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Grad Student Studying Management of Catalina Bison

Calvin Duncan Is Monitoring the Use of a Contraceptive Vaccine to Manage Herd Size

Oct. 15, 2013

Calvin Duncan, grad student and wildlife biologist, prepares a vaccine as part of his thesis research project to manage the herd of bison on Catalina Island. Photo: Julie King/Courtesy of Catalina Island Conservancy

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To find an economical and effective solution to manage the herd of bison on Catalina Island, biology graduate student Calvin Duncan has launched a multiyear study on the use of a contraceptive vaccine for his thesis research project.

"It's a project with a lot of conservation issues," said Paul Stapp, professor of biological science and Duncan's graduate research adviser. "This could prove to be a way to control — using nonlethal means — a nonnative species that has destructive environmental effects on the island."

Back in 1924, a film production company introduced the iconic bison, commonly known as buffalo, to the island. The movie never got made, but the 14 bison were left behind. Over the years, the bison population continued to expand, and by the mid-1980s, the free-roaming herd reached an estimate of more than 500.

Population management has been achieved through costly roundup and shipment of bison to the mainland, including to Native American reservations in South Dakota, explained Duncan. While the vaccine may be the key to maintaining bison on the island in a sustainable way, the contraceptive measure also could have far-reaching effects to bison management in other areas, such as Yellowstone National Park.

Duncan is a wildlife biologist at the Catalina Island Conservancy, a private land trust that manages most of the island. The Conservancy has conducted several research projects to support the ongoing management of the bison herd and also is a collaborator on Duncan's thesis project, in which he has received grant funding. He plans to complete his thesis project and earn his master's degree in 2015.

What is the focus of your thesis project?
The project focuses on applying a contraceptive vaccine called porcine zona pellucida, or PZP, to female bison on Catalina Island, in an attempt to manage the island herd at a stable population of approximately 150 individuals. We are testing how well it works and examining the costs and efforts required to apply the vaccine annually; the reversibility of the vaccine relating to, if and how long, it takes for a bison cow to once again produce a calf once we stop administering the vaccine; and if the vaccine affects the length or timing of the breeding season. To date, no study has determined the efficacy, or practicality of fertility control in large, wide-ranging bison herds.

What do you expect the outcome will be?
This is a management-based research project — meaning that it is specifically designed as a tool in the management of bison on Catalina, and possibly in other areas. Bison-culling activities using lethal methods has been used within several publicly and privately managed herds as a result of habitat loss, ownership issues and disease spread. Our research will assess whether PZP can be applied as an effective and cost-efficient alternative to lethal control.

How has your research mentor guided you?
Dr. Stapp has been extremely encouraging and supportive of the whole project. He applies just enough pressure to keep me moving forward and on schedule, and he has had a significant influence on my ability to present formal research, including presenting at the International Conference on Fertility Control in Wildlife. He has reinforced in me the value of scientific ethics and professionalism, and his leadership has always been by example.

What do you value about this research experience?
I have really enjoyed every aspect of the project so far, and I am excited about the potential influence that this project may have on the management of bison, and perhaps other wildlife species, in the future.

How will this work help you in achieving your academic and career goals?
Wildlife biology is a very competitive career area. Jobs are in relatively short supply, and more people than ever are choosing this as a career path. I am hopeful that by completing this project, and my master's degree, that I will increase my job security and expand my options in this field.

Tags:  Academics & Research