Laboratory for the Conservation of Endangered Species, CSIR-Centre for Cellular and Molecular Biology, Hyderabad, India.
PLoS One. 2013 May 22;8(5):e63685. doi: 10.1371/journal.pone.0063685. Print 2013.
Understanding changes in the host-parasite relationship due to habitat fragmentation is necessary for better management and conservation of endangered species in fragmented landscapes. Pathogens and parasites can pose severe threat to species in restricted environments such as forest fragments where there is increased contact of wildlife with human and livestock populations. Environmental stress and reduced nutritional level in forest fragments can influence parasite infection and intensity on the native species. In this study, we examine the impact of habitat fragmentation on the prevalence of gastrointestinal parasites in lion-tailed macaques in a fragmented rainforest in Western Ghats.
The prevalence of different gastrointestinal parasites was estimated from 91 fecal samples collected from 9 lion-tailed macaque groups in nine forest fragments. The parasites were identified up to genus level on the basis of the morphology and coloration of the egg, larva and cyst. The covariates included forest fragment area, group size and the presence/absence of human settlements and livestock in proximity. We used a linear regression model to identify the covariates that significantly influenced the prevalence of different parasite taxa.
Nine gastrointestinal parasite taxa were detected in lion-tailed macaque groups. The groups near human settlements had greater prevalence and number of taxa, and these variables also had significant positive correlations with group size. We found that these parameters were also greater in groups near human settlements after controlling for group size. Livestock were present in all five fragments that had human settlements in proximity.
The present study suggests that high prevalence and species richness of gastrointestinal parasites in lion-tailed macaque groups are directly related to habitat fragmentation, high anthropogenic activities and high host density. The parasite load partially explains the reason for the decline in immature survival and birth rate in small and isolated rainforest fragments in Anamalai Hills.
理解由于栖息地破碎化而导致的宿主-寄生虫关系的变化，对于在破碎化景观中更好地管理和保护濒危物种是必要的。病原体和寄生虫会对受限制环境中的物种构成严重威胁，例如森林碎片，其中野生动物与人类和牲畜种群的接触增加。森林碎片中的环境压力和营养水平降低会影响寄生虫对本地物种的感染和强度。在这项研究中，我们研究了栖息地破碎化对西高止山脉破碎雨林中长尾猕猴胃肠道寄生虫流行率的影响。
从 9 个森林碎片中的 9 个长尾猕猴群体中收集了 91 份粪便样本，估计了不同胃肠道寄生虫的流行率。根据卵、幼虫和囊的形态和颜色，将寄生虫鉴定到属的水平。协变量包括森林片段面积、群体大小以及附近是否存在人类住区和牲畜。我们使用线性回归模型来确定显著影响不同寄生虫类群流行率的协变量。
在长尾猕猴群体中检测到 9 种胃肠道寄生虫。靠近人类住区的群体具有更高的流行率和更多的类群，这些变量也与群体大小呈显著正相关。我们发现，在控制群体大小后，这些参数在靠近人类住区的群体中也更高。牲畜存在于所有五个有人居住的碎片中。
本研究表明，长尾猕猴群体中胃肠道寄生虫的高流行率和物种丰富度与栖息地破碎化、高度的人为活动和高宿主密度直接相关。寄生虫负荷部分解释了安纳马拉山小而孤立的雨林碎片中幼体存活率和出生率下降的原因。
