detail,” said Emily Wroblewski, assistant professor of biological anthropology in Arts & Sciences.
Wroblewski is working with Monica McDonald, program coordinator for the Association of Zoos and Aquarium’s Reproductive Management Center at the Saint Louis Zoo, to analyze DNA from fecal samples from the colobus monkeys in zoos and in the wild to determine their relationship. “We’re trying to understand the patterns of genetic diversity,” Wroblewski said.
McDonald has 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 requires more than samples from zoos, however; they need to be compared to the animals in the wild.
Between 2007 and 2010, McDonald carried out a study to investigate genetic differences among populations of Peters’ Angolan colobus monkeys by analyzing fecal DNA of wild individuals across their range. She found a good deal of genetic diversity between the Kenyan and Tanzanian monkeys, suggesting they might actually be two separate subspecies, but she was unable to gather samples near the countries’ border, leaving this question unresolved.
More recently, Cunneyworth approached McDonald to collaborate and revisit these questions, 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.
Cunneyworth was able to acquire the necessary permits and head out into the field, far from the areas that McDonald sampled. “I traveled to the remote areas of Tanzania collecting colobus fecal samples for the study and sent them to Monica and Emily,” she said.
The samples Cunneyworth collected will help fill this gap in knowledge, leading to a better understanding of how many subspecies exist, and should help clarify whether the genetic differences seen in McDonald’s earlier study represent the extreme ends of a continuous range of diversity, or if there are two subspecies.
“Are these animals in captivity all Tanzanian? Kenyan? A mix of the two? We’re trying to use wild population genetics to inform our understanding of the captive population,” Wroblewski said.
“The results should help zoos determine how representative their monkeys are of the wild population,” said McDonald, who holds her doctorate in anthropology from Washington University. “The studbooks say the founders are from Tanzania,” she said, “but preliminary genetics from a few individuals found they pooled with Kenyan colobus.” Studbooks are a record of births, deaths and lineage that help inform zoo management.
The results of this study will provide essential data to best protect animals in the wild. “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.”