Wildlife Epidemiology Laboratory, Department of Veterinary Clinical Medicine, College of Veterinary Medicine, University of Illinois, Urbana, IL 61802, USA,
Wildlife Epidemiology Laboratory, Department of Veterinary Clinical Medicine, College of Veterinary Medicine, University of Illinois, Urbana, IL 61802, USA.
J Zoo Wildl Med. 2019 Sep;50(3):594-603. doi: 10.1638/2018-0154.
Health assessment of free-ranging populations requires an integrated approach, often incorporating a method to measure mass as a representation of the animals' ability to utilize environmental resources. In chelonians, direct measurements of mass have historically served as a corollary for body condition. However, this method may not accurately represent the true fat volume (FV) and may be skewed by the presence of eggs, shell size, or muscle mass. The objective of this study was to use computed tomography (CT) to develop a model for determining body condition index (BCI) in free-ranging Blanding's turtles (). Mass, shell measurements, and FV were measured by CT in 65 free-ranging Blanding's turtles from Lake and DuPage counties in Illinois. Twenty-one different models were built for BCI using both FV and fat percentage (FP) as dependent variables. The best fit model for FP included the relationship between mass and carapace length with nearly 60% model support. The model for FV demonstrated a similar relationship but had only 18% support. Linear models with BCI as the dependent variable showed that juveniles had a higher FP than adults and females with more eggs had a lower FP. FP can be calculated in the field with nearly 60% accuracy compared to CT-assessed FP as a component of a physical exam and population health survey to assess the effectiveness of conservation efforts for the endangered Blanding's turtle.
对自由放养种群进行健康评估需要采用综合方法，通常包括一种测量体重的方法，以代表动物利用环境资源的能力。在龟鳖类动物中，体重的直接测量历来是身体状况的一个指标。然而，这种方法可能无法准确代表真实的脂肪量（FV），并且可能会因存在卵子、壳尺寸或肌肉质量而产生偏差。本研究的目的是使用计算机断层扫描（CT）来建立一个模型，以确定自由放养的斑鳖（）的身体状况指数（BCI）。在伊利诺伊州的莱克和杜佩奇县的 65 只自由放养的斑鳖中，通过 CT 测量了体重、壳测量值和 FV。使用 FV 和脂肪百分比（FP）作为因变量，为 BCI 构建了 21 个不同的模型。FP 的最佳拟合模型包括质量与甲壳长度之间的关系，模型支持率接近 60%。FV 的模型表现出类似的关系，但仅得到 18%的支持。以 BCI 为因变量的线性模型表明，幼体的 FP 高于成体，卵数较多的雌性 FP 较低。FP 可以通过现场计算，与 CT 评估的 FP 相比，准确度约为 60%，作为体检和种群健康调查的一部分，以评估保护濒危斑鳖的努力效果。
