Black Bear: Ursus americanus floridanus
The Florida black bear (Ursus americanus floridanus), is a subspecies of the American black bear. The Florida Black Bear is 1 of 3 subspecies of bears recognized in the southeastern United States
The Florida black bear can be distinguished from other subspecies by genetic and skeletal differences.
Black bears originated in North America, and have been here at least 1.5 million years.
The taxonomic tree of Florida black bears.
Scientists assign all living organisms a Latin name, also called the binomial name. Using Latin avoids confusion caused when people from different places, speaking different languages, use different names to talk about the same animal or the same name to talk about different animals. The process of organizing organisms into groups (taxons) by shared characteristics is called "taxonomy". These taxonomic groups work from the most general characteristics to specific traits, and reflect how creatures are related through evolution.
The complete "taxonomic tree" for the Florida black bear is:
Kingdom: Animalia (animals, not plants or single celled organisms)
Phylum: Chordata (they have spinal chords)
Sub-phylum: Vertebrata (they have a back bone)
Class: Mammalia (they are mammals)
Order: Carnivora (classified by body structure as carnivores)
Family: Ursidae (the Latin word for bear family)
Genus: Ursus (Latin for bear)
Species: americanus (from America)
Subspecies: Floridanus (from Florida)
What Do Black Bears Have in Common With All Bears?
Like all members of the bear family, black bears are large, powerful mammals with rounded ears, short tails, 5-toed feet, and large canine teeth.
Black bears may look slow because they walk flat on their feet (called plantigrade) like people, and travel with a shuffling gait, but they can run up to 30 miles an hour.
With their stout, heavily-curved claws, black bears climb trees very well; these claws are non-retractable and can be easily seen in their tracks.
Although black bears in western states may have several color phases, all black bears in the Southeast, including Florida black bears, are black.
The muzzle may be tan or nearly black, and blonde or white chest blazes of all shapes and sizes are common.
Bears are sexually dimorphic. This phrase means that adult males are larger than adult females, however because smaller males are similar in size to adult females, it is difficult to determine the sex of a bear by their size alone.
Some people think that because white-tailed deer body size is reduced from northern to southern states, especially key deer, then black bears in Florida are smaller than more northern bears. This is not true.
Adult males in Florida normally weigh between 250 - 450 pounds, and adult females in Florida normally weigh between 125 - 250 pounds.
There have been two male bears that set a record for the state in excess of six hundred pounds. One was a 635 lb bear harvested in 1945 in Volusia County. The other was a 624 lb, eight year old male roadkill in December 1988 in Collier County.
The record weight for a female bear is 400 pounds, roadkill in January 2007 in Liberty County. Bears that habitually feed on human supplied foods such as garbage and wildlife feed or pet food to be abnormally large.
The weight of individual black bears varies greatly throughout the year.
Food availability is low during the winter months, even in Florida, and both male and female bears lose weight.
Bears can lose up to 25% of their body weight while denning.
As plants grow new shoots in the spring, bears begin to gain weight.
During the summer breeding season, males spend most of their time searching for mates. Females with or without cubs spend most of their time foraging.
Most people find it hard to estimate the size of a bear that they have seen in the wild. One good method is to pay attention to the relative size of their ears.
Because the ears of black bears reach full length when they are juveniles, small, skinny yearlings appear to have very long "Mickey-mouse" ears on slender faces, while large males seem to have very small, rounded ears on wide, round heads.Also, adult males tend to have wide, wedge shaped faces, while females have more slender looking faces.
As breeding season ends and fall begins, both sexes forage and gain up to 1-1/2 times their summer weight. This is called "hyperphagia."
Male bears, may stay active and eating all winter. Gaining weight allows bears to make it through the winter months.
Females need to be in good condition to produce and feed cubs during denning. Bears can gain or lose over a 100 pounds over one year!
Black Bear Senses
Vision: Black bears have good eyesight, possibly equal to humans, and recent research has found that they have color vision.
Hearing: They have acute hearing.
Smelling: They have an excellent sense of smell (bears can smell more than a mile away!). Their rumored poor vision may be due to their reliance on their sense of smell, as well as behavior.
Black bear are curious animals. They often do a lot of sniffing, and may stand up on hind legs to get a better view and smell their surroundings. This is normal non-threatening behavior and is not a sign of aggression.
Bear cubs are very small at birth, only 225 - 450 grams (8 - 15 ounces) and the size of a small squirrel.
They have a very fine coat of hair but their eyes are closed. Litters range from 1 to 5 cubs, but 2 or 3 are most common in Florida.
The cubs nurse and play in the den until leaving in spring.
Cubs stay with their mother for a year and a half, and will usually/almost always den with her the following winter.
Since bear cubs stay with their mother until the summer of their second year, young bears may be called either "cubs of the year" or dependent yearlings" when they are still with their mother, depending on their age and size.
During their second summer, the family group breaks up, the juveniles wander off on their own, and the adult female is ready to breed again.
Female yearlings will likely establish their home ranges near or overlapping their mothers, while male yearlings will find new areas to establish home ranges.
Taking care of the cubs for 2 summers means that adult females will typically only breed every other year.
In Florida, males and non-pregnant females may den up in dense vegetation for only a few weeks or a month.
Pregnant females will den up for the entire winter, and because their cubs will be born in the den, they often select more protected sites.
Dens may be in tree cavities, under blow-downs or fallen logs, or ground 'nests' in dense thickets.
Bears are called omnivores because they eat both plant and animal matter. A bear's diet consists of 80% plant and 20% animal matter.
Black bears eat mainly acorns, nuts, berries, and other vegetation as well as insects.
A small percentage of their diet is meat which is mostly obtained from scavenging.
The black bear diet varies seasonally and yearly depending on fluctuations in plant productivity but it is also based on geographic variation from one region of Florida to the next. For example, saw palmetto berries are a high portion of bear diets in the Osceola population, but insignificant in the Apalachicola population. This ability to find and eat a wide variety of food types can bring bears into contact with humans. For example bears can be attracted to garbage, honey, barbeque grills, wildlife feeders, etc.
Bears are solitary by nature, except when in family groups or pairings during the mating season.
Bears will congregate in areas of high food density, such as oak stands or berry patches. These groupings happen more because one bear cannot defend such a rich food source from competitors than because they enjoy the company.
While bears may defend a food resource, in general, bears are not territorial in that they do not defend a "specific area" from intrusion by other bears.
The area they inhabit in search of food, water, and adequate cover is called a home range.
Individual bear home ranges may overlap.
The size of a home range may vary each season and year depending on food availability, the sex, age, and reproductive status of the bear, and bear population density.
During major droughts and mast failures, bears will explore new areas in search of food.
In Florida, male bears typically have home ranges of 50 to 120 square miles; female ranges generally are 10 to 25 square miles.
Bears have the ability to navigate homeward from unfamiliar areas.
Bears have been able to return to their original home range (up to 168 miles away) after having been relocated.
Bears are quiet creatures, but occasionally they make sounds to communicate.
Cubs bawl and moan when distressed, and make a sort of grunting purr when suckling.
Sows communicate with their young by grunts or moans and can send their cubs up trees for safety, or have them follow her.
An aggressive bear does not growl like a dog. Instead, they will stare, protrude their lower lip, and flatten their ears. If the source of their unease remains, they may slap the ground, "huff" or "blow", and snap or "gnash" their jaws.
If these behaviors don't scare off the source of their unease, the bear may bluff charge or fully charge.
Bears respond to people as they would other bears. Understanding the various responses and ways bears communicate can help people to coexist with bears.
Black bears bite and claw marks onto trees between 5 and 7 feet high, both conifers and hardwoods, but the reason for such markings is unknown. Marks occur along defined game trails, with the mark facing the trail. Often bears rub against these trees as well. Four untested theories are:
the marks are related to male dominance hierarchies,
marks communicate breeding status to ensure males and females are synchronized successfully for breeding,
marking territory boundaries among females may mimic territorial behavior, and
marks may serve to help orient bears in new or little used areas (marking increases when a bear enters a new areas).
Most likely there are several reasons why black bears mark trees.
Black bears do not hibernate instead they experience what is often called 'partial hibernation' or 'winter lethargy'.
This period of reduced activity occurs in all black bear populations because winter lethargy is an adaptation to the lack of available food, not low temperatures.
Bears in southern states, from North Carolina south to Louisiana, den for shorter periods and sleep less deeply than bears in colder climates.
While denned bears in northern states are very lethargic and less responsive to people, bears in the South readily run away when people come close to their den.
The breeding season for black bears runs from June to July, but cubs are not born until late January to early February.
Bears have delayed implantation. If the mother is in poor condition and nutritionally stressed, the fertilized egg may be "reabsorbed"; the partially developed fetus will not develop further; or cubs will be miscarried and eaten by the female.
This adaptation to periodic food shortages prevents the sow from producing offspring for which she cannot care.
Under normal circumstances, the fertilized egg will implant in November or early December, and grow normally until birth in about 8-12 weeks.
Life Expectancy and Mortality
Determining the average life-span for wild black bears is very difficult.
The 2 oldest known bears from Florida were 20 years old (killed in 1985 during a legal bear hunt held on Apalachicola Wildlife Management Area) and 19 years old (captured in 2004 as part of a University of Kentucky Glades/Highland Bear Population Study). Both bears were females (sows). The oldest known male, from the Ocala population, was killed by a vehicle at age 16.
In zoos, black bears have been known to live into their 30's. Adult black bears have no predators besides humans and other bears, but do suffer mortality from other sources such as transportation related mortality.
Cubs: Approximately 25-50% of all cubs die before they turn one year old. Natural causes of death include drowning, den cave-ins, hypothermia due to flooded dens, starvation, infections from injuries, and predation (by other bears). They are also struck by vehicles.
Juveniles: Yearlings will establish their own home range once they disperse from their mother. Yearlings are susceptible to high mortality rates as a result of starvation, predation by other bears, and vehicle collisions. About a quarter will die before they turn two years old.
Young, independent females establish a home range close to their mother. About 20% die before reaching adulthood (~4 years old).
Juvenile males travel farther in search of a new home range. The traveling needed to forage and find new den sites in unknown territory increases mortality risks, and approximately 46% of males will die before reaching adulthood.
Adults: Once fully grown, black bears have no predators besides humans and other bears. Main causes of mortality are old age, vehicle collisions, starvation, and poaching (Florida has no legal hunting season), other bears, disease, and accidents.
The legal bear hunting season was reduced to certain areas of the state in 1974, then further reduced until it was closed statewide in 1994. Click the link to see a timeline of including hunting regulations and other state management activities regarding the Florida Black Bear.
Disease and Parasites:
Little information is available on the diseases and parasites of wild black bears. Research shows that, while bears host external parasites (ticks and mites) and several types of internal parasites (helminths, nematodes, trematodes, and acanthocephalams); they are not believed to cause any significant health problems to bears.
Image Credit: M Orlando