Podarcis siculus siculus - Southern Italian Wall Lizard

(The species Podarcis muralis - Common Wall Lizard, has also been introduced into the United States in Indiana, Kentucky, and Ohio, and onto Vancouver Island in British Columbia, which you can see here.)

PODARCIS SICULUS (Italian Wall Lizard). USA: CALIFORNIA: Los Angeles Co.: San Pedro ....  23 April 2010 and 7 May 2010. Gary Nafis and Guntram Deichsel. Verified by Werner Mayer. Museum of Natural History in Vienna, Austria (photo voucher and tissue sample; catalogue number: NULA-1). Two additional voucher specimens are deposited at the Natural History Museum of Los Angeles County (LACM 180482–180483).

First verified record of P. s. siculus from the USA. Burke and Deichsel (2008. In Mitchell et al. [eds.], Urban Herpetology, pp. 347–353. Herpetological Conservation Vol. 3. SSAR, Salt Lake City, Utah) present an overview of occurrences of P. siculus in the U.S. and mention introduced P. siculus campestris only for New York, Pennsylvania, and Kansas. Stebbins (2003. A Field Guide to Western Reptiles and Amphibians. Houghton Mifflin Co., Boston, Massachusetts. 544 pp.) does not mention P. siculus in the area covered in this book.

Werner Mayer analyzed mtDNA from the tissue sample and submitted the result to GenBank (accession number HQ154646). A sequence of 887 bp of the mitochondrial cytochrome b gene differed only by 1% mismatches from respective sequences of P. s. siculus from both the city of Agrigento (on the SW coast of Sicily) and from the Monti Peloritani mountains in the northeast of the island. The difference Agrigento–Peloritani is 0.9% mismatches. Sequences from Sicily differ by 1.9–2.4% from sequences from the opposite Italian mainland, i.e., extreme southern Calabria (W. Mayer, pers. comm.).

Approximately 50% of the Californian individuals are of the “concolor” (syn. “olivacea”) morph characterized by plain green dorsa. Intergrades with faded, mid-dorsally lined (females) or faded checkered dorsa (males) are also present. Venters are plain white, orange, red, or white with beige spots. This inter-individual variation of coloration is consistent with a Sicilian origin: on the Italian mainland all P. s. siculus have plain white venters whereas on Sicily both plain white and colored venters occur (Henle and Klaver 1986. In W. Böhme [ed.], Handbuch der Reptilien und Amphibien Europas vol. 3 [Lacertidae III: Podarcis], pp. 254– 342. Aula Verlag, Wiesbaden).

JH surveyed the area several times after 7 May 2010, confining the occurrence to a ca. 300 m (NW–SE) x 400 m (NE–SW) rectangle centered at ... ... ... ... .... We estimate the total population size as over 1,000 animals. By interviewing residents, JH identified the person who originally introduced four females and three males, all adults, from Taormina on Sicily in September 1994. According to this person, “20 male and 24 female adult Southern Italian Wall Lizards, many juveniles, and lots of hatchlings co-exist together with 2–3 Southern Alligator Lizards and 4-5 Western Fence Lizards, all adults” in his/ her yard as of 29 June 2010. The total area of the person’s lot minus house footprint is 474 m2, yielding a population density of adult Southern Italian Wall Lizards of roughly one per 10 m2. In another resident’s garden measuring 72 m2, GD counted nine Podarcis, yielding a similar local density. In its home range, P. s. siculus can reach much higher densities. We recommend that the expansion of this alien species be monitored and possible interactions with native lizard species should be investigated.

Submitted by GUNTRAM DEICHSEL, Friedrich-Ebert-Str. 62, Biberach an der Riss, Germany DE-88400 (e-mail: Guntram. Deichsel@gmx.de); GARY NAFIS, (e-mail: grynaf@yahoo.com); and JONATHAN HAKIM, (e-mail: hakim.ndmva@gmail.com).