Black BearThe American black bear (Ursus americanus) is the most widely distributed bear in North America. Due to its current population levels, International Union for Conservation of Nature classifies the black bear as of “least concern” regarding threats to its existence.
There are as many as 16 different subspecies of Black bear listed in North America, with some such as Florida and Mexican black bears listed as endangered under the Endangered Species Act (ESA). Many subspecies are regulated as game mammals, and are hunted in limited regions within states such as California.Black bears are primarily omnivorous, feeding largely on vegetable matter, nuts, berries and insects. They are known, however, to be predators of young ungulates such as fawns of deer, and calves of elk and moose. Black bears are also known predators of bald eagle nests, and have been recorded raiding cave nests of California condors and killing condor chicks.
Hunt for Truth is investigating black bear predation on California condors, especially in the context of future condor reintroduction sites as in Yurok tribal lands in Northern California, and in Oregon’s Columbia River Valley.
Black bear have also been known to scavenge available carrion. As such, environmental activists contend that the potential for lead poisoning from hunter’s game left in the field may call for additional lead ammunition bans. Hunt for Truth is currently investigating allegations of poisoning and mortality related to secondary ingestion of lead shot and lead bullet fragments contained in carrion.
Grizzly BearThe grizzly bear (Ursus arctos horribili), is a large land omnivore currently occupying portions of the Northern Rockies within the lower 48 states, Canada and significant portions of Alaska.
Male grizzlies in the lower 48 contiguous states can reach average weights up to 600 pounds, while occasionally growing to as much as 1,000 pounds. Female grizzlies can reach average weights of up to 350 pounds. When standing on their hind legs, grizzlies can reach heights greater than 8 feet. A sprinting grizzly bears can achieve land speeds up to 45 miles an hour over varying distances.
As an apex predator, grizzlies utilize a wide variety of food sources. These include wild ungulates (moose, elk and deer), buffalo, fish, livestock (cattle, horses, and sheep), black bears, carrion, insects, and a wide variety of vegetable matter (white pine nuts and grasses).
Grizzly bears normally can live an average of 25 years or more in the wild, with specimens in captivity living as long as 40 years.
Grizzly bears are solitary other than during breeding season, and can utilize home ranges estimated as large as 187 square miles for females, and 505 square miles for males. Grizzly bears will defend food, territory and “personal space” to varying degrees, which in turn can cause fatal interactions with humans.
Grizzly bears were listed as threatened under the ESA on July 28, 1975 for the lower 48 states. Grizzly bear Recovery Zones are identified in Montana, Wyoming, Idaho, Washington State, and the San Juan Mountains in Colorado, totaling at least 38,700 square miles of important habitat. Additional reintroduction zones are being considered in Colorado and the Bitterroot Zone in Idaho and Montana. Currently there are no critical habitat designations for the Grizzly bear.
On March 22, 2007, a Distinct Population Segment of grizzly bears in the Yellowstone National Park Recovery Zone was delisted as a recovered population, no longer meeting the definition requirements for a threatened listing under the ESA. That delisting was later vacated in a Montana Federal District Court on September 21, 2009. While the U.S. Fish and Wildlife Service is appealing that ruling, the Yellowstone Distinct Population Segment remains designated as threatened.
Due to the grizzly bears reliance on carrion as a food source, certain researchers have inferred that grizzlies are threatened by ingestion of lead ammunition fragments from gut piles and game lost by hunters. Recently, however, a 2011 study undertaken by Craighead Beringia South and the University of Montana found that grizzly bears in Greater Yellowstone, where hunting is prohibited, had high blood-lead levels that were not linked to lead ammunition. The high blood-lead levels noted in the study and the conspicuous absence of a causal link between the blood-lead levels and hunters’ lead ammunition, directly indicate an alternative source of lead in the environment. Hunt for Truth continues to review studies addressing blood-lead levels in grizzly bears and other wildlife species for any objective and credible evidence allegedly linking lead poisoning to lead ammunition.