wolf

Wolves are wild relatives of dogs and are represented by two species, the gray and red wolf, with variations within each species for a total of thirtytwo described subspecies. At one time, wolves lived throughout Europe, Asia, and North America. The gray wolf, also called the timber wolf, is the most common wolf species living in North America and can be found mostly in Canada and Alaska. Considered extinct in western Europe, with a few exceptions, gray wolves live in Russia, southeastern Europe, and Asia. Wolves’ ranges have decreased due to urbanization. Most wolves live in sparsely populated forest, tundra, wilderness, and mountain regions and tend to avoid people, approaching settled areas only when they are starving or when natural crises, such as floods, fires, and blizzards, cause their migration to populated places to seek emergency food sources. Gray wolves can attain a body length (from nose to base of the tail) of 1.2 meters (4 feet) and height of 90 centimeters (3 feet) at the shoulder. They average forty-five kilograms (one hundred pounds) in weight, with some wolves weighing twice that amount, and have sharp teeth, thick coats, tall legs, and bushy tails. Gray wolves have primarily gray coats with some black, yellow, and brown fur, although some gray wolves are solid black or white, particularly in the Arctic. An endangered species, red wolves live in the forests and brush of the south central United States and can be colored a hue ranging from reddish gray to black. Hunting of gray wolves escalated as farmers and ranchers penetrated wolf territory, their livestock offering easy targets for the wolves. Humans’ retribution threatened decimation of the gray wolf population. Efforts to replenish the number of wolves include the reintroduction of gray wolves toYellowstone National Park in 1995.
Pack Behavior
Hunting alone and in packs, wolves usually roam over large territories with a family group consisting of parent wolves and their offspring. Zoologists believe that wolves mate with the same partner for life, producing from three to nine cubs annually in late winter. Digging an underground den or appropriating a cave or hollow tree, wolves give birth and raise their cubs in this space, where the parents bring food until the cubs attain sufficient maturity to hunt. During winter and other stressful conditions, wolf families occasionally establish a larger pack of as many as thirty animals. The leader of a wolf pack, known as the alpha male, disciplines pack members. Wolves prey on both large and small animals, including deer, moose, rabbits, birds, and mice and also eat vegetables, fruit, and carrion. They tend to hunt at night and can leap over obstacles 4.9 meters (16 feet) high, and travel up to fifty-six kilometers per hour (thirty-five miles per hour) to capture prey, sustaining thirty-two kilometers per hour (twenty miles per hour) for several hours when endurance is necessary to wear down elusive prey. Wolves migrate to follow prey to other areas. Scientists hypothesize that wolves howl in order to communicate with other wolf packs.

Baleen whales belong to the order Cetacea, the only mammals which spend their entire lives in the water of the earth’s oceans. There are seventysix cetacean species, and the baleen whales make up ten of them. Among baleen whales are blue (sulfur-bottomed) whales, the largest animals that have ever lived. They grow to lengths of over one hundred feet and can weigh 400,000 pounds (200 tons). This makes them more than fifty times the size and weight of a bull elephant andmuchlarger than any dinosaur. Like all whales, baleen whales are thought to be descendants of a land animal, believed to have been an early ungulate (hoofed mammal). The huge size of the baleen whale is possible because it lives in the water. This supports its mass and frees it from the limitations of land animals, which can only grow to the sizes and weights their legs will support or their wings can carry into the skies. Whythe ancestors of baleen whales entered the oceans is not understood. It is guessed that the return to the oceans was due to the need for a new food supply or to escape frompredators. Most paleontologists believe that it happened sixty million years ago, twenty million years before the first whale fossils occur.No fossil that links baleen whales to their landbound ancestors has yet been found, although the search goes on.

Wasp and Hornet

Wasps are stinging insects of the order Hymenoptera. Many live in large colonies which have a queen, males, and sterile female workers. Such social wasps are hornets.Wasps are called solitary if they do not live in communities, but build small brood nests to hold their young. Social wasps (hornets) make paper nests. One example is white-faced hornets, found all over North America. These wasps, 1.25 inches long and black with white markings, build nests, up to halfbushel size, in tree limbs. Yellow jacket species live in colonies of many thousands, close to or under the ground. Giant European hornets, in the United States since the 1850’s, are brown with yellow streaks and nest in hollow trees. In some wasp species, no workers are born and females lay eggs in the nests of other wasps.Wasp size varies from parasitic wasps, that can develop in insect eggs, to species attaining body lengths of over two inches.

Physical Characteristics of Wasps and Hornets
Wasp bodies, which are covered by coarse hairs, have a head, thorax (midbody), and abdomen (hind body) segments. Thoraxes hold four wings and six legs. The bodies are steel blue, black, yellow, or red, with abdominal rings. Reproductive, digestive, and excretory systems are in abdomen and thorax. Females have stingers at abdomen ends. Parasitic wasps use stingers to insert eggs into hosts. Female nonparasite wasps (which are most wasps) use stingers to paralyze their prey and inject venom. The stings are painful, because the venom contains histamine and a factor that dissolves red blood cells. Wasp stings, especially by hornets, can kill allergic humans. Wasp heads contain sharp, strong mandibles (jaws), designed to chew hard things, tear up food, dig burrows, and pulp wood and earth. Wasp mouths can also lap liquids. Above the mandibles, their heads contain paired, keen, compound eyes and paired sensory antennae. Queen wasps in social species are reproductive females who use sperm obtained in mating flights to fertilize eggs that become females. Unfertilized eggs become drones (males). Production of queens-tobe or female workers depends on diet.

Wasp Nests and Life Cycles
Nests of social wasps range from combs without protecting covers, to round nests up to ten inches in diameter, having paper tiered combs and waterproof outside covers. Social wasps nest wherever possible. Small combs occur under porch roof and rafters or in trees. There are two yellow jacket types, the long-faced and short-faced species. Long-faced yellow jackets nest in trees, bushes, and roofs, while the short-faced type nests in the ground. A wasp colony lasts one year. Wasps store no food, and in fall the whole colony dies except for the future queens. They hibernate in crannies over the winter and become queens of new colonies in spring. Acolony starts after a queen makes a few cells, lays an egg in each, and feeds larvae with chewed-up insects. Next, larvae spin cocoons and pupate for several weeks, emerging as workers. After this, a queen does nothing except lay eggs. The eggs yield worker wasps until late summer, when the queen lays eggs that will become males and queens.Workers tend the young and enlarge the nests. A hornet nest may have thousands of males, females, workers, and young. Solitary wasps live alone except for breeding. Afterward, females build flat, one-comb nests. Instead of being papermaker wasps, they are mason, carpenter and digger wasps. Among mason wasps are potters and stoneworkers. Potters wasps make mortar of mud and saliva and place brood nests in trees. Mud dauber wasps mix mud with saliva and build nests under porch roofs. Stone worker wasps mix pebbles with mud and nest on rocks. Carpenter wasps tunnel into trees and digger wasps tunnel into the ground. All adult wasps eat caterpillars, spiders, beetles, flies, other insects, and nectar. Solitary wasp species feed their larvae with specific live insects. Mothers set up nurseries, paralyze prey by piercing nerve centers with their stings, and take the live food to nests. Then they lay an egg on each body. Larvae feed on the insects until they begin spinning cocoons to pupate, emerging after pupation as adult wasps.

Yellow Jackets
North American short-faced yellow jacket wasps (hornets) are 0.75 inches long, with yellow and black head, thorax, and abdomen markings that give them their name. They nest below grass level near decaying wood. Their nests are paper, made from saliva and wood. Each nest has a queen, who lays all eggs. Fertilized eggs become females and unfertilized eggs become males. Reproductive females are produced when the colony is ending its one-year life span. Sterile females tend the nest and larvae. Reproductive females eventually become queens, and males mate with queens-to-be. The yellow jacket diet is insects, fruit, and nectar. Only worker yellow-jackets hunt food, which they eat by tearing it with their mandibles. Queens live for ten months, while drones or workers only live for a few weeks.

Helpful Wasps
Most wasps help humans and the environment. They damage some fruit, but they destroy myriad caterpillars, beetles, flies and other harmful insects. Thus, they do far more good than harm. Several species pollinate farm crops. Furthermore, the parasitic varieties lay their eggs in the bodies and eggs of pests such as aphids, thereby reducing their numbers.

Vulture

Vultures comprise two groups of carrioneating birds. They are useful because they eat carrion, which otherwise might decay and endanger the health of other animals. The twenty-one vulture species inhabit temperate to tropical regions of the Americas, Europe, Asia, and Africa. All vultures exhibit similar eating habits, behavior, and appearance, including bare heads and necks. Many also have somber-colored feathers. Vultures of Europe, Asia, and Africa (Old World vultures) arise from eaglelike birds. Vultures of the Americas (NewWorld vultures), similar in appearance to OldWorld vultures, are anatomically related more closely to storks.

Some Characteristics of Vultures
Vultures have bare heads and necks and hooked bills. Carrion is their main food, and on some occasions they attack newborn or wounded animals. Most hunt by long-distance soaring to scavenge with their keen sight. New World vultures differ from OldWorld vultures in their lack of the ability to vocalize. Six species compose New World vultures. Three live in North America: turkey vultures of the southern United States and northern Mexico; black vultures of the southwestern United States and Central America; endangered California condors; king vultures; Andean condors; and yellow-headed turkey vultures of South America. There are fourteen Old World vulture species. Among the most interesting are the cinereous (with a color resembling ashes) vultures of southern Europe, northwest Africa, and Asia; the similar griffon vultures; white (Egyptian) vultures found from the Mediterranean to India; and the bearded vultures (lammergeiers) of Europe, Asia, and Africa. Vultures lack feathers on their heads and necks, which keeps them free of gore fromcarrion. Among New World vultures, several have interesting appearances. Black vultures have black heads and plumage, with white feathers under the wings. King vultures, in contrast, have feathered neck ruffs and yellow, red, white, and blue heads. California condors, the largest North American land birds, average four feet in length, with wingspans up to eleven feet. They have black neck ruffs, bald, orange to yellow heads, and black plumage except for white feathers under wings. Andean condors are similar. South American yellow-headed turkey vultures resemble North American turkey buzzards. Notable among Old World vultures are cinereous vultures, about four feet long with bare, pinkish heads and black feathers. They inhabit Europe, northwest Africa, and Central Asia. Griffon vultures are similar in size and appearance. Egyptian vultures, two feet long, have yellow heads and white feathers except for black wings. They inhabit Mediterranean areas and are found as far east as India. Bearded vultures (lammergeiers) are especially interesting. They live on Asian, African, and European mountains. They have tan plumage on the chest and stomach and dark brown wing and tail plumage. Lammergeiers have red eyes in white heads. Conspicuous black feathers surrounding the eyes end in beardlike tufts and led to the name “bearded.” These vultures average four feet long and weigh up to twenty-four pounds. Their huge wings allow soaring for hours on thermal updrafts. Lammergeiers are unusual in building large, conical nests on or in rock ledges or caves. A mated, monogamous pair uses the nests many times.

Life Cycles of Vultures
Most vultures nest on bare ground underneath mountain overhangs, or in caves. They build no nests, and females lay eggs on bare rock. After hatching, both parents feed the chicks partly digested carrion regurgitated into their mouths. For example, Andean (great) condors live in mountain caves, and females lay one or two greenish-white to bluish-white eggs on the cave floor. Both parents incubate the eggs until they hatch. The scarcity of the California condor is partly due to the fact that it lays only one egg at two- to three-year intervals. Young condors fly in six months, but parents feed them for another eighteen months. Andean condors first mate at seven years old, and at two-year intervals after that. They are monogamous and maylive for forty-five to fifty years. Lammergeiers, as noted, are unusual in building several nests used over and over. The female lays her eggs, incubates them, and feeds chicks with the help of the male.

Marabous: Storks or Vultures?
Marabou storks (marabous) combine stork and vulture anatomy and occur throughout Africa. Adults are five feet tall. They have long, storklike legs and sharp, straight bills. Their heads and necks are vulturelike. Most marabou food is deer, antelope, and zebra carrion. Marabou plumage is gray on the back and wings, with white bellies and ruffs encircling red necks. Most inhabit African wetlands, rivers, and lakes. Pairs build nests in trees or on rocky terrain. Usually, three eggs are laid and incubated by both parents. Chicks hatch during dry season when carrion is plentiful. They stay with their parents for six months. Marabous live for over twenty years. Vultures consume carrion, preventing decay and danger to health. This activity is one of their main ecological functions. Some vultures (such as condors) eat live food, giving them another ecological function, killing injured or weak members of other species. This helps the species that are eaten to select for individuals which enhance long-term survival.

Turtle and Tortoise

Turtles, tortoises, and terrapins are all turtles. The term "tortoise" is used for terrestrial turtles with high-domed shells and elephantine hindlimbs, whereas the term "terrapin" is used properly for some highly aquatic turtles (genus Malaclemys) of eastern North America, although it frequently is used in error for American box turtles in the genus Terrapene. Turtles are easily recognized and distinguished from all other vertebrates by their shells. Shells are composed of a dorsal carapace and a ventral plastron. These are usually rigidly connected on the sides by bridges. Shells are composed of bony plates that form within the skin. These are fused to underlying vertebrae and ribs. Most shells have a covering of horny plates made of keratin, a protein which, in other vertebrates, forms scales, hair, nails, claws, or horns. In some turtles, the plates of bone and keratin are reduced or absent, and the shell is covered by leathery skin. Many turtles have one or more hinges in their shells, usually in the plastron. These allow the shell to completely enclose the withdrawn head, limbs, and tail. The plastron of males in many species is indented to accommodate the female's shell during mating.

Turtle Lifestyles
Shell shape largely determines the lifestyle of its owner. Terrestrial (land-dwelling) turtles such as box turtles (Testudo) and tortoises (Geochelone) have high-domed shells. These reduce surface area through which water is lost and also are difficult for predators to grasp and break. Most aquatic and all marine turtles have relatively flat, streamlined shells for ease in swimming. However, African pancake tortoises (Malacochersus) have flat shells that allow them to hide in rocky crevices, and some bottom-dwelling aquatic turtles, such as the mud turtles (Kinosternon) of the southeastern United States, have high-domed shells. Snapping turtles in the genera Chelydra and Macrochelys have rough shells on which algae grow. This camouflages these turtles as they wait to ambush prey. Limbs also provide clues to lifestyles. Aquatic turtles have webbed feet, and sea turtles have forelimbs modified into flippers that allow them to "fly" through water. In contrast, terrestrial turtles often have spadelike feet for digging and/or columnlike limbs to support them as they walk. Regardless of shape or function, the girdles to which the limbs attach are enclosed by the ribs and shell. Turtles are the only vertebrates with this skeletal arrangement. Other anatomical modifications include nostrils on top of the snout or at the very tip of a long proboscis; these allow aquatic turtles to breathe at the surface with minimal exposure. Modern turtles, like modern birds, lack teeth. Instead, they have horny beaks of keratin variously shaped to cut leaves, tear flesh, or crush the shells of snails or clams. Because the shell prevents expansion and contraction of the thorax when breathing, turtles compress or expand the lungs by altering the location of other internal organs to which the lungs are attached. Shells limit mobility to a great extent; consequently, turtles have long and flexible necks. These allow them to reach up to browse or down to graze, or to quickly extend their necks in order to ambush quicker prey. In addition, neck vertebrae are modified to allow the head to be withdrawn into the shell, either by pulling it straight back while the neck assumes an S-shape (cryptodiran turtles) or by laying it to the side under the overhanging lip of the carapace (pleurodiran or sideneck turtles).

Origins and Future of Turtles
Fossil turtles are known from the Jurassic. Most systematists (biologists who study evolutionary relationships) group turtles with some extinct relatives in a clade called the Parareptilia. Although turtles traditionally have been considered reptiles, many expertsnowplace them a separate vertebrate class. Regardless, the ancestors of turtles arose from the first amniotes before the ancestors of other reptiles. This and their many unique features justify placing turtles into their own class. Unlike many reptiles, turtles are perceived positively by most people. Nevertheless, many species are threatened or endangered. Habitat destruction and alteration are responsible in most cases. Aquatic habitats are drained or polluted and nesting sites, especially beaches, are developed, rendering them unusable by turtles. Many species are exploited as food, either as eggs or adults, and others are killed for their shells or body parts, which are thought by some cultures to have medicinal or aphrodisiac qualities. Exotic predators, such as rats and dogs, dig up nests and kill adults. Hundreds of thousands of wild-caught turtles die each year in the pet trade, much of it illegal. Many species become roadkills when they migrate to new habitats or breeding sites. Only a few species are formally protected in at least some parts of their ranges, and several, including the sea turtles,maybe nearing extinction in spite of efforts to conserve them.

Turkey

Triceratops

Triceratops became the first genus of horned dinosaur known to science when its skull was described by Othniel C. Marsh in 1889. The remains of its horns were originally attributed to the high-horned bison (Bison alticornis), and its occipetal condyle was originally named Ceratops montanus. In his preliminary description of the skull, Marsh named its owner Ceratops horridus and felt it was related to the stegosaurs. After the skull had been cleaned, Marsh changed the name to Triceratops horridus. Thirteen species of Triceratops have been described, but only one (or possibly two) species actually occurred in nature. Triceratops lived in western North America at the end of the Cretaceous, between 68 and 65 million years ago.

Characteristics
The most characteristic feature of the animal was its large, V-shaped head which terminated in an elongate frill. The skull can be more than 6 feet long (2.2 meters). Only whales have larger skulls. The frill allowed an animal to recognize members of the same species as well as members of the opposite sex. Since Triceratops had color vision, the frill was probably pigmented, and its ornamentation was designed for visual display and not for protection or to serve as a point of attachment for the jaw muscles. The head bore three horns that functioned in display, ritual combat, and protection frompredators. One short horn arose over the nose, and two others, the longest, arose over the eyes. Males had large, erect horns while females had smaller, somewhat forward-pointing horns. The large number of skulls that have been found indicates that Triceratops was an abundant, gregarious species. No complete skeletons are known. A composite, presumably female, skeleton on display at the Science Museum of Minnesota is 26 feet (7.9 meters) long and 9 feet, 7 inches (2.9 meters) high. With a weight of 8.5 metric tons (9.4 tons), Triceratops was three times heavier than a rhinoceros. The shin bone (fibia) was notably shorter than the thigh bone (femur). The size relationship between these two bones is the reverse of what is seen in animals that are fast runners. Evidence from ceratopsian trackways and the anatomy of its shoulder (the hind legs were located directly below the hips while the forelimbs sprawled outward and were not located below the shoulders) also indicates that Triceratops was rather slow. Its running speed has been estimated at about 4.2 kilometers per hour (2.6 miles per hour).