College of Science and Engineering, Flinders University, Bedford Park, SA, 5001, Australia.
Konrad Lorenz Research Center, Core Facility for Behaviour and Cognition, Department of Behavioural and Cognitive Biology, University of Vienna, Vienna, Austria.
Parasitol Res. 2022 Jan;121(1):63-74. doi: 10.1007/s00436-021-07350-1. Epub 2021 Nov 20.
Understanding the range and behaviour of an invasive species is critical to identify key habitat areas to focus control efforts. Patterns of range use in parasites can differ temporally, across life stages and between sexes. The invasive avian vampire fly, Philornis downsi, spends the larval stage of its life within bird nests, feeding on developing nestlings and causing high levels of mortality and deformation. However, little is known of the ecology and behaviour of the non-parasitic adult fly life stage. Here, we document sex-specific temporal and spatial patterns of abundance of adult avian vampire flies during a single Darwin's finch breeding season. We analyse fly trapping data collected across 7 weeks in the highlands (N = 405 flies) and lowlands (N = 12 flies) of Floreana Island (Galápagos). Lowland catches occurred later in the season, which supports the hypothesis that flies may migrate from the food-rich highlands to the food-poor lowlands once host breeding has commenced. Fly abundance was not correlated with host nesting density (oviposition site) but was correlated with distance to the agricultural zone (feeding site). We consistently caught more males closer to the agricultural zone and more females further away from the agricultural zone. These sex differences suggest that males may be defending or lekking at feeding sites in the agricultural zone for mating. This temporal and sex-specific habitat use of the avian vampire fly is relevant for developing targeted control methods and provides insight into the behavioural ecology of this introduced parasite on the Galápagos Archipelago.
了解入侵物种的范围和行为对于确定关键的栖息地区域以集中控制努力至关重要。寄生虫的范围使用模式可能会随时间、生命阶段和性别而有所不同。入侵性鸟类吸血蝇 Philornis downsi 在其幼虫阶段生活在鸟巢内，以正在发育的雏鸟为食，导致高死亡率和畸形。然而，对于非寄生性成虫阶段的生态学和行为知之甚少。在这里，我们记录了在达尔文雀繁殖季节的单个周期内，成年鸟类吸血蝇的雌雄特定的时间和空间丰富度模式。我们分析了在弗洛雷纳岛（加拉帕戈斯群岛）高地（N=405 只苍蝇）和低地（N=12 只苍蝇）收集的 7 周苍蝇诱捕数据。低地的捕获时间较晚，这支持了这样的假设，即一旦宿主繁殖开始，苍蝇可能从食物丰富的高地迁移到食物匮乏的低地。苍蝇的丰富度与宿主筑巢密度（产卵地点）无关，但与到农业区（觅食地点）的距离有关。我们一直靠近农业区捕获到更多的雄性苍蝇，而远离农业区捕获到更多的雌性苍蝇。这些性别差异表明，雄性苍蝇可能在农业区的觅食地点为交配而进行防御或求偶炫耀。这种鸟类吸血蝇的时间和性别特异性栖息地利用对于开发有针对性的控制方法很重要，并为了解这种引入性寄生虫在加拉帕戈斯群岛的行为生态学提供了线索。
