Lizards and Roadrunners in the Desert Landscape
By Matt Griffiths
Greater Roadrunner, Mick Thompson
A fun and unique aspect of life in the Sonoran Desert is the opportunity to observe lizards—lots of lizards! In fact, the 100-mile circle around the Tucson area is home to 44 different kinds of lizards and this equates to one-third of all the species in the US. A major factor in this is that Tucson is situated at the crossroads of multiple bioregions, and it’s a meeting place where lizards of the west bump up against lizards from the east. Lizards from the mountainous south in Mexico also come north to join the party in our Sky Island mountains ranges. Nowhere else can you find such a beautiful diversity of species including but not limited to spiny, whiptail, horned, alligator, collared, and leopard lizards, desert iguana, and of course, the Gila monster, our largest native lizard and the only venomous one in the US.
Most Tucsonans don’t have to worry (or get excited!) about Gila Monsters outside their door, but lizard numbers are still surprisingly good even in the urban core of the city. Many of us can count on seeing ornate tree lizards, desert spiny lizards, Sonoran spotted whiptails, and an occasional zebra-tailed lizard right in our own yards. It’s fun to watch the lizard calendar year unfold right before your eyes: the first signs of warmer weather when a spiny lizard awakens from hibernation in March; the onset of fall when you realize you haven’t seen a whiptail in over a week and it’s October.
What’s not to like about lizards? They are charismatic little reptiles that bask in the sunny patches of our yards, do push ups on our rocks, and love the desert heat even more than we do. It’s great fun to watch their dramas, relationships, and territorial actions play out on our patios. Lizards keep the desert ecosystem in check by consuming large amounts of insects.
|Desert spiny lizard, Doris Evans|
Lizards also contribute to the overall health of the desert by becoming a food resource for other animals including many carnivorous birds such as the American Kestrel. One local bird that has a taste for all manner of small vertebrates still relies heavily on eating lizards, especially when it has young to feed. The Greater Roadrunner’s primary source of protein for rapidly growing chicks is lizards, and it rarely nests in an area without them. If you’re ever lucky enough to view a roadrunner nest for an extended period of time, you would likely be amazed at how many lizards it takes to raise a pair of young birds.
Also known as Chaparral Cock, Snake Killer, and Medicine Bird, the Greater Roadrunner looks unlike any other bird in the US (although there is the similar Lesser Roadrunner in southern Mexico). At about two feet in length from bill tip to the end of that very long tail, roadrunners could actually be mistaken for a tiny velociraptor patrolling the desert floor using short, low flights and their parallel-to-the-ground running style.
The Greater Roadrunner is found in deserts and arid grasslands across the southwest and northern Mexico and has a number of adaptations that allow it to thrive in these hot and dry habitats. They can flutter the unfeathered area under the chin to shed heat (gular fluttering), maximize water intake from the prey they eat, and also conserve water by secreting concentrated salt through eye glands, a trait shared with seabirds. Like woodpeckers, owls, parrots, and osprey, roadrunners have zygodactyl feet (two toes forward and two toes back) that likely give them greater dexterity when running at speeds of up to 20 mph. The Loop trail is a good place to spot them.
How can you increase the chances of getting lizards and roadrunners to inhabit your outdoor spaces? Here are a few things you can do:
Create rock and brush piles
These features help lizards hide from predators, buffer temperature fluctuations, and provide safe winter hibernation locations. A rock pile at the base of a large tree also helps protect arboreal lizards by providing a safe haven for them when they fall from a tree. We don’t want to make it too easy for the roadrunners!
Plant native plants
Native desert trees, especially velvet mesquite, that are allowed to grow in their natural shapes provide ideal temperature control and contain lots of bark crevice hiding places for lizards as well as the insect food they require. Plant the native grama grasses and resulting seeds that support harvester ant colonies, a preferred food source of horned lizards.
Eliminate pesticide use
A healthy, pesticide-free insect population in your yard will not harm the lizards that hunt them.
Greater Roadrunners favor areas of natural desert or larger urban patches that contain thick mesquite, prickly pear, and cholla. These will be places they can hide, hunt, and build nests. If there is a healthy lizard population, they just might show up!
Visit tucsonaudubon.org/habitat today to learn more about attracting lizards, roadrunners, and other wildlife to your yard in Tucson Audubon’s Habitat at Home program.
Matt Griffiths is Communications Coordinator for Tucson Audubon.