Showing posts with label Animals. Show all posts
Showing posts with label Animals. Show all posts

5 Famous Birds in Suborder Tyranni (Suboscines) | All About Perching Birds

 
Many of these perching birds can sing. However, their vocal organs are not as well developed as those of the Oscines.

1. Ovenbirds


The family Furnariidae consists of approximately 220 species of ovenbirds. These small- to medium-sized drab brown South American birds live in a variety of habitats, from the coast to the Andes, from swamps and jungles to grasslands and rocky mountain slopes.

The ovenbird family derives its common name from members of the genus Furnarius, which build large, elaborate mud-and-cow-dung nests that look like old-fashioned ovens.

2. Woodcreepers


About 50 species of woodcreepers make up the family Dendrocolaptidae. These solitary tree dwellers live from Mexico and the Caribbean islands south to Argentina.

The woodcreeper ranges in length from 5 to 16 inches (12.7 to 40 centimeters); most species have olive plumage with reddish wings and tail. Its legs are short and strong; its bill is stout, long, and adapted for probing bark to find insects and spiders -its main foods.

3. American Flycatchers


The tyrant flycatchers make up the family Tyrannidae. There are more than 350 species, found throughout the Americas but most numerous in the tropics. They are not to be confused with Old World flycatchers, birds that belong to the thrush family (Muscicapidae).

In temperate areas, the American flycatcher prefers open country, thin woods, orchards, or gardens. It spends much time perched on branches and poles, from which it darts after insects, its chief food. Other species live in deserts and tropical rain forests.

The American flycatcher has small, weak feet, a short neck, and a large head. Its bill, broad and flat at the base, tapers down to a hooked tip. The mouth, which has bristles at its corners, can open wide.

The "tyrant" nickname derives from this bird's aggressive behavior -perhaps most obvious when it drives off larger birds, such as hawks and crows, that encroach on its territory.

Among the most fearless Tyrannidae are the kingbirds, genus Tyrannus. The Eastern kingbird, Tyrannus tyrannus, is a bit smaller than a robin; its plumage is white, black, and gray, with an orange crown. This bird nests in rural areas in eastern North America, and winters in Central America and parts of northern South America.

A particularly striking member of the family is the many-colored rush tyrant, Tachuris rubrigastra, of South America. Its plumage includes vibrant shades of greens, oranges, and reds, as well as black and white.

The family also includes the small phoebe, of the genus Sayornis, and the Eastern wood pewee, Contopus virens. These sparrow-sized creatures have gray-brown or olive feathers above and whitish ones below. Pewees prefer woodlands; phoebes, human habitations.

4. Cotingas


The 90 species of the family Cotingidae all live in the New World, from Central America south into South America. These forest dwellers have short, sturdy legs and large, hooked beaks. Cotingas usually eat insects and fruits.

The birds in this family differ greatly in appearance from one species to another. Most have dull-colored plumage, but some are brightly colored. The male cock-of-the-rock of the genus Rupicola has bright red or orange feathers; atop its head is a flattened, disklike crest. The female, by contrast, while also having a crest, is substantially smaller and has unremarkable brown plumage.

5. Lyrebirds


The beautiful lyrebirds (family Menuridae) are perhaps best known for the adult male's magnificent tail -a true extravaganza in which two large outer feathers fringe 12 filamentary feathers; all the tail feathers have silvery undersides. On some males, the feathers reach 2.5 feet (76 centimeters) in length! During the courtship ritual, the male spreads the tail feathers and brings them forward over his back, all the time dancing and singing to the female, often mimicking the songs of other forest birds.

Without its remarkable tail, the lyrebird looks somewhat like an ordinary hen. It has a large head; long neck; and short, rounded, and rather weak wings. Its long legs terminate in feet equipped with heavy claws.

General Characteristics of Perching Birds

 
The melodious songs that waft through the window on a sunny spring morning are produced by the flying vertebrates known as perching birds -the bird group that has most successfully adapted to human environments. Most species of perching birds can be further narrowed into another category: songbirds. In fact, there's little question that these merry creatures are the birds that are most familiar to humans.


Of the 9,000 or so species of birds officially known to us, well over half -some 5,500- are classified as perching birds. Perching birds comprise the order Passeriformes. The great majority of passeriformes are members of the suborder Oscines -the songbirds.

On each foot, perching birds have four toes, one of which points backward. This arrangement enables the bird to easily perch on everything from leaf stems to thick branches. Tendons in the feet help the bird to flex its toes and grasp its perch tightly. Any movement that threatens the bird's equilibrium will cause the feet to tighten their grip. This explains why perching birds do not fall off thin telephone wires -even when the creatures are asleep on a windy night.

Perching birds vary greatly in appearance. In size, they range from tiny wrens only 3 inches (7.6 centimeters) long to the lyrebirds, which may be more than 40 inches (100 centimeters) long -counting their 30-inch (75-centimeter)-long tail. Colorwise, some species -such as the Baltimore, or northern, oriole and the cock-of-the-rock -have brilliant plumage. Others, such as the wood warblers and the house sparrows, are dressed in dull-colored feathers.

The beaks vary, depending on the food eaten by the bird. For example, wrens have long, slender, slightly downcurved bills -ideal for picking insects off leaves. Cardinals have large, heavy bills adapted to crushing seeds. The strong bills of the drongos hook at the tip and are slightly notched -the better to hold insects captured while in flight.

Most songbird species can be recognized by their distinctive song or songs. A few, such as crows and jays, imitate the calls of other birds.

A number of different taxonomic systems are used by scientists to classify the Passeriformes. In general, the group is divided into more than 50 families; more than 40 of these families comprise the suborder Oscines -the songbirds. Members of the other families are sometimes called Suboscines.

Cool Facts About Gila monster (Heloderma suspectum)

 
There are more than 3,000 kinds of lizards. Of all those, only two are poisonous. These are the Gila monster and its close relative, the beaded lizard. The Gila monster does not use its poison for catching food. It uses it for defense. Its venom can kill small animals. But it rarely kills a person. Gila monsters will only attack people if they are provoked. When provoked, they hiss, just like their cousins, the snakes.


Basic facts:


Class: reptiles

Order: scaled reptiles

Family: beaded lizards, gila monsters

Length: up to 23 inches

Weight: up to 31/4 pounds

Diet: rodents, rabbits, and birds

Number of Young: 3 to 15

Home: northern United States and southwestern Mexico

Gila monsters live in the deserts of the southwestern United States and northern Mexico. They were named after the Gila River basin in Arizona. Spanish explorers first saw them hundreds of years ago.

They are most active during the rainy season. Gila monsters rest during the heat of the day. They lie in the shade or under the sand. They come out at night to look for food. Gila monsters eat bird and reptile eggs, birds, and other small animals.

They are slow-moving, except when they spot something to eat. Then they dart quickly with their powerful legs. Their jaws and teeth are very strong. They clamp on to their prey until it dies. Gila monsters can go without eating for many months.

Gila monsters mate during the summer. The female digs a shallow hole in the sand. She lays her eggs in the hole. Then she covers them with sand. The eggs hatch in about a month. There are usually between 3 and 15 offspring.

Facts About Bluefish (Pomatomus saltatrix): The Chopping Machine

 
The bluefish's huge appetite has earned it a nasty reputation as a "chopping machine." Schools of bluefish attack other fish by biting and slashing at them. They can leave behind a trail of blood and injured fish miles long. Sometimes this "Cuisinart of the deep" will even attack when it's not hungry.


Some basic facts about Bluefish


Class: ray-finned fishes, spiny rayed fishes

Order: perch-like fishes

Family: bluefishes

Length: 4 feet

Weight: 25 pounds

Diet: fish, notably mackerel, herring, and menhaden

Number of Eggs: unknown

Home: warm and temperate waters

The bluefish fears only one predator: humans. In the United States alone, commercial fishermen catch 4 million pounds of bluefish a year. According to one count, sports fishermen catch ten times that amount! This fish is loved for its delicious taste. It also puts up an exciting fight before it is reeled in. Years ago, fishermen told tales of catching bluefish weighing 50 pounds. Today, however, the largest are about half that size.

The bluefish may actually appear silvery colored. It has a bluish or greenish back and black splotches at the base of each pectoral fin. It migrates, roaming from Florida to Maine in the warm months. It spends most of the year in tropical and subtropical waters. It was originally found only around the Americas. But in the past 50 years it has become common off the coast of France.

Bluefish lay their eggs (spawn) during summer. Their eggs hatch within two days. The young grow fast. They reach about 16 inches in their first year. These young fish inherit the big appetites of their parents. They are called snappers for good reason. They feed on smaller prey near the shore.

What are Zoogeographical Regions and Subregions?

 
A zoogeographical region is a geographical subdivision of the world that possesses a unique fauna. Based on Sclater's and Wallace's work, the world was divided into zoogeographic regions. This scheme was modified by Karl P. Schmidt in 1954. Schmidt divided the world into three realms: Arctogaean, Neogaean, and Notogaean. The Arctogaean consists of two regions: the Holarctic, with the subregions Arctic, Nearctic, Caribbean, and Palearctic; and the Paleotropical, with the subregions Oriental, Ethiopian, and Malagasy. The Neogaean consists of but a single region and subregion, the Neotropical. The Notogaean is composed of two regions: the Australian, containing the Australian and Papuan subregions; and the Oceanian, which is formed of the New Zealandian, Oceanic, and Antarctic subregions.


These regions are not as distinctive as this listing would imply, for there are always groups of animals whose ranges extend through more than one region. In general, however, each of these areas has a distinct fauna with enough elements peculiar to it to warrant its listing as a zoogeographical region.

Most distinctive of all regions is the Australian which includes Australia and New Guinea. These areas have been isolated from other regions for so long that they have a distinctive fauna. Here are found the monotremes (egg-laying mammals) such as the duckbill; a large and varied assemblage of marsupials; and unusual birds like the emus, lyrebirds, honey eaters (honeysuckers), cockatoos, and the remarkable birds of paradise. The Australian lungfish, distinctive tortoises, and many unique invertebrates also belong to this region.

The Oceanian region includes New Zealand, Antarctica, and the oceanic islands of the Pacific. In New Zealand is found the curious lizardlike Sphenodon, only survivor of an ancient group, and the kiwi bird. The oceanic islands of this region are characterized more by the lack of many groups of animals than by the presence of particular ones. There are, however, many distinctive shore fishes about the islands.

The Neotropical region, consisting of South America, has sloths, anteaters, armadillos, monkeys with prehensile tails, vampire bats, and marmosets. Among the unusual birds are the rheas, toucans, hoatzins, guans, and cassowaries. Many distinctive snakes are found, including boas, anacondas, and tropical pit vipers.

The Oriental subregion of the Paleotropical region includes southern India, southeast Asia, and the Malay Archipelago. It has many distinctive birds including pheasants, babbling thrushes, and barbets. Among the mammals are the Indian elephants, some lemurs, tigers, orangutans, gibbons, and some antelopes.

The Ethiopian subregion of the Paleotropical is formed of Africa south of the Sahara. It contains the aardvark, chimpanzee, gorilla, lion, and many kinds of antelopes. Among the birds are the ostrich and secretary bird. Close to Africa is the Malagasy subregion, consisting of the island of Madagascar and neighboring islands of the Indian Ocean. Madagascar has crayfishes that are lacking in Africa. It also has many different types of lemurs, including the aye-aye, and such unusual birds as the extinct gigantic Aepyornis, an ostrich-like bird that may have survived until historic times.

The Palearctic subregion of the Holarctic region consists of Europe, most of Asia, and Africa north of the Sahara. The Nearctic subregion consists of Canada, the United States, and a small portion of Mexico. These two subregions have many faunal elements in common, including distinctive deer, bears, wolves, rodents, and ungulates.

The Caribbean is a transitional subregion between the Holarctic and Neotropical regions. This area of Central America, Mexico, and the Caribbean islands possesses fauna derived from both the other regions as well as some distinctive features. The Arctic subregion is characterized by severe climatic conditions and various circumpolar mammals.

While each region has its unique faunal elements, it also shares other elements with different regions. The boundaries between them are at best hazy and ill defined. Nowhere is the tenuous nature of these boundaries more evident than in the various lines drawn to separate the Australian and Papuan subregions from the Oriental subregion.

Zoogeography: Definition, History, and Facts

 
Zoogeography is the science that deals with the distribution of animals over the surface of the earth. In addition to mapping the distribution of animals, it attempts to develop theories to account for the discovered facts. It thus involves a consideration of geological, geographical, and ecological factors and their influences upon animals and their movements.


Few kinds of animals are distributed worldwide; most are restricted to certain geographical areas. Thus each portion of the world has a characteristic fauna that differs from the others in varying degrees. For example, the animal population of each of the islands of the West Indies differs only slightly from that of any neighboring island, while the animals of the opposite sides of the North American continent, though showing some like characteristics, differ in many respects. Some elements of the fauna of the western United States bear closer relationships to the animal population of Europe than to that of the eastern coast, and the whole of the North American fauna is much more similar to the fauna of Europe than to that of its southern neighbor, South America. The fauna of Australia is, in general, totally unlike that of any other continent, although certain species have relatives in North and South America. Most famous of these are the marsupial opossums of the New World.

So long as the belief in special creation was adhered to, these facts of distribution presented no problem, but with the development of the concept of evolution they challenged the attention and imagination of biologists. It soon became apparent that related species had common origins and must have dispersed from certain centers.

History

Many early naturalists noted details of animal distribution and were struck by its peculiarities. Voyages such as Capt. James Cook's three-year circumnavigation of the globe (1768–1771) and Matthew Flinders' expedition to Australia (1801–1803) brought back to Europe ample evidence that different regions of the world possessed different faunas. Charles Darwin during the famous voyage of the Beagle (1831–1836) collected sufficient zoological materials and observations to enable him later to discuss the facts of animal distribution with authority. This voyage was the impetus for his later development of evolutionary theories that finally enabled scientists to explain some of the peculiar facts of animal distribution. One of the most important ideas in the development of the science of zoogeography was contributed by the 19th century geologist Charles Lyell, who pointed out that the present distribution of animals is conditioned by past changes involving major landmasses.

In 1858 Philip Lutley Sclater attempted to divide the world into zoogeographical regions, basing his work on studies of perching birds. Alfred Russel Wallace expanded Sclater's work in The Geographical Distribution of Animals (1876), basing his analysis on mammals. Wallace had worked as a field naturalist in the Malay Archipelago and South America and was impressed with the differences and similarities of these two distinct faunas. In his book, which is still one of the most important volumes on the subject, he divided the world into six zoogeographical regions, which he named Palaearctic, Nearctic, Ethiopian, Oriental, Australian, and Neotropical. Since his time zoogeographers have been engaged in further studies of the regions, more careful analysis of the fauna, and the incorporation of new geological facts, evolutionary theories, and ecological principles in the interpretation of zoogeographical data.

Seeing Red: How Primates Evolved beyond Color Blindness

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Human beings suffering from red-green color blindness may represent as little as 2% of the world's population, but they are among the majority of mammals on the planet. Only certain species of primates---humans among them---are genetically endowed with trichromatic color vision, which allows them to not only perceive color but also distinguish between red and green. The scarcity of trichromatic color vision among mammals, and the evolutionary impetus behind its development, has interested scientists for years.


All mammals capable of perceiving color, with the exception of certain primates, have dichromatic color vision. This means that their retinas contain only two types of cone receptors instead of the three varieties of cones that enable trichromatic vision. The various types of cones in the eye are tuned to react to different wavelengths of visible light, which create nerve signals that the brain interprets as color. Dichromatic vision employs groups of "short" and "long" cones, which decipher the color of light based on where it falls between the high and low wavelength extremes. Trichromatic vision adds the benefit of "middle" cones, which allow the perception of color to become more finely tuned, particularly the ability to distinguish between red and green.

The vast majority of evolutionary anthropologists agree that primates evolved trichromatic color vision as a means of locating edible plants. The need to identify food species against a backdrop of dense foliage meant that color, as well as shape, became a crucial marker. The ability to locate food in this way provided the competitive advantage necessary to encourage the gradual development of trichromatic color vision. Scientists continue to debate, however, whether trichromatic color vision evolved specifically to allow primates to select the most nutritious leaves, many of which have red hues instead of green, or if it developed to enable them to select the most ripe and nutritious fruits available, which also tend to have a red hue.

Further complicating the "leaves-versus-fruits" debate is the inconsistent distribution of the full-color vision trait across primate species. All but one species of trichromatic mammals are so-called Old World (Eastern Hemisphere) primates (the exception being the New World howler monkey). The distribution of color vision in New World (Western Hemisphere) primates, however, is gender-specific, with only females possessing trichromatic vision. In these cases, the trichromatic trait requires two X chromosomes, which only occurs in females. The competitive advantage of the color vision trait should have been comparable in both New and Old World environments, but color vision did not develop simultaneously in both locations. While it is likely that contemporary primates use trichromatic vision to locate red, immature, protein-rich leaves, this may not have always been the case, and the possibility that different factors may have influenced the development of trichromatic color vision on separate continents has clouded the evolutionary debate.

Regardless of whether the identification of fruits or leaves compelled certain primate species to evolve trichromatic vision, there is mounting evidence that the development of extraordinary color perception resulted in a reduction of a sense of smell in those same species. Vision operates accurately at a much greater distance than smell, particularly when it comes to the detection of sexual maturity in potential mates. The rise of color vision likely allowed for more "long-range" sexual cues than pheromone detection did, which is why humans and our close primate cousins often possess a less acute olfactory sense than do other primates. Seeing red, it seems, is not without a sensory cost. Thus while humans and other primates enjoy the advantages of full color vision, the reasons why this trait developed have yet to be definitively determined.