June 30, 2004 - Island Night Lizard

The most interesting thing about the Island Night lizard (Xantusia riversiana) is that they are not necessarily nocturnal. Well, sometimes they are.  But sometimes they’re not.  It just depends on their mood. But wouldn’t one expect, with a name like Night lizard …oh forget it.

There are actually quite a few interesting things about the Island Night lizard. As the name implies, they are found on three of the Channel Islands off the coast of Central California – San Clemente, Santa Barbara, and San Nicolas. (There have been reported sightings on Santa Catalina, but so far, no proof). These three islands provide a variety of habitats, from coastal strand and sand dunes to chaparral and woodlands, and the lizards are found in all of them.  It’s not known which of these habitat types they prefer, but it is apparent that the main thing they’re looking for is habitat, which provides abundant cover.

The Island Night lizard grows to be between 5 and 8 inches long. They are among the largest of the Night lizard Species. They have no eyelids and their pupils are vertical. Cool. They are gray to yellowish brown with dark spots.  Some have a light stripe with dark edges. The Island Night lizard is referred to as a soft-skinned lizard, as the scales are generally small and appears to be loose around the neck. So much for all those hand lotion commercials. Not a whole lot is known about the mating habits of the lizard, but one interesting aspect is that they give live birth, bearing 3-9 juveniles at a time.

Apparently, the lizards get water from dew, as there are very few fresh water sources on the islands on which they have been found. They are omnivorous – they eat insects, plants and possibly even small mammals.  They are known as “food opportunists”, who will eat just about anything in an environment in which there is no competition. Sort of like Ed’s dog.

The Island Night lizard in its entire range was placed on the Federal Endangered Species list on August 11, 1977. They are also on the state list of Species of Special Concern and are protected by the State of California.  The main threat to the lizard has been the introduction of non-native mammals to the Channel Islands.  Goats and pigs stripped the lizard's habitat of the plant cover that is needed for survival, leaving them exposed to introduced cats and rats. Evidently, they find soft-skinned lizards to be tasty. Over the past several years, efforts have been made to restore Island Night lizard populations.  They have included removing introduced grazing animals, as well as feral cats and other non-native mammals from the islands.

Of course removing non-native mammals has never been easy. Yesterday’s contest to identify this lizard wasn’t easy either. There were not as many correct guesses as we had for the mosaic lizard contest, but quite a few considering how xantusia Riversiana keeps such a low profile.  Four subscribers to be exact. And, in a simultaneous effort to be generous AND increase the population of people wearing EDHAT T-Shirts in Santa Barbara, we award a shirt to all 4 of them: Rodan, JButtress, Twacky9er, SBKah.

For your viewing pleasure, here is a list of all the answers we received.

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