The dynamics of pine marten predation on red and grey squirrels
The dynamics of pine marten predation on red and grey squirrels
复制标题
松貂捕食红松鼠和灰松鼠的动态
作者：
Joshua P. Twining;W. Montgomery;D. Tosh
外来入侵物种是对全球生物多样性的最大威胁之一。在欧洲的部分地区，引进的东方灰松鼠（Sciurus carolinensis）已经引起了当地红松鼠（Sciurus vulgaris）的区域性灭绝。然而，暴露于松貂（Martes martes）已被证明可以逆转红松鼠和灰松鼠之间的竞争结果。这种效应发生的机制尚不清楚。据推测，直接捕食，促进缺乏行为反应，是驱动这种关系的机制。我们回顾了文献并重新分析了新的数据集，以提供有关松貂粪便中这两种松鼠的发生的进一步数据。这两种松鼠都发生在松貂的粪便中，证实了它作为这些物种捕食者的作用。灰松鼠的捕食量显著高于红松鼠，且仅在春季和夏季有记录。我们的审查提供了证据的机制，推动目前在爱尔兰和苏格兰的灰松鼠下降，并支持的假设，即在一个共享的捕食者的存在下，直接捕食影响本地红色和非本地灰松鼠之间的物种相互作用的结果。
Invasive alien species pose one of the greatest threats to global biodiversity. In parts of Europe, introduced eastern grey squirrels ( Sciurus carolinensis ) have caused regional extinctions of the native red squirrel ( Sciurus vulgaris ). However, exposure to pine martens ( Martes martes ) has been demonstrated to reverse the competitive outcome between red and grey squirrels. The mechanism whereby this effect occurs remains unclear. It is hypothesised that direct predation, facilitated by a lack of behavioural response, is the mechanism driving this relationship. We review the literature and reanalyse a new dataset to provide further data on the occurrence of both squirrel species in the scats of pine marten. Both squirrel species occurred in the scats of pine marten confirming its role as a predator of these species. Predation of grey squirrels was significantly higher than red squirrels and was recorded only in spring and summer. Our review provides evidence for the mechanism driving the current decline in grey squirrels in Ireland and Scotland and supports the hypothesis that in the presence of a shared predator, direct predation influences the outcome of species interactions between native red and non-native grey squirrels.