Introduction

Adult Black-crested Titmouse; Texas, April

Figure 1. Year-round range of the Black-crested Titmouse.

The Black-crested Titmouse is a common songbird of dry oak, mesquite, and riparian woodlands from Oklahoma and Texas south through northeastern Mexico. Indeed, this species along with various others, such as the Least Grebe (Tachybaptus dominicus), Green Kingfisher (Chloroceryle americana), Golden-fronted Woodpecker (Melanerpes aurifrons), and Couch’s Kingbird (Tyrannus couchii), is really a subtropical species whose range extends north into the southern United States. Although thought of as a “Texas speciality” in the U.S., the Black-crested Titmouse is more widespread in northeastern Mexico and, like the aforementioned woodpecker, actually reaches southwestern Oklahoma.

The Black-crested Titmouse is closely related to the Tufted Titmouse (B. bicolor) and has often been considered conspecific with it, largely because of a broad front of hybridization in central Texas; these titmice also hybridize in southwestern Oklahoma. Unlike its widespread sister species, however, comparatively little field work has been conducted on the Black-crested Titmouse. Nonetheless, it is generally assumed to be similar in most aspects of its ecology, demography, and behavior, although it is slightly smaller and differs in habitat and, somewhat, in song. That said, the species may differ in some key aspects in their ecology. For example, the Black-crested Titmouse is thought to be less overtly agonistic than the Tufted, and it may use its black crest as a signal in territorial disputes.

Building on early studies by George B. Sennett, Joselyn Van Tyne, and Alden H. Miller, much of what we know about the Black-crested Titmouse is rooted in the seminal work of Keith L. Dixon. He was the first to study carefully the central Texas hybrid zone in detail—culminating in a thick monograph (Dixon 1955)—and he remains one of few to have conducted field research on basic foraging ecology and microhabitat use.