By - Ragoo Rao

Winter is quietly creeping in and the rains are fading out and the scenario is changing over to a different mood. Most of the Bird and Animal watchers may be preparing to study their interest in its winter settings. Down South here it's a haven for animal study groups to visit our Sanctuaries. Most of the ungulates are with their young ones. Specially the young fawns of spotted deer and Gaur calves. Its a sight to see them gamboling around their herds with abandon. The forest cover is also beautiful this time of the year as most of the deciduous trees are in bloom and flocks of Crimson headed parakeets swarm the Erythrina blooms.

This month I have chosen the Rose ringed parakeet for our Bird of the Month slot.

The most loved among the pet birds all over the world is undisputedly the Parrot. The Parrots come in a variety of sizes and colors depending upon their Geographical locations. From the small Budgerigars (Love birds) to the huge Scarlet Macaws they all belong to one family-Psittacidae.

The Rose ringed parrot is very familiar to both urban and rural areas. The green colored birds with red hooked beaks and a pointed tail is practically distributed all over the country. The males have a dark pink ring like marking around their neck-hence the name. Often large flocks can be seen in the late evenings in leafy trees in the country side noisily settling down to roost. The same large flocks also roost amid bustling urban area avenue trees. These flocks raid maize crops of farmers often wasting more than what they actually eat. Orchards are a favorite foraging area for these birds. They are gregarious feeders.

These birds are not shy and they always make known their presence with their loud Keeeak....keeek...keeeeak calls. When a breeding pair is noticed quietly without disturbing them, one can hear varied vocalizations.They could be found interacting vocally with each other which appear like mumbling. Parrots have a large vocabulary.

The main nesting season is between February and May varying locally depending upon the food availability and weather. A natural hollow is selected in tall trees and both the birds work out by carving out their requirement with their powerful beaks. When one bird is busily carving inside the other stands at the entrance to warn any intrusion. With one loud k week.... from the guard bird both of them bolt off. Sometimes high barn walls are also selected for nesting.4 to 6 white eggs are laid. Both sexes share all the domestic chores. In about 6 weeks the fledglings are ready to start their own life.

By - S.Ananthaanrayanan

David Hu and John Bush have reported in Nature that insects move at 30 body lengths a second when they strike a pose and move up the slope of water at the edges of a puddle, without even moving their legs!

The water surface

Water molecules consist of 2 positively charged hydrogen atoms linked to one negatively charged oxygen atom, but the way the atoms are placed is not symmetrical. Thus, at short distances, water molecules showpolarity, like magnets with N and S poles, and exert powerful electric forces.

When well within a body of water, where other molecules surround a molecule, there is no net effect of these forces. But at the surface, with a mass of water on one side and nothing on the other, the surface molecules feel a strong inward pull. The surface of water is thus like a tight membrane, which resists anything creating a gap in the surface and getting in.

The surface can thus support a reasonable weight and the surface of ponds or puddles supports a whole universe of tiny, millimeter-scale life-forms, which find the water surface as rigid as any other.

Getting their feet wet

This is so long as the insects' feet stay dry. If they got wet and the separation between the feet and the mass of water then disappeared, the feet would sink. We may have seen that a drop of water on a glass sheet that is just a little greasy does not spread out, but forms a little bubble, as it tries to pull itself into a ball, its smallest surface. But if the glass is clean, then the forces between the water molecules and the glass are as strong as the force of the water mass and the drop spreads out.

The attraction of glass for water molecules, in fact, is quite strong and we can see that the edge of water in a glass tumbler slopes upwards at the sides of the tumbler. If we dip a thin glass tube into water, the force can raise the water to a considerable height. This capillary effect is what helps nutrients flow up the roots of plants and trees.

But if the insects' feet are dry, the surface of water does not break and the insects can ride the surface like a sledge over snow, using the fore and rear legs as support and the middle legs as paddles. The insects' secret is that their feet are covered with the fine hair which traps air, to keep the water away from the feet!

The research at MIT

For all the facility of moving over the water surface, tiny insects face a challenge when they come to the edges of the surface. At the edges, the surface slopes upward, like at the side of a glass tumbler. And for a millimeter-scale insect, the slope is high and steep and slippery! Many insects do need to come to dry land. But they may well be trapped on the water by the gradient-barrier at the water edge.

The MIT scientists used high speed video – 500 frames a second – to capture the action. They found that the insects adopt a specific posture along the edges of the pond or puddle and then make capillary forces propel them out of the water! The insect does this by selective wetting of its front and rear feet, while keeping the middle ones dry.

As the insect approaches the sloping edge of the water, it lets down claws that it otherwise keeps drawn in from its front and rear feet. They then take up a stance where the front and rear limbs pull up the surface of water while the middle feet push down. The capillary forces that draw the feet that are wet then add up to a net force that pulls the insect up the slope.

It is a delicate operation, with the limbs to be stretched just so, somewhat like a sailor ‘tacking' the sails to move against the wind. But the insects manage to reach speeds of around 10 cms a second!

“The normal locomotion of animals is to use muscles to move or raise things”, say Hu and Bush. But with water walking insects, the muscular force is used to deform a surface, to tap molecular forces.

[The writer can be contacted at simple­­science@gmail.com ]

Photographs courtesy David Hu and John Bush . More photographs of the insects in action can be seen at the following url:

http://www-math.mit.edu/~dhu/Climberweb/climberweb.html

- Shivani Thakur

With winters setting in most parts of northern India and designers showcasing their fall collection, it also means bringing out the prized shawls by the rich and the famous. If the Pashminas are considered good buys, the Shahtoosh are considered to represent class and sophistication. The toosh shawls as they are infamously known, are considered to be an investment worth its weight in gold by many among the well placed. Whereas the Pashminas are easily available in open market, Shahtoosh are only available on very high discretion because of the ban on their sale.

Pashmina is made from the mountain goat found in the upper Himalayan regions where as Shahtoosh is obtained from the endangered species of the Tibetan antelope found in Tibet . The wool is woven to perfection in Kashmir . The wool woven is so fine that the whole shawl can pass through a ring finger. Yet the warmth it gives is no match to any other wool. Chiru as the Tibetan antelope is known is found mostly in Tibet with about 10-12 per cent of its population in the Ladakh-Kashmir region. It is estimated that there are about 75,000 antelopes left in the wild. Wool from five Chiru's is required to make one shawl. The weavers claim that the wool they use is not acquired by slaughtering them but what is usually collected from the bushes where Chiru roam. But this is not so as around one lakh chiru have died in the past few decades. The wool is often obtained by bartering tiger bones and skin. Thus not only the chiru but we are also ending up losing the tiger and pushing our eco system to collapse.

A drive by Wildlife Department was carried out to declare the shahtoosh shawls so as to stop their illegal trade. In Delhi alone and particularly South Delhi 25,000 shawls were declared. Officials say that more than 200 families own more than 5 shawls. Each shawl costs about Rs 50,000 in the open market. Brigadier (retired) Ranjeet Talwar of the World Wildlife Fund explains that the main reason for many big addresses of Delhi owning these shawls is to confirm the social standing in the society. Many a times these shawls are passed from one generation to another. Also, they are gifted to each other to convey their status. In Mumbai too 20,000 shawls have been declared. In July Swiss custom officials had confiscated 537 shawls estimated to cost about 2.5 million Euros meant for sale in Switzerland , UK , France and the US . Wildlife experts estimate that at least 1,600, more than 3 per cent of the population, could have been slaughtered to produce the seizure.

An act in 1972 under Schedule 1 of Indian Wildlife Act has banned the sale and trade of shahtoosh shawls yet the trade is alive and kicking in Kashmir . Belinda Wright of the Wildlife Protection Society of India remarks that the wool from Tibet is smuggled into Kashmir where the shawls are made. The finished product then probably reaches Switzerland through China and Korea . She also adds that the trade has seen an upsurge in the past few months and the production of shahtoosh shawls in Kashmir has increased.

In October 2003 the Government of India made the failure to declare wildlife items a punishable offence. But this has not stopped the production of the shawl as the demand for it is now seen in other parts of the world. To curb this is a difficult task as now it is not just one endangered species, which is being exploited for wool; We are on the verge of losing the species for ever. Will a hand me down wool shawl satisfy the wanderlust of your grandchild who is willing to travel to the Himalayan regions to catch a glimpse of the Chiru?

Photograph : Chiru on Tibetan Plateau by Liu Wulin ( IFAW)