The Cheetah has been one of the most fascinating species to me since I started watching the Big Cat Diary on BBC from 1996 to around 2006. As they can reach incredible speeds around 70 – 75 mph for distances up to 1,600 feet and accelerate to around 62 mph in three seconds that is not the impressive part. In the wild, the cheetah is a prolific breeder, with up to nine cubs in a litter. The majority of cubs do not survive to adulthood, mainly as a result of depredation from other predators. The rate of cub mortality varies from area to area, from 50% to 75% and in extreme cases such as the Serengeti ecosystem, up to 90%. Cheetahs are notoriously poor breeders in captivity, though several organizations, such as the De Wildt Cheetah and Wildlife Centre, have succeeded in breeding high numbers of cubs.
Beavers are known for building dams, canals, and lodges (homes). They are the second-largest rodent in the world. Their colonies create one or more dams to provide still, deep water to protect against predators, and to float food and building material.
· Beavers use goggles too! Beavers possess a set of transparent eyelids which enable them to see under water.
· Beavers are second only to humans in their ability to manipulate their environment - the largest dam in existence is located in Wood Buffalo National Park, Alberta, Canada. It stretches for 850m, and is visible from space.
· Beavers homes, called lodges, are domelike constructions built from branches and mud. They are positioned in open water for protection from predators and have underwater entrance holes.
· Beavers don’t mind the cold, they can be seen active throughout winter and maintain use of their ponds even when covered with a layer of ice.
· Beavers are among the largest rodents on earth. Their large rodent teeth never stop growing. The beavers constant gnawing on wood keeps their teeth from growing too long.
· There are two species of beaver; the North American beaver and the European beaver. Although very similar in appearance and behaviour, the two species are not genetically compatible.
· The work of beavers makes them a keystone species in maintaining habitats that are relied on by many others. As well as wetland, beavers create standing dead wood (by drowning some trees) which is inhabited by insects, and in turn attracts bird life.
· Beavers are good house guests. Their lodges typically contain two dens, one for drying off after entering the lodge under water, and a second, dryer den where the family will live and socialise.
· Beavers have been known to share their lodges with families of muskrats!
· A beaver will fell a particular tree for a particular reason; a larger mature tree will be felled to form the basis of a dam. A young, second growth tree will be felled for food. Beavers will also fell broad-leaved trees to encourage re growth (food) closer their reach.
· Beavers use their broad, stiff tails like rudders to steer under water, and for balance while sitting on land. They also use their tails to slap the water as a warning of danger, or a warning to keep away.
Weapons System AR-15 | M6 | M16 | M4
As a Marine Corps Veteran, I was exposed to a series of weapons and had to know and understand the full understanding of the
Gas Operated - Gas is tapped from the barrel as the bullet moves past a gas port located above the rifle's front sight base. The gas rushes into the port and down a gas tube, located above the barrel, which runs from the front sight base into the AR-15's upper receiver. Here, the gas tube protrudes into a "gas key" (bolt carrier key) that accepts the gas and funnels it into the bolt carrier.
The bolt and bolt carrier together form a piston, which is caused to expand as the cavity in the bolt carrier fills with high-pressure gas. The bolt is locked into the barrel extension, so this expansion forces the bolt carrier backward a short distance in line with the stock of the rifle to first unlocks the bolt. As the bolt carrier moves toward the butt of the gun, the bolt cam pin, riding in a slot on the bolt carrier, forces the bolt to turn and unlock from the barrel extension. (The gas system only serves to unlock the bolt once the projectile has exited the barrel). Once the bolt is fully unlocked it begins its rearward movement along with the bolt carrier. The bolt's rearward motion extracts the empty cartridge case from the chamber, and as soon as the neck of the case clears the barrel extension, the bolt's spring-loaded ejector forces it out the ejection port in the side of the upper receiver. The bolt is much heavier than the projectile, and along with the recoil-spring pressure inside the stock buffer-tube performs the cartridge ejection function and chambers the following cartridge.
Behind the bolt carrier is a plastic or metal buffer, which rests in line with a return spring that pushes the bolt carrier back toward the chamber. A groove machined into the upper receiver traps the cam pin and prevents it and the bolt from rotating into a closed position. The bolt's locking lugs then push a fresh round from the magazine, which is guided by feed ramps into the chamber. As the bolt's locking lugs move past the barrel extension, the cam pin is allowed to twist into a pocket milled into the upper receiver. This twisting action follows the groove cut into the carrier and forces the bolt to twist and "lock" into the barrel's unique extension.