A Virtual Ecotour of Species from the American Southwest: Zeroing in on the Lizards of the Bootheel

Jones, Lawrence L. C.

3975 S Wolf Spider Way

Tucson, AZ 85735

gilaman@comcast.net

The epicenter of lizard diversity in the United States lies in the American Southwest, especially along the borderlands with Mexico. About 90% of all native U.S. species live in the Southwest. Some of the lizard hotspots along the border include southern California, the Madrean Archipelago of Arizona and New Mexico, and West and South Texas. Although Texas is separated from Mexico by the Rio Grande River, they share the same “saurofauna.” Chihuahuan Desert species occur here, including the Mesquite Lizard, Canyon Lizard, and Texas Alligator Lizard. Similarly, the area known as the Madrean Archipelago is half in northern Mexico and half in southeastern Arizona and adjacent New Mexico. This is the area to be emphasized in the presentation. Here you can find species from two deserts, grasslands, and mountains. The area around Rodeo, New Mexico, is an ideal place to observe a diverse lizard assemblage. Rodeo is within the famous “Cochise Filter-Barrier,” where Sonoran Desert creatures coexist with Chihuahuan Desert creatures—or else, they are filtered by the transitional habitats. This region boasts the highest diversity of taxa such as horned lizards and whiptails—many of the latter are parthenogenetic forms. Various lizard species occur all the way to the top of the nearby Chiricahua Mountains. In the morning you can see desert dwellers such as Tiger and Whiptails in the valleys, then drive up to Onion Saddle to find Slevin’s Bunchgrass Lizards and Yarrow’s Spiny Lizards, which somehow eke out a living at more than 3,000 m in elevation.