Gila monster sightings are rare. One reason is because these huge lizards spend up to 98% of their time below ground. But urban sprawl has also affected their numbers. They are listed as near threatened and are protected by state laws in Arizona and Nevada.
I have observed Gila monsters only four times in Tucson over the past 15 years. The
last time was at Sabino Canyon in July 2008 while it was raining.
My son and I were delighted to see this Gila Monster (Heloderma suspectum) the other morning just outside of DeGrazia's
Gallery in the Sun. It was about a foot and a half long.
Most Gila monsters are camera shy. The creature did move away from us at first, swinging its head from side to side as it lumbered along. We only briefly saw its black forked tongue.
But then it apparently settled into a comfort zone in the shade where it stayed for at least an hour.
Gila monsters are the largest lizards in the US, and one of only two known venomous lizards in the world. Their venom is as toxic as that of rattlesnakes, but in such small amounts to rarely be fatal to humans. The bite does hurt though, because the lizard clamps on and chews the venom into the victim. If harassed, Gila monsters will gape and hiss before striking. Here's a
sound clip of a hissing Gila monster from the Desert Museum.
Since they are slow moving, Gila monsters mostly eat helpless prey such as bird and reptile eggs or newborn rodents. They store fat in their tails and only need to eat five to ten times per year. Females lay eggs in the summer and the eggs incubate over the winter until the next year. Hatchlings are venomous and can bite.
There have been many legends regarding Gila monsters, for example that their breath can kill a man. But there actually is a drug for type 2 diabetes made from a synthetic form of a protein derived from Gila monster saliva.
Gila monster scales appear in shades of either pink, orange or yellow combined with black into intricate patterns. The designs remind me of Native American art.
The beadlike scales are bony plates called
osteoderms. Gila monsters are regarded as living fossils as osteoderms of that species from the Pleistocene period have been found. Check out the bumps on the skull pictured below:
Even though they are found in the desert, Gila monsters don't seem to care for arid weather. That might be why they mostly stay underground. They have been observed swimming and wading in the creek and a neighbor reported finding one alive in a swimming pool.
We shared this Sonoran Desert treasure with some other visitors at the gallery and a hummingbird seemed curious about the Gila monster as well. I doubt that I will ever have another opportunity to capture both a hummer and a monster in the same picture. But nature is full of surprises! No matter where in the world one lives, there are all sorts of natural wonders to discover, often just outside the door.
Sorry about the blurry photo below. I wanted to catch this male in action, showing off his expanded throat dewlap and blue belly patches as he was doing push-ups. Lizards do push-ups mainly to display strength. I found a very short YouTube clip of a lizard doing push-ups. It looks like it's on our backyard wall, but it's someone else's.
Here is a pair of male and female spiny lizards. The head of the female sometimes turns orange during breeding season, like this one:
Besides basking on top of rocks, these lizards also like to hang out on walls and tree trunks, with head pointing towards the ground, ready to seek shelter.
Like most lizards, Desert Spinies are peaceful creatures, harmless to humans unless picked up. I like having lizards around the yard. Besides being fun to watch, they eat insects that are considered pests.
