What is Black, Brown, White and Blue but still Black Through and Through?
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Transcript of What is Black, Brown, White and Blue but still Black Through and Through?
What is Black, Brown, White and Blue but still Black Through and Through?
American Black BearUrsus americanus
Fur
Covered in 2 types of hair: soft dense fur for insulation and coarse guard hairs that keep the dense fur clean and dry.
Fur color can be black, brown, blonde, cinnamon, chocolate white and even blue
The best theory behind this is heat regulation
Black colored Black bears favor the eastern forests where there is plenty of shade
Brown colored Black bears are typically found in western forests where they feed on exposed hillsides during the day
Blue colored or glacier Black bears are found along the southeast coast of Alaska.
All color phases can produce black cubs, but not all cubs stay the same color when they grow into adults.
Geographic Distribution
During the last Ice Age, Black Bears inhabited the forests and plains of what is now the United States and Mexico.
This includes areas around western mountains, the Appalachians, the swamps of the Gulf and the coasts of Florida (Taylor).
Grizzlies took over the vacant range when the ice retreated, but black bears were able to control grizzly expansion in the forested areas of North America
This is because black bears are smaller and require less amounts of food
Physical Characteristics
Adult Males Adult Females
Full skeletal growth by 7 years
Grow in weight in another 3-4 years
Typically weigh between 120-180 kg (265-627 lb.)
Nose to Tail: 193-190 cm (51-75 in)
Height of Shoulder: 100 cm (40 in)
Full Skeletal growth by 5 years
Grow in weight in another 3-4 years
Typically weigh between 45—182 kg (100-400 lb)
Nose to Tail: 110-170 cm (43-67 in)
Height of Shoulder: 80 cm (31 in)
Black bears have a “droopy” backside that makes their back legs appear short than their front legs.
Claws range from 2.5-3.5 centimeters (1-1.4 in)
The bigger the ears are, the younger the black bear is.
Diet
During patterns of climate change in the Northern hemisphere, bears adapted to seasonal abundances of food
These include plants, fish, and other animals
When one food source was no longer available, the bears simply switch to another
During the winter, when food supplies are low, bears sleep the barren season away on stored fat
•Although they are carnivores by definition, 80-85% of the black bear’s diet consists of plant material. •Most of the animal matter they consume are insects, including caterpillars and bees.
Hibernation
To prepare for hibernation, bears will eat up to 3 times more food per day
This “binging” is called hyperphagia
After the feeding stage, bears enter a state of walking hibernation: they are alert, but consume very little
Body systems slow down and blood flow to limbs decreases
By this point, a den site has been chosen, although some bears try out sites for a few days
Dens must be dry, away from danger and fairly cramped
Heart rate only drops 8-10 beats and body temperature only drops 3-7º C (5-9º F)
How long black bears hibernate depends on their location
Alaskan black bears may hibernate for three-quarters of the year while southern black bears may only sleep for a few days
Dens
Denning order: 1 Pregnant Sows 2 Older sows with cubs 3 Solitary females 4 Sub-adults 5 Adult males
Usually reappear in reverse order
Although they sleep through the entire winter, it is possible to wake a sleeping bear…
Mating
Female black bears reach sexual maturity in the third year
Typically breed in the third year and once every two or three years after that
Finding a mate is harder that it seems: Black bears are solitary animals and would rather avoid each other
When in estrus, a female will wander through her home territory to increase her chances of finding a mate
Mating usually occurs from May until mid-July
This lengthy season gives the female time to find a mate
Male are capable of breeding around 3-4 years, but do not usually get the chance until about the 8th year, when they can hold their own against older males.
Female bears play hard-to-get but during the mating period, the male and female are inseparable
After the mating period, the male and female go their separate ways, usually to find another mate
Mother and Cubs
Female black bears give birth to their cubs during hibernation
This ensures that they are fully developed by the spring and it conserves energy
The mother is half-awake for the birth of her cubs, usually twins or triplets
The cubs weight between 240-330 grams (16-20 ounces)
Once hibernation is over, the mother doesn’t eat for 2 weeks ( this is the same for males)
The cubs however continue to suckle through their first year, sometimes into the second
A mother bear will fight to the death to protect her cubs
They will lead their cubs up to 100 km away from the den
When they are in danger, the best escape route it to climb tall trees