Saturday, November 28, 2009

Sunday Article: Peacock

Sunday article by Mohan Pai
PEACOCK
Pavo cristatus




The icon of beauty, love & romance

The male Indian peafowl is commonly called Peacock. This gorgeous and majestic bird Peacock, Pavo cristatus is the national bird of India. It’s a symbol of beauty, joy, grace and love. Indian tradition is full of references to this glamourous bird and it has been repeatedly used as popular art motif. Due to its close proximity to humans for thousands of years, the peacock is featured in ancient Indian stories, songs and poems as symbol of beauty & pose. In two epic poems of Kalidasa (Meghadutam and Kumarasambhava) the beauty of the peacock has been used as an ornate literary tool. The peacock is a prominent motif both in Rajasthani & Mughal schools of paintings. The lovelorn, pining Nayikas in Rajasthani miniatures have the peacock as a companion. The Jataka tales Mahamayur Jataka describes the earlier birth of Bhagavan Buddha as a golden peacock.



Hindu mythology describes the peacock is to be the vahan or the vehicle for Karthikeya also called Murugan, the brother of Ganesha, the goddess Saraswati, and the goddess Mahamayuri. Indian Peacock (called Mayura in Sanskrit) has enjoyed a fabled place in India since ancient times. In imagery Lord Krishna is always represented wearing a peacock feather tucked in his headband. Peacocks often live in proximity to humans. Ancient kings in India were said to have gardens to raise peacocks where guests were invited to see the famous male peacock dance during the mating season. Due to this close proximity to humans for thousands of years, they have entered ancient Indian stories, songs and poems as symbols of beauty and poise. As the mating season coincides with the onset of monsoon rains and the month of Shravan in the Hindu calendar, many songs of rains have peacock-dance mentioned in them. One possible origins of the name of the famous Maurya dynasty of ancient India is probably derived from the word Mayura as the ancestors of the Mauryas are thought to be peacock-keepers of a royal court in eastern India.




The main figure of the Kurdish religion Yezidism, Melek Taus, is most commonly depicted as a peacock. The Yezidi's claim Indian origins.


This colourful bird has a fan-shaped crest on its head, a white patch under its eye and a long-slender neck. The male of species is more beautiful with a gleaming blue breast and an iridescent blue-green coloured plumage. The train feathers have a series of eyes and are best seen when the elongated tail is fanned. When displaying to a female, the peacock erects this train into spectacular fan, presenting the ocelli(eye-spots) to their best advantage.

Physical Features

The peacock, is one of the most recognisable birds in the world. These large, brightly colored birds have a distinctive crest and an unmistakable ornamental train. The train (1.4-1.6 meters in length) accounts for more than 60% of their total body length (2.3 meters). Combined with a large wingspan (1.4-1.6 meters), this train makes the male peafowl one of the largest flying birds in the world. The train is formed by 100-150 highly specialized uppertail-coverts. Each of these feathers sports an ornamental ocellus, or eye-spot, and has long disintegrated barbs, giving the feathers a loose, fluffy look. When displaying to a female, the peacock erects this train into a spectacular fan, presenting the ocelli to their best advantage.

The more subtly coloured female Peafowl is mostly brown above with a white belly. Her ornamentation is limited to a prominent crest and green neck feathers. Though females (2.75-4.0 kg) weigh nearly as much as the males (4.0-6.0 kg), they rarely exceed 1.0 meter in total body length.
 
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.
 
Social Characteristics

Peacock or peafowl Large bird belonging to the pheasant family, in East Asia being its native region. The crested common peacock during courtship displays his elongated upper tail which converts into a magnificent green and gold erectile train adorned with green blue " eyes " before the duller plumaged peahen. The peacock is a ornamental bird and is of quarrelsome nature and does not mix well with other domestic animals.

Habitat & Diet

They are omnivorous, obtaining most of their food by scratching the leaf litter with their strong feet. Indian Peafowl do most of their foraging in the early morning and shortly before sunset. They retreat to the shade and security of the forest for the hottest portion of the day. Foods include grains, insects, small reptiles, small mammals, berries, drupes, wild figs, and some cultivated crops.

Peacock distribution

The peacock is widely found in the Indian sub-continent from the south and east of the Indus river, Jammu and Kashmir, east Assam, south Mizoram and the whole of the Indian peninsula. The peacock enjoys immense protection. It is fully protected under the Indian Wildlife Protection) Act, 1972.
 
Peacock Throne
 
The legendary ‘Peacock Throne’ (also known as Takht-e-Tavous) of Ml Emperor Shah Jahan is a wonder of Mughal Art. It was yet another example of Shah Jahan’s unparallel aesthetic sense and love of art. This is counted as the costliest single treasure crafted in the last thousand years. In fact, the Peacock Throne was twice as costly as the total cost of the Taj Mahal. The original Peacock Throne was built in the 17th century and it was placed in Delhi’s royal court known as Diwan-i-Aam.


It acquired its name from its unique shape. It had the figures of two peacocks standing behind it, their tails being expanded and the whole was inlaid with sapphires, rubies, emeralds, pearls and other precious stones of appropriate colors so as to represent life. As described by the French jeweler Jean Baptiste Tavernier, who visited Delhi in 1665, the throne as of the shape of a bed (a "takhta" i.e. platform), 6 ft. by 4 ft., supported by four golden feet, 20 to 25 in. high, from the bars above which rose twelve columns to support the canopy; the bars were decorated with crosses of rubies and emeralds, and also with diamonds and pearls. There were 108 large rubies on the throne, and 116 emeralds. The twelve columns supporting the canopy were decorated with rows of splendid pearls, and according to Tavernier, these were the most valuable part of the throne. Among the historical diamonds decorating it were the famous Kohinoor (186 carats), the Akbar Shah (95 carats), the Shah (88.77 carats), the Jehangir (83 carats) and the second largest spinel ruby in the world — the Timur ruby (283 carats). A-20 couplet poem by the Mughal poet-laureate Qudsi, praising the Emperor, was embedded in the throne in emerald letters.


Delhi was invaded by Nader Shah in 1738 and the priceless Peacock Throne was one of the rare treasures he plundered from India. The legendary throne was carried to Iran. It glorified the palace of Iran till it was destroyed in the chaos following the assassination of Nader Shah in 1747.
 
 
References: Wikipedia, wildlife-tour-india.com
 
 
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Saturday, November 21, 2009

Sunday Article: House Sparrow

Sunday article by Mohan Pai



House Sparrow
Passer domesticus




...there’s a providence in the fall of a sparrow
                                                  -Hamlet (Shakespeare)
 
India’s foremost ornithologist Dr. Salim Ali published his autobiography in1985. He very aptly gave the title “The Fall of a Sparrow”.


Universally familiar in appearance, the widespread and once abundant house sparrow has become a mystery bird and is becoming increasingly rare all over the world. Perky and bustling, house sparrows have always been seen, mingling with finches in the fields in autumn and winter, but now weeks pass without a single one putting in an appearance.

They are vanishing from many big cities, but are still not uncommon in small towns and villages. India has seen a massive decline of sparrows in recent years and on the world map too. Once a commonplace bird in large parts of Europe, its numbers are decreasing. In the Netherlands, the House Sparrow is even considered an endangered species. Their recent decline has earned them a place on the Red List in the Netherlands. Similar precipitous drops in population have been recorded in the United Kingdom. French ornithologists have charted a steep decline in Paris and other cities. There has been an even sharper fall in the urban areas in Germany, the Czech Republic, Belgium, Italy and Finland.

History

It is thought that the House sparrow originated in the Mediterranean and expanded into Europe with the growth of civilization. At the insistence of man did the sparrow make its way across the Atlantic to the United States in 1850.

The house sparrow is an intelligent bird that has proven to be adaptable to most situation, i.e. nest sites, food and shelter, so it has become the most abundant songbird in the world.
 
Sparrows are very social birds and tend to flock together through most of the year. A flock’s range covers 1.5-2 miles, but it will cover a larger territory if necessary when searching for food. The sparrow’s main diet consists of grain seeds, especially waste grain and live stock feed. If grain is not available, its diet is very broad and adaptable. It also eats weeds and insects, especially during the breeding season. The parasitic nature of the house sparrow is quite evident as they are avid seekers of garbage tossed out by humans. In spring, flowers (especially those with yellow colours) are often eaten crocuses, primroses and aconites seem to attract the house sparrow most. The birds also hunt butterflies.

Housing

House sparrows are generally attracted to buildings for roosting, nesting, and cover. They look for any man-made nook or cranny to build their nests. Other nesting sites are clothes line poles with the end caps open, lofts, kitchen garden etc. The sparrow makes its home in areas closely associated with human habitation.

The House Sparrow (Passer domesticus) is a member of the old world sparrow family Passeridae. Some consider it to be a relative of the Weaver Finch Family. A number of geographic races have been named, and are differentiated on the basis of size and cheek colour.
Birds of the western hemisphere are larger than those in the tropical South Asian populations.


In India, it is popularly known as Goraiya in the Hindi belt. In Tamil Nadu and Kerala it is known as Kuruvi. Telugu language has given it a name, Pichhuka, Kannadigas call it Gubbachchi, Gujaratis call it Chakli where as Maharashtrians call it Chimani. It is known as Chiri in Punjab, Chaer in Jammu and Kashmir, Charai Pakhi in West Bengal, and Gharachatia in Orissa. In Urdu language it is called Chirya while Sindhi language has termed it as Jhirki.

Features

This 14 to 16 cm long bird has a wing span of 19-25 cm. It is a small, stocky song bird that weighs 26 to 32 grams. The male sparrow has a grey crown, cheeks and underparts, and is black at the throat, upper breast and between the bill and eyes. The bill in summer is blue-black and the legs are brown. In winter the plumage is dulled by pale edgings, and the bill is yellowish brown. The female has no black coloring on the head or throat, or a grey crown her upper part is streaked with brown. The juveniles are deeper brown, and the white is replaced by buff the beak is dull yellow. The House Sparrow is often confused with the smaller and more slender Tree Sparrow, which, however, has a chestnut and not grey crown, two distinct wing bars and a black patch on each cheek
The sparrow’s most common call is a short and incessant, slightly metallic cheep, chirrup.

Reproduction

The nesting sites are varied – in holes in buildings or rocks, in ivy or creepers, on houses or riverbanks, on sea-cliffs or in bushes in bays and inlets. When built in holes or ivy, the nest is an untidy litter of straw and rubbish, abundantly filled with feathers. Large well- constructed domed nests are often built when the bird nests in trees or shrubs, especially in rural areas.

The House Sparrow is quite aggressive in usurping the nesting sites of other birds, often forcibly evicting the previous occupants, and sometimes even building a new nest directly on top of another active nests with live nestlings. Eggs are variable in size and shape as well as markings. Eggs are incubated by the female. The sparrow has the

shortest incubation period of all the birds, 10 -12 days, and a female can lay 25 eggs each summer. The reproductive success increases with age and this is mainly by changes in timing, with older birds breeding earlier in the season.


Causes of Decline

There are various causes for dramatic decrease in their population, one of the more surprising being the introduction of unleaded petrol, the combustion of which produces compounds such as methyl nitrite, a compound which is highly toxic for small insects, which forms a major part of a young sparrow’s diet. Other being areas of free growing weeds, or reduction in number of badly maintained buildings, which are important nesting opportunities for sparrows. Ornithologists and wildlife experts speculate that the population crash could also be linked to a variety of factors like the lack of nesting sites in modern concrete buildings, disappearing kitchen gardens, increased use of pesticides in farmlands and the non- availability of food sources.


The widespread use of chemical pesticides in farmlands has resulted in the killings of insects on which these birds depend. Seed-eating birds like sparrows have to depend on soft- bodied insects to feed their young ones. The other possibility could be increased predation by crows and cats, while crows have grown in number as a result of garbage accumulation in the city. Changing lifestyles and architectural evolution have wreaked havoc on the bird’s habitat and food sources. Modern buildings are devoid of eaves and crannies, and coupled with disappearing home gardens, are playing a part in the disappearing act.

Today, one sadly misses the sight of sparrows hopping from branch to branch in the bushes outside one’s house and their chirping.

House Sparrow -Native range in dark green and introduced range in light green

References: House Sparrow - Declining Population by Kalpana Palkhiwala, Wikipedia


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Saturday, November 14, 2009

Sunday Article: Seahorse - The Pregnant Male!!!

Sunday article by Mohan Pai


Seahorses
Hippocampus

The Pregnant Male !!!

Seahorses are among the only animal species on Earth in which the male bears the unborn young. Male seahorses are equipped with a brood pouch on their ventral, or front-facing, side. When mating, the female deposits her eggs into his pouch, and the male fertilizes them internally. He carries the eggs in his pouch until they hatch, then releases fully formed, miniature seahorses into the water.


When people first hear about seahorse male getting pregnant, the question that naturally follows is, “So what makes them male?” The simple answer is sperm. The distinction between scarce round eggs and prolific tadpole-like sperm is essentially all that separates woman from man.
 
 
This delicate, diminutive creature (size of a tea cup) has enchanted people for thousands of years. It was Aristotle, the Greek philosopher who first wrote about the unusual habits of the Syngnathidae family in the third century BC..
In ancient Rome, the people believed that when Neptune, the god of the ocean, traveled, he swished through the water in a chariot drawn by gigantic, enchanted horses who could breathe underwater. When fishermen first saw the minute sea horses, they thought that they must be the offspring of Neptune’s horses, and they were fascinated with the little creatures.

Now we know that sea horses are, of course, not horses at all, they are merely a unique kind of fish. But these petite sea creatures with the elongated snout still seem as magical to us as they were to the ancient Romans.They are playful and graceful, and divers often stop to watch these marvelous creatures frolic around in the depths of the sea.


Habits

Sea horses don’t have scales the way that many other kinds of fish do. Instead, they have bony plates underneath their skin, like a small suit of armor to protect them from harm. There are numerous different kinds of sea horses, and they come in varying colors and sizes. Sea horses can be very tiny, and some are no larger than the length of the fingernail on your pinkie finger. Many types of sea horses have a unique way to camouflage themselves and hide from their enemies. Some can change colors, and chameleon-like, blend in with their surroundings. Some sea horses look so much like their surroundings that it is difficult to see them unless one is looking closely, and this helps to hide them from predators. One kind of sea horse even grows hair-like skin extensions so that they will blend in with the plant life whose fronds wave gently in the water of the ocean. Seahorses have no teeth and no stomach. Food passes through their digestive systems so quickly, they must eat constantly to stay alive

Breeding

It is the male, not female, sea horses who are impregnated, and they can have up to 1500 babies at one time. Males have a special patch or pouch on their belly that provides incubation for the female’s eggs. The female transfers the eggs to the male’s pouch, and they then attach to the wall of the male’s pouch. After the male fertilizes the eggs, they are retained within the brood pouch to develop. When the young hatch, the male expels them from the pouch and they emerge looking like miniature versions of the adults. During the entire pregnancy, a mated pair of sea horses will dance in the water together every day just after the sun has risen. Scientists have speculated for years on the reason for this, but no one really knows why the sea horses execute this peculiar, beautiful greeting dance.
 
 

Seahorse distribution map


They are found in shallow, coastal, tropical and temperate waters from about 45°S to 45°N. They inhabit many ecologically sensitive aquatic habitats, including coral reefs, sea grasses, mangroves and estuaries, with most species in the Indo-Pacific and western Atlantic regions. Sea horses primarily occupy inshore habitats in narrow strips along the coast and prefer shallow waters (< 15 m depth), but have been encountered in shallow rock pools. Many temperate and tropical sea horse species inhabit sea grass meadows, while others inhabit mangrove ecosystems and coral reefs.

In medicine

Ironically, it is their very popularity that places them in danger, as they are sought in large numbers for use in traditional medicine, aquarium fish and curios (souvenirs).

Seahorses are used as an ingredient in traditional medicine, particularly in southeast Asia where traditional Chinese medicine and its derivatives (e.g. Japanese and Korean traditional medicine)are practiced and have been used perhaps for about 600 years. Seahorses are credited with having a role in increasing and balancing vital energy flows within the body, as well as a curative role for such ailments as impotence and infertility, asthma, high cholesterol, goitre, kidney disorders, and skin afflictions such as severe acne and persistent nodules. They are also reported to facilitate parturition, act as a powerful general tonic and as a potent aphrodisiac.

It was conservatively estimated that at least 20 million sea horses (more than 56 metric tonnes) were caught for the traditional medicine market. In addition, more than one million live sea horses are caught for aquarium trade, mostly destined for sale in North America, Europe, Japan and Taiwan. The value of sea horses is quite high; the price of dried sea horses in Hong Kong markets ranges from Rs 11,500 to 50,400 (US$ 275 to 1200) per kg depending on the species, quality and size. About 50 countries are involved in sea horse exploitation.

Medicinal seahorse

India is one of the largest exporters of dried sea horses globally, exporting at least 3.6 tonnes (~ 1.3million sea horses) annually, and contributes to about 30% of the global seahorse trade. There is also a significant trade in sea horses as aquarium fishes,


as supplements in some specialized cuisine and as curios. Sea horses are exploited both as an incidental catch (by-catch in trawl nets) and target catch, for export. Presently, the commercial exploitation of sea horses is being carried out from Tamil Nadu and Kerala coasts. Along Ramnad coast in Tamil Nadu, dried sea horse is used as a medicine to arrest whooping cough in children.

Goa– Maharashtra coast also indicated a similar usage. Demand for medicinal purposes has increased 10-fold during the 1980s and continues to grow at an annual rate of about 8–10% in China alone, predominantly due to China’s economic boom which promotes increased consumer-spending on traditional medicines.
 
Today, sea horse populations face an unpredictable future. They are not as yet on the endangered list, or even the potentially threatened list, but scientists and other experts are worried. Fishermen are catching far too many of them, and more of their underwater habitats are destroyed each day by pollution and other human carelessness.
 
Population data for most of the world’s 35 seahorse species is sparse. However, worldwide coastal habitat depletion, pollution, and rampant harvesting, mainly for use in Asian traditional medicine, have made several species vulnerable to extinction.

In Mythology

The hippocamp or hippocampus in Greek and often called a sea-horse in English, is a mythological creature shared by Phoenician and Greek mythology, though the name by which it is recognised is purely Greek; it became part of Etruscan mythology. It has typically been depicted as a horse in its forepart with a coiling, scaly, fishlike hindquarter.

Hippocamp in Roman mosaic in the thermae at Aquae Sulis (Bath)

Homer described Poseidon, who was god of horses (Poseidon Hippios) as well as of the sea, drawn by "brazen-hoofed" horses over the sea's surface, and Apollonius of Rhodes, being consciously archaic in Argonautica describes the horse of Poseidon emerging from the sea and galloping away across the Libyan sands In Hellenistic and Roman imagery. However, Poseidon (or Roman Neptune) often drives a sea-chariot drawn by hippocampi. Thus hippocamps sport with this god in both ancient depictions and much more modern ones, such as in the waters of the eighteenth-century Trevi Fountain in Rome surveyed by Neptune from his niche above.


Poseidon's horses, which were included in the elaborate sculptural program of gilt-bronze and ivory, added by a Roman client to the temple of Poseidon at Corinth, are likely to have been hippocamp.
 



References: Wikipedia, National Geographic, essortment.com, National Institute of Oceanography, Goa.

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Saturday, November 7, 2009

Coral Reefs - 'Living organisms'

Sunday article by Mohan Pai

Coral Reefs
"The Living Organisms"

Some of the biodiversity of a coral reef, in this case the Great Barrier Reef, Australia

Called “rainforests of the sea”, coral reefs are living organism and the oldest, most productive ecosystems on earth.

Existing for more than 500 million years, Corals are marine organisms from the class Anthozoa and exist as small sea anemone-like polyps, typically in colonies of many identical individuals. The group includes the important reef builders that are found in tropical oceans, which secrete calcium carbonate to form a hard skeleton.


A coral "head", commonly perceived to be a single organism, is formed from myriads of individual but genetically identical polyps, each polyp only a few millimeters in diameter. Over thousands of generations, the polyps lay down a skeleton that is characteristic of their species. An individual head of coral grows by asexual reproduction of the individual polyps. Corals also breed sexually by spawning, with corals of the same species releasing gametes simultaneously over a period of one to several nights around a full moon.

Although corals can catch small fish and animals such as plankton using stinging cells on their tentacles, these animals obtain most of their nutrients from photosynthetic unicellular algae called zooxanthellae. Consequently, most corals depend on sunlight and grow in clear and shallow water, typically at depths shallower than 60 metres (200 ft). These corals can be major contributors to the physical structure of the coral reefs that develop in tropical and subtropical waters, such as the enormous Great Barrier Reef off the coast of Queensland, Australia. Other corals do not have associated algae and can live in much deeper water, with the cold-water genus Lophelia surviving as deep as 3,000 metres (9,800 ft). Examples of these can be found living on the Darwin Mounds located north-west of Cape Wrath, Scotland. Corals have also been found off the coast of Washington State and the Aleutian Islands in Alaska.Corals coordinate behaviour by communicating with each other.
 
Globally, coral reefs are under threat from climate change, ocean acidification, overuse of reef resources, and harmful land-use practices. High nutrient levels such as those found in runoff from agricultural areas can harm reefs by encouraging excess algae growth.
 
Formations

Coral reefs can take a variety of forms, defined in following:

Fringing reef – a reef that is directly attached to a shore or borders it with an intervening shallow channel or lagoon.

Barrier reef – a reef separated from a mainland or island shore by a deep lagoon (Great Barrier Reef).

Patch reef – an isolated, often circular reef, usually within a lagoon or embayment.

Apron reef – a short reef resembling a fringing reef, but more sloped; extending out and downward from a point or peninsular shore.

Bank reef – a linear or semi-circular shaped-outline, larger than a patch reef.

Ribbon reef – a long, narrow, somewhat winding reef, usually associated with an atoll lagoon.

Atoll reef – a more or less circular or continuous barrier reef extending all the way around a lagoon without a central island.

Table reef – an isolated reef, approaching an atoll type, but without a lagoon.

Distribution
Coral reefs are estimated to cover 284,300 square kilometers, with the Indo-Pacific region (including the Red Sea, Indian Ocean, Southeast Asia and the Pacific) accounting for 91.9% of the total. Southeast Asia accounts for 32.3% of that figure, while the Pacific including Australia accounts for 40.8%. Atlantic and Caribbean coral reefs only account for 7.6%.
 
 

Location map of coral reefs
Locations of coral reefs.
Although corals exist both in temperate and tropical waters, shallow-water reefs form only in a zone extending from 30°N to 30°S of the equator. Tropical corals do not grow at depths of over 50 m (165 ft). Temperature has less of an effect on the distribution of tropical coral, but it is generally accepted that they do not exist in waters below 18 °C., and that the optimum temperature is 26-27° Celsius for most coral reefs. The reefs in the Persian Gulf however have adapted to temperatures of 13° Celsius in winter and 38° Celsius in summer. Deep water coral is more still exceptional since it can exist at greater depths and colder temperatures. Although deep water corals can form reefs, very little is known about them.

Famous coral reefs and reef areas of the world include:

The Great Barrier Reef - largest coral reef system in the world, Queensland, Australia;

The Belize Barrier Reef - second largest in the world, stretching from southern Quintana Roo, Mexico along the coast of Belize to the Bay Islands of Honduras.

The New Caledonia Barrier Reef - second longest double barrier reef in the world, with a length of about 1500 km.

The Andros, Bahamas Barrier Reef - third largest in the world, following the east coast of Andros Island, Bahamas, between Andros and Nassau.


The Red Sea Coral Reef - located off the coast of Israel, Egypt and Saudi Arabia.

Pulley Ridge - deepest photosynthetic coral reef, Florida

Numerous reefs scattered over the Maldives

Ghe Raja Ampat Islands in Indonesia's West Papua province offer the highest known marine diversity.


                                                                    Anatomy of Coral Polyp


References: Wikipedia


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http://paimohan-mohanpai.blogspot.com/
(Traditional Hindu Central Courtyard Houses of Goa)

Mohan Pai’s email: mohanpai@hotmail.com