Fig 1.
Schematic representing the white-tailed deer life cycle used in the parameter validation model.
Table 1.
Initial population and age structure for the first year of the population model.
Population size and sex ratio were derived from helicopter surveys and age structure was estimated based on field studies in South Texas.
Table 2.
Reported field study values, parameter values, and references used to construct a population model that was compared with observed trends from deer helicopter surveys in South Texas.
Fig 2.
Fawn:doe ratios observed during helicopter surveys in South Texas, 1996–2015.
Horizontal line indicates mean fawn:doe ratio.
Fig 3.
Percent of adult males and females harvested annually.
Percent of deer harvested was based on number of adult males and females observed during September helicopter surveys in South Texas.
Fig 4.
Comparison between observed, 3-year moving average, and modeled deer population size trends.
White-tailed deer were counted via helicopter surveys in South Texas during 1996–2015 and compared well with output of parameter validation model (solid line).
Fig 5.
Schematic representing the white-tailed deer life cycle used in CWD simulations.
Table 3.
Initial population and age structure for the first year of the simulations.
Sex- and age-specific numbers were derived from median values generated in year 7 of simulations based on South Texas data without CWD and without harvest.
Table 4.
Parameter values used to simulate CWD effects on deer population dynamics in South Texas.
Fig 6.
Plots of simulated white-tailed deer population trajectories.
One thousand 25-year simulations were run to predict future populations without CWD and 2% harvest (top left) and with CWD and without harvest (top right) with fawn:doe ratios from South Texas, with CWD and 2% harvest (bottom left) and 16% harvest (bottom right) with fawn:doe ratios from Laramie, Wyoming. Slow CWD was modeled to increase 0.26% annually. White line indicates median of the 1,000 simulated projections.
Fig 7.
Age structure of male and female population after 25-year simulations with and without CWD.
Slow CWD started at 1% prevalence and increased 0.26% annually.
Fig 8.
Sex- and age-specific prevalence at the end of simulated years in the slow CWD increase model.
Prevalence is the percent of the median number of infected sex- and age-specific deer in the population at the end of each simulated year. Slow CWD started at 1% prevalence and increased annually by 0.26%.
Fig 9.
Maximum annual harvest of adult male and female deer with slow, medium, and rapid CWD prevalence growth rates.
CWD increased annually at rates of 0.26% (slow), 0.83% (medium) or 2.3% (rapid). Absent bars indicate scenarios when harvest of both sexes caused a population decline.