Thursday, August 12, 2010

The Jeweled Lizard

Each monsoon season brings the marvelous Gila Monster out of its underground burrow in search of protein, usually bird or reptile eggs. Here in Portal near the eastern edge of its range, the beast is rather rare––or at least seen only occasionally. It was an exciting moment when Helen Snyder investigated the reason her dog was barking so emphatically. A phone call later, and several of us are braving the gnats to photograph this beautiful lizard before he decides to retreat.

Gila Monster in noble profile (Photos by Narca)

Gila Monsters are living fossils, little changed over a span of more than 10,000 years. Although their movements are usually sluggish, their potent venom generally protects them from predators. Gila Monsters can't inject venom the way snakes do; they have to release it by chewing. Once a Gila Monster grabs hold, its very powerful jaws are almost impossible to dislodge without killing the animal.

A herpetologist professor of mine once said that anyone bitten by a Gila Monster deserved it, because the victim had to have been harassing the lizard! This sentiment is echoed by Dr. Ward in the Arizona Graphic, 1899: "I have never been called to attend a case of Gila Monster bite, and I don't want to be. I think a man who is fool enough to get bitten by a Gila Monster ought to die. The creature is so sluggish and slow of movement that the victim of its bite is compelled to help largely in order to get bitten." There are actually no confirmed cases of humans being killed by a Gila Monster bite, although the bite is painful and the venom neurotoxic. The venom has been extensively studied, and one of the active peptides may inhibit tumor growth in lung cancer! Another substance based on Gila Monster saliva is effective in helping diabetics.

Tasting the air with a dark blue tongue

The beautiful lizard with its beaded scales exerts a strong fascination. Gila Monsters spend about 95% of their time underground. During mating season––May and June––males search for females by scent, using receptors in those flat, blue tongues. Female choice rules: if she rejects the male's advances, he'll get bitten for his troubles. Females lay up to a dozen eggs in July or August, and the young hatchlings emerge the following spring. They are fully venomous upon hatching. They are thought to live up to 20 years in the wild.

These are protected animals, the first venomous creature to receive legal protection, more than a half-century ago. A good telephoto lens is needed to get closeup photos without harassing them.




On my way to see the cause of the dog's frenzy, another Gila Monster crossed the road in front of the car––a very small, colorful individual. Yes, it is indeed monsoon season!

2 comments:

  1. WOW!! What a gorgeous animal! And to see one in Portal! Nice. We just spent 5 day in and around Portal and managed to see some great herps (and mammals), but a gila would be the holy grail. We've only seen one once at Saguaro National Park over 10 years ago. Great animal and great shots.

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  2. WOW!! What a gorgeous animal! And to see one in Portal! Nice. We just spent 5 day in and around Portal and managed to see some great herps (and mammals), but a gila would be the holy grail. We've only seen one once at Saguaro National Park over 10 years ago. Great animal and great shots.

    ReplyDelete