Predator-Prey Interaction, Niche Partitioning, and Eavesdropping -Ecological and Behavioral Relationships among Terrestrial Vertebrates in Madagascar

在每个季节，实地调查进行了10月至2月，这是研究地点的雨季，Ampijoroa干林。在这一时期，对蜥蜴，特别是壁虎和变色龙，以及蛇进行了生态学研究，以调查他们的食性，觅食行为，营养形态的基础上直接观察和标记-再捕获方法。无线电遥测研究进行了四种蛇，被认为或证实是捕食鸟类。在塔那那利佛大学研究生的帮助下，这些蛇被追踪了一到两年。这些研究表明，蛇是该森林中许多陆生脊椎动物的重要捕食者，但没有专门捕食鸟类的蛇。这意味着其他动物，如雀鹰和狐猴可能是鸟类蛋和雏鸟的主要捕食者。我们还进行了几个试点测试，以检查不同类型的蛇对诱导鸟群的频率的影响，通过呈现蛇模型和真实的蛇。另一方面，蜥蜴的防御反应进行了研究，提出了一个模型的雀鹰，这表明，一个飞行模型接近蜥蜴诱导强烈的逃避反应。蜥蜴对鸟类报警叫声的窃听试验是用马达加斯加的长尾鲨、棘尾鬣蜥和板蜥进行的。研究结果强烈表明，马达加斯加昼壁虎改变自己的身体颜色，以响应鸟类的警报呼叫，使他们的身体更神秘的背景。鸟类经常对褐狐猴表现出围攻行为，表明狐猴是它们的重要捕食者。总体而言，再加上我们以前的调查结果，它表明，爬行动物和鸟类通过捕食者-猎物的相互作用，竞争和窃听生态相关。

In each season, the field research was conducted from October to February, which is the rainy season of the study site, Ampijoroa dry forest. Throughout these periods, ecological studies on lizards, particularly geckos and chameleons, and snakes were made to investigate their food habits, foraging behavior, and trophic morphology based on direct observations and a mark-recapture method. Radio-telemetric study was conducted with four species of snakes that were presumed or confirmed to be predators of birds. With the aid of graduate students of Antananarivo University, these snakes were tracked over one to two years. These studies revealed that snakes are important predators of many terrestrial vertebrate species in this forest, but there are no snakes that specialized on eating birds. This implies that other animals such as sparrowhawks and lemurs may be major predators on eggs and chicks of birds. We also made several pilot tests to examine the effects of different types of snakes on the frequency of inducing mobbing of birds by presenting snake models and real snakes. On the other hand, defensive responses of lizards were investigated by presenting a model of a sparrowhawk, which demonstrated that a flying model approaching to the lizards induces a strong escape reaction of them. The tests of eavesdropping on alarm calls of birds by lizards were conducted using Madagascan day gackos, spine tailed iguanas, and plated lizards. The results strongly suggested that Madagascan day geckos change their body color in response to alarm calls of birds so as to make their body more cryptic against the background. Birds often displayed mobbing behavior to brown lemurs, suggesting that the lemurs are important predators of them. Overall, coupled with the results of our previous surveys, it is demonstrated that reptiles and birds are ecologically related through predator-prey interactions, competition, and eavesdropping.