Friday, September 30, 2011

National Geographic(Macaws)

Macaws are beautiful, brilliantly colored members of the parrot family.
Many macaws have vibrant plumage. The coloring is suited to life in Central and South American rain forests, with their green canopies and colorful fruits and flowers. The birds boast large, powerful beaks that easily crack nuts and seeds, while their dry, scaly tongues have a bone inside them that makes them an effective tool for tapping into fruits.
Macaws also have gripping toes that they use to latch onto branches and to grab, hold, and examine items. The birds sport graceful tails that are typically very long.
Macaws are intelligent, social birds that often gather in flocks of 10 to 30 individuals. Their loud calls, squawks, and screams echo through the forest canopy. Macaws vocalize to communicate within the flock, mark territory, and identify one another. Some species can even mimic human speech.
Flocks sleep in the trees at night, and in the morning they may fly long distances to feed on fruit, nuts, insects, and snails. Some species also eat damp soil, which may help to neutralize chemicals in their fruity diet and ease their stomachs.
Macaws typically mate for life. They not only breed with, but also share food with their mates and enjoy mutual grooming. In breeding season, mothers incubate eggs while fathers hunt and bring food back to the nest.
There are 17 species of macaws, and several are endangered. These playful birds are popular pets, and many are illegally trapped for that trade. The rain forest homes of many species are also disappearing at an alarming rate.
Hyacinth, red-fronted, and blue-throated macaws are seriously endangered. The glaucus macaw and Spix's macaw may already be extinct in the wild.

National Geographic (Portuguese man-of-war)

Anyone unfamiliar with the biology of the venomous Portuguese man-of-war would likely mistake it for a jellyfish. Not only is it not a jellyfish, it's not even an "it," but a "they." The Portuguese man-of-war is a siphonophore, an animal made up of a colony of organisms working together.
The man-of-war comprises four separate polyps. It gets its name from the uppermost polyp, a gas-filled bladder, or pneumatophore, which sits above the water and somewhat resembles an old warship at full sail. Man-of-wars are also known as bluebottles for the purple-blue color of their pneumatophores.
The tentacles are the man-of-war's second organism. These long, thin tendrils can extend 165 feet (50 meters) in length below the surface, although 30 feet (10 meters) is more the average. They are covered in venom-filled nematocysts used to paralyze and kill fish and other small creatures. For humans, a man-of-war sting is excruciatingly painful, but rarely deadly. But beware—even dead man-of-wars washed up on shore can deliver a sting.
Muscles in the tentacles draw prey up to a polyp containing the gastrozooids or digestive organisms. A fourth polyp contains the reproductive organisms.
Man-of-wars are found, sometimes in groups of 1,000 or more, floating in warm waters throughout the world's oceans. They have no independent means of propulsion and either drift on the currents or catch the wind with their pneumatophores. To avoid threats on the surface, they can deflate their air bags and briefly submerge.

National Geographic(Ring-tailed Lemurs)

Lemurs are primates found only on the African island of Madagascar and some tiny neighboring islands. Because of its geographic isolation, Madagascar is home to many amazing animals found nowhere else on Earth. Lemurs may have floated there eons ago on "rafts" of vegetation and evolved in isolation over countless centuries.
Ring-tailed lemurs are unmistakable because of their long, vividly striped, black-and-white tail. They are familiar residents of many zoos.
Lemurs use their hands and feet to move nimbly through the trees, but cannot grip with their tails as some of their primate cousins do. Ring-tailed lemurs also spend a lot of time on the ground, which is unusual among lemur species. They forage for fruit, which makes up the greater part of their diet, but also eat leaves, flowers, tree bark, and sap.
Ring-tailed lemurs have powerful scent glands and use their unique odor as a communication tool and even as a kind of weapon. Lemurs mark their territory by scent, serving notice of their presence to all who can smell. During mating season, male lemurs battle for dominance by trying to outstink each other. They cover their long tails with smelly secretions and wave them in the air to determine which animal is more powerful.
Ring-tailed lemurs live in groups known as troops. These groups may include 6 to 30 animals, but average about 17. Both sexes live in troops, but a dominant female presides over all.
Ring-tailed lemurs are endangered, largely because the sparse, dry forests they love are quickly vanishing