Almost the color of sage brush in which they are constantly found, incessantly noisy, there is no Southwestern bird more frequently heard, less easily located than these small, perky, busy, bluegray and black insect hunters.
They are local migrants frequenting foothills or mountain slopes according to the season. However, high or low, they most commonly frequent brushgrown washes of California rivers, dry as a bone all summer and grown to a mass of thick shrubbery about waist high — in some places almost impenetrable.
Here the twit, twit of one or a pair of Gnatcatchers will be heard for at least every hundred feet of progress made. If the way be particuarly easy, so the observer makes little noise, the birds will come boldly about him, keeping up an incessant chatter, perhaps a trifle noisier if the nest be near. They are whimsical in site selection for these homes, building them one season in a well wooded wash and the next in barren places while around are much better situations — from a human standpoint. —Dunn.
Lower Sonoran zone from southeastern California, southern Nevada, central Arizona, west central New Mexico and the Rio Grande valley south to Cape San Lucas.