Density of Axis Deer in Texas: Management Implications for Native White-tailed Deer and Associated Habitats

Abstract

Abstract Axis deer Axis axis have been widely introduced to new geographic ranges, and in the United States, free-ranging axis deer have become well established in the Edwards Plateau ecoregion as well as other portions of Texas. However, no estimates of axis deer population density nor size have been conducted since 1994. It is hypothesized that axis deer on the Edwards Plateau are potentially competing with native white-tailed deer Odocoileus virginianus for food, space, and habitat resources, and causing damage to important riparian habitats. Our goal was to estimate regional densities of axis deer and white-tailed deer, and provide insight about the potential impacts axis deer may have on native wildlife and their habitats. Estimated using distance sampling techniques in 2018 and 2019, average axis deer density was 19.7 (95% CI: 14.1–25.6) axis deer/km2 compared with 23.0 (95% CI: 18.2–27.5) white-tailed deer/km2, and axis deer densities ranged from 16.9 to 171.0/km2 among eight different land cover types in Kimble County, Texas, with a county-wide estimate of 61,078 (95% CI: 30,407–100,369) axis deer. Axis deer densities were greatest in riparian land cover types, and they selected for two riparian land cover types and upland grasslands. Axis deer population estimates clearly indicate their population size has increased substantially since introduction to Texas in the 1930s. Population management of axis deer is warranted to limit impacts to native wildlife from potential habitat usurpation, or damage to riparian vegetation communities, soil, and water quality.