Dinosaurs in the Desert
Of all the wonderful birds found in the Southwest, none symbolizes the desert more than the Greater Roadrunner. Perhaps it’s the result of all those hours spent watching nature programs and Saturday morning cartoons, but the roadrunner is an icon to birders and non-birders alike.
Roadrunners are members of the cuckoo family, related to the graceful Yellow-billed Cuckoo of the riparian forest. Though many of their relatives are long-distance migrants, the roadrunners’ stubby wings are only suitable for short flights, and they spend most of their time on the ground. They are voracious predators, hunting invertebrates, reptiles, small mammals, and birds, sometimes lying in wait stretched out in the grass like a terrestrial alligator.
As paleontologists find more and more evidence of the link between birds and dinosaurs, one need only watch a Greater Roadrunner sneaking through the brush in search of prey to see the resemblance to the velociraptors of Jurassic Park. The Greater Roadrunner is the state bird of New Mexico; maybe it should also be the state dinosaur. (And yes, there is a Lesser Roadrunner, a pint-sized cousin found from northwestern Mexico to northern Central America.)
Cool, crisp fall mornings are an excellent time to see the roadrunners’ basking behavior. Their body temperature may drop overnight by as much as 15°F., conserving energy but leaving them sluggish and vulnerable at dawn. As soon as the sun breaks the horizon, the bird will stand tall, back to the sun, with its back feathers erected to expose its “solar collector,” a patch of black skin covered by sparse, dark gray down. On sunny but chilly winter days, the bird will stop every so often for another basking session. Researchers Robert D. Ohmart and and Robert C. Lasiewski found that this behavior offers a significant energy savings for roadrunners dealing with cold temperatures, averaging 551 calories per hour. This behavior seems reptilian, almost like a basking lizard, and may provide clues to how the earliest warm-blooded animals coped with extremes of climate.