Tag Archive: lizard


New Discovery: Your Dinner

New lizard

Lizard dinner. Image by Dr. Lee Grismer.

New to science, this lizard managed to escape “discovery,” despite being on the menu in diners in southern Vietnam. They found that this is another reptile that produces asexually-the females (and only females) all clone themselves. Read about the discovery here.

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Western fence lizard

A western fence lizard perched on my hand. Image taken in the San Francisco Bay Area.

If you enjoy hiking and live on the west coast of the United States, chances are you have come across this little lizard. This is a western fence lizard, which is also known as a “blue belly.” Blue belly is a good nickname for this lizard because…well, look:

Western fence lizard belly

A western fence lizard showing why they have earned the nickname "blue bellies." Image taken in the San Francisco Bay Area.

They do actually have blue bellies. The males are generally more blue than the females and will flatten to flash their blue when potential mates approach. When they are mating, some of the brownish scales will also turn bright blue. The only problem with the nickname blue belly is that there are a few species of lizard that have blue bellies, so it can get confusing.

Anyway, both female and male western fence lizards create a territory and they return to the same area year after year to reclaim it. This happens in the spring, which is a really good time to stop and watch them; this is when a lot of their interesting behaviors happen. While establishing their territory, they’ll posture and mark the area with chemical cues. Breeding males with do push-ups to try and attract females. If they succeed, they’ll bite the female’s neck and mate with her. If the female changes her mind however, she’ll flip over and use all four feet to kick the male off of her.

But aside from being entertaining, these little lizards that you see running around all of the time also provide a wonderful service for hikers, in what is probably the coolest animal fact I have uncovered since the photosynthesizing sea slug. Here’s what it does:

A tick on western fence lizard

A tick feeding on a western fence lizard. Image taken in the San Francisco Bay Area.

That lump on its neck is a tick. (Notice the lizard in the second picture has two, one on each side) The western black-legged tick is the main vector of Lyme disease for humans in our area. However, the blood of a western fence lizard has a protein in it that kills the bacteria that causes Lyme disease. If one of these ticks feasts on a western fence lizard, it becomes “disinfected.” If it had the offending bacteria, it no longer does and can no longer cause disease in humans! What’s more, these ticks, especially the nymphs, love to feast on fence lizards. The overall result? In areas that are not lucky enough to have these lizards around, about half of these ticks carry the Lyme disease causing bacteria. Where there are western fence lizards, that percentage drops to between 1 and 5%. Even if we get bitten by the right species of tick, the likelihood of getting the disease is really low.

When I find out about something as unlikely as this, it always reminds me that we are a part of an overall balance and cannot possibly know the effects of removing one species from it. So many factors like this crisscross in ways we have yet to uncover. Before the late ’90s, when this was discovered, who would have guessed that if the western fence lizards were to disappear, we could face an increase in cases of Lyme disease? Or that their blood would have a Lyme disease-bacteria-killing protein in it? And how awesome is that!

Anyway, thank you western fence lizard; your sacrifice is much appreciated.

Lagarto

Che Lagarto

Che Lagarto Hostel sign. Image taken in Santiago, Chile.

Lagarto is the spanish translation for the word lizard. The word alligator came from the word lagarto, because they look sort of like giant lizards. However, alligators and lizards are not even closely related. In fact alligators are more closely related to birds than they are to lizards or snakes. This was a pretty cool hostel, BTW and they have a few locations throughout South America.

Bearded Dragon, Duke

A bearded dragon, Duke, enjoys the warm sun. Image taken at the San Francisco Zoo.

These friendly little lizards have an awesome temperament. It’s rare that I would recommend a herp as a pet, but if you can take care of them these lovely lizards are really fun to just hang out with, hence the title, lounge lizards.

This particular lizard shown above is Duke and he was the most awesome-est bearded dragon ever. My most memorable moment with him was when I was holding him for an “open house” at the San Francisco Zoo and he suddenly started to get squirmy, which was unusual for him. The guitarist from Green Day was enjoying our open house and he and some other folks came up to touch Duke and that was when Duke pooped in my hand. He did try to warn me first. Duke passed away not too long ago, and I really miss him. So this post is dedicated to my lost lizard friend, Duke.

Like many animals, bearded dragons have a plethora of ways to protect themselves from predators. The first is of course camouflage. Their coloration helps them to blend in, but it is also worth noting that their color changes for various reasons, including temperature control, as they get darker when they need to absorb more heat and lighter when they need to reflect heat. (And here we are wasting precious calories making our own heat! Ha!) If a beardie is spotted, the next thing it’ll do is try to intimidate a potential predator by puffing out the extra skin around its throat to make a big black beard and to make their soft spikes stick up to look sharp and threatening. If the predator is not fooled, the lizard still won’t give up- instead it’ll high-tail it out of there by getting up on its two hind legs and running. And last but not least, if the predator should catch the lizard by its tail, it can drop its tail and the nerve endings in the tail will make it twitch and hopefully keep the predator distracted while the rest of the lizard makes its getaway. This last defense though is a one time only tactic, as they don’t regenerate their tails like some other lizards will.

I also think its cool that bearded dragons communicate with each other using different gestures. If two bearded dragons are cruising along and they run into each other, one way they might say “hello, I’m the same species as you” is to walk up and lick each other.  They will sometimes wave one arm in big circles as well, which might also serve as a sign of submission. They are not usually aggressive towards each other (although they can have “ritualistic sparring matches.”) and so they can sometimes be housed together, allowing me to have the opportunity to take adorable pictures of them, like these:

Tully and Derby

Tully and Derby, bearded dragon brothers, making a lizard pile. Image taken at the San Francisco Zoo.

Tully and Derby again

More of Tully and Derby's lizard pile. Image taken at the San Francisco Zoo.