VANISHING CIRCLES

In an earlier post I covered my acrylic painting technique in a step-by-step demonstration of the painting of a Desert Tortoise (Gopherus agasizii). The painting was commissioned for Vanishing Circles, a project for the Arizona-Sonora Desert Museum in Tucson, Arizona. At the time, I promised to post more about the Vanishing Circles project, and it's taken me until now to actually do that. Vanishing Circles is the brainchild of Priscilla Baldwin, a trustee of the Museum. About the project, she says:

"It is a collection of paintings depicting the threatened and endangered species and places of the Sonora desert area. This includes the southern part of Arizona, The whole of Sonora, Mexico, the Sea of Cortez (Gulf of California) and most of Baja California. Places as well as species are included because species are endangered for the most part due to what is happening to their habitat.

"This collection, which I hope will become a book and a traveling collection, is intended to bring attention to these species and their predicament in the world today. I am hoping that this collection will be a role model for other institutions to use art to further their and our efforts to conserve and preserve the world we live in today. Also, if a species does become extinct in the future, we will have an accurate recording of that species and information about it which is current for today.

"I just learned that the national botanical illustration organization wants to start a collection (for tour) of threatened and endangered plants. They, however, are not confining this collection to one region as I have done with Vanishing Circles. I believe they have learned of the idea of Vanishing Circles and changed it to fit their criteria, as I have asked some of their members to do the plants that are threatened in the Sonoran desert region. This is exactly the kind of event that I had hoped would happen as I cannot do it all, but other organizations in other regions of our country can bring attention to the threatened species in their region."

I'm currently at work on a Mexican Beaded Lizard for the collection. This is a particularly enjoyable task for me, after having worked closely with my old pal Dan Beck in illustrating the cover for his fabulous book, Biology of Gila Monsters and Beaded Lizards.

Before the tortoise and beaded lizard, I painted a pair of interesting lizard species for Vanishing Circles. The San Esteban Chuckwalla (Sauromalus varius), a cousin of the well-known Common Chuckwalla (S. ater=obesus) of the American Southwest, is found only on three small Islands in the Gulf of California: San Esteban, Roca Lobos and Pelicanos. Also known as the Piebald Chuckwalla, Painted Chuckwalla, or Giant Chuckwalla, this species can top two feet in length, making it by far the largest member of its genus, and a textbook example of insular gigantism, the tendency of small animals to increase in size once they're established on an island. In 1964, J. Bristol Foster published his Island Rule, which essentially states that larger creatures are more vulnerable to capture by predators, and on an island, where terrestrial predators are often lacking, small creatures tend to grow large, and fill new niches, while large creatures tend to become smaller, and less of a burden on limited food resources. Foster's Rule has been ammended and fine-tuned by Robert MacArthur, E. O. Wilson, Ted Case and others, but its basic principles are still generally accepted. An interesting contemporary example of insular gigantism is taking place on Gough Island, in the South Atlantic, where introduced House Mice (Mus musculus) have tripled in size in just a few decades. The giant mice prey on seabird chicks. Because of its extremely limited habitat, the San Esteban Chuckwalla was listed as an endangered species in 1980. The Arizona-Sonora Desert Museum maintains a sizeable colony of these reptiles, and has been responsible for a great deal of important research on the species.

The Giant Spotted Whiptail (Cnemidophorus burti stictogrammus) is another giant lizard restricted to a few small locales. Although it has a larger range in the Mexican state of Sonora, its US range is restricted to the Pajarito, Santa Catalina, Santa Rita, San Luis and Baboquivari Mountains, and part of the Santa Cruz River Basin of Arizona, and Guadalupe Canyon in southwestern New Mexico. Presumably, the lizard was formally distributed throughout the region. It's not clear why it died out in most of its American range, leaving these few disjunct, relict populations. It's thought to have been extirpated by human development in the Tucson Basin and the Santa Cruz Basin between Tucson and Nogales. At a length of as much as a foot and a half, the Gaint Spotted Whiptail is by far the largest whiptail found in the U.S., although other large members of its genus are found south of the border, and its South American cousins the tegus (Tupinambis spp.) and Caiman Lizards (Dracaena spp.) can exceed a yard in length. The taxonomic designation of the Giant Spotted Whiptail has been the subject of some controversy. It has usually been considered one of four subspecies of the Canyon Whiptail (C. burti), two of which occur in the U.S., two in Mexico, but some authorities prefer to conflate it with the Mexican species C. sacki, and there is a growing school advocating full species status.
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upper: SAN ESTEBAN CHUCKWALLA (2005) acrylic 30" x 20"
lower: GIANT SPOTTED WHIPTAIL (2006) acrylic 30" x 20"