Managing a Wildlife Conception Center and Biorepository
By Rick Michels
Marketing Director, Freezerworks
For exotic and endangered wildlife, whether it be the giant panda, white rhino, mountain gorilla, or even the humble koala, fertility is our ally and great hope for species preservation. When such animals successfully mate in captivity and bear surviving offspring, we naturally celebrate. Such stories are so heart-warming and popular that we don’t often consider the other side of the equation: what does a zoo do to prevent a population explosion? Public service announcements remind us of the importance of having our pets neutered, so much so that it often seems this is the only form of animal birth control. But is it? Do tigers and lions utilize artificial contraception like humans do?
The answer is yes. Wildlife contraception is a lesser known but important part of wildlife management: whether that management takes place in a zoo, a natural park, or even in those rapidly shrinking open spaces. And just as humans remain concerned about health and safety issues as they relate to contraception, researchers who work in animal contraception are similarly concerned with the safety and efficacy of chemical based birth control.
“A birth control device in human populations goes through various testing procedures for safety, from in vitro testing, to animal models (mice, then rabbits and primates) and finally to human trials. It’s a very long process,” explains Dr. Dalen Agnew, a veterinary pathologist at Michigan State University who operates the Reproductive Health Surveillance Program (RHSP), associated with the Association of Zoos and Aquariums (AZA) Reproductive Management Center (RMC) based at the St. Louis Zoo. “Veterinary drugs have a much shorter process. In zoos, we can’t do that kind of testing. We don’t have enough tigers, for example, to get a good control population. So what we do is make our best guess, use them, and then monitor for side effects.”
In its work, the RHSP operates a unique wildlife biorepository, currently storing 3,000-4,000 reproductive tracts and related tissue from roughly 400 species.
The RMC has a unique arrangement with participating zoos and other animal conservation and research groups. When the center provides contraception (often in the form of an implant, much like the Norplant contraceptive used in humans), the RHSP in return receives the reproductive tract (i.e., uterus and ovaries or testicles) when the animals die or are spayed or neutered. The RHSP also receives the histopath blocks, cytologies, and tissues such as mammary and pituitary glands that are hormonally related to the tract, as well as blood spots. The latter are valuable sources of DNA, which are particularly useful in searching for genetic markers for reproductive diseases or cancer.
Why cancer? Agnew pointed out how the RHSP learned very early on that reproductive and other tissues not directly related to reproduction can be affected by contraceptive devices and drugs, and how preservation and storage of organs and tissues beyond the reproductive tract is important.
“The first drug we tried on tigers created a marked increase in mammary cancer. We’re now using a different drug,” Agnew explained.
The Intersection between Animal and Human Reproductive and Cancer Research
Through their ongoing research, Agnew is learning that not all big cats react the same way to contraception, and the interplay between methods and overall health produces some interesting and potentially useful observations. Take the tiger’s cousin, the jaguar. Whereas most cats find a higher incidence of cancer when using birth control, the jaguar stands apart from the feline crowd, and contraception may actually be protective against some kinds of cancer.
A current project Agnew is working on includes a collection of blood spots from jaguars, comparing the genetics of the North American captive population with the wild populations found in Central and South America. Agnew and other researchers collaborating in the study are concerned that certain genes may be present in the captive population, even genes that resemble the BRCA gene that is linked to female human breast cancer. However, unlike the tiger, the contraceptives at use may actually be helping the jaguar avoid cancer. Jaguar contraception: think about that during your next Race for the Cure.
The jaguar-human breast cancer resemblance is something that was not lost on science writer Kathryn Bowers, author of Zoobiquity. The popular book discusses the harmonization of human and non-human health issues. When a member of Agnew’s research staff attended a recent Zoobiquity meeting at Seattle’s Woodland Park Zoo and shared their jaguar findings, Dr. Bowers was later seen in front of the Zoo’s jaguar exhibit, a fitting backdrop, as she shared with the assembled experts what jaguars like these in captivity can teach us about breast cancer.
Origins of the RHSP
The RHSP began with the work of the late Dr. Linda Munson, who in the 1970’s headed the veterinary pathology service at the University of California at Davis. It was a special project, dear to Munson’s heart. As section head and a full professor, Munson was able to keep it adequately funded. Agnew worked with Munson for many of those years and similarly developed a passion for reproductive diseases research.
“At about the same time Munson was taking an interest in reproductive diseases, the zoo community was starting to realize they needed to manage their zoo populations,” Agnew recalled. “The old fashioned way to do so was to castrate, spay, or you separate the animals. Of course, there’s usually not enough space in zoos to separate animals.”
Unfortunately for the public, abstinence through separation often detracts from the zoo experience, and can also be considered somewhat cruel to the animal. In fact, current research shows that many of the same diseases induced by pharmaceutical contraception are also induced by abstinence.
“We like to display animals in social groups, but we don’t have room for a hundred tiger cubs.” Agnew explained. “We also need to manage the populations. We need to say, for example, ‘These two tigers have produced fifty young. They’re done.’ So we have today curators with PhDs in genetics, who can determine which animals should breed with which for genetic purposes. They need the tools to manage animal populations, so we began to develop contraceptives.”
Although the primary focus of Agnew’s work is with zoos, his work takes on a more global nature. Wildlife custodians call on the RHSP to provide knowledge and understanding for all the earth’s non-human creatures. Zoos today are more than a place to view animals. They are conservation and research centers in their own right.
When Munson contracted cancer herself and died six years ago, she bequeathed her work, and her labor of love, to Agnew and a network of colleagues around the country. It was a challenge, because whereas the vision and the passion were passed on, the same was not necessarily true regarding the finances. And so, to keep things going, Agnew was going to have to get creative.
Wildlife Biobanking and the Sustainability Conundrum
Pulling together the necessary funding and support to keep the program going has been a challenge for the center. Agnew and his team lend their considerable expertise in reproductive health and contraceptive knowledge for the wide variety of species held in zoos. In return, the zoos and associated research and preservation groups send them their specimens to continue their research and population surveillance efforts. But the shoestring funding is taking its toll on research that would play a large part in efforts to protect and nurture wildlife biodiversity. Agnew explained the unique nature of wildlife health research and the struggle for funding to help move it along:
“For ten years now, I’ve been trying to figure out a way to successfully fund a reproductive tract archive. Often granting agencies don’t see the purpose, because funding is often directed to hypothesis-driven research. You have to be able to say to these agencies ‘Here’s my question. And here’s how I am going to be able to answer it.’
“But if, in order to answer your question, you need fifty years of data, or fifty years of collecting tissues, the funding needs to be more forward looking.
“For instance, if I was interested in liver tumors in humans, it would take me six months to find enough liver tumors to do what I needed to do. But if I wanted to look at liver tumors in lemurs, it would take me twenty years to collect the liver tumors I would need to make that same study. We need to collect long before you think you even know the question. So we need to develop these archives researchers can use to delve into when they have a question to answer.
“We’ll get small grants (using this approach). We’ll get a thousand dollars or so for looking at red wolves one year, or otters, or lemurs in another year. And that will pay for glass, and blocks, for a year. But how do you get the funding for the ongoing maintenance and support for managing an ongoing archive?” Agnew asked, quickly noting that the center got a very good score for funding for a grant from the Institute for of Museum and Library Services (IMLS). Unfortunately, a grant from the IMLS, while significant, now comes with a requirement for matching funds, a situation that that perpetuates the funding conundrum.
The RHSP faces an additional challenge in that its unique service as a shared resource contributes to a struggle to create a sense of “ownership” by the community it serves. “When you share a biobank, it’s like when you share a computer, for example,” Agnew explained while pointing to my desk. ”There’s less of a sense of ownership when it’s shared.”
According to Agnew, animal health research borrows heavily from human research, which makes sense considering the tremendous resources poured into the latter by comparison. But perhaps, as regulations designed to protect the privacy rights as well as the health of human subjects makes research in humans more costly and cumbersome, we may find the more flexible research protocols that animal health research offers begin to lead the way in various areas of inquiry – areas like contraceptive research. And then, perhaps he and his center can make the persuasive case for sustainable funding to those who control the research dollars.