No 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 or 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 to 23.0 (95% CI: 18.2 – 27.5) white-tailed deer/km2, and axis deer densities ranged from 16.9 – 171.0 /km2 among eight different land cover types in Kimble County, TX, with a county wide estimate of 61,078 (95% CI: 30,407 – 100,369) axis deer. Axis deer densities were greatest in riparian habitats, and they selected for two riparian habitats and upland grasslands. Axis deer population estimates clearly indicate their population size has increased substantially since introduction to Texas in the 1930’s. 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.

Axis deer ( Axis axis ) occur both in captivity and free-ranging populations in portions of North America, but to-date, no data exist pertaining to the species’ susceptibility to CWD. We sequenced the prion protein gene ( PRNP ) from axis deer. We then compared axis deer PrP C sequences and amino acid polymorphisms to those of CWD susceptible species. A single PRNP allele with no evidence of intraspecies variation was identified in axis deer that indicates axis deer PRNP is most similar to North American elk ( Cervus canadensis ) PRNP . Therefore, axis deer may be susceptible to CWD. We recommend proactively increasing CWD surveillance for axis deer, particularly where CWD has been detected and axis deer are sympatric with native North American CWD susceptible species.