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Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Superorder: Afrotheria
Order: Tubulidentata
Family: Orycteropodidae
Genus: Orycteropus
Species: O. afer
Scientific Name: Orycteropus afer
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| Conservation Status |
PHYSICAL CHARACTERRISTICS:
Aardvarks have elongated, or stretched-out, heads with a pig-like snout and tubular ears. Their muscular, arched bodies are protected by a thick, grayish brown skin that is covered with bristles. The front feet have four toes as well as sharp claws, while the back feet have five toes. The cone-shaped tail is short and tapered, smaller at the end. The long tongue is sticky to help catch insectsAdult aardvarks are 67 to 79 inches (170 to 200 centimeters) long and weigh anywhere from 88 to 143 pounds (40 to 65 kilograms).
The word aardvark means "earth pig" in Dutch. In addition to having a pig-like snout, this mammal resembles a pig in the way it uses its front feet to dig. Like the tail, the snout tapers at the end, and it has two nostrils that can be closed. Although the legs are short, they are powerful—strong enough to break through rock-solid termite mounds. The back legs are slightly longer than the front legs. Despite having soles on the hind feet, aardvarks move on their toes and use the front feet, with their long claws, for digging.
ADULTS:
Adults have about twenty teeth, and they are located in the back of the mouth. These column-shaped teeth grow throughout the aardvark's lifetime and, unlike human teeth, do not have protective enamel coating. Instead, each tooth is made of dentin, a material that is harder than bone.
HABITAT:
The deciding factor for where aardvarks live is availability of food. They also require sandy soil, as opposed to rocks, so that they can dig for termites. Aardvarks live in underground burrows that are 6.5 to 9.8 feet (2 to 3 meters) long, at 45 degree angles. At the end of the tunnel is a rounded "room" where the aardvark curls up to sleep. Female aardvarks give birth in this chamber. Although burrows usually have just one entrance, some have numerous entryways as well as several tunnels extending from the main passage.Aardvarks are nocturnal in habit.
DIET:
Aardvarks began eating termites thirty-five million years ago, and that's still their preferred meal. A hill of termites is not enough to satisfy an aardvark, however, so it searches for entire termite colonies. These colonies march in columns 33 to 130 feet (10 to 40 meters) long, which makes it easy for the aardvark to suck the termites through its nostrils. When attacking a termite mound, the aardvark starts digging at the base with his front claws. Once the termites begin escaping, it extends its tongue and traps them with its sticky saliva. Aardvarks also eat ants and locusts, a type of grasshopper.
In addition to these insects, aardvarks eat an underground fruit of the cucumber species, probably as a source of water. Cucumis humifructus is known in South Africa as the "aardvark pumpkin" or "aardvark cucumber." One tribe of native people, the !Kung San, call this plant "aardvark dung" because the aardvark buries its feces outside abandoned aardvark burrows and the plant grows from seeds left in the aardvark's feces.
REPRODUCTION:
The mating season of the aardvark varies. In some areas, mating occurs between April and May, with offspring born in October or November. In other regions, offspring are born in May or June. Females carry their offspring for seven months before giving birth, and they bear only one offspring with each pregnancy. The baby weighs approximately 4 pounds (2 kilograms). Newborn aardvarks are hairless with pink, tender skin. They remain in the burrow with their mothers for two weeks. After two weeks they follow their mothers in the nightly search for food. The infant aardvark does not eat solid food until around three months, preferring its mother's milk until that time.
GESTATION PERIOD:
Aardvarks move away from the mother's den after six months and build burrows a few feet (meters) away, but they continue to forage together. Male aardvarks leave their mothers completely during the next mating season, but females stay with mothers until the birth of the next baby. Male aardvarks roam while females remain in a consistent home range. Because of this, experts believe aardvarks to be polygamous (puh-LIH-guh-mus), having more than one mating partner.
HUNTERS:
Humans are not the only hunters of aardvarks. Lions, leopards, and hyenas are the main predators, animals that hunt them for food, of aardvarks. Pythons feed on young aardvarks as well. When they sense danger, aardvarks retreat to the nearest hole. If a hole is not nearby, they use their powerful claws to dig one. The claws push the dirt backwards while the tail sweeps it away. In the event they cannot get to safety, aardvarks will lie on their back and fight with all four feet.
BEHAVIOR:
Aardvarks are solitary creatures, they prefer to live alone and have never been found in large numbers. Because they are nocturnal, nighttime, animals, they are not seen very often. In the warmer seasons, they come out of their burrows just after the sun sets. They are able to hunt and forage, gather food, even if it is a moonless night because they rely on their sense of smell to locate termites. Aardvarks cover 1.2 to 3 miles (2 to 5 kilometers) each night at a rate of 1,640 feet (500 meters) per hour.
When searching for food, aardvarks move about in a zigzag formation with their noses to the ground. It is thought that the fleshy tentacles, hair-like growths, around the nostrils might actually be chemical receptors that help find food.
Aardvarks are known for their digging abilities. In fact, aardvarks can dig a burrow 3.3 feet (1 meter) deep faster than a group of six adults with shovels!
ENDANGERED STATUS:
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| Aardvark Range |
Aardvark are least concern,and they are becoming extinct.
Kingdom:,Animalia.
Phylum:,Chordata.
Class: Mammalia
Order: Artiodactyla.
Family: Bovidae
Genus; Capra.
Species: Capra hircus
Physical characteristics:
They are typically white in colour with red head, blaze and pigmented skin, drooping ear, long leg and good conformation. Average wither height is reported to be 78 cm.
Origin and distribution:
The Boer goat is also known as Afrikaner, South African common goat and Boerbok goat. Boer goats evolved in South Africa from the indigenous African and the introduced European stock (Epstein 1971; Mason 1981; Campbell 1984). These include Bantu and Nubian, Saanen, Toggenburg and probably Angora. Out of South Africa, they are also found in Botswana, Lesotho, Swaziland, Zimbabwe, Namibia, Kenya, Burundi, Mozambique, Australia, USA, New Zealand, Germany, Israel, France and China (Malan 2000).
Breed status:
The Boer goat Breeders' Society was established in 1959, after which there followed selection guidelines and breed standards involving short legs, fleshiness, good thighs and hindquarters. The potential of Boer goats to produce cashmere hair has been recognized recently and is still being investigated (Couchman 1988). The estimated number of Boer goats is 2.12 million. According to J. Hendrik Hofmeyr, in DAD-IS 2004, the Boer goat population of South Africa in 2003 decreass.
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Archaeopterygiformes
Family: Archaeopterygidae
Genus: Archaeopteryx
Species: ithographica
PHYSICAL CHARACTERISTICS:
Archaeopteryx (meaning "ancient wing") is a very early prehistoric bird, dating from about 150 million years ago during the Jurassic period, when many dinosaurs lived. It is one of the oldest-known birds. Archaeopteryx had a wingspan of about 1.5 feet (0.5 m) and was about 1t foot ( 30 cm) long from beak to tail. It probably weighed from 11 to 18 ounces (300 to 500 grams).This crow-sized animal may have been able to fly, but not very far and not very well. Although it had feathers and could fly, it had similarities to dinosaurs, including its teeth, skull, lack of a horny bill, and certain bone structures.
EVOLUTION:
Paleontologists think that Archaeopteryx was a dead-end in evolution and that coelurosaurian theropods (a group of dinosaurs that included the Dromaeosaurs Deinonychus, Utahraptor, and Velociraptor) led to the birds.
FOSSILS RECORD:
Amazingly detailed Archaeopteryx fossils have been found in fine-grained Jurassic limestone in southern Germany. This fine-grained limestone is used in the lithographic process, hence the species name "lithographica" given to the early Archaeopteryx specimen. The first Archaeopteryx fossil (a feather) was found in 1860 near Solnhofen, Germany, and was named by the German paleontologist Hermann von Meyer in 1861. That year he also discovered the first specimen of Archaeopteryx. A total of eight Archaeopteryx specimens have been found, plus the feather.
The Feather:
Found in 1860 near Solnhofen and a revelation when it was described by H. v Meyer in 1861. The surprise was not the age of the fossil, since several ornithopod dinosaur footprints erroneously ascribed to birds were known from the Triassic, but the detail that was preserved.
Archaeopteryx specimens:
The London Specimen:Found in 1861, near Langenaltheim. Probably the best known (together with the Berlin specimen). Its discovery was announced by H. v Meyer in 1861 and the specimen was subsequently bought by the British Museum of Natural History in London (under the instruction of Richard Owen). It cost 700 UK Pounds - a small fortune in those times, but for that price Owen also received just over a thousand other fossils from Solnhofen. The specimen was sold by amateur collector and local doctor Carl Haberlein, who had received it in lieu of payment for medical treatment. Owen described the specimen in 1863. He saw at once that it was an important find and recognised that it represented a transitional form - but not in the "Darwin" sense. Owen was a staunch "evolutionist", however he did not believe in Darwin's model of evolution. Interestingly Huxley, who was a staunch "Darwinist" failed to recognise the true import of the fossil and merely remarked on it as a "reptile-like bird". It wasn't until close comparisons were made with the dinosaur Compsognathus that Archae's true worth was realised.
The Berlin Specimen:Found in 1877 near Blumenberg. This was a better specimen than the London specimen, principally because it had a complete head, albeit badly crushed, and was snapped up by the Berlin museum. It was sold to them by Carl Haberlein's son (talk about keeping it in the family!). It was described by W. Dames in 1884
The Maxburg Specimen:Found in 1958 near Langenaltheim (same as London Specimen). This specimen is of the torso only and is the only specimen to still be in private hands. In 1992, after the death of its finder and owner Eduard Opitsch, the specimen was found to be missing and it is thought that it was sold secretly (Abbott 1992). It's whereabouts remain unknown. The specimen was described by Heller in 1959.
The Haarlem or Teyler Specimen:This specimen was actually found near Reidenburg in 1855, 5 years before the feather! It lay in a museum after being classified as Pterodactylus crassipes by H. v Meyer in 1875. Curiously, Mayer described it as having a flight membrane unlike any other known pterodactyl, now we know why! A re-examination of the fossil in 1970 by Ostrom revealed feathers and its true identity.
The Eichstatt Specimen:Found near Workerszell in 1951, it was described by P. Wellnhofer in 1974. This is the smallest of all the specimens, being some 2/3 the size of the others. It also differs in other aspects such as the tooth structure and the poorly ossified shoulder bones. It has been suggested that this is a separate genus, however the differences can also be ascribed to the possible juvenile stage of the animal and/or a different feeding niche. However, this specimen has the best preserved head, from which the litany of Archae's reptilian cranial features were described. At the moment it still resides within A. lithographica.
The Solnhofen Specimen:Found in the 1960's near Eichstatt by a Turkish worker. First identified as Compsognathus, by a amateur collector, however, further examination showed that the arms were too long for the body size and preparation revealed feather traces. Described by P. Wellnhofer in 1988.
Soft tissue remnants discovered in Archaeopteryx fossil:
It boasts more than just beautiful impressions of long-gone feathers. One of the world's most famous fossils – of the earliest known bird, Archaeopteryx – also contains remnants of the feathers' soft tissue.
"It's amazing that that chemistry is preserved after 150 million years," says Roy Wogelius, a geochemist at the University of Manchester, UK. Wogelius and colleagues scanned the "Thermopolis specimen" using a powerful X-ray beam from a synchrotron at the Stanford Synchrotron Radiation Lightsource in California.
The synchrotron excites atoms in target materials to emit X rays at characteristic wavelengths. The scan reveals the distribution of elements throughout the fossil. The green glow of the bones in this false-colour image shows that Archaeopteryx, like modern birds, concentrated zinc in its bones. The red of the rocks comes from calcium in the limestone that had encased the fossil since the animal died.
Copper and zinc are key nutrients for living birds, and their presence in the fossil bones shows the evolutionary link with dinosaurs. The study also revealed phosphorous along the main shaft of the feathers in the fossil: palaeontologists had long thought that only impressions remained.
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