School of Molecular and Life Sciences, Curtin University, Bentley, WA, 6102, Australia.
School of Molecular and Life Sciences, Curtin University, Bentley, WA, 6102, Australia.
Environ Pollut. 2022 Feb 15;295:118674. doi: 10.1016/j.envpol.2021.118674. Epub 2021 Dec 11.
Urban ecosystems and remnant habitat 'islands' therein, provide important strongholds for many wildlife species including those of conservation significance. However, the persistence of these habitats can be undermined if their structure and function are too severely disrupted. Urban wetlands, specifically, are usually degraded by a monoculture of invasive vegetation, disrupted hydrology, and chronic-contamination from a suite of anthropogenic pollutants. Top predators-as bioindicators-can be used to assess and monitor the health of these ecosystems. We measured eight health parameters (e.g., parasites, wounds and scars, tail loss and body condition) in a wetland top predator, the western tiger snake, Notechis scutatus occidentalis. For three years, snakes were sampled across four wetlands along an urban gradient. For each site, we used GIS software to measure the area of different landscapes and calculate an urbanisation-landscape score. Previously published research on snake contamination informed our calculations of a metal-pollution index for each site. We used generalised linear mixed models to assess the relationship between all health parameters and site variables. We found the metal-pollution index to have the most significant association with poor body condition. Although parasitism, tail loss and wounds differed among sites, none of these parameters influenced body condition. Additionally, the suite of health parameters suggested differing health status among sites; however, our measure of contemporary landscape urbanisation was never a significant predictor variable. Our results suggest that the health of wetland predators surrounding a rapidly growing city may be offset by higher levels of environmental pollution.
城市生态系统和其中的残余栖息地“岛屿”为许多野生动物物种提供了重要的据点，包括具有保护意义的物种。然而，如果这些栖息地的结构和功能受到严重破坏，它们的持久性就会受到损害。具体来说，城市湿地通常会因入侵植被的单一栽培、水文破坏以及一系列人为污染物的慢性污染而退化。顶级掠食者——作为生物指标——可用于评估和监测这些生态系统的健康状况。我们测量了湿地顶级掠食者西部虎蛇（Notechis scutatus occidentalis）的八个健康参数（如寄生虫、伤口和疤痕、尾巴缺失和身体状况）。三年来，我们在城市梯度上的四个湿地中对蛇进行了采样。对于每个地点，我们使用 GIS 软件测量不同景观的面积，并计算城市化景观得分。之前关于蛇污染的研究为我们计算每个地点的金属污染指数提供了信息。我们使用广义线性混合模型来评估所有健康参数与地点变量之间的关系。我们发现金属污染指数与较差的身体状况最相关。尽管寄生虫、尾巴缺失和伤口在不同地点有所不同，但这些参数都没有影响身体状况。此外，一系列健康参数表明各地点的健康状况不同；然而，我们对当代景观城市化的衡量标准从未成为显著的预测变量。我们的研究结果表明，在一个快速发展的城市周围的湿地捕食者的健康可能会因更高水平的环境污染而受到影响。
