2025-6 San Diego Trip - Tracking Invasive Reptiles

Our last trip of the year was be a weeklong trip in San Diego California. We will spend our time filming native lizards, crabs and other wildlife for a new film.

Another goal of the trip was to track the many invasive reptiles that have entered our state. These invasive reptiles have entered San Diego from places like Florida or even from the Old World like Asian and Europe. The main cause for this is the pet trade. People who no longer want their pet lizards will mindlessly dump them in nearby urban parks, uninformed about the damage this does to native populations. The escaped lizards will reproduce. Especially in places like San Diego where the climate is similar to the lizards native origin, they will reproduce readily. Since these lizards have aren't part of the natural food chain, they don't have any predators and will prey on native lizards, threatening the local ecosystem.

For example, take the Italian Wall Lizard, which we discussed in a separate post. It likely did not arrive in SoCal due to the pet trade but their introduction is similar. The Italian Wall Lizard lives up to it's name. It's native range is, well, Italy, though the Podarcis genus is spread throughout most of southern Europe. It is thought that a traveler who came back from Sicily in 1994 with a suitcase full of lizards and released them in Coastal San Pedro. Really odd, huh? Scientists have conducted DNA tests and found that this population is genetically similar to the Sicilian population of lizards P. s. spp. siculus which supports that someone may have brought these lizards from Sicily.

These lizards have since populated. As San Pedro has a similar Mediterranean as Italy, the density has reached almost 1 lizard per 10 square meters!

We have a goal of finding finding at least 5 non native species including

1. Mediterranean house gecko

A crepuscular gecko native to the Mediterranean regions of Europe, this lizard is supposedly common in SoCal and other cities with similar climates like Phoenix, AZ. It was likely stowed away on boats from Europe that arrived in the U.S

1. Green Anole

These lizards are native to the humid south atlantic coast. They were used as food for larger animals at the San Diego Zoo but over time many escaped. As a result, there is a large, dense wild population at the zoo and smaller, sparse populations throughout urban parks in San Diego.

3. Italian Wall Lizard

4. Sonoran Spotted Whiptail:

(We might not see this species due to the cold weather.) In contrast to the other lizards discussed in the post, the Sonoran Spotted Whiptail's range is pretty close - the Sonoran Desert. They are similar and often coexist with our two native whiptails - the Coast Whiptail The largest population of these are in Irvine, California.

5. Flat Tailed house gecko

Native to Asia, the flat tailed house gecko may have arrived and established similar to the Green Anole. There is a feral population near a specific building in the San Diego Zoo, but that is the only known population that exists in the City