Milenkaya Olga, Weinstein Nicole, Legge Sarah, Walters Jeffrey R
Department of Biological Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA.
VA-MD Regional College of Veterinary Medicine, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA.
Conserv Physiol. 2013 Jul 16;1(1):cot020. doi: 10.1093/conphys/cot020. eCollection 2013.
Body condition indices are increasingly applied in conservation to assess habitat quality, identify stressed populations before they decline, determine effects of disturbances, and understand mechanisms of declines. To employ condition indices in this manner, we need first to understand their baseline variability and sources of variation. Here, we used crimson finches (Neochmia phaeton), a tropical passerine, to describe the variation in seven commonly used condition indices by sex, age, breeding stage, time of day, and year. We found that packed cell volume, haemoglobin, total plasma protein, and scaled mass were all significantly affected by an interaction between sex and breeding stage. Furcular fat varied by sex and breeding stage and also trended by year, scaled mass showed a positive trend with age and varied by time of day, and haemoglobin additionally varied by year. Pectoral muscle scores varied and heterophil to lymphocyte ratio trended only by year. Year effects might reflect a response to annual variation in environmental conditions; therefore, those indices showing year effects may be especially worthy of further investigation of their potential for conservation applications. Pectoral muscle scores and heterophil to lymphocyte ratio may be particularly useful due to the lack of influence of other variables on them. For the other indices, the large variation that can be attributed to individual covariates, such as sex and breeding stage, suggests that one should not interpret the physiological condition of an individual as measured by these indices from their absolute value. Instead, the condition of an individual should be interpreted relative to conspecifics by sex, breeding stage, and possibly age.
身体状况指数在保护生物学中越来越多地被用于评估栖息地质量、在种群数量下降之前识别受胁迫的种群、确定干扰的影响以及理解种群数量下降的机制。要以这种方式使用状况指数，我们首先需要了解它们的基线变异性和变异来源。在这里，我们以热带雀形目鸟类绯红澳梅花雀（Neochmia phaeton）为例，描述了七种常用状况指数在性别、年龄、繁殖阶段、一天中的时间和年份方面的变化情况。我们发现，红细胞压积、血红蛋白、总血浆蛋白和标化体重均受到性别和繁殖阶段相互作用的显著影响。叉骨脂肪因性别和繁殖阶段而异，并且在年份上也有变化趋势；标化体重随年龄呈正趋势变化，并且因一天中的时间而异；血红蛋白还因年份而异。胸肌评分存在变化，而异嗜性粒细胞与淋巴细胞比率仅在年份上有变化趋势。年份效应可能反映了对环境条件年度变化的响应；因此，那些显示出年份效应的指数可能特别值得进一步研究它们在保护应用中的潜力。胸肌评分和异嗜性粒细胞与淋巴细胞比率可能特别有用，因为其他变量对它们没有影响。对于其他指数，可归因于个体协变量（如性别和繁殖阶段）的较大变异性表明，不应从这些指数的绝对值来解释个体的生理状况。相反，个体的状况应该相对于同物种的个体，根据性别、繁殖阶段以及可能的年龄来进行解释。
