Comparative habitat use of Montezuma Quail in the Edwards Plateau and Trans-Pecos ecoregions of Texas

Montezuma quail (Cyrtonyx montezumae) are a secretive and understudied bird species inhabiting the southwestern United States (Texas, Arizona, and New Mexico), and populations have been declining for the past century. Two populations of Montezuma quail are found in Texas, and they occupy the Edwards Plateau and Trans-Pecos Mountains and Basins ecoregions. A common vegetation characteristic found in both ecoregions is juniper, with Ashe (Juniperus ashei) and alligator juniper (Juniperus deppeana) being the dominant juniper species in the Edwards Plateau and Trans-Pecos, respectively. Ashe juniper has increased over the past several decades and created dense stands of woody cover leading to a decline in usable space for Montezuma quail, while alligator juniper occurs throughout the western portion of the Montezuma quail’s geographic distribution. Comparisons of Montezuma quail use of juniper species between these 2 ecoregions have not been conducted. I compared Montezuma quail habitat use at the micro-scale (16-m radius) for both ecoregions and at the macro-scale (350-m radius) for the Edwards Plateau. During 2018–2020, I collected vegetation data at used locations of quail in the Edwards Plateau (n = 24) and the Trans-Pecos (n = 13), as well as at random locations (n = 41 and n = 29, respectively). Resource selection analyses indicated avoidance of areas with ≥ 20‒30% Ashe juniper cover at both scales in the Edwards Plateau and a selection/indifference to alligator juniper cover (≥ 8% to ≤ 50%) in the Trans-Pecos at the micro-scale. Land managers in should reduce dense stands of Ashe juniper to create usable space for Montezuma quail in the Edwards Plateau but no management may be necessary in the Trans-Pecos