State-space modeling to support management of brucellosis in the Yellowstone bison population

The Yellowstone bison (Bison bison) exemplifies the challenge of conserving large mammals that migrate across the boundaries of conservation areas. Bison in Yellowstone are infected with brucellosis (Brucella abortus). Their seasonal movements can expose livestock to infection. We developed a Bayesian state-space model to reveal the influence of brucellosis on the dynamics of the Yellowstone bison population and to inform decisions on bison management. A model of frequency dependent transmission was superior to a density dependent model in its ability to predict out-of-sample observations of the probability of horizontal transmission (mean square prediction error frequency model = 0.78, density dependent model = 0.91). Conditional on the frequency dependent model, the median transmission rate of brucellosis was 1.86 year-1 (95% equal-tailed credible interval, BCI = 1.5, 2.2). The median of the posterior distribution of the basic reproductive ratio (R0) was 1.76 (BCI = 1.47, 2.36). Serop...黄石野牛（Bison bison）堪称跨保护区域边界迁徙的大型哺乳动物保护难题的典型代表。黄石公园内的野牛感染有布鲁氏菌病（Brucella abortus），其季节性移动可能使家畜面临感染风险。本研究构建了贝叶斯状态空间模型（Bayesian state-space model），以揭示布鲁氏菌病对黄石野牛种群动态的影响，并为野牛管理决策提供依据。频率依赖传播模型（frequency dependent transmission model）在预测水平传播（horizontal transmission）概率的样本外观测值方面，表现优于密度依赖模型（density dependent model）：频率依赖模型的均方预测误差（mean square prediction error）为0.78，密度依赖模型为0.91。基于该频率依赖传播模型，布鲁氏菌病的中位传播速率为1.86 年⁻¹（95%等尾可信区间（BCI）= 1.5, 2.2）；基本再生数（basic reproductive ratio, R0）后验分布的中位值为1.76（BCI = 1.47, 2.36）。血清学……