Three state threatened raptors are the focus of this study the zone-tailed hawk (buteo albonotatus), the gray hawk (buteo plagiatus), and the common black hawk (buteogallus anthracinus)

This $305,237 Formula Grant awarded by the U.S. Department of the Interior's Fish and Wildlife Service under the State Wildlife Grants (CFDA 15.634) program supports a 3-year study on the status and ecology of three state-threatened raptor species in Texas: the zone-tailed hawk, gray hawk, and common black hawk. The Texas Parks and Wildlife Department, the state agency responsible for conserving Texas' natural resources, is the prime recipient for this award.

The project will conduct systematic surveys across Texas to assess the current status and distribution of these three raptor species, which have been hampered by data gaps on their ecology and habitat requirements. The research will measure nest habitat characteristics, track foraging and movement patterns using GPS transmitters, and use the resulting data to inform population modeling and species status assessments. A sub-award to Texas Tech University will support portions of the fieldwork and analysis. The findings are expected to enhance conservation planning and management strategies for these state-listed threatened raptor species.

Status assessments for these three species have been hampered by a lack of basic ecological information, known or presumed rarity, and a lack of presence data across presumed potential distributions in texas. All three species are known to be associated with desert arid lands riparian systems with either permanent or ephemeral surface water. Additionally, the zone-tailed hawk is known to also occupy hilly and mountainous woodlands, but again, along riparian drainages. In this study we will conduct systematic surveys in 1) areas with reports of the species presence, and 2) areas modeled to be likely to habitat for the three species. Following the breding season, we will measure nest habitat characteristics to add to the sparse existing data (e.g., matteson and riley 1981, skidmore 2020) to better understand habitat requirements. These data can better inform habitat models and be extrapolated such that population estimates can be derived. We will also capture and attach GSM transmitters to a sample of zone-tailed hawks and gray hawks. Data from the GSM transmitters will allow US to obtain foraging habitat use data, and home range size data. These data allow better, more informed, modeling of suitable habitat and species-specific tolerance densities, which translate, again, to better understanding of habitat availability and species-specific population sizes in texas. This, in turn, will facilitate informed species status assessments