A bonus while working on the island is observing the myriad wildlife around me. One of these critters is the ubiquitous Western Fence Lizard or “Blue Belly.” Scaloporous occidentalis, so called “Swifts” for their remarkable speed, and can be seen sunning themselves or doing their pushups on the rocks around the island. And I’m quite sure you have seen them while out in open areas.
A dinosaur relative, they have existed for 10 million years and are considered a keystone species because they eat any number of insects, spiders, and other arthropods. In turn, they become food for many birds, snakes, and other mammals.
Though ground dwellers, they appear drab to the naked eye, but when observed through close focusing binoculars, it’s possible to see blue and green scales shimmering in the sunlight. Additionally, black and brown patterns criss cross their backs. They are most active during the day but then return at dusk. Bluebellies are ectotherms, which means they are an animal that requires the sun’s heat to function at which time they become more active. Since they cannot dig, they will sleep in abandoned ground squirrel burrows, wood or earth crevices, woodrat houses and sometimes under leaf litter.
From late October to March, Western Fence Lizards are in a hibernation-like state called brumation. However, during warm fall and winter days, juvenile lizards often appear. Blue bellies are easy prey for predator’s while brumating, which may be the reason they have developed a “third eye” or sleeping with one eye open. This is called “asynchrous eye closure” which allows the brain hemisphere connected to the closed eye to sleep, while the hemisphere connected to the open eye remains awake and vigilant.
Look for more Western Fence Lizard “stories” at a later date.