The White Tiger of the shores

I remember that day more than four years ago. We were heading to the beach from college after a long, tiring day. As we walked along the narrow road chatting, I caught sight of a huge white bird, black underwing, soar just above us. As I looked up in awe, another followed suit bearing excess baggage in its talons -- a snake! I had just seen a pair of White-Bellied Sea Eagles returning after successfully hunting a sea snake!

For the first time in months, disregarding the slip disc I had suffered, I ran to locate the eagle’s perch. My friends ran after me to make sure I didn't collapse from the exertion. The pair of raptors flew into a walled compound bordering the beach. Scanning about for a good five minutes, I found both birds on an open perch. One, presumably the female, was feeding on the snake. The other, probably the male, was slightly smaller in size as is the case with most raptors.


After this encounter I saw them several times during my two-year college sojourn. They nested on a tall casuarina tree on the beach, very close to the water. It was an enormous construction of more than 3 feet diameter and was approximately 40 feet above the ground near the top of the tree. Although I saw the birds build and maintain the nest, I never saw them exhibit any behavior that accounted for raising chicks such as fetching food or lingering near the nest.

The eagle with a fish

Last December, more than two years since I left college, I paid the site a visit with my camera. And this time I did see some activity near the nest. While walking down the same narrow road towards the beach, I told my friend Amith that I hoped to see something interesting. Almost immediately he exclaimed, “Snake!” I turned to see a huge rat snake slither across our path. I considered this a sign of luck. With a wide grin I continued walking. On reaching the beach, we found sandpipers foraging close to the water. While I was trying to get close to them Amith said, “Isn’t that the bird you are looking for?” 


I looked up and saw the sea eagle flying in with a fish in its talons. As we watched, it made for the clump of trees that housed the nest.

The eagle on its nest

On reaching the trees we saw the nest and its owner perched next to it. I am not sure what happened to the fish - did it store it to be eaten later or pass it onto a chick in the nest? Presently, its partner flew in from behind the trees with something in its talons. I shot a picture and reviewed it on the LCD screen -- a small, half-eaten snake. 


This bird then headed out to sea and returned within a couple of minutes, landing close to the nest. Then the first bird took off. At any given time one bird remained near the nest. They took off and landed so many times that I lost track of the take-offs and landings. Although all this activity near the nest made me curious, I had no way way of confirming occupancy.

The eagle carrying the thin body of the half eaten snake

White-bellied sea eagles are ashy above with a white head, neck and underparts. The scientific name Haliaeetus leucogaster roughly translates to 'sea eagle with white stomach' (hali = salt, aeetus refers to eagle, leuco = white and gaster refers to stomach). The underside of the wings are white-bordered with broad black covering the primaries and the outer and inner secondaries. The secondaries are broad and appear bulged against the line of the wing. The wedge-shaped tail has a stiff black band across it. While sailing, the wings almost always maintain a wide 'V' shape.

'V' shaped wings while sailing

Salim Ali, in The Book of Indian Birds, states that if undisturbed, White-bellied Sea Eagles occupy the same locality or nest for years together. Though scores of visitors to the beach don't seem to bother the pair for now, I am concerned for the future as there are not many lofty trees left along that stretch of beach. I hope they remain undisturbed for years to come and successfully raise future generations.


I remained there, observing the Sea Eagles until darkness crept in. I bade them goodbye and I guess they heard me, for one of them waved back.

Waving goodbye

This post has also been published in The Green Ogre

Malabar Grey Hornbill

What's so different about a Malabar Grey Hornbill(Ocyceros griseus) when compared with the other three hornbills found in the western ghats? The casque ofcourse, or rather the absence of it. Although the attention grabbing casque is not present, the bright orange beak(in males) makes up for it and you realise the true meaning of the word "Hornbill". The bill is shaped exactly like a cow's horn, which is the literal meaning of its family name, Bucerotidae. This it uses mainly to feed on fruits and berries although they also take small vertebrates. All hornbills come under the order Coraciiformes.

The sexes of the Malabar grey hornbills are dimorphic(different in morphology) where the males have a bright ornage bill with a yellow tip where as the females have a yellow bill with black at the base of the bill. Both are mainly greyish and have a white, broad superciliam running down till the neck.

These birds are endemic to the western ghats. They mate for life and are secondary cavity nesters, that is , they don't make their own cavity nests but use existing cavities that they search for and find. Generally these nesting sites are used year after year. Like many other hornbills, the females imprison themselves in the cavity during nesting and undergo a complete moult and come out after the eggs hatch. During this time it is upto the male to feed her through a narrow slit in the cavity. I think that one of the reasons that hornbills have a long bill may be because they pass food through this slit. This is my surmise and open to debate.

After a fleeting glimpse of this bird at Agumbe, three years ago I observed them to my heart's content at Dandeli, earlier this year. As we (the Ogres) were busy observing the larger Malabar Pied Hornbills at the timber depot in the heart of Dandeli town, these guys landed on a couple of fruiting trees and started posing for us. It was interesting to observe them feeding on berries.

Although IUCN (International Union for Conservation of Nature) lists them as LC (Least Concern), rapidly shrinking habitat is a cause for worry.


This post has also been published in The Green Ogre

Sand Boa saved from becoming "Tar" Boa

Six of us were driving back to Bangalore after a trip when Sunil shouted from the back seat, "Snake! Stop the car!"

Sand Boa where we found it

Khusro pulled over to the side and four of us ran back to the spot. In the available light Sunil and I tried to identify the snake. At first glance the stout body gave us the impression that it was a small Russell's Viper. Peering closer, aided by the head light of an oncoming vehicle, we determined that it was a Sand Boa (Eryx conicus).

We had to prevent it from becoming another all-too-common roadkill. While I stopped vehicles speeding past us, Sunil took off his tshirt, draped it over the snake and lifted it off the road. He has been working with snakes for a while and was comfortable handling the boa. We then put the snake in front of Khusro's vehicle. Under headlights, we checked it for injuries. It seemed all right.

When Sunil put the snake down, it exhibited an odd behaviour. Rather than try to slither away, it coiled up between his shoes. This is the Sand Boa's defense strategy - to get into a hole or crevice and coil up, keeping its head protected within its coils. When handled the snake was aggressive and ready to strike.

Snake lashing out trying to land a strike

It was only my fourth touch of a snake, but this felt different. The sturdy, muscular serpent had rough, hard scales. True to its name the Sand Boa spends most of its life under the sand or in loose earth, and its tough skin offers protection while burrowing. Its scales were rougher and harder than that of the other three snakes I had handled. Boas are thick, short snakes with rough, keeled scales. Although individuals up to 90 centimetres have been measured, on an average they grow to around 60 centimeters.

At first glance, they can be confused with Russell's Vipers but the viper has a clear pattern and a triangular, arrow-like head that is broader than the neck. The Sand Boa's head is hardly distinguishable from its neck. Its body is short and thick and it has a rounded snout and a short, tapering tail. The eyes are small with vertical slits in the pupil. The snake's upperparts are grey with large, irregular brown or reddish-brown blotches, which may or may not be joined.

Note the pattern on the back and the shape of the head

The Sand Boa is often mistaken for the venomous Russell's Viper and therefore killed. Other reasons for its declining numbers are the illegal trade in animals and poaching for its skin. These snakes are caught and sold as pets and their skin is coveted for making fancy purses and wallets.

Sand Boas are a part of the subfamily Erycinae under a family of non-venomous snakes called Boidae. So, how do they kill their prey? The snake wraps its coils around its prey after restraining it by biting and holding with its several sharp teeth. Then it constricts the captured animal until it suffocates to death.

Sand Boas are found in arid and semi-arid regions and are generally active at dusk and night. They are ovoviviparous, producing 3-16 live young. The breeding season is usually November.

Ready for release

We took a few shots of the snake before releasing it away from the busy road. I have seen and heard snakes being run over. Yes, "heard". The sound that is produced as a vehicle runs over a snake is a sickening snap. I am glad I didn't have to hear it this time.



This post has also been published as an encounter series in the The Green Ogre

The Lord of the Timber Depot - Malabar Pied Hornbill

When you mention Dandeli, people respond in two ways. "Rafting!" exclaim the majority. The others enthusiastically say: "Hornbills!" On our trip, we (Sahastra, Bijoy, Andy, Satish and I) didn't even consider the former.

Four species of Hornbills are found in the Western Ghats. At Dandeli, it was the Malabar Pied Hornbill (Anthracoceros coronatus) that held our rapt attention for over two hours. After catching mere glimpses of these birds the previous day close to the core area of the reserve, we were in for a treat as we entered the timber depot in the heart of Dandeli town. Just as we alighted from our vehicle at the entrance to the depot, we saw a flurry of movement on a fruiting tree. Our jaws dropped. When the folks at the Kulgi Nature Camp told us that we would find hornbills at the depot, we imagined that they were referring to the commoner Malabar Grey Hornbill (Ocyceros griseus). But here, as we watched open-mouthed, four or five Malabar Pied Hornbills, among the most endangered hornbills in India, fed on berries while several others flitted around just about everywhere.

The Malabar Pied Hornbill is primarily a frugivore, feeding mainly on figs. Hence they play a vital part in the dissemination of seeds. Their preferred habitat is lowland riparian forest (adjoining a large water-body such as a stream, river or lake). The Dandeli Timber Depot, where we saw them, is close to the Kali river.

Getting ready to swallow

Although these birds are categorised as 'NT' (Near Threatened) by the IUCN, they did not appear to be threatened here. Like B2 bombers, they would appear out of nowhere, transfix us with their graceful glides, and disappear as swiftly as they had arrived.

Hornbills are classified under the family Bucerotidae in the order Coraciiformes. Birds of the this family are characterized by long, downward-curving bills which resemble horns. In some species the bill has a casque on the maxilla (upper jaw/beak). The scientific name of the family refers to the bill's shape -- "Buceros" meaning cow's horn in Greek. Hornbills are the only birds in which the axis and atlas (the first and second vertebrae) are fused together. This skeletal structure is believed to help support the huge bill, better. They are also the only birds with a two-lobed kidney (in all other birds it is three-lobed). The casque is mostly hollow and is made up of keratin (the same material that makes up the beak).

The large downward-curving beak is characteristic of hornbills

The use of the casque is a subject that is widely debated. Some consider that it serves as an indicator of the bird's age, sex etc. There are others who contend that it is used in fighting rivals or for displays. Some are of the opinion that it helps to amplify the make the bird's call and make it resonant.

The Malabar Pied Hornbill's casque is more than half of its beak in length and the posterior ends in black

The female bird can be easily differentiated from the male by the white region around the eye. In the male this region is completely black. The Malabar Pied Hornbill, like many other hornbills, are monogamous. They build their nests in the hollows of large tree-trunks. The female then imprisons herself inside the hollow by sealing the opening with a plaster that is mainly made up of mud, faeces and fruit pulp. During this time it is up to the male to feed her. This he does by passing food through a slit in the sealed opening. During incubation, the female undergoes a complete and simultaneous moult (shedding of existing feathers and growing new ones). Perhaps the old feathers serve as lining material for the nest by the time the chicks hatch (this is my surmise and it is gladly open to correction). When the chicks hatch and the nest cavity becomes too small to accommodate all of them, the mother breaks open the seal and emerges. She then starts assisting the male in feeding the chicks.

A female - The white around the eye is distinctive

A Male Malabar Pied Hornbill - The eye is surrounded by black

IUCN justifies classifying these birds as Near Threatened based on the extent of continuing habitat loss. Within a short span of just 16 years the bird has been moved to this category from the 'LC' (Least Concern) status. The felling of old-growth trees, which the birds require to nest and breed, impacts their ability to multiply as it takes several decades for young trees to attain a size that is conducive for the hornbills' nesting.

The sun started to set and we had to leave soon. I sat on a log and watched as a male hornbill clambered up a tree to its top to reach a female that was perched there. As he hopped from one branch to another, he did something very curious - he would bend his neck and look underneath every branch as if searching for something. He continued until he reached the female. Unfortunately, I couldn't understand the reason for this peculiar behaviour.

The male inspecting the underside of a branch

Once the male reached the female, the pair proceeded to groom each other and display several other courtship or bonding rituals. They clasped beaks and gripped each others' necks in their beaks.

The pair clasping beaks

As we watched the mutual grooming behaviour of the pair, Beej mused,"Isn't this a call for conservation in itself?" Unless the habitat that they require to sustain themselves in terms of food and nesting sites is maintained strictly, these birds might be lost to the next category of IUCN.

But there is hope. The sight of these birds moving about fearlessly and living in such close proximity to humans in the heart of a busy town proves that it is possible for man and bird to co-exist

Photograph of the Male Hornbill by Bijoy Venugopal

This post has been published as an 'Encounter Series' in The Green Ogre

An Encounter with Radial Symmetry

While walking along the Marakkanam beach close to Pondicherry, we came across something green and symmetrical, with radiating bands from a central hole at its top.

[Five white bands radiating from the centre can be seen]

We stumbled upon a couple names such as sea cucumbers, sea sponges etc. before we got the name right- Sea Urchins.

Sea Urchins are members of Echinodermata, which also constitute starfishes, sea cucumbers etc. Echinoderms are spiny-skinned invertebrates that live on the ocean floor. There are around 200 different species of recognized sea urchins in the world. Which species we saw, I'm not sure.

Adult sea urchins have five-fold radial symmetry with a chitinous skin or outer covering. They have spines that stick out from this shell, and these in some cases, are venomous.

[The purple coloured spines are clearly visible. When alive, the entire surface would have been covered with these]

Sea Urchins use their tubed feet for locomotion. With these they move around and feed on algae/seaweed(especially brown algae, also called kelp), small invertebrates etc. They tear up algae and plants using a special structure with teeth called the Aristotle's Lantern which is situated on the their underside. The larger opening on the underside is used for feeding and the smaller opening at the top is used to expel fecal matter.

[The picture shows the upper part and the underside of Sea Urchins]

Although many echinoderms reproduce asexually, sea urchins are dioecious(having separate male and female individuals. They participate in mass spawning in which many individual animals release their gametes(sperm and eggs) into the water and thereby fuse externally. This mass spawning increases the chances of fertilization.

In Japan, sea urchin roe(egg mass or spawn of crustaceans) is considered a delicacy. Sea urchins are also believed to be an aphrodisiac by certain cultures.

Other than humans, they have a few natural predators. While Sea urchins are preyed upon by marine inhabitants such as fish, sea otters etc., they in turn feed on algae, thereby maintaining a delicate balance between algal grazing and kelp forest productivity. In case this balance is tipped either way, entire reefs could be affected.

Photograph displaying upper part and underside of the sea urchin by Bijoy Venugopal.

References:

http://library.thinkquest.org

http://www.ehow.com/facts_5475717_sea-urchin-habitat.html

http://www.starfish.ch/reef/echinoderms.html#urchin

http://www.sciencemag.org/content/314/5801/940.full.pdf

http://science.jrank.org/pages/3752/Kelp-Forests-Sea-urchins-sea-otters-kelp.html

http://www.springerlink.com/content/hnnv43y6ehn6wc4j/

Metamorphosis at my doorstep

Somebody had planted it there, the Scarlet Milkweed. Didn’t give much thought about it. Noticed it only when it started having brightly coloured flowers garnished with vividly coloured caterpillars. These were the larvae of the Plain Tiger(Danaus chrysippus), a species of Danainae ("milkweed butterflies", which lay their eggs on various milkweeds, on which their larvae feed), a subfamily of the brush-footed butterly family, Nymphalidae.

Scarlet milkweed(Asclepias curassavica) also known as Bloodflower and Indian Root is native to South America but has spread across many parts of the globe. Its flowers attract many butterflies to its nectar. The plant’s sap is poisonous, which in turn is transferred to caterpillars, making them poisonous as well. The caterpillar of the plain tiger sports bright colours to serve as a warning to predators of its bad taste.

The adult plain tiger lays its eggs on the underside of leaves. The egg hatches after approximately five days and then the larval stage begins with the first instar of the caterpillar. Instars are stages between moulting. The skin of caterpillars, like insects don’t grow as the animal grows. So, in order to grow, the caterpillar moults (sheds old skin exposing new larger skin underneath) four times, moving from the first instar to the second, the second to the third, and so on till the fifth and final instar. During these moulting stages the caterpillar grows incredibly in size, as the only job of a caterpillar is to eat. It’s virtually an eating machine.

During the fifth and final instar, the caterpillar will look for a suitable spot to pupate (pupa is the third stage in a butterfly’s lifecycle). Once it locates the ideal spot, it hangs upside down, forms the shape of a ‘J’ and moults for the last time. The new skin underneath will form the chrysalis. Chrysalis is the pupa of a butterfly. It is a hard chitinous shell (Chitin is a tough, protective, semitransparent substance which forms the principal component of arthropod exoskeletons). The pupa may be green or brown if in natural surroundings or pink otherwise. Although it looks dormant, a lot happens within the pupa. This is the stage where the caterpillar transforms into an adult butterfly.

[A caterpillar in its final instar getting ready to moult one last time]

[The chrysalis or pupal stage of the butterfly]

After approximately two weeks as chrysalis, the butterfly emerges. The butterfly frees itself off the chrysalis and settles nearby to wait for the wings to gain shape and size. The wings of the butterfly are small and wet when it emerges. It then starts pumping fluids from its abdomen into the wings so that they expand to their actual size. While this is happening, a brownish liquid may be seen coming out from the butterfly, this is meconium (Meconium is waste product from the pupal stage that is expelled through the anal opening of the adult butterfly). After this the wings have to dry up and warm before the butterfly can exercise its flight muscles and take off. All this takes only a couple of hours.

[The meconium can be seen flowing down]

[The empty chrysalis can be clearly seen]

And, now that the plain tiger is in its last stage of life, its sole purpose is to seek a mate and breed. Although the Plain tiger had put on its best suit, the same cannot be said of the Milkweed. All that was left of the plant after the caterpillars had had their fill, were stems stripped off their leaves.

But milkweeds being hardy plants, no cause for worry. They would bounce back to their former glory in no time.

Flat Forest - The Abode of the Frogmouths

Thattekad Bird Sanctuary also known as Salim Ali Bird Sanctuary is located between branches of the Periyar river in Ernakulam district of Kerala. Salim Ali had done a survey at Thattekad in 1930 and described it as the richest bird habitat in the peninsula. He later recommended the Kerala Government to notify it as a sanctuary. In 1983, it was declared one.

The sanctuary covers around 25 sq kms of tropical semi-evergreen and tropical decudious low-land forests. Hence the name Thattekad(Thattekad literally translates to 'flat forest' in Malayalam). According to our guide, Sudeesh(a crackshot at spotting), excluding the settlements inside the forest, the sanctuary would have only 15 to 16 sq kms of actual forest cover. But thats the most intriguing part. Within this small area, reside over 250 species of birds! Now that's a density almost unheard of, in the south.

Our stay at Thattekad was short(1.5 days. Birds Spotted-77). The first day of birding started only by 8:30 in the morning. Sudeesh took us around through several estates that border the sanctuary. We still managed to spot quite a few species including the Ashy Woodswallows(Artamus fuscus) and the Mottled Wood Owl (Strix ocellata). Sudeesh took us to the tree where it usually roosts. The bird was so well camouflaged that it took me some to figure out where exactly the it was. Another raptor that we saw was the Crested serpent eagle(Spilornis cheela).

[A pair of Ashy Woodswallows]

[Crested Serpent Eagle]

At one of the estates, I saw a lizard steadily working its way up the trunk of a tree, all the while catching insects that it found on the bark. I paused for a second wondering if it could be the dragon that I've always longed to see. And the next second when it exposed its yellow gular pouch, I knew it was the dragon- Draco dussumieri or the Western Ghats Flying Lizard! And although I couldn't get a shot of it in flight, I did see it glide gracefully for a span of approximately 12 feet from one tree to the other. It landed on the trunk, very close to the base of the tree and started moving up in the same fashion as it had done with the previous tree.

[Western Ghats Flying Lizard. The skin membrane used for gliding is clearly visible]

Later in the evening we took a trail that was marked as the Salim Ali Nature Trail. This area was well wooded and we encountered quite a couple of species like the Emerald Dove(Chalcophaps indica), Eurasian Black Bird(Turdus merula) and the Malabar Trogon(Harpactes fasciatus) to name a few. It was also during this evening stroll that George(fellow birder) saw a Mouse deer(Moschiola meminna) run across the path just a few feet in front of him!

The next morning's birding session was the most productive with quite a lot of sightings. Around 7 O'clock, Sudeesh took us to a rocky outcrop near Kallipara that overlooks the core area of the sanctuary. This was an extremely good vantage point. All you had to do was select a suitable spot, sit and start watching. The birds were pretty good at running their show. Here we saw the Grey-headed bulbul(Pycnonotus priocephalus), Brown capped pygmy woodpecker(Dendrocopus nanus), Green Imperial pigeon(Ducula aenea) among many others. We also spotted a Malabar Giant Squirrel(Ratufa indica) resting in the canopy.

[The rock served as a good lookout point]

[A pair of Hill Mynas(Gracula religiosa) high in the canopy]

After spending a couple of hours there we proceeded to our final mission - to see the Srilankan Frogmouths(Batrachostomus moniliger). For this, Sudeesh took us to Urulanthanni. After alighting from the bus, he led us along the road and leaning on a very thin tree, turned around and said, "On this tree, there are three frogmouths". It took me a split second to decipher what he had said. My jaw dropped as I looked above. There, just three or four feet above where he stood, were a family of three Frogmouths huddled together!

[The highly camouflaged Frogmouth family]

The entire experience of the sanctuary even though for such a short while, was great. An important thing I noticed about Thattekad is the abscence of any kind of plastic waste. Nowhere on the trails that I took, did I find any sort of plastic or other garbage. The forest floor was filled only with dry leaves. The people whom i interacted with, the guide, cook, home-stay owner all seemed to be aware of and accept the the fact that the birds are the actual source of their livelihood. They knew the importance of protecting the birds and the environment that they live in. This is the kind of sense/spirit that local communities around a protected area should be helped to develop.

Photos of the river and Kallipara rocks by George Tom