American black bears are primarily a species of temperate and boreal forests, but they also range into subtropical areas of Florida and Mexico as well as into the subarctic. They live at elevations ranging from sea level to 3,500 m, and inhabit areas as diverse as dry Mexican deserts and scrub forests, Louisiana swamps, Alaskan rainforests, and Labrador tundra (where they occupy the typical niche of the grizzly bear; Veitch and Harrington 1996).  Between these extremes they occupy assorted deciduous and coniferous forest types, each providing a different array of foods.

The American black bear is a generalist, opportunist omnivore. Depending on location and season, they consume herbaceous vegetation, roots, buds, numerous kinds of fleshy fruits, nuts, insects in life stages from egg to adult, and vertebrates from fish to mammals, including their own kills as well as carrion.  Moreover, they readily consume various human-related foods, from garbage and birdseed to a variety of agricultural products from cropfields and orchards, including corn, oats, soybeans, sunflowers, wheat, and apples, and brood and honey in apiaries.  Black bear predation upon livestock has also been documented in some areas. The ability of black bears to adjust their diet to the circumstances has enabled them to persist not only in a diversity of habitat types, but also in highly fragmented forested areas in proximity to humans (Pelton 2003, Benson and Chamberlain 2006, Ditmer et al. 2015).

A key habitat feature in many areas is a source of fall mast that enables black bears to increase their fat reserves for winter hibernation.  Historically, American chestnuts (Castanea dentata) likely were a key fall food for bears (and other wildlife) in eastern North America, but after a blight eliminated this food source in the early and mid-1900s, oak (Quercus spp.) acorns and beechnuts (Fagus grandifolia) have become the principal fall foods for bears throughout this region (Vaughan 2002).  However, oaks are now declining in eastern North America due to forestry practices, insects, disease, and over-abundance of deer (McShea et al. 2007), and a disease accidentally introduced in the late 1800s is now spreading widely across beech forests in northeastern U.S. (Morin et al. 2007). In parts of the range where oaks and beech are absent or uncommon, hazelnuts (Corylus spp.), whitebark pine nuts (Pinus albicaulis), saw palmetto (Serenoa repens) berries, madrone (Arbutus xalapensis), manzanita (Arctostaphylos spp.), huckleberries (Vaccinium spp.), buffaloberries (Shepherdia canadensis), wild cherries (Prunus sp.), mountain ash (Sorbus spp.), or other fruits, or sometimes meat, are the fall dietary mainstays.  In the southwestern U.S. and in Mexico, succulents such as yucca (Yucca spp.) and cactus fruits also play important roles in providing food, especially during drought (Doan-Crider 2003).  American black bears may migrate considerable distances (up to 200 km) to find more abundant food sources, especially in late summer and fall, prior to hibernation (Garshelis and Pelton 1981, Beck 1991, Hellgren et al. 2005, Noyce and Garshelis 2011).

American black bears hibernate for up to 7 months in the northern portions of their range (Bertram and Vivion 2002, Chaulk et al. 2005), but for considerably shorter periods in more southerly areas (Wooding and Hardisky 1992, Waller et al. 2012).  In some southern and low-elevation areas, where food is available year-round, some bears may remain active during winter (Hellgren and Vaughan 1987, Graber 1990, Doan-Crider and Hellgren 1996, Hightower et al. 2002).  However, all parturient females den to give birth to cubs, typically in January–February.  American black bears use a wide variety of den structures: existing caves or tree cavities, underground chambers that they excavate, root masses, brush piles, or even above-ground nests. Adequate denning sites or structures are rarely thought to be limiting, except in habitats that flood (because young cubs may drown or die of exposure; White et al. 2001), or where bears preferentially choose certain types of dens, such as hollow trees, that are being reduced through logging (Davis et al. 2012).

Mating typically occurs in May–July, but may be extended in southern latitudes (Garshelis and Hellgren 1994, Spady et al. 2007).  Females can have as many as 3 estrous cycles (B. Durrant, personal communication, 2014). Implantation is delayed, and active gestation is only 2 months.  Females give birth beginning at age 3–10 years: their rate of growth and maturity varies with food availability, and hence tends to be especially delayed in northern boreal forests.  They can produce cubs every other year, but in places with less food, this interval may be extended to 3 years.  Average litter size is approximately 2.5 cubs in eastern (ranging up to 5 or rarely 6 cubs) versus <2.0 cubs in western North America (Alt 1989, Garshelis 1994, Bridges et al. 2011).  Reproductive rate in this species is highest among the ursids, although there is a clear dichotomy between Eastern (including Midwestern) and Western populations.

American black bears range across three countries: 12 provinces and territories of Canada (all except Prince Edward Island, where they were once abundant, but the last known one shot in 1927; Sobey 2007); 41 U.S. states (with sightings but undefined ranges in 5 other states); and 6 states of northern Mexico (Scheick and McCown 2014) (with sightings in 4 other Mexican states and a recent record of a dead bear farther south in the state of Hidalgo; Rojas-Martínez and Juárez-Casillas 2013). The species never existed outside of these three countries, although the southern historic limit is not well known. The present range falls within 69°29´ to 23°14´ N (with the incidental record in Hidalgo at 21°05’30” N) and 52°49´ to 164°10´W.

In western parts of their range, American black bears broadly overlap and compete with grizzly/brown bears (Ursus arctos) (Mattson et al. 2005, Mowat et al. 2013). Black bears occupy several islands off the coast of Alaska and British Columbia, but do not coexist with brown bears on any islands.  Northward, black bears narrowly overlap with polar bears (Ursus maritimus) along the Québec coast of Ungava peninsula, the Ontario and Québec coasts of James Bay, and along the Ontario and Manitoba coasts of Hudson Bay.  Climate change seems to have enabled black bears to range farther north. For example, there have been recent sightings of black bears near Salluit, the second northernmost Inuit community in Québec (62°12'N) (S. Côté, Laval University, Québec City, personal communication, 2015).  Along the western shore of Hudson Bay in Nunavut, local hunters from the community of Arviat (61°5'N) have observed black bears about 50 km west of the village.  These sightings have occurred since 2005, were of single individuals, and are considered to be rare (D. Lee, Nunavut Tunngavik Incorporated, personal communication, 2014) but are farther north than similarly rare excursions noted by Jonkel and Miller (1970).

Loss of habitat and unregulated hunting/persecution resulted in extirpation of black bears across large portions of their range by the early 1900s.  Present occupied range covers 10.5 million km², representing 65–75% of the historical range, depending on whether Midwestern prairies are counted as historical range (Scheick and McCown 2014).  Black bears were documented along some wooded river courses through the Great Plains (e.g., Lewis and Clark expedition, 1804–1806; Laliberte and Ripple 2003), but were likely scarce in the grasslands. More of the original distribution remains in Canada (>95%; 6.9 million km²) than the U.S. (45–60%; 3.5 million km²). However, recolonization from growing neighboring populations, in some cases assisted by translocations, have occurred across the U.S., including several previously extirpated states: Rhode Island and Connecticut in the Northeast (Cardoza 1976, Scheick and McCown 2014), Kentucky in the Southeast (Unger et al. 2013), Ohio, Oklahoma and Missouri in the Midwest (Bales et al. 2005, Scheick and McCown 2014, Wilton et al. 2014; although genetic studies suggest that Missouri bears may not have been completely extirpated ― Faries et al. 2013, Puckett et al. 2014), and Texas (Onorato and Hellgren 2001) and Nevada in the Southwest (including areas that were erroneously thought to be outside historic range; Lackey et al. 2013). The current distribution in Mexico (at least 99,000 km²) is believed to have been drastically reduced from an unknown historical extent due to deforestation, hunting, and incidental killing from predator poisoning (Delfín-Alfonso et al. 2012); however, these bears are also now expanding and reoccupying portions of their former range, and possibly new areas because of artificial water and food sources.

n the U.S. and Canada, black bears are managed by individual states and provinces, so although an IUCN conservation action plan exists for this species (Pelton et al. 1999), each state and province sets their own goals and methods for achieving those goals.  As a whole, this has worked well to re-establish robust populations of black bears across their range. Several key factors aided the rapid rebound of American black bears since the 1980s: (1) improved habitat, (2) large dispersal distances in high-quality habitat (Moore et al. 2014), (3) relatively high reproductive rates, (4) reduced human-caused mortality, and (5) better information about the biology and ecology of bears combined with better population monitoring techniques (Miller 1990).

Much forested habitat, essential for black bears, was cleared indiscriminately for agriculture during the 1700s–mid-1900s, but has since returned in many parts of the U.S. Most notably, northeastern U.S. (New England) has been naturally reforested back to near its pre-colonial extent (~400 years ago; Hall et al. 2002), although tree composition is different (fewer hard mast-producing trees as food for bears; Thompson et al. 2013).  Some states and provinces also manage habitat to benefit bears (e.g., space, foods, travelways, den sites; Pelton et al. 1999).

Through the 1800s and early 1900s in some areas, black bears were extensively hunted for meat, skins, and grease (i.e., market hunting; Smith et al. 1991, Unger et al. 2013) or hunted or poisoned with the intent of eliminating or severely reducing their numbers to reduce damage to crops and livestock (Cardoza 1976, Raybourne 1987).  Governments often paid a bounty to encourage the killing of black bears.  Protection and recovery occurred state-by-state and province-by-province during 1902–1983 as laws were changed and bears gained protection as a big game species (Miller 1990). Thereafter, the number and sex of bears killed were more closely controlled through hunting regulations and restrictions on numbers of hunters.  By the 1980s, under the belief that black bears reproduced slowly and were easily over-harvested, most management agencies took a conservative approach to black bear hunting to enable populations to increase (Hristienko and McDonald 2007). Moreover, an infrastructure of wildlife management agency personnel and hunters policed illegal take.

Wildlife management agencies have also taken an increasingly active role in reducing the number of bears killed in conflict situations through stricter laws against shooting and feeding (in some jurisdictions, feeding bears is illegal), and educational programs aimed at coexisting with bears by reducing attractants, promoting public tolerance, and recognizing that black bears are typically not a threat to human safety (Treves et al. 2009, Baruch-Mordo et al. 2014).

In Mexico all hunting seasons for American black bears have been closed since 1985, and the species is considered nationally endangered. Numerous conservation initiatives established by large private ranches and land cooperatives in northern Mexico have created large blocks of suitable habitat (e.g., oak-dominated forests) with protection from poaching (Doan-Crider 2003). Changing public attitudes toward bears in Mexico have also contributed to the recovery and expansion of the species (SEMARNAP 1999, Onorato and Hellgren 2001). Although bear populations are clearly increasing, population estimation and monitoring efforts are lacking because funding (normally associated with hunting fees in the U.S. and Canada) is not available. Hunting bans will likely not be lifted without better documentation of population size and trend.

In the southeastern U.S., where black bears now occupy 27–37% of their historic range (depending on whether primary range or total bear range are counted as occupied range; Scheick and McCown 2014), population recovery was aided by the establishment of national parks and other sanctuaries in the Appalachian Mountains and the Coastal Plain (Pelton and van Manen 1997). These large areas protect the habitat (especially mast-producing trees) and restrict hunter access. Beginning in the early 1970s, additional areas were established where bear hunting was prohibited, thus linking protected areas to other forested lands, including many private lands. the resulting conglomerates serve as dedicated or defacto sanctuaries, especially for adult females, that are a source for bears expanding into other areas (Beringer et al. 1998, Unger et al. 2013).

In some areas, populations of American black bears have either been augmented or reintroduced after former extirpation by transplanting bears from elsewhere (Clark et al. 2002).  Reintroductions into Arkansas during the 1960s were highly successful (Smith et al. 1991).  Licensed hunters in this state now harvest several hundred bears annually, and bears from Arkansas have expanded into neighboring states. Further reintroductions within Arkansas have been conducted more recently (Wear et al. 2005). A successful reintroduction augmented a newly-spawning population in Kentucky (Unger et al. 2013). Augmentation of several populations in Louisiana during the mid-1960s likely contributed to population recovery there.

The Louisiana black bear (U. a. luteolus), a recognized subspecies of American black bear, was listed as threatened under the U.S. Endangered Species Act in 1992 as a result of severe loss and fragmentation of its habitat combined with unsustainable human-caused mortality (Bowker and Jacobson 1995). At the time of the listing, and since then, the validity and integrity of this subspecies has been debated (Pelton 1991, Kennedy et al. 2002, Csiki et al. 2003, Puckett et al. 2015). Under this ruling, all bears within the historic range of the Louisiana black bear, from east Texas to southern Mississippi, have been protected. Much of the bottomland hardwood forest that the Louisiana black bear historically inhabited had been converted to agriculture. Since 1992, remnant bottomland hardwoods have been protected, and some marginal farmland converted to hardwood trees.  Moreover, a new population of bears within Louisiana was established by translocating bears from other Louisiana populations (Benson and Chamberlain 2007) in order to create a stepping-stone between two separated populations; this enabled bears to travel between them (Laufenberg and Clark 2014). One irony is that the stepping-stone successfully linked a population that was believed to be native Louisiana black bears with a population that had previously been established by translocating U. a. americanus bears from Minnesota (1964–1967). The Minnesota bears had clearly adapted to the very different habitat and weather conditions in Louisiana, as they have been established there for three generations and their numbers have been increasing. However, if the luteolus subspecies has any merit, the successful establishment of a conservation corridor reduced the purity of that genetic stock.

The conservation efforts in Louisiana have been further enhanced through public information and education. This management program is organized by a broad coalition of state and federal agencies, conservation groups, forestry and agricultural industries, and private landowners. As a result, bears have been noticeably increasing in numbers and distribution in all three range states, although a breeding population does not yet exist in east Texas.  Large, contiguous forested habitat capable of sustaining a population of black bears exists within the historical range of the subspecies in east Texas (Kaminski et al. 2013); however, surveys of local people indicate concern over potential conflicts with an established bear population in the area (Morzillo et al. 2010). In 2015, the U.S. Fish and Wildlife Service proposed delisting the Louisiana black bear, based largely on a rigorous study (Laufenberg and Clark 2014) that showed that all of the population criteria for recovery had been attained and adequate safeguards against future threats were in place (Fuller 2015).

Another typically-accepted subspecies of black bear (U. a. floridanus) was listed as threatened by the state of Florida in 1974, although legal hunting continued in some population strongholds until 1994. Habitat degradation, and bears being killed on highways and in conflicts with people are the primary threats to these bears. The fragmented habitat contributes to the high vehicle kills and human interactions. A public petition to the U.S. Fish and Wildlife Service to list the Florida black bear as a federally threatened species was denied in 1992. A black bear management plan, adopted in 1993, directed the state management agency to conserve habitat and reduce human-caused bear mortalities. These efforts, particularly habitat conservation measures and changes in human attitudes toward bears, supported a steady population increase (Florida Fish and Wildlife Conservation Commission 2012). Florida black bears have been expanding into areas of unoccupied habitat as regrowth of understory and forests improve habitat quality, even as development reduces habitat quantity.  In 2010 the status of the Florida black bear was re-evaluated using IUCN redlisting criteria, and after a thorough, peer-reviewed biological assessment and development of a management plan, the species was removed from the state’s threatened species list in 2012 (Florida Fish and Wildlife Conservation Commission 2012). A hunt was initiated in 2015.

In British Columbia much conservation attention has been directed toward the Kermode subspecies (U. a. kermodei). This animal is commonly referred to as the “spirit bear” because it possesses a gene that when homozygous is manifested as white pelage (Ritland et al. 2001).  White-phased animals have long been protected from hunting.  A large system of protected areas was established in 2006 (Great Bear Rainforest Agreement) to ban or severely restrict logging within >200,000 ha of coastal temperate rainforest inhabited by this subspecies of black bear, as well as by brown bears.  Additionally, the spirit bear was selected as the official provincial mammal of British Columbia.

Since 1992 all American black bears have been listed in Appendix II of CITES, under the similarity of appearance provision (Article II, para 2b).  This listing stipulates that documentation of legal harvest is necessary for the import and export of body parts in order to prevent these from being confused as parts from illegally obtained bears.  This listing was not designed to protect American black bears, but rather other species of threatened bears, particularly the Asiatic black bear (U. thibetanus), whose parts might otherwise be sold under the guise of being from American black bear.