How Wolves Arrived and Once Flourished in the U.S.

As you probably have heard, the US Fish and Wildlife Service has delisted gray wolves across the Lower 48. This means that the management of wolves will be given to each individual state. Sadly, in most states “management” means “killing.” This delisting will be fought in the courts by a number of conservation organizations. Hopefully—by supporting these organizations and raising our voices—the delisting will be overturned. Today I begin a series of posts that help explain why protecting wolves is so important. Each post will end with a link to a site where you can show your support for wolves. Here's the amazing story of how wolves arrived and once flourished here.

More than 100,000 years ago, Canis lupus, the essential predators we call gray wolves, were following their four-legged food supply through Eurasia.  They came upon the Bering Land Bridge that connected Siberia with Alaska. The name “bridge” misleads. This land bridge was not long and thin like a highway bridge. It was more of a dry subcontinent, called Beringia, that was about five times the size of present day Alaska. Beringia’s cold-hardy vegetation drew many grazers and hungry wolves followed.

When gray wolves reached North America, they turned and travelled south into what we now call the Lower 48. There they encountered dire wolves (Canis dirus), the then dominant wolf in North America. Dire wolves had appeared abruptly and fully evolved across North America thousands of years earlier, according to Ronald Nowak, writing in Wolves: Behavior, Ecology, and Conservation. He speculates that dire wolves migrated here from South America. 

While we tend to picture dire wolves as huge, Nowak contends they varied in size. Some were the biggest wolves ever; others were smaller, about the size of a large gray wolf. Dire wolves had massive heads, huge teeth, and short legs relative to their body size. Though fossilized remains of these wolves have been found across the Lower 48, dire wolves seemed to prefer a warmer climate; they never migrated to the northern reaches of the Lower 48 (such as Montana, Michigan, Minnesota, and Wisconsin), leaving that territory to Canis lupus as gray wolves entered from Beringia.

Map by William Harris. (CC BY-SA 4.0)

The dire wolf disappeared about 8,000 years ago along with some of its large prey, the mastodons, wooly mammoths, and camels that had been plentiful in North America during the Ice Age. But not all ancient herbivores perished, writes James Bailey in American Plains Bison: Rewilding an Icon. Ancestors of Yellowstone’s bison survived this mass extinction, as did elk and caribou, moose and musk ox, and bighorn sheep and mountain goats.

The dire wolf’s disappearance may have been caused, writes Nowak, by increasing numbers of humans taking the dire wolf’s prey. Or dire wolves may have been outcompeted by gray wolves and red wolves (Canis rufus), both better suited to hunting the relatively smaller and faster prey that was becoming prevalent as large herbivores vanished. (Red wolves had crossed the Bering Land Bridge long before gray wolves and howled in the eastern and southeastern US.)

Whatever the cause, the dire wolf’s extinction left gray wolves as the dominant wolf in North America. With plenty of game to dine upon, Canis lupus flourished. “Its range,” writes Nowak, “was more extensive than that of any other terrestrial mammal.” Except humans.

Eventually, these ubiquitous gray wolves began to morph into five subspecies of Canis lupus as each type of wolf slowly adapted to its specific habitat, prey, and climate. This adaptation led to the development of the different sizes and behaviors seen in these five subspecies. 

The arctic wolf (Canis lupus arctos) inhabited the cold far north. The northwestern wolf (Canis lupus occidentalis) roamed Alaska and western Canada. The plains wolf (Canis lupus nubilus) claimed the largest territory, a wide swath from Oregon to Newfoundland and from Hudson Bay to Texas. The eastern wolf (Canis lupus lycaon) had the smallest range, prowling a compact, football-shaped portion of the northeastern US and southeastern Canada. The Mexican wolf (Canis lupus baileyi) stalked its prey in Mexico and the deep southwestern US.

This North American suite of millions of wolves would remain healthy and complete until we humans came to conquer the continent. Then the killing of wolves began. And hasn’t stopped.

The plains wolf was killed off by 1926.

The Mexican gray wolf—killed off in New Mexico by 1927—is endangered with more wolves living in captive breeding programs than in the wild. 

The red wolf was driven to near extinction by the mid-1900s and remains critically endangered.

The remaining eastern wolves are protected in both the US and Canada. There is a scientific debate, according to the International Wolf Center, that some or all the wolves in Minnesota, Wisconsin, and Michigan are eastern wolves (Canis lupus lycaon). 

The arctic wolf survives in Canada’s Queen Elizabeth Islands. 

Map from Center for Biological Diversity

The northwestern wolf ranges from Canada into the northwestern US, including Montana, Wyoming, Idaho, Oregon, Washington, and California. This population grew in the Lower 48 after reintroduction of wolves into Yellowstone and Idaho. The population also increased under protection of the Endangered Species Act—the very protection that the USFWS is removing. But as the map shows, wolves now survive in only a tiny portion of their historic range. They are not recovered. They need protection.

In an upcoming post, I’ll describe how two million wolves disappeared from the Lower 48.

Here’s a site to visit if you want to tell the governors of states with wolves to act in a way that helps wolves recover. 

Rick Lamplugh writes and photographs to protect wildlife and wild lands.

His bestselling In the Temple of Wolves; its sequel, Deep into Yellowstone; and its prequel, The Wilds of Aging are available signed. 

His books are also available unsigned or as eBook or audiobook on Amazon.