Horned Lizards

 Central America, Deserts, North America, Reptiles  Comments Off on Horned Lizards
Jan 102010
photo provided courtesy of soulsurvivor08 on Flickr Creative CommonsHomeSouthern North America, Central America
Favorite Foodants
Length6 inches or less
StatusSome Species Threatened
Threatshabitat destruction, pesticides, invasive ant species

Of all the animals that can scrape out a living in the world’s deserts, lizards are among the most adapted to such harsh environments. Their hard scales provide a barrier against water loss and the abrasiveness of wind and sand. They obtain most of their water from their diverse diets and can survive long stretches of time without food. Horned lizards are among the most successful group of desert reptiles and comprise 14 different species of lizards that live in the arid regions of North and Central America.

As their name implies, horned lizards have a number of spiked projections on their head, body, and tail. In addition to their flattened, toad-like bodies, horned lizards are often referred to as horned toads or horny toads. The horns are used in courtship displays and also act as a defense against predators. However, it’s their rough, mottled skin blending seamlessly with their rocky surroundings that affords them the best protection. As long as the lizard remains still, it is virtually invisible to most predators. Some horned lizards possess more specialized defenses, like shooting blood from the eyes to confuse and frighten predators.

One of the most pressing issues of life in the desert is regulating body temperature. Like all reptiles, horned lizards are at the mercy of their surroundings when it comes to their internal heat. In order to maintain optimal temperature in the desert land of extremes, horned lizards will burrow into the sand or soil to avoid the murderous midday sun and cold temperatures at night. As the morning sun creeps over the horizon, they will raise their heads out of their burrow in order to first warm their brains. As soon as all systems are operational in the nervous system, horned lizards will then remove the rest of their bodies from the sand and begin their daily routines of basking in the sun and searching for ants to gobble up.

photo provided courtesy of Ben Goodwyn on Flickr Creative CommonsHorned lizards are still common across the deserts of the Southwestern United States and Mexico. Since they live in an environment that is inhospitable to man, they have been spared much of the trouble that has befallen many of their lizard relatives in other regions of the world. However, human development in arid regions still poses a looming threat.

The Plumed Basilisk

 Central America, Reptiles, Tropical Forests  Comments Off on The Plumed Basilisk
Jan 092010
photo provided courtesy of wwarby on Flickr Creative CommonsHomeCentral America
Habitattropical forest
NicheArboreal omnivore
Favorite Foodanything it can fit in its mouth
Lengthup to 30 inches
Weighta few pounds
StatusLocally Common
Threatshabitat destruction

When it comes to walking on water, there are a few animals that carry on the miracle’s legacy. One is the plumed basilisk, a bright green lizard of Central America that grows to over two feet in length. Because of their unique ability to evade predators by traversing the surface of a pool of water, these tropical reptiles have earned the nickname “Jesus Christ lizard.”

The secret to the Jesus walk is in the plumed basilisk’s feet. The lizard will slap the water with a hind foot with enough force to create a pocket of air between the foot and the surrounding water. Then, with lightning speed, it will pull the foot up before the air pocket fills with water. Using this method, the plumed basilisk can scamper across the surface of several feet of water in order to evade predators that can’t follow.

Basilisks are the ultimate omnivores in the tropical forests of Central America, feeding on insects, small mammals, birds, amphibians, and even certain flowers and fruits. They are active by night and day in tree branches, waiting for prey to come within range. These lizards choose their perches over water so that they can drop in and escape if the need arises. In addition to their ability to run across the surface, plumed basilisks are also excellent swimmers. The raised crests on the head, back, and tail allow propulsion through the water for a quick getaway.

Male plumed basilisks are fiercely territorial during the mating season and will defend their turf with gusto if challenged by another male. The dominant males earn the right to mate with several females in their range, increasing the chance their genes will be passed on to the next generation. Females will lay a clutch of around 20 eggs several weeks after mating. As with all reptiles, the chance of youngsters reaching adulthood is low due to predation, so laying many eggs increases the chance that at least one will survive.

Plumed basilisks are still common in the forests of Central America due to their adaptability and unspecialized diet. However, they can’t live without trees, and as logging continues to clear habitat in the land bridge between the Americas, the Jesus Christ lizard might find that its tricks are not enough to overcome.

The Boomslang

 Africa, Grasslands, Reptiles, Tropical Forests  Comments Off on The Boomslang
Dec 302009
photo provided courtesy of wwarby on Flickr Creative CommonsHomeSub-Saharan Africa
Nichearboreal predator
Favorite Foodchameleons
Body Lengthbetween 4 and 6 feet

One of Africa’s deadliest snakes doesn’t lurk in rock crevices or along the ground. Instead, the venomous boomslang spends most of its time in trees, slinking along the leaves in search of dinner. In fact, the word “boom” is Dutch for tree. Although it has no limbs, it propels its muscular body with ease over branches and can anchor itself with its tail when ambushing small animals, especially chameleons. Living nearly everywhere in Africa south of the Sahara Desert, these are among the most successful snakes on earth.

Boomslangs belong to the largest group in the snake family, the colubrids. Members of this group have very flexible skulls, allowing them to tackle prey much larger than their head. Although they have fangs, boomslangs don’t chew their food. Instead, they use specialized teeth in their throat to pull their paralyzed prey into their gullet, whole. Like other snakes, the boomslang has a specialized sensory organ called the Jacobson’s organ, allowing it to detect smells gathered from the air on its tongue. This remarkable organ lets them to “smell through” the main defense of chameleons, their ability to blend in visually with their surroundings. If the boomslang gets close enough, it can detect exactly where the chameleon is sitting by smelling the air around it.

Boomslangs are deadly because of the venom they deliver through their fangs. It belongs to a family of poisons called hemotoxins, attacking the blood and causing internal bleeding in the victim. The venom is so powerful that it is potentially deadly to humans, and deaths from boomslang strikes are reported yearly in many regions of Africa. But like most snakes, boomslangs do not generally attack people unprovoked. Usually they strike out of self-defense when threatened or cornered.

The Rhinoceros Iguana

 North America, Reptiles, Tropical Forests  Comments Off on The Rhinoceros Iguana
Dec 302009
Photo provided courtesy of Silvain de Munck on Flickr Creative CommonsHomeCarribean
Habitatdry rocky ground with cacti
Nichelarge herbivore
Favorite Foodleaves and berries
Body Lengthbetween 3 and 4 feet
Weight10 to 20 pounds
StatusVulnerable to Extinction
ThreatsHabitat loss, competition from invasive species

The rhinoceros iguana is a massive lizard, weighing as much as a beagle and rivaling the length a German shepherd from nose to tail tip. It gets its name from its mottled gray skin and protruding scales on its nose that resembles a rhino’s horn. Although they look ferocious, these iguanas are vegetarian.  They subsist exclusively on tender leaves and fruit from low-hanging shrubs in the rocky interior of the island of Hispaniola and immediate Caribbean. More often than not, these shy iguanas will bolt away from danger at high speed and seek refuge in hiding. However, it’s unwise to corner a startled rhinoceros iguana, for it can deliver a powerful bite and will strike out repeatedly with its muscular tail.

Females lack the large nose “horns” and domed helmet of the males, who are fiercely territorial during the mating season and will attack intruders to drive them from their territory and assert dominance. After mating, the female will lay between 10 and two dozen eggs that she will guard with her life in a small burrow. After three months, the eggs will hatch and the youngsters will be left by the mother to fend for themselves in a dangerous world. Few will be lucky enough to reach adulthood.

photo provided courtesy of Anubis333 on Flickr Creative CommonsDespite their formidable size and strength, rhinoceros iguanas are now vulnerable to extinction. Like many animal species native to islands, these iguanas are threatened by invasive species brought by colonial ships centuries ago. Predation and competition for food from pigs, dogs, rats, and cats have cut the numbers of wild rhinoceros iguanas significantly. Habitat destruction in the fragile economies of Haiti and the Dominican Republic has also driven this monster lizard from much of its former range. Its future is in doubt.

The Blue Tongued Skink

 Australia, Grasslands, Reptiles  Comments Off on The Blue Tongued Skink
Nov 062009
photo provided courtesy of wwarby on Flickr Creative CommonsHomeNortheast and Southeast Australia
Habitatvaried: coastal woodlands, grasslands
Nichesmall opportunistic predator
Favorite Foodinsects
Lengthup to 20 inches
Weighta few pounds

Imagine you’re a small predator looking for a meal. After some time prowling the dusky landscape of northern Australia, you spy a sluggish lizard basking in the sun. You observe from a distance that it moves slowly and clumsily even in the heat of midday. Deciding that it will be your next meal, you move in. As you move within striking distance, something unexpected happens. All of a sudden, the reptile you took for an easy meals puffs up and opens its mouth wide, hissing as it flicks out a monstrous-looking blue tongue. You run.

At first glance, the blue tongued skink doesn’t seem like anything special. In fact, due to its coloration and sluggish nature, it’s often mistaken for a fallen tree branch in the coastal woodlands and interior grasslands of Australia where it lives. It’s a locally common reptile in Australia and feeds on a variety of insects, slugs, and snails, with the occasional berry or flower. It’s also been known to scavenge at picnic sites for tasty scraps left over from human visitors. Active by day, it will seek refuge under debris or inside logs as shelter from the cold night.

The blue tongued skink has a large triangular head, and a long, heavily-built body. It’s big for a skink, with adults measuring between 14 and 22 inches. But it’s not size that makes the blue tongued skink so special. As its name implies, it has a striking, blade-like blue tongue that the animal uses to frighten away threats. For most would-be predators, the mere sight of bright blue is enough to deter an attack. In the animal kingdom, bright colors often signify that an animal is venomous, or at the very least, dangerous. However, behind all the bluster, the blue tongued skink is mostly harmless. If cornered, it can deliver a powerful bite to a person, but its tiny dull teeth are unlikely to break the skin. Like other skinks, its tail is one of its main defenses against predators. If its blue tongue fails to frighten away a carnivore and it manages to bite the skink’s tail, it will break off, allowing an escape. The tail will grow back in a matter of weeks.

Mating is serious business for the skinks and the males are territorial, defending their turf and prospective mates against other males. Courtship involves a brief chase and a love bite delivered by the male on the back of the female’s head. 150 days after mating, the female will give birth. Blue tongued skinks don’t lay eggs, but rather give birth to a litter of between 5 to 25 live young. If they’re fortunate enough to survive the trials of growing up in the forbidding Australian wilderness, they’ll reach maturity in about 3 years. Blue tongued skinks have relatively long lifespans and in captivity have reached 25 years of age.

Although behind its characteristic feature, the blue tongued skink might just seem like just another chunky lizard, it’s yet another striking example of the wild diversity of reptiles in Australia, and on planet earth.