Historical ecologists estimate that in the early 1800s, before the widespread colonization of the United States, prairie dogs numbered in the billions. Much has changed on the continent since that time, as anthropogenic (human) pressure has had lasting effects on the wildlife, ecosystems, and even the climate. For prairie dogs, once revered as special to many Native American tribes, being a staple of the western landscape (from southern Canada to Mexico) meant they were underfoot of the great European advance into the grasslands of the American frontier. And while our conservation and outreach efforts over time have, supported by research, given us a greater understanding and appreciation for prairie dogs, they are still widely considered pests by people who want to use or work the land.
For 200 years, ranchers and farmers, developers, and local and federal agencies used all manner of methods to clear prairie dogs from the landscape, including shooting, trapping, and especially poisoning. Add to this persecution a loss of range from human encroachment, habitat pollution, the rise of infectious disease, and the pressing threat of climate change, and prairie dog peril is as much an issue of the present as it is the past and future. While conservation efforts have adapted and become more robust for these species, these very real threats continue to loom.
A Keystone Species
Prairie dogs are keystone species in the grassland of the American west. A keystone species is defined by the Oxford Dictionary of Zoology as:
A species that has a disproportionately strong influence within a particular ecosystem, such that its removal results in severe destabilization of the ecosystem and can lead to further species losses.
Simply put, keystone species are irreplaceable. While we would argue that ALL species are irreplaceable, of course, keystone species play significant affecting roles in their ecosystems, so that without them both flora and fauna suffer extreme negative consequences. Research has shown prairie dog activities have a positive effect on soil and plants (increasing soil fertility, controlling invasive species, etc.), that their burrows provide living space and refuge to a number of animals (from spiders to burrowing owls), and that their place in the food web provides sustenance to countless predators and scavengers, such as the well-known relationship between the prairie dog and the black-footed ferret.
The Black-Footed Ferret
Once numbering fewer than 20 individuals from overexploitation and persecution, the black-footed ferret (mustela nigripes) has been a conservation miracle of sorts thanks to exhaustive recovery efforts over the last few decades. Much of the risk to these predators has everything to do with prairie dogs and the risks their populations face as well. The black-footed ferret feeds almost exclusively on prairie dogs, and depends on prairie dog populations at every life stage. When determining where to locate or relocate ferrets, wildlife and rangeland managers need to know the dynamics and status of prairie dogs in the area. It’s also important that prairie dog populations not be overly depleted due to overexploitation, excessive persecution, habitat loss, or any of the many pressures that threaten them and their habitats. Many black-footed ferret action plans include the relocation or reintroduction of prairie dogs themselves, and understanding as much as we can about prairie dog behavior, colonial dynamics, and demographic nuances will ensure that these efforts are successful. Prairie dog conservation and black-footed ferret conservation are essential to each other.
In the early 20th century, a bacteria called Yersinia pestis (originating in Asia) made it to the United States. This was the same bacteria responsible for the Black Death across Europe in the 14th century, and is a fast-acting organism that decimates entire colonies of prairie dogs (as well as contributing to the peril of a myriad of other species). Plague survives in flea populations and can manifest in several forms, bubonic (also called sylvatic) being of most concern to prairie dogs (as well as black-footed ferrets). Plague can wipe out an entire colony of prairie dogs in a matter of several days to a couple of weeks. Because of the close quarters in which prairie dogs live and interact both under- and aboveground, fleas are able to travel, populate, and infect at high rates within colonies.
Plague is one of many threats the prairie dog continues to face today. Researchers like John have attempted to combat plague by dusting prairie dogs and their burrows with flea-killing insecticide, and have found that doing so helps to keep flea populations under control. The flea is an effective vector for the plague bacteria, being highly populous and highly mobile. Because Y. pestis is a non-native organism, prairie dogs did not evolve to combat it physiologically. While autogrooming and allogrooming may serve to limit flea infestations, once plague hits a colony it is only a matter of time before the population collapses. Because of its high fatality, it is important that we consider and plan for plague events in managing prairie dog populations for conservation.
The u.s. Endangered Species Act
As a North American animal, every species of the prairie dog has gone under review for listing as threatened or endangered under the Endangered Species Act (ESA) administered by the U.S. Fish & Wildlife Service. At the start of John's research in the mid-1970s, all but the white-tailed prairie dog were protected under the ESA. Periodic reviews are conducted for species not currently protected, according to scientific and public opinion. Listed species currently under protections receive reviews to determine status once every five years (called the five-year status review). Current statuses under the ESA for our subjects are:
NOT LISTED | Black-tailed prairie dog (last review completed 2009), white-tailed prairie dog (last review completed 2010), Gunnison's prairie dog (last review completed 2013)
THREATENED | Utah prairie dog
ENDANGERED | Mexican prairie dog
The International Union for the Conservation of Nature (IUCN) conducts separate reviews and conservation assessments of species across the globe. While the IUCN's Red List of Threatened Species does not afford special protections to species, the program has provided invaluable comprehensive data to governments and organizations worldwide to inform conservation decisions. Current statuses under the IUCN Red List of Threatened Species are:
OF LEAST CONCERN | black-tailed prairie dog, white-tailed prairie dog, Gunnison's prairie dog
ENDANGERED | Utah prairie dog, Mexican prairie dog
The Convention on International Trade in Endangered Species of Wild Flora and Fauna (CITES) is an international agreement among global governments. Under CITES, species of concern who may suffer consequences to their populations and habitats due to trade and trafficking are afforded protection from trade by laws in each member country. Protections under the CITES agreeement are graded under three appendices: Appendix I provides the most extensive protections and trade prohibitions, Appendix III provides the least stringent protections, and Appendix II falls between the extremes. Currently, there is only one species of prairie dog provided extra protections under CITES:
APPENDIX I | Mexican prairie dog