Colorado State University Study Looks Into Use Of Reproductive Inhibitors As Possible Control For Prairie Dogs

October 17, 1997

FORT COLLINS--Does a sterile prairie dog still act like a prairie dog?

Associate Professor William Andelt hopes to find out in a study that begins this month on Fort Collins open space and neighboring areas where prairie dogs make their homes.

The study, in cooperation with the U.S. Department of Agriculture's National Wildlife Research Center in Fort Collins, will investigate whether surgically castrated male prairie dogs still fill the designated role as defender of their home territory.

If sterilization does not affect prairie dog behavior--and pilot studies have shown that it does not--Andelt and graduate student Aaron Schwartz believe that special baits or other nonsurgical methods that cause sterility in prairie dogs could be a more acceptable way of controlling the population than with lethal means, such as poison bait or fumigation.

"We're not doing this to see if surgical castration is a viable management tool for prairie dogs, because it would be impractical on a large scale," Andelt said. "We want to find a nonlethal way of controlling prairie dog populations--particularly near urban areas of Colorado and the West, where part of our public objects to poisoning them. That kind of approach is in the best interest of the public and the prairie dogs, because these animals can grow dramatically in number while habitat diminishes."

This month, the researchers will begin marking over 200 male and female prairie dogs. About 40-50 of the males will be trapped and will undergo surgical castration under anesthesia, performed by licensed veterinarians. Each prairie dog will receive an analgesic after surgery, then released the same day to prevent other males from taking over their territory.

During the study, Andelt and Schwartz will monitor the castrated and uncastrated prairie dogs in the wild to see if lower testosterone levels brought on by the surgery changes male behavior. They also will determine if castrating yearling and adult males increases or decreases dispersal of juvenile males from prairie dog towns and if castrated males have a greater or lower tendency to disperse. It is typical for young males to leave home and start a new one in another location. The researchers also plan to monitor the marked females to determine if they are bred by other unsterile males.

Prairie dogs live in colonies commonly referred to as prairie dog towns. Small groups within the prairie dog towns, called coteries, are generally composed of one or two adult males, three adult females and six offspring. It's the responsibility of adult males to fend off potential invaders--including other male and female prairie dogs--but the adult females and yearlings of both sexes also help.

Andelt and Schwartz do not think sterilization will have much impact on prairie dogs, other than to possibly control their numbers. In a pilot study this summer, five castrated male prairie dogs showed no signs of behavioral changes by continuing to defend their coterie territories, Andelt said. In fact, some of the castrated prairie dogs were seen making territorial calls the same day of surgery--an indication that surgery caused little discomfort and that territorial tendencies were still intact.

Controlling prairie dog populations has been controversial in Colorado and the West because of the three options used: reducing populations by lethal means, relocating problem prairie dogs to new habitat or excluding them with barrier fences, which has not been completely successful.

Currently, an estimated 5 million prairie dogs occupy about 1 million acres of rangeland in Colorado. Rapid development is taking place in areas that once were prime prairie dog habitat, making relocation an even more remote option than it was in the past. Few landowners want to accept relocated prairie dogs because the animals compete with livestock for forage or sometimes transmit plague to pets and humans. As development continues, encounters between humans and prairie dogs also is becoming a public health concern. Prairie dogs, which are hosts for fleas, occasionally carry bubonic plague. Domestic cats can transmit the plague to humans via flea bites or by breath, sometimes causing death.

However, prairie dogs are an important food source for several species, including the endangered black-footed ferret, badgers, coyotes and birds of prey. Their burrows serve as homes for burrowing owls, cottontail rabbits, rattlesnakes and other animals.

Exacerbating the problem is the prairie dogs' stealth reproductive abilities. Each female usually gives birth to three to five pups each spring, enabling a colony to grow by as much as 30 percent each year.

Andelt hopes that eventual use of reproductive inhibitors will strike a balance between the need to control prairie dogs that are a threat to public health with the need to keep healthy prairie dog populations part of Colorado's natural environment.

Andelt said other scientists are currently working on reproductive inhibitors that might specifically target prairie dogs. Reproductive inhibitors are being developed for horses and deer, but these have been delivered by injections, darts or biodegradable bullets. A future challenge will be to develop a practical way to administer reproductive inhibitors to prairie dogs, such as through baits.

"We need to treat animals as humanely as possible. We think this approach could really help sustain healthy prairie dog populations in Colorado and still prevent them from being a threat to public health or safety," Andelt explained.

-30-


Colorado State University

Related Public Health Articles from Brightsurf:

COVID-19 and the decolonization of Indigenous public health
Indigenous self-determination, leadership and knowledge have helped protect Indigenous communities in Canada during the coronavirus disease 2019 (COVID-19) pandemic, and these principles should be incorporated into public health in future, argue the authors of a commentary in CMAJ (Canadian Medical Association Journal) http://www.cmaj.ca/lookup/doi/10.1503/cmaj.200852.

Public health consequences of policing homelessness
In a new study examining homelessness, researchers find that policy such a lifestyle has massive public health implications, making sleeping on the street even MORE unhealthy.

Electronic health information exchange improves public health disease reporting
Disease tracking is an important area of focus for health departments in the midst of the COVID-19 pandemic.

Pandemic likely to cause long-term health problems, Yale School of Public Health finds
The coronavirus pandemic's life-altering effects are likely to result in lasting physical and mental health consequences for many people--particularly those from vulnerable populations--a new study led by the Yale School of Public Health finds.

The Lancet Public Health: US modelling study estimates impact of school closures for COVID-19 on US health-care workforce and associated mortality
US policymakers considering physical distancing measures to slow the spread of COVID-19 face a difficult trade-off between closing schools to reduce transmission and new cases, and potential health-care worker absenteeism due to additional childcare needs that could ultimately increase mortality from COVID-19, according to new modelling research published in The Lancet Public Health journal.

The Lancet Public Health: Access to identification documents reflecting gender identity may improve trans mental health
Results from a survey of over 20,000 American trans adults suggest that having access to identification documents which reflect their identified gender helps to improve their mental health and may reduce suicidal thoughts, according to a study published in The Lancet Public Health journal.

The Lancet Public Health: Study estimates mental health impact of welfare reform, Universal Credit, in Great Britain
The 2013 Universal Credit welfare reform appears to have led to an increase in the prevalence of psychological distress among unemployed recipients, according to a nationally representative study following more than 52,000 working-age individuals from England, Wales, and Scotland over nine years between 2009-2018, published as part of an issue of The Lancet Public Health journal on income and health.

BU researchers: Pornography is not a 'public health crisis'
Researchers from the Boston University School of Public Health (BUSPH) have written an editorial in the American Journal of Public Health special February issue arguing against the claim that pornography is a public health crisis, and explaining why such a claim actually endangers the health of the public.

The Lancet Public Health: Ageism linked to poorer health in older people in England
Ageism may be linked with poorer health in older people in England, according to an observational study of over 7,500 people aged over 50 published in The Lancet Public Health journal.

Study: Public transportation use linked to better public health
Promoting robust public transportation systems may come with a bonus for public health -- lower obesity rates.

Read More: Public Health News and Public Health Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.