Saturday, November 21, 2009

Peafowl

Peafowl

The term peafowl can refer to the two species of bird in the genus Pavo of the pheasant family, Phasianidae. The African Congo Peafowl is placed in its own genus Afropavo and is not dealt with here. Peafowl are best known for the male's extravagant tail, which it displays as part of courtship. The male is called a peacock, the female a peahen, though it is common to hear the female also referred to as a "peacock" or "female peacock." The female peafowl is brown or toned grey and brown.

The two species are:

* Indian Peafowl, Pavo cristatus (Asiatic)
* Green Peafowl, Pavo muticus (Asiatic)

The Indian Peafowl is a resident breeder in the Indian subcontinent. The peacock is designated as the national bird of India.

The Green Peafowl breeds from Burma east to Java. The IUCN lists the Green Peafowl as vulnerable to extinction due to hunting and a reduction in extent and quality of habitat.






Taxonomy
Green Peafowl

The Indian Peafowl is monotypic, while the Green Peafowl has 3 subspecies, P. muticus spicifer, P. m. imperator and the nominate P. m. muticus. The two species are largely allopatric but will hybridize in captivity.

While the form of Green Peafowl in Yunnan is not separated taxonomically, it differs in a few aspects from other forms, particularly in its forest-dwelling habits, an "odd, monal-like bill," a curiously long hind toe and longer, more slender wings (K. B. Woods in litt. 2000). Some have suggested this is a new subspecies.

Some pheasant breeders have suggested that the Green Peafowl may have more subspecies.

Peafowl have sometimes been included in a distinct family from Pheasants .


Plumage
Close-up of a male Indian Peafowl's plumage

The male (peacock) Indian Peafowl has iridescent blue-green or green coloured plumage. The so-called "tail" of the peacock, also termed the "train," is not the tail quill feathers but highly elongated upper tail coverts. The train feathers have a series of eyes that are best seen when the tail is fanned. Both species have a crest atop the head.

The female (peahen) Indian Peafowl has a mixture of dull green, brown, and grey in her plumage. She lacks the long upper tail coverts of the male but has a crest. The female can also display her plumage to ward off female competition or danger to her young.

The Green Peafowl is different in appearance to the Indian Peafowl. The male has green and gold plumage and has an erect crest. The wings are black with a sheen of blue.

Unlike the Indian Peafowl, the Green Peahen is very similar to the male, only having shorter upper tail coverts and less iridescence. It is very hard to tell a juvenile male from an adult female.

Many of the brilliant colours of the peacock plumage are due to an optical interference phenomenon (Bragg reflection) based on (nearly) periodic nanostructures found in the barbules (fiber-like components) of the feathers.

Different colours correspond to different length scales of the periodic structures. For brown feathers, a mixture of red and blue is required: one colour is created by the periodic structure, and the other is a created by a Fabry-Perot interference peak from reflections off the outermost and innermost boundaries of the periodic structure.

Such interference-based structural colour is especially important in producing the peacock's iridescent hues (which shimmer and change with viewing angle), since interference effects depend upon the angle of light, unlike chemical pigments.

Macaw Parrots

Macaws

Macaws are small to large, often colourful New World parrots. Of the many different Psittacidae (true parrots) genera, six are classified as macaws: Ara, Anodorhynchus, Cyanopsitta, Primolius, Orthopsittaca, and Diopsittaca. Previously, the members of the genus Primolius were placed in Propyrrhura, but the former is correct in accordance with ICZN rules. Macaws are native to Mexico, Central America, South America, and formerly the Caribbean. Most species are associated with forest, especially rainforest, but others prefer woodland or savannah-like habitats.

Large, dark (usually black) beaks, and relatively hairless, light coloured, medial facial (facial patch) areas distinguish macaws. Sometimes the facial patch is smaller in some species, and limited to a yellow patch around the eyes and a second patch near the base of the beak in the members of the genus Anodorhynchus, or Hyacinth Macaw. A macaw's facial feather pattern is as unique as a fingerprint.

Some of the macaw species are known for their impressive size. The largest parrot in length and wingspan is the Hyacinth Macaw. The heaviest macaw is the Buffon's, although the heaviest parrot is the flightless Kakapo. While still relatively large parrots, the macaws of the genera Cyanopsitta, Orthopsittaca and Primolius are significantly smaller than the members of Anodorhynchus and Ara. The smallest member of the family, the Red-shouldered Macaw, is no larger than some parakeets of the genus Aratinga.

Macaws, like other parrots, toucans and woodpeckers, are zygodactyl, having their first and fourth toes pointing backwards.

Friday, November 20, 2009

Butterfly

Butterfly

A butterfly is an insect of the order Lepidoptera. Like all holometabolous insects, butterflies' life cycle consists of four parts, egg, larva, pupa and adult. Most species are diurnal. The diverse patterns formed by their brightly coloured wings and their erratic flight have made butterfly watching a hobby.[citation needed]

Butterflies comprise the true butterflies (superfamily Papilionoidea), the skippers (superfamily Hesperioidea) and the moth-butterflies (superfamily Hedyloidea). Butterflies exhibit polymorphism, mimicry and aposematism. Some migrate over long distances. Some butterflies have evolved symbiotic and parasitic relationships with social insects such as ants. Butterflies are important economically as agents of pollination. In addition, a few species are pests, because they can damage domestic crops or trees in their larval stage.

Culturally, butterflies are a popular motif in the visual and literary arts.



Elephant

Elephant
Elephants are large land mammals in two genera of the family Elephantidae: Elephas and Loxodonta. Three species of elephant are living today: the African Bush Elephant, the African Forest Elephant and the Asian Elephant (also known as the Indian Elephant). All other species and genera of Elephantidae are extinct, some since the last ice age: dwarf forms of mammoths may have survived as late as 2,000 BC. Elephants and other Elephantidae were once classified with other thick-skinned animals in a now invalid order, Pachydermata.

Elephants are the largest land animals now living. The elephant's gestation period is 22 months, the longest of any land animal. At birth it is common for an elephant calf to weigh 120 kilograms (260 lb). They typically live for 50 to 70 years, but the oldest recorded elephant lived for 82 years. The largest elephant ever recorded was shot in Angola in 1956. This male weighed about 12,000 kilograms (26,000 lb), with a shoulder height of 4.2 metres (14 ft), a metre (yard) taller than the average male African elephant. The smallest elephants, about the size of a calf or a large pig, were a prehistoric species that lived on the island of Crete during the Pleistocene epoch.

The elephant has appeared in cultures across the world. They are a symbol of wisdom in Asian cultures and are famed for their memory and intelligence, where they are thought to be on par with cetaceans and hominids. Aristotle once said the elephant was "the beast which passeth all others in wit and mind". The word "elephant" has its origins in the Greek ἐλέφας, meaning "ivory" or "elephant".

Healthy adult elephants have no natural predators, although lions may take calves or weak individuals. They are, however, increasingly threatened by human intrusion and poaching. Once numbering in the millions, the African elephant population has dwindled to between 470,000 and 690,000 individuals according to a March 2007 estimate. While the elephant is a protected species worldwide, with restrictions in place on capture, domestic use, and trade in products such as ivory, CITES reopening of "one time" ivory stock sales, has resulted in increased poaching. Certain African nations report a decrease of their elephant populations by as much as two-thirds, and populations in certain protected areas are in danger of being eliminated Since recent poaching has increased by as much as 45%, the current population is unknown (2008).



Saturday, November 7, 2009

World wild Life

Wildlife includes all non-domesticated plants, animals and other organisms. Domesticating wild plant and animal species for human benefit has occurred many times all over the planet, and has a major impact on the environment, both positive and negative.

Wildlife can be found in all ecosystems. Deserts, rain forests, plains, and other areas—including the most developed urban sites—all have distinct forms of wildlife. While the term in popular culture usually refers to animals that are untouched by human factors, most scientists agree that wildlife around the world is impacted by human activities.

Humans have historically tended to separate civilization from wildlife in a number of ways including the legal, social, and moral sense. This has been a reason for debate throughout recorded history. Religions have often declared certain animals to be sacred, and in modern times concern for the natural environment has provoked activists to protest the exploitation of wildlife for human benefit or entertainment. Literature has also made use of the traditional human separation from wildlife.