Gérard Agathe, Jourdan Hervé, Millon Alexandre, Vidal Eric
Institut Méditerranéen de Biodiversité et d'Ecologie marine et continentale (IMBE), Aix-Marseille Université, UMR CNRS-IRD-UAPV, UMR 237 IRD, Centre IRD Nouméa-BP A5, 98848, Nouméa Cedex, Nouvelle-Calédonie.
Institut Méditerranéen de Biodiversité et d'Écologie marine et continentale (IMBE), Aix-Marseille Université, UMR CNRS-IRD-UAPV, Europôle de l'Arbois, BP 80, 13545, Aix-en-Provence, France.
PLoS One. 2016 Mar 15;11(3):e0151545. doi: 10.1371/journal.pone.0151545. eCollection 2016.
The impact of alien predator species on insular native biota has often been attributed to island prey naïveté (i.e. lack of, or inefficient, anti-predator behavior). Only rarely, however, has the concept of island prey naïveté been tested, and then only a posteriori (i.e. hundreds or thousands of years after alien species introduction). The presence of native or anciently introduced predators or competitors may be crucial for the recognition and development of adaptive behavior toward unknown predators or competitors of the same archetype (i.e. a set of species that occupy a similar ecological niche and show similar morphological and behavioral traits when interacting with other species). Here, we tested whether two squamates endemic to New Caledonia, a skink, Caledoniscincus austrocaledonicus, and a gecko, Bavayia septuiclavis, recognized and responded to the odor of two major invaders introduced into the Pacific islands, but not yet into New Caledonia. We chose one predator, the small Indian mongoose Herpestes javanicus and one competitor, the cane toad Rhinella marina, which belong respectively to the same archetype as the following two species already introduced into New Caledonia in the nineteenth century: the feral cat Felis catus and the golden bell frog Litoria aurea. Our experiment reveals that geckos are naïve with respect to the odors of both an unknown predator and an unknown competitor, as well as to the odors of a predator and a competitor they have lived with for centuries. In contrast, skinks seem to have lost some naïveté regarding the odor of a predator they have lived with for centuries and seem "predisposed" to avoid the odor of an unknown potential competitor. These results indicate that insular species living in contact with invasive alien species for centuries may be, although not systematically, predisposed toward developing adaptive behavior with respect to species belonging to the same archetype and introduced into their native range.
外来捕食者物种对岛屿本地生物群的影响通常归因于岛屿猎物的天真（即缺乏或低效的反捕食者行为）。然而，岛屿猎物天真这一概念很少得到验证，而且只是事后验证（即在引入外来物种数百年或数千年之后）。本地或古老引入的捕食者或竞争者的存在，对于识别和发展针对同一原型的未知捕食者或竞争者的适应性行为可能至关重要（即一组占据相似生态位且在与其他物种相互作用时表现出相似形态和行为特征的物种）。在此，我们测试了新喀里多尼亚特有的两种有鳞目动物，一种石龙子，即南新喀里多尼亚石龙子（Caledoniscincus austrocaledonicus），以及一种壁虎，即七嵴巴韦壁虎（Bavayia septuiclavis），是否能识别并对引入太平洋岛屿但尚未引入新喀里多尼亚的两种主要入侵物种的气味做出反应。我们选择了一种捕食者，即小印度猫鼬（Herpestes javanicus）和一种竞争者，即海蟾蜍（Rhinella marina），它们分别与19世纪已引入新喀里多尼亚的以下两种物种属于同一原型：野猫（Felis catus）和铃蟾（Litoria aurea）。我们的实验表明，壁虎对于未知捕食者和未知竞争者的气味以及与它们共存了几个世纪的捕食者和竞争者的气味都很天真。相比之下，石龙子似乎对与它们共存了几个世纪的捕食者的气味不再那么天真，并且似乎“倾向于”避开未知潜在竞争者的气味。这些结果表明，与入侵外来物种接触了几个世纪的岛屿物种，尽管并非一概而论，但可能倾向于针对属于同一原型且引入其原生范围的物种发展适应性行为。
