Italian Wall Lizards have made a significant impact on Long Island's ecosystems. They were first introduced to the area in the 1970s.
These lizards are native to the Mediterranean region and have adapted surprisingly well to Long Island's climate. They can thrive in a variety of habitats, from rocky outcroppings to backyards with gardens.
One of the most notable effects of the Italian Wall Lizard's presence is the impact on native species, particularly the Eastern Fence Lizard.
Related reading: Texas Horned Toad Lizard
As an Introduced Species
The Italian wall lizard has become quite at home on Long Island, with populations found in various locations including Topeka, Kansas; Long Island, New York; and the Cincinnati area of Ohio, Indiana, and Kentucky.
These lizards have been spotted in high concentrations in the Cincinnati area, where they've become so well-established that the Ohio Department of Natural Resources now classifies them as a resident species rather than an invasive species.
In the Cincinnati area, it's not uncommon for people to trade P. muralis lizards with others who live in areas with high populations of P. siculus, often releasing significant numbers of lizards in their own yards and rock walls.
The species is extending its range from an initial colonization event in western Long Island, likely using railroad tracks as dispersal corridors along the middle East Coast.
Wall lizards have also colonized along the southwest Connecticut coast near Greenwich, as well as around Burlington County, New Jersey, with some reports suggesting they descended from a group of lizards released in Mount Laurel in 1984.
In 2020, a large number of P. s. campestris entered Great Britain as stowaways among shipments of grapes, before being intercepted.
The Italian wall lizard has also entered the Iberian Peninsula as an invasive species, competing with the native Podarcis virescens species and leading to displacement of P. virescens lizards.
Habitat and Behavior
The Italian wall lizard, P. siculus, is a habitat generalist that thrives in many environments, including forests, grasslands, shrublands, rocky areas, and farmland.
It's able to live in open habitats due to its high thermophily, or ability to thrive in high temperatures. I've seen similar adaptability in other species that can survive in a variety of conditions.
P. siculus is oviparous, meaning females lay eggs, and can produce 3 or 4 clutches of 4-7 eggs per year. The reproductive season typically begins in May and ends in July.
Gravid females, or those carrying eggs, engage in more basking behavior than non-gravid females. This is likely due to the energy required to incubate the eggs.
The lizards on the island of Pod Mrčaru were found to have a larger average size, shorter hind limbs, and altered response to simulated predatory attacks compared to the original population on the island of Kopište.
These changes were attributed to "relaxed predation intensity" and greater protection provided by vegetation on Mrčaru. This highlights the importance of habitat in shaping the behavior and physiology of P. siculus.
In 2008, further analysis revealed that the Mrčaru population had significantly different head morphology and increased bite force compared to the original Kopište population. This change in head shape corresponded with a shift in diet, with the Mrčaru lizards eating more plant matter.
The discovery of cecal valves, which slow down food passage and provide fermenting chambers, was a significant finding in the Mrčaru population. This unique adaptation allows the lizards to digest plant material more efficiently.
The activity period of P. siculus campestris on Long Island was reduced compared to its Italian counterparts, likely due to colder mean temperatures. This highlights the importance of temperature in shaping the behavior of P. siculus.
Habitat's Impact
The Italian wall lizard on Long Island has a reduced activity period compared to its counterparts in Rome, where lizards are active year-round.
Colder mean temperatures in the New York habitat of P. siculus campestris may explain why this population's activity is limited to the months of April through October.
The photoperiod of Long Island is similar to that of Rome, but temperature seems to be the main factor influencing the discrepancy in activity levels.
P. siculus campestris was active for fewer hours during the day compared to its Roman counterparts, suggesting that temperature also affects their daily activity patterns.
This difference in activity levels highlights the importance of considering habitat when studying the behavior of the Italian wall lizard.
If this caught your attention, see: Horned Lizard Texas
Featured Images: pexels.com
