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

Few amphibians exhibit a more dramatic change in appearance than male Crested Newts in breeding condition.  It really is something to see and, fortunately, breeding this species is actually quite feasible.  Breeding the crested newt in captivity also has great conservation value, as this species is in decline throughout Europe.  Furthermore, any information garnered is applicable to other species of concern, including the Alpine Newt, Triturus alpestris and the Swiss Newt, T. helveticus.

Natural History

The Crested Newt, which may reach 6.4 inches in length, is grayish to black above and orange with round black spots below.   

Living a largely terrestrial existence for most of the year, both sexes enter breeding ponds in late winter or early spring.  At this point, the males’ colors intensify and a large, comb-like dorsal crest develops. In both sexes the tail also becomes more paddle-like to facilitate swimming. Males also usually develop a white line along the sides of the tail, while reproductively active females sport a white line down the back.

Bringing Newts into Breeding Condition

While breeding may occur spontaneously in captivity, the most consistent results will be obtained if the newts are over-wintered at 36-42 F.  An increase in water depth may stimulate breeding outside of the normal cycle, but fewer viable eggs will be produced).

Upon emergence from hibernation, the newts should be housed in aquarium, or their terrestrial terrarium should be modified to provide a large water area. Resting sites such as cork bark slabs or basking platforms should be provided.

Due to their unique egg-laying behavior (females fold a plant leaf around each egg), crested newts slated for breeding are best housed in well-lit aquariums stocked with live plants.  The water should, if possible, be maintained at 54-65 F (a cool basement or garage often proves ideal).

We’ll take a look at raising the larvae next week. 

Despite – or perhaps because of – its immense size, impressive armament of teeth and scarcity, the spectacular Crocodile Monitor Lizard (Varanus salvadorii) is often considered the crown jewel of private and public monitor collections.

I became acquainted with these formidable giants when they were first imported into the USA, and have cared for several at the Bronx and Staten Island Zoos.  Their husbandry is straightforward, but little is known about their lives in the wild.  Today I would like to summarize what we do know; please see the article referenced below for notes on captive care.

Description

Crocodile Monitors approach 9 feet in length – nearly as long as the famed Komodo Dragon, but less stoutly built.  There are recurring but unverified reports of much longer individuals.

The Crocodile Monitor’s prehensile tail often exceeds 5 feet in length.  The body is dark gray to black in color and marked with yellow spots, making for quite a spectacular appearance.  The snout area, especially in mature males, is large and bulbous.

Crocodile Monitors are unusually large for canopy dwelling lizards…the 3 foot long black tree monitor is far more typical.  However, aided by slender bodies, long claws and prehensile tails, they are very agile climbers.

Their teeth are unique among monitors, being serrated and over-lapping – possibly an adaptation for carrying large prey high above the forest floor.

Range and Habitat

Crocodile Monitors are found only in southern New Guinea.  Highly arboreal, they seem restricted to the canopies of mangrove swamps and lowland forests along rivers.

Status

Little studied due to the inaccessibility of their habitat, the Crocodile Monitor’s limited range renders it a conservation concern.  Listed on CITES Appendix II.

Reproduction

Females lay 6-12 eggs at a time, and up to 3 clutches per year in captivity (multiple clutches may be a function of food availability), with arboreal nest sites being favored.  In common with other tree-dwelling monitors, they likely deposit eggs in tree hollows and similar sites above ground in the wild.

Diet

Their natural diet has been little studied, but probably includes nearly any animal that can be overpowered.  Likely candidates would be cuscus, tree kangaroos, naked-tailed rats, bandicoots, possums, bats, birds, frogs, snakes, lizards, invertebrates and carrion.

An Undiscovered Giant in New Guinea?

Long a creature of legend, the Crocodile Monitor is the source of rumors alleging “Papuan Dragons” of 20 feet in length.  This specie’s habitat is inaccessible and barely explored….I like to believe that it or an as yet un-described monitor may indeed reach such lengths.

A Calculating Reptile

Like all Varanids, Crocodile Monitors are highly intelligent.  One huge adult that escaped its enclosure at the Bronx Zoo wedged himself behind a cage while attempting to hide from myself and a co-worker.  As we moved into position to flush him, he very deliberately peered around first one and then the other side of his hideout, trying to keep us both in sight.  When we backed off, he followed our progress, again changing position periodically to ascertain where we were.

The lizard remained stationary while we were near, and only ran when we gave him some space.  When he did move, the old fellow made unerringly for a more secure retreat that he had obviously “decided upon” while in hiding.

Further Reading

Please see my article Monitor Lizards: an Overview for information about the captive care of this and related species.

A comprehensive field report on the crocodile monitor’s habitat is posted here.

 

Crocodile Monitor image referenced from wikipedia and originally posted by Ltshears

Our favorite animals’ own holiday, Reptile Awareness Day (RAD), will soon be upon us. On Wednesday, October 21st, herp enthusiasts can participate by doing something special for reptiles – educate someone about reptiles, clean up a reptile habitat, do something special for your pet, make a donation to a conservation organization…the possibilities are endless.

The Bronx River as Herp Habitat?

I’ve been involved in a few such endeavors over the years. One of the most gratifying was in conjunction with Bronx River Restoration. Neighborhood children were recruited to help remove debris that had accumulated along that part of the Bronx River that passes through the Bronx Zoo. A surprising array of reptiles and amphibians (i.e. snapping, painted and musk turtles, green and bull frogs, dusky salamanders) live along the river, but they need a hand on occasion.

We also trimmed overgrown banks to let in sunlight and improve basking opportunities for resident Eastern painted turtles and added tree stumps to the shallows. On return visits to the river, the children were happy to see both turtles and water snakes utilizing the new basking spots.

Water Snakes in NYC

Another surprisingly effective project that I enjoyed was the reintroduction of northern water snakes to the banks of the Bronx River and nearby ponds. Working on conjunction with several wildlife agencies, I collected water snakes from approved areas and released several gravid females. I also held back a few animals for captive breeding, and released the young (1 huge female gave birth to 89 live young, a near record!).

I’m delighted to report that the water snakes are breeding in their new habitat. If this can be accomplished in the center of the country’s most densely populated city, just imagine the potential that exists elsewhere!

Please Note: Reintroduction programs must be carefully researched and approved by your state Fish and Wildlife Agency.

Have Fun, Help Reptiles and Win Prizes!

Forgotten Friend Reptile Sanctuary, a reptile rescue and education organization located in Elizabethtown, PA, is sponsoring a contest in support of Reptile Awareness Day (RAD). So lending a hand to reptiles will not only feel good…it may just earn you some great prizes as well (Including a $50 gift card from That Fish Place/That Pet Place)!

To enter, simply post a note describing your “reptile friendly” good deed on Forgotten Friend’s site.

Radio Broadcasts

Anyone in the Central Pennsylvania area should be sure to tune in to the morning shows at FM 97 or WJTL FM 90.3 on October 21st – Forgotten Friend Reptile Sanctuary representatives will discuss their important work and suggest ways that we can help to make the world a better place for our reptile friends.

Amphibian Awareness Day?

We don’t have an Amphibian Awareness Day yet, but please don’t forget that frogs, salamanders and caecilians also need a hand. As you can see from the photo, even the youngest herpetologists among us can express real tenderness towards small creatures (the sturdy little fellow pictured here usually goes through life like a bulldozer!). Children are the conservationists of the future – include them in your hobby if at all possible.

 

Today we’ll take another look at those oddest of lizards, the chameleons (Family Chamaeleonidae), followed by some tips on the care of the Senegal Chameleon (Chamaeleo senegalensis).

Eyes

The cone shaped torrents that enclose the chameleon’s eyes are actually made up of fused, overlapping sets of eye lids.  By covering all but the eye’s pupil, they offer excellent protection to this most important organ.

Chameleon eyes contain far more visual cells than do our own, and can be rotated 180 degrees.  Uniquely among all animals, the eyes can focus either independently (on different objects) or together.

Vision, Learning and Hunting Accuracy

When a chameleon focuses both eyes on an insect, it hits its target 9 out of 10 times.  In laboratory situations, accuracy falls to 0 when 1 eye is covered.  However, by the second day hunting accuracy rises to 20%.  On day 4, the one-eyed hunters successfully capture insects on 50% of their attempts.

Senses of Hearing and Smell

Chameleons do not hear well …like snakes, they detect air vibrations and low-pitched sounds only.

The Jacobsen’s organ, which allows many other reptiles to “smell” chemical particles in the air, is vestigial (much reduced) in chameleons.  It is therefore assumed that they do not detect most odors.

Distribution

Madagascar is the center of chameleon diversity, with over 75 species, many endemic, living there.  Neighboring Africa, despite being vastly larger, boasts only 100 or so species.  Only 2 species make their homes in the Middle East, 2 in Europe and 2 in India and Sri Lanka.

At least 2 species of chameleon have established feral populations in foreign habitats.  The veiled chameleon (Chamaeleo calyptratus) thrives in Florida, Hawaii and Mexico, while the Jackson’s chameleon (C. jacksonii) has been breeding on Hawaii since the 1970’s and has recently been discovered in California.

The Senegal Chameleon, Chamaeleo senegalensis

Hailing from tropical West Africa (Senegal to Cameroon), this dark-spotted, tan to olive chameleon inhabits brushy savannas and forest edges.  Often abundant and easy to collect, it has long been a pet trade staple.

Some Cautions

Despite its long history in captivity, the Senegal does not breed regularly, and presents some problems as a pet.  Wild caught specimens should be avoided, as they are usually heavily parasitized and afflicted with stress related ailments.

Captive Environment

Senegal Chameleons need quite, heavily planted screen cages or an outdoor aviary , abundant UVB radiation and should be kept well-hydrated via frequent spraying or the use of a mister.  An ambient temperature of 76F with a basking site of 85F and a nighttime dip to 69-70F suits them well.

Breeding

If you are lucky enough to obtain a breeding pair, you’ll have your hands full…healthy females may lay 20-70 eggs at a time, twice each year!  Incubation time averages 6 months at 77 F, and sexual maturity may be reached by 5 months of age.

The Smooth Chameleon

The range of East Africa’s Smooth Chameleon overlaps that of the Senegal in Cameroon.  Formerly classified as a subspecies, the smooth chameleon has now been given full species status as Chamaeleo laevigata.

Male Chameleon in Madagascar image referenced from wikipedia and originally posted by Mbz1
Veiled Chameleon in Madagascar image referenced from wikipedia and originally posted by Billybizkit

Please see Part I of this article to learn about the natural history of the Panamanian Golden Frog , Atelopus zeteki, including it’s unique mode of communication.

Status of Wild Populations

Panamanian Golden Frog numbers are plummeting, most likely due to an epidemic of the largely incurable fungal infection

Chitridiomycosis. The fungus responsible, Batrachochytrium dendrobatidis, has been implicated in the declines and extinctions of numerous amphibian species worldwide. This frog is also threatened by deforestation, stream siltation, pollution and collection for use as a promotional tool in Panama’s restaurant, hotel and tourism industries (this practice is illegal, but enforcement is often lax).

It is estimated that Golden Frog populations have declined by 80% in both numbers and extent of occurrence over a 10 year period. At least 2 distinct populations are extinct, with 1 such extinction occurring within the span of several months. Golden Frogs are designated as “Critically Endangered” by the IUCN and listed on Appendix I of CITES. They are legally protected by Panama and the subject of a cooperative rescue program, administered by the USA and the Republic of Panama, known as “Project Golden Frog”. Fortunately, the Golden Frog breeds well in captivity.

Unique Skin Toxins

This frog’s skin contains extremely virulent nerve toxins that differ from those produced by other amphibians. Known as “zetekitoxins”, the poison contained in the skin of a single 2-inch-long frog is sufficient to kill 1,200 mice! It is believed that these toxins are produced in association with symbiotic bacteria, but this has not yet been definitively documented.

Cultural Significance

The Panamanian Golden Frog is the national animal of the Republic of Panama, and has traditionally been associated with matters relating to good fortune. Pre-Columbian indigenous people molded its likeness in gold and clay talismans known as “huaces”.

Further Reading

You can learn more about Project Golden Frog by clicking here.