Post by Deinobrontornis on Oct 21, 2011 11:03:16 GMT -5
[a href="American Alligator - Alligator mississippiensis"]American Alligator - Alligator mississippiensis[/a]
The American alligator (Alligator mississippiensis), sometimes referred to colloquially as a gator, is a reptile endemic only to the Southeastern United States.
The American alligator has a large, slightly rounded body, with thick limbs, a broad head, and a very powerful tail. Adult Alligators generally have a green, olive, brown, gray or nearly black color with a creamy white underside. Algae-laden waters produce greener skin, while tannic acid from overhanging trees can often produce darker skin. Juvenile alligators have a striped pattern for camouflage that they lose as they mature. Averaging about 9.5 in (24 cm) in length when newly hatched, alligators reach sexual maturity when they measure about 5–7 ft (1.5–2.1 m). Adult male alligators average 11.2 ft (3.4 m) in length, while adult females average 8.2 to 9.8 ft (2.5 to 3.0 m). Average body weights are reported from 270 to 800 lb (120 to 360 kg), with a few exceptionally large and old males exceeding 14 ft (4.3 m) and 1,000 pounds (450 kg). One American Alligator reached a length of 19 feet 2 inches (5.84 m) and 2,200 lb (1,000 kg), which made it not only the largest alligator ever recorded, but also among the largest crocodilians on record (although the related Black Caiman and 5 other crocodilians are believe to equal or exceed this size and prehistoric crocodilians such as Sarcosuchus, Deinosuchus, and Purussaurus reached much greater size). The tail, which accounts for half of the alligator's total length, is primarily used for aquatic propulsion. The tail can also be used as a weapon of defense when an alligator feels threatened. Alligators travel very quickly in water and while they are generally slow-moving on land, alligators can lunge short distances very quickly. They have five claws on each front foot and four on each rear foot. American Alligators have the strongest laboratory measured bite of any living animal, measured at up to 9,452 newtons (2,125 lbf) in laboratory conditions. It should be noted that this experiment has not (at the time of the paper published) been replicated in any other crocodilians.
[a href="American black bear - Ursus americanus"]American black bear - Ursus americanus[/a]
The American black bear (Ursus americanus) is a medium-sized bear native to North America. It is the continent's smallest and most common bear species.
The skulls of American black bears are broad, with narrow muzzles and large jaw hinges. Females tend to have more slender and pointed faces than males. Their claws are typically black or grayish brown. The claws are short and rounded, being thick at the base and tapering to a point. Claws from both hind and front legs are almost identical in length, though the foreclaws tend to be more sharply curved. The hind legs are longer than those of Asiatic black bears. The tail is usually 4.8 inches (12 cm) long. The ears are small and rounded, and are set well back on the head. The soles of the feet are black or brownish, and are naked, leathery and deeply wrinkled. Black bears are highly dexterous, being capable of opening screw-top jars and manipulating door latches. They also have great physical strength, having been known to turn over flat-shaped rocks weighing 310 to 325 pounds (140 to 147 kg) by flipping them over with a single foreleg. They move in a rhythmic, surefooted way and can run at speeds of 25–30 mph (40–50 km/h). Black bears have good eyesight, and have been proven experimentally to be able to learn visual discrimination tasks based on color faster than chimpanzees and as fast as dogs. They are also capable of rapidly learning to distinguish different shapes, such as small triangles, circles and squares.
Black bear weight tends to vary according to age, sex, health, and season. Seasonal variation in weight is very pronounced: in autumn, their pre-den weight tends to be 30% higher than in spring, when black bears emerge from their dens. Black bears on the East Coast tend to be heavier on average than those on the West Coast. Adult males typically weigh between 57–250 kg (130–550 lb), while females weigh 33% less at 41–109 kg (90–240 lb). Adults have a typical size range of 120–200 cm (47–79 in) in length, and 70–105 cm (28–41 in) in shoulder height. The tail is 7.7–17.7 cm (3.0–7.0 in) long. Although they are the smallest species in North America, large black bears reach over 800lbs with 6 such specimens being harvested in Pennsylvania between 1992 and November 19, 2010 (Pocono Record NewsPaper). The biggest wild American black bear ever recorded was a male from New Brunswick, shot in November 1972, that weighed 409 kg (900 lb) after it had been dressed, meaning it weigh an estimated 500 kg (1,100 lb) in life, and measured 2.4 m (7.9 ft) long.
The American alligator (Alligator mississippiensis), sometimes referred to colloquially as a gator, is a reptile endemic only to the Southeastern United States.
The American alligator has a large, slightly rounded body, with thick limbs, a broad head, and a very powerful tail. Adult Alligators generally have a green, olive, brown, gray or nearly black color with a creamy white underside. Algae-laden waters produce greener skin, while tannic acid from overhanging trees can often produce darker skin. Juvenile alligators have a striped pattern for camouflage that they lose as they mature. Averaging about 9.5 in (24 cm) in length when newly hatched, alligators reach sexual maturity when they measure about 5–7 ft (1.5–2.1 m). Adult male alligators average 11.2 ft (3.4 m) in length, while adult females average 8.2 to 9.8 ft (2.5 to 3.0 m). Average body weights are reported from 270 to 800 lb (120 to 360 kg), with a few exceptionally large and old males exceeding 14 ft (4.3 m) and 1,000 pounds (450 kg). One American Alligator reached a length of 19 feet 2 inches (5.84 m) and 2,200 lb (1,000 kg), which made it not only the largest alligator ever recorded, but also among the largest crocodilians on record (although the related Black Caiman and 5 other crocodilians are believe to equal or exceed this size and prehistoric crocodilians such as Sarcosuchus, Deinosuchus, and Purussaurus reached much greater size). The tail, which accounts for half of the alligator's total length, is primarily used for aquatic propulsion. The tail can also be used as a weapon of defense when an alligator feels threatened. Alligators travel very quickly in water and while they are generally slow-moving on land, alligators can lunge short distances very quickly. They have five claws on each front foot and four on each rear foot. American Alligators have the strongest laboratory measured bite of any living animal, measured at up to 9,452 newtons (2,125 lbf) in laboratory conditions. It should be noted that this experiment has not (at the time of the paper published) been replicated in any other crocodilians.
[a href="American black bear - Ursus americanus"]American black bear - Ursus americanus[/a]
The American black bear (Ursus americanus) is a medium-sized bear native to North America. It is the continent's smallest and most common bear species.
The skulls of American black bears are broad, with narrow muzzles and large jaw hinges. Females tend to have more slender and pointed faces than males. Their claws are typically black or grayish brown. The claws are short and rounded, being thick at the base and tapering to a point. Claws from both hind and front legs are almost identical in length, though the foreclaws tend to be more sharply curved. The hind legs are longer than those of Asiatic black bears. The tail is usually 4.8 inches (12 cm) long. The ears are small and rounded, and are set well back on the head. The soles of the feet are black or brownish, and are naked, leathery and deeply wrinkled. Black bears are highly dexterous, being capable of opening screw-top jars and manipulating door latches. They also have great physical strength, having been known to turn over flat-shaped rocks weighing 310 to 325 pounds (140 to 147 kg) by flipping them over with a single foreleg. They move in a rhythmic, surefooted way and can run at speeds of 25–30 mph (40–50 km/h). Black bears have good eyesight, and have been proven experimentally to be able to learn visual discrimination tasks based on color faster than chimpanzees and as fast as dogs. They are also capable of rapidly learning to distinguish different shapes, such as small triangles, circles and squares.
Black bear weight tends to vary according to age, sex, health, and season. Seasonal variation in weight is very pronounced: in autumn, their pre-den weight tends to be 30% higher than in spring, when black bears emerge from their dens. Black bears on the East Coast tend to be heavier on average than those on the West Coast. Adult males typically weigh between 57–250 kg (130–550 lb), while females weigh 33% less at 41–109 kg (90–240 lb). Adults have a typical size range of 120–200 cm (47–79 in) in length, and 70–105 cm (28–41 in) in shoulder height. The tail is 7.7–17.7 cm (3.0–7.0 in) long. Although they are the smallest species in North America, large black bears reach over 800lbs with 6 such specimens being harvested in Pennsylvania between 1992 and November 19, 2010 (Pocono Record NewsPaper). The biggest wild American black bear ever recorded was a male from New Brunswick, shot in November 1972, that weighed 409 kg (900 lb) after it had been dressed, meaning it weigh an estimated 500 kg (1,100 lb) in life, and measured 2.4 m (7.9 ft) long.
