How Wolves Change Rivers

Arguments for removing gray wolves from endangered species protection are incorrect

Researchers from Princeton University and the University of California-Los Angeles who investigated the genetic ancestry of North America's wild canines have concluded that the U.S. Fish and Wildlife Service's scientific arguments for removing gray wolves from endangered species protection are incorrect.

The study, which contradicts conventional thinking, finds that all of the continent's canids diverged from a common ancestor relatively recently and that eastern and red wolves are not evolutionarily distinct species but a hybrid of gray wolf and coyote ancestry. The study will appear in the journal Science Advances.

Gray wolves once ranged across much of the United States but were hunted to near-extinction in the late 1800s and early 1900s. In 1973, the U.S. Fish and Wildlife Service listed the gray wolf under the Endangered Species Act, in part, because its geographic range once included the Great Lakes region and 29 eastern states. Since then, gray wolves have rebounded due to protections, reintroduction and natural repopulation, making wolf recovery in the West one of the most successful efforts under the ESA. Gray wolves also still live in the Great lakes area but not in the 29 eastern states. The red wolf also was protected under the ESA as a distinct species in 1973, but the eastern wolf, which was only recently recognized as a distinct species, is not protected.

The Fish and Wildlife Service will decide this fall whether to remove the gray wolf from protection, drawing renewed attention to the conflict between conservationists, ranchers, hunters and others who see the iconic predator either as a threat or as part of a healthy ecosystem. The agency says the gray wolf should be delisted because the eastern wolf - not the gray wolf - lived in the Great Lakes region and eastern states. Essentially, the presence of the eastern wolf, rather than the gray wolf, in the eastern United States would cause the gray wolf's original listing to be annulled. With the exception of the Mexican wolf, the gray wolf would lose protection from its entire North American range under the proposed rule change.

In their new study, lead author Bridgett vonHoldt, an assistant professor in ecology and evolutionary biology at Princeton, and her colleagues analyzed the complete genomes of 12 pure gray wolves (from areas where there are no coyotes), three pure coyotes (from areas where there are no gray wolves), six eastern wolves (which the researchers call Great Lakes wolves) and three red wolves.

Results showed that eastern and red wolves are not evolutionary distinct species but the result of a relatively recent interbreeding: Eastern wolves are about 75 percent gray wolf and 25 percent coyote, while red wolves are about 25 percent gray wolf and 75 percent coyote.

"We found no evidence for an eastern or red wolf that has a separate evolutionary legacy," vonHoldt says. "These results suggest that arguments for delisting the gray wolf are not valid."

The researchers also conclude that the ESA should protect hybrid species because interbreeding in the wild, thought to be uncommon when the ESA was passed in 1973, has been shown to be common and may not be harmful.

"Our findings demonstrate how a strict designation of a species under the ESA that does not consider genetic admixture can threaten the protection of endangered species," vonHoldt says. "We argue for a more balanced approach that focuses on the ecological context of genetic admixture and allows for evolutionary processes to potentially restore historical patterns of genetic variation."

Management efforts for elk and deer may not benefit all wildlife

COLORADO STATE UNIVERSITY

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IMAGE: THIS IS TRAVIS GALLO, PH.D. STUDENT, COLORADO STATE UNIVERSITY. view more 

CREDIT: COLORADO STATE UNIVERSITY

It's no surprise that most conservation efforts in the United States focus on animals that are hunted. But a new study from Colorado State University researchers found that improving habitats for game animals has mixed consequences for other animals in the same setting. 

The study calls for more scrutiny of and a more holistic approach to current management efforts.

Hunting provides substantial economic benefits for states. Deer and elk hunters in Colorado, for example, must apply for permits annually. A deer license for non-residents runs $432; a permit for in-state residents is $43. A license to hunt elk is nearly $500 for non-residents; the in-state charge is $48. Nearly $2 million from these fees support wildlife management and public land conservation in the state each year.

"There's this notion that habitat management that's good for game species is good for all wildlife," said Travis Gallo, Ph.D. student in the Department of Fish, Wildlife and Conservation Biology, and lead author of the study. "There's a lot of money that goes into habitat management for game species, and we wanted to see if there were any synergies between game management and conservation of species that were not the target of management actions."

While conducting a review of published papers, Gallo said that he and Associate Professor Liba Pejchar, also in the Department of Fish, Wildlife and Conservation Biology, switched gears once they saw the lack of scientific research on the topic. The duo ended up writing an opinion piece or perspectives essay on the issue. 

"We found only 26 studies that measured the direct and indirect effects of game management efforts on non-game animals," said Gallo.

Among the studies that did measure the effects of game management on non-game species, they found both positive and negative effects: a study of sage grouse management in the Western U.S. found that conservation efforts would likely protect 13 songbird species, while a study in Spain found that an increased abundance in wild boar, red deer and aoudad sheep decreased resources for native species. 

The team also found instances where there were no effects. For example, a study that looked at prescribed fire on lizard abundance in central Texas found no short-term effect on other species.

Gallo said that one way to even the management playing field is to create new funding sources for wildlife conservation. The federal Pittman-Robertson excise tax -- which was implemented in 1937 -- has successfully raised more than $10.1 billion from sales on sporting goods that involve hunting, like ammunition and guns, fishing rods and reels. In 2009, following a similar model, a group of more than 6,300 state fish and wildlife agencies, biologists, hunters, birdwatchers and others proposed the Teaming with Wildlife Act, which would have provided additional funding for wildlife preservation through a small tax on all outdoor gear, including camping gear, binoculars and outdoor apparel. This bill, however, failed to pass through Congress.

Gallo said that there's talk in the conservation community about reviving this sort of proposal. "A tax like this would not only increase funding for conservation, but it may create a sense of investment by those people that are now helping pay for conservation," he said.

Gallo -- who will graduate in May -- said his research provides a good example, and hope, for the type of holistic approach that is needed. 

"My research is piggy-backed on a mule deer experiment in northwestern Colorado," he said. "Colorado Parks and Wildlife was removing pinyon-juniper trees to increase the shrubs and grasses that mule deer like to eat. We collaborated with them and added another layer of research to assess the effects that this management may have on all the other birds and mammals in the area."

"The hunting and fishing communities contribute a lot of money and effort to wildlife management," he added. "If you can find synergies between management for hunted species and conservation for biodiversity, we would be more effectively and holistically managing the land."

The article, "Improving habitat for game animals has mixed consequences for biodiversity conservation," was published in advance online in Biological Conservation. The study will appear in the May print issue of the journal.