The western fence lizard is also known as a blue-belly because of the brightly colored scales under its throat and at the outer edges of the underbelly. It is a fossorial (burrowing) poikilotherm (an animal that regulates body temperature by sun basking or dirt burrowing).
In females and youngsters, the blue markings are faint or not there at all.
Characteristics
This lizard measures 2 inches to 3.5 from nose to snout. Eight inches total, including the tail.
Because of its pointed, overlapping scales, it’s a member of the spiny lizard genus – Sceloporus.
Colors range from sandy, black, brown to green. Some may have back stripes. Under the arms may be yellowish. Western fence lizards have the ability to change colors. Biologists think this adaptation relates to maintaining body temperature rather than for camouflage.
Third Eye
The third or parietal eye is located at the top of the lizard’s head. It’s covered by a translucent scale. Its purpose is to sense light throughout the year, signal the onset of reproduction and it helps control body temperature.
Behavior
The length of winter hibernation is dependent on climate conditions.
Defenses
- Fast, biting, and defecating on predators
- Dropping tail – caudal autotomy or self-amputation (Scientists measure from snout to vent because of the break-away tail)
Push-Ups
Functions of the Push-ups;
- courtship – fitness demonstration – the more brilliant colors, the healthier the male (low parasite load)
- territorial defense display – in mating season, males defend an approximate 25-foot radius from a high perch
- may also relate to food availability within the territory
- a dominant male guarding at the highest point in the territory is known as a tyrant
Diet
A blue-belly’s favorite food is insects. It will eat beetles, grasshoppers, ants, wasps, aphids, mosquitoes, ticks, scorpions, centipedes, and spiders. It will also eat other western fence lizards!
Shedding
As they grow, lizards shed skin in pieces. Sometimes, it becomes a snack. Successful shedding depends on diet, health status, and environmental conditions.
Life Span
5-7 years
Predators
Birds, snakes, alligator lizards, and cats.
Male Identification
Like birds, male western lizards are more brightly colored and showy than females. Where the tail meets the body, males have two large scales near the vent, a single opening used for waste elimination and reproduction.
While copulating, the male’s blue color is at its most brilliant.
Reproduction
Male identification at 2:17
Western fence lizards begin breeding after one year.
Mating Season – March – June
Egg size is largest with the first clutch. The number of clutches laid in a season depends on temperature and elevation. At lower elevations, females will lay between 1-4 clutches. At higher elevations, they’ll lay between 1-3 clutches. Each clutch can contain between 3-17 eggs.
Eggs and Hatching
Eggs incubate for approximately 2 months. Once hatched, babies fend for themselves.
Disease Benefits to Humans
Western fence lizards have a protein in their blood that filters out the spirochete bacterium in Deer Ticks that cause Lyme disease. After a tick feeds on a lizard it will not spread Lyme disease to its next, larger, host during its life cycle.
If you liked this post, you may also like Deer Tick, A Questing Blood Sucker
Resources:
Bay Nature – How You Can Tell Male from Female Lizards?
In Tech Open – Reptilian Skin and Its Special Histological Structures
John Muir Laws – Lizards, Ticks, and Lyme oh my! (audio)
MonkeySee – How to Care for Pet Lizards (video)
Natural History Museum of Los Angeles – ‘Tis the Season fo Baby Lizards
Purdue University – Shedding Reptiles (PDF)
Reptilian Third Eye
San Francisco State University – Department of Geography – The Biogeography of Sceloporus occidentalis
Sci Show – How Do Animals Re-Grow Limbs (And Why Can’t We?)
UC Berkeley News – Tick population plummets in absence of lizard hosts
University of California Agriculture & Natural Resources – Pests in Gardens and Landscapes – Lizards
“Lizards cause no measurable damage to plants in gardens and may be beneficial by eating pest insects and should be left alone.”
BioWeb – Western Fence Lizard
WIRED – Lizards Use Third Eye to Steer by the Sun
Wikipedia – Western Fence Lizard
