Lacertid Lizards on the loose

The Italian Wall Lizard (Podarcis siculus) is a medium sized, colorful green lizard that is native to Italy and surrounding countries. Being in the Lacertoidea family and close relative of West Coast Native Whiptail Lizards, Podarcis siculus are very skittish due to a complex nervous system that allows them to accelerate to high speeds in short amount of time.

P siculus usually inhabits Mediterranean climates and lives in high densities on brick walls, platforms, and anywhere around human development. Due to it's high reproductive rates, it can populate any favorable area in a short period of time

In 1951, a boy from Cincinnati, Ohio traveled to Sicily, Italy for vacation. He was infatuated with the native wall lizards in the area, causing him to smuggle around 10 lizards on the plane to keep as pets. He eventually got tired of caring for the lizards, and released them in his backyard.

Since that singular introduction, the lizard's population have expanded into the thousands, possibly millions in Ohio's suburban areas.

Almost a year ago, an observation of an invasive Italian Wall Lizard was spotted right here in the Bay Area - at Fremont High School in San Jose. After the observer confirmed the original location to be in San Jose, several experts traveled to the school's garden area to document the lizard population. Thankfully, one iNaturalist user reported that the lizard population was only restricted to the garden area and the surrounding regions. In addition, the lizards were likely to be imported from another established P siculus population within the U.S (e.g the one in Cincinnati).

In the future, scientists hope to catch some lizards from this area to do DNA tests. This way, they can pinpoint the source of this odd lizard population.

Each population across Europe is divided into subspecies based on external morphology and genetic testings. P. siculus usually inhabits Italian islands. After long periods of time of being isolated on an island the lizards external morphology slowly shifts to match the conditions of the island. For example the North Italian Wall Lizard (P. s. ssp. campestris) is known for it's robust black and green patterns.

Other morphs and varieties are shown to be morphologically different than each other, but scientists have not categorized into subspecies. Below are six morphologically different morphs of P. siculus:

Source: https://www.mdpi.com/2076-2615/13/3/386

At the CCAG we plan to travel to this school's garden area to document the lizards. Based on external morphology (e.g. color, snout length, behavior) I believe these lizards are P. s. ssp. campestris, originally hailing from North Italy and surrounding areas.

However, much more must be done to address this population’s impact on the environment before meaningful studies on subspecies and genetic variation can be conducted!