That Reptile Blog – Reptile, Amphibian and Exotic Pet Care and Information

While working in a large tropical bird exhibit at the Bronx Zoo some years back, I was startled to come across tiny frogs hidden among the leaf litter.  I was able to identify them as Greenhouse frogs, Eleutherodactylus planirostris (an apt name, it turns out).  These 1.4 inch-long Cuban natives have been transported around the world, hidden among plants and soil.  Their eggs are laid on land, and the tadpole stage is passed within the egg, so the frogs readily establish themselves in greenhouses and other warm, humid habitats.  It always pays to (discretely) poke around in walk-through zoo exhibits and such places – you never know.

The greenhouse frog belongs to the family Eleutherodactylidea, which contains over 800 species.  Recent research at Pennsylvania State University revealed that all types currently found in Mexico, Central America and the Caribbean arrived there by rafting on vegetation over the open seas from South America, rather than across an ancient land bridge, as was previously assumed.  Apparently, individuals of a single species landed in Mexico, and others (again, 1 species) in Central America, and then each evolved into the large number of species found in these places today.

Another world traveler, the Flowerpot snake (or Brahminy blind snake), Ramphotphlops braminus, also utilizes a unique reproductive strategy to establish new populations in far-flung habitats.  All individuals of this species are female and reproduce via parthenogenesis, so only 1 animal is needed to start a colony.  I’ve had the good fortune of running into this odd creature, as well as “banana” spiders, rattlesnakes and others, in unexpected surroundings – more on that next time.

An informative article on this frog’s history in Florida, along with a photo, is posted at:

http://nis.gsmfc.org/nis_factsheet.php?toc_id=205

Growing up near the Bronx Zoo, I became fascinated by giant snakes early on, as these magnificent creatures were always featured prominently in my favorite building, the Reptile House.  So it was with great anticipation that, after some years as a reptile keeper for the zoo, I set off for Venezuela to assist in field studies of the green anaconda, arguably the world’s largest snake.

Accounts of what I observed and learned during three visits to that country’s central llanos area (seasonally flooded grasslands) would fill several books.  I would like here to just give you some facts and photos – in the future, I will highlight some of my experiences in longer articles.

Despite long-standing legends to the contrary, (and, recently, a plethora of internet photos) there is only one reasonably reliable account of a snake measuring over 30 feet in length (I’ll cover the details of this and related stories in the future).  In fact, the Bronx Zoo offered a cash reward, established, as legend has it, by Theodore Roosevelt, for a living snake in excess of 30 feet.  That reward, now withdrawn, stood uncollected for nearly 100 years (I was involved in the last attempt to collect it – please look for details in the future).

The snake you see pictured here was the largest that I and my colleagues encountered.  It measured just over 17 feet long and weighed 215 pounds.  As you can see from the close-up of my hand on its head, she (all anacondas
of this size are females) put up a quite vigorous battle when captured – indeed, one of her teeth remains imbedded in my wrist till this day as a reminder!  A number of the 500+ green anacondas that were marked during the study were in the 15 to 16 foot range.

I was fortunate to come upon quite a few anacondas in the process of feeding upon a wide array of animals, including capybara, caiman, jacanas and other birds, turtles and, most unforgettably, a deer of 60 pounds in weight.  Please look for future articles on the details of these most fascinating encounters.

The Venezuelan llanos, especially in the dry season, offers a wildlife-viewing extravaganza that is difficult to put into words.  Encounters with crab-eating foxes, freshwater dolphins, giant anteaters, armadillos, electric eels, caiman, scarlet ibis and countless other creatures large and small are all but guaranteed.  Cougars, jaguars, giant otters, tamandua, tree boas, tegus and a host of others are also a real possibility.  I am planning to write an article for people who might like it explore (and “exploration” it is, in the true sense of the word) this area – please look for it in the future.

You can learn more about the field research project I described in this article at:

Anaconda Expert Wades Barefoot in Venzuela’s Swamps

It is often difficult to determine what a snake will do in a particular situation, as their external cues are quite subtle. A great deal is going on behind those unblinking eyes, I can assure you, but most species give us little to go on. Not so, however, with the cobras – active, alert and intelligent, their behaviors are much more evident to us.

Among professional herpetologists, the king cobra has the reputation of having all the aforementioned cobra qualities in excess. This, combined with a length of up to 18 feet (it is the longest of the venomous snakes) renders the king cobra among the world’s most formidable animals.

Those I worked with at the Bronx and Staten Island Zoos invariably watched and reacted to each of my movements instantly, in almost “mammalian” fashion. The doors to snake exhibits are equipped with metal panes that can be slid open to reveal a small window, thus allowing the keeper a look inside. Nearly always, king cobras respond to the pane’s movement immediately by rearing up and peering back through the window – quite unnerving the first time it happens to one! No other snake has responded in this way in all my many years of working in zoos.

So it was with some trepidation that I responded to a call from an airport official who claimed that a “giant” cobra (escaped snakes are always “giants”!) had escaped from its shipping crate (I have agreed not to reveal the identity of the airport). Fortunately, the animal was contained with a small, relatively bare room. Armed with a pair of tongs and a garbage can lid, I entered, thoughts of Frank Buck’s similar story, related in his classic book “Bring ‘Em Back Alive,” bouncing about in my mind.

The snake, about 9 feet long, reared up in typical cobra fashion and, its head at my waist level, advanced. I have been in my share of tussles with wild animals, but the phrase “Discretion is the better part of valor” never rang truer. I backed out and asked for a secure box with a hole cut in one side. I pushed this into the room and, as I had hoped, the cobra darted inside – for once the species’ alertness working in my favor. The lack of cover in the room had strengthened its will to fight – provided with a way out, the snake retreated. I was able to secure it without incident.

A group of NYC police officers had gathered outside the room. The younger ones were quite disappointed that I had not leapt upon the snake and subdued it with a grasp to the neck. The oldest officer, the sergeant in charge, simply said “Thanks for sparing me a wild ride to the hospital and a ton of paperwork”!

One of my fondest “reptilian” memories is of snake hunting with famed herpetologist Romulus Whitaker.

Captive Breeding – my experience
The king cobra’s taste for other snakes complicates breeding efforts in zoos. During my years as a zoo keeper I experienced several successes and failures. I once housed a pair in adjoining exhibits, separated by a screen panel, for 3 months in order to gauge their reactions to each other. They seemed to get along well and, indeed, co-habited peacefully for several weeks. Always well fed, there were no signs of aggression. Unfortunately, however, there was also no sign of the female one morning – the 12 foot long male had swallowed all 8 feet of her – quite a feat even for a snake!

Working With King Cobras
Although rumored to be aggressive in nature, king cobras often (but not always!) flee when confronted by humans if given the opportunity. Captives are, however, extremely alert and seem, at least upon casual observation, to evince learning abilities not possessed by other snakes. I have always preferred to house them in exhibits equipped with shift cages, into which the snake may be secured before I entered the exhibit – they are just too fast to work with close at hand (my predecessors at the Bronx Zoo seemed to feel likewise – in an old storage area I came across an old wooden “cobra shield” – I like to think it may have been used by the eminent Raymond Ditmars, first reptile curator at the Bronx Zoo). When shifts are not available, I exercise extreme caution and, as with all venomous snakes, alert co-workers of my whereabouts.

King cobras are notorious escape artists, even for snakes, and the cause of much lost sleep in the zoo world. Some years ago a major zoo was closed down for 3 days while an escaped specimen was at large (it was, luckily, re-captured without incident). I’ll relate my own experience with 3 escaped spitting cobras in a future article.

Cobra Classification and Venom
King cobras and the 300 or so other members of the family Elapidae are known as “Proteroglyphous Snakes” – a term referring to the fact that their hollow, venom conducting teeth (fangs) are fixed in position and cannot be erected as can those of the vipers and their relatives (the Solenoglyphus Snakes).

Cobras inject venom by biting and employing a chewing motion, and cannot utilize the stab and release action of the vipers. The venom of most species is highly effective, and large specimens can deliver huge quantities of venom in a single bite. It is often said that an adult king cobra may carry enough venom to “kill a small elephant” – while that is difficult to quantify, a cobra of any species is a most dangerous animal.

Other Cobras and Their Relatives
Elapids reach their greatest diversity in Australia, dominating the snake fauna there. There are over 50 species in the Americas, with coral snakes being the only representatives found in the USA. Arboreal, aquatic and burrowing forms occur in Africa and Asia. Several African cobras can eject venom at the eyes of enemies (they hunt in usual cobra fashion), an adaptation to life in grasslands populated by large hoofed mammals. Sea snakes, kraits and mambas are related to cobras and also classified as Elapids.

The Cobras’ Hood
The defensive display of cobras involves rearing up and flaring out a wide hood of skin about the head and upper body. This is accomplished by raising a series of elongated ribs, which in turn stretch the skin between them to form the hood. A large king cobra may raise over 4 feet of its body from the ground when agitated – a most impressive (and convincing!) display.

Information concerning king cobras in India is posted at:
http://www.india-wildlife-tours.com/wild-animals-in-india/indian-wildlife-king-cobra.html

Physical Description
The king cobra is the world’s longest venomous snake, and may exceed 18 feet in length (average length is 12-15 feet).

Its color and pattern varies greatly across the huge range, with unique color morphs being distinctive of certain geographic areas: specimens from Southeast Asia are usually a uniform olive or yellowish-olive in color, while those originating in India tend to be olive with yellow bands and a black tail. Chinese specimens are often dark brown or black, and banded with white, brown or yellow.

Range and Habitat
This snake’s enormous range extends from northern India through Myanmar, Bangladesh and Cambodia to southeastern China (including Hong Kong and Hainan) and south through Laos, Thailand, Vietnam and much of Indonesia (Sumatra, Java, Borneo, Sulawesi) to western Malaysia and the Philippines.

King cobras occupy a wide variety of habitats but are usually found near a permanent water source. They occur in rainforests, dry forests, lightly wooded areas, overgrown fields, bamboo thickets, mangrove swamps, agricultural areas and along the outskirts of towns.

Status in the Wild
Not well studied. King cobras adapt to some disturbance and often frequent farms in search of other snakes (the favored prey) that are drawn there by rodents. Listed on Appendix II of CITES.

Diet
The king cobra feeds almost exclusively upon other snakes, although lizards are occasionally taken (the Greek-derived Genus name means “Snake-eater”). It hunts by day and actively searches for prey. Keen sighted and quick, king cobras are well-suited to pursuing fast-moving snakes.

In zoos, hatchlings and wild-caught adults often refuse all but snakes as food. Reptile keepers resolve this problem by “scenting” mice and rats (the snakes thrive on a rodent-based diet) with dead snakes that are kept frozen for this purpose. Usually, rubbing a snake on the rodent does the trick. Particularly choosy cobras sometimes force us to become resourceful – boiling a piece of an expired snake in water and soaking the rodent therein is the standard method used in these cases. Most king cobras can eventually be weaned onto a diet of non-scented rodents.

“Scenting” is used to induce other serpentine food specialists to accept alien food items as well. Eastern hog nosed snakes, Heterodon platirhinos, for example, are confirmed toad-eaters but eagerly take toad-scented mice.

Reproduction
King cobras are the only snakes known to construct a nest for their eggs. Using loops of her body, the female scrapes together a pile of rotting leaves and other vegetation, into which the eggs are deposited. Some construct a two-chambered nest, with the upper chamber serving as retreat for the female, while others merely coil on top of the leaf pile.

The female guards her 20-60 eggs for the 60-80 day incubation period. There is some evidence of mate fidelity that the male may also remain in the vicinity of the nest, but this has not been accurately documented.

The hatchlings are 18-22 inches in length and differ markedly from the adults, being boldly striped in black and white.