|A pair of Side-blotched Lizards photo by Rick Halliburton|
When a lizard goes searching for real estate, their dream home has many of the same features we may have on our list: Beautiful landscaping, a sunny spot to relax in when it's cool, a shady spot to hang out when it gets hot, a neighborhood that is safe from predators and easy access to good food. They're not going to list granite countertops, but a large granite boulder to bask on would make a lot of lizards very happy.
Recent surveys in the Phoenix urban area by reptile biologists at Arizona State University have shown that, indeed, all fourteen native species of lizards in the area seem to prefer the same areas occupied by prime real estate. In an article called "Rich Lizards," PhD student Jeff Ackley and colleagues report that the diversity of lizards in the urban area is highest in more affluent neighborhoods. They call it the "luxury effect." Characteristics that tend to increase value for real estate also make for better quality lizard habitat. This includes: closeness to desert preserves, greater diversity of plants, more natural open space and less asphalt. Affluent neighborhoods also tend to have larger yards with more native plants and fewer lawns. A side benefit of all these features is that air temperatures are slightly cooler, especially during summer nights. This is because there is more shade during the day and a reduced "urban heat island" effect at night.
|Regal Horned Lizard photo by Kathy Darrow|
However, each species of lizard has particular wants and needs that may limit where they can thrive, just as we humans all have various things that keep us most comfortable. What a Regal Horned Lizard needs most, for instance, is ants, and around here, a certain species of seed harvester ant: Pogonomyrmex rugosus. These ants prefer open flat areas where there are plenty of native seeds to harvest, so very few populations of Regal Horned Lizards have survived in the urban area. Flat ground is the first to go when development is planned.
Only two of the ten Phoenix desert preserves that have been surveyed have more of what Horned Lizards want: Deem Hills and Cave Buttes have enough flat ground to support healthy harvester ant populations. You will most easily find these reddish ants by looking for their nest holes, which are usually near the center of a 3-6 foot wide gravelly circle. After summer rains is the best time to watch harvester ants at work gathering seeds from afar, which they tore in special chambers below ground. Horned Lizards will seek out an active colony and snatch them up with their short, fat, sticky tongues. One of the ways biologist can tell if there are horned lizards around is by finding their fecal pellets (aka poop) nearby, which are masses of ant parts a couple of inches long.
|Desert Iguana photo by Brian Sullivan|
What do other kind of lizards want?
*Desert Iguanas want creosote bushes to feed on and lots of space to run.
*Chuckwallas gotta have crevices to climb into, just the right size, so they can take a deep breath and wedge themselves in. Plus, they are picky eaters: palo verde, globe mallow and showy goldeneye are some of their favorite foods.
*Tiger Whiptails like rodent burrows to dodge into for shade and protection from predators.
*Ornate Tree Lizards want trees to climb, but vertical walls will do, and thus, they are the most abundant type of lizard in the urban area.
|Ornate Tree Lizard photo by Kathy Darrow|
What all lizards really want, though, is to be left in the wild with room to roam, places to hide and where it's easy to find their favorite foods. you can add a little luxury to an urban lizard's life, and maybe even boost your own real estate value, by planting native trees and shrubs in your yard, plus a large boulder or two for basking.
To learn more about local lizards, check out the website for "A Field Guide to Reptiles & Amphibians of Arizona" by Thomas Brennan and Andrew Holycross: www.reptilesofaz.org