| 要旨トップ | 本企画の概要 | | 日本生態学会第73回全国大会 (2026年3月、京都) 講演要旨 ESJ73 Abstract

シンポジウム S07-7 （Presentation in Symposium）

#### Reptiles in Ampijoroa and their ecological roles in the animal community【E】

*Akira MORI（Kyoto Univ.）

In tropics, species richness of reptiles is generally higher in rain forests than in dry forests. This is true also in Madagascar. However, our research, which was started in 1999 as a collaboration project between Japan and Madagascar, revealed that the Ampijoroa dry forest is exceptional in this point, where diversity of reptilian species is comparable to that of rain forests in Madagascar. We have conducted long-term research of reptiles in Ampijoroa, including basic faunal and natural history surveys and specifically focused ecological and behavioral studies. So far, we have confirmed 32 species of lizards, 20 species of snakes, three species of turtles, and one species of crocodiles in the Ampijoroa forest and its surrounding areas. These reptiles play important roles in the ecological community of this forest as predators, prey, and competitors of other animal taxa. Extensive examinations of stomach contents of snakes as well as occasional direct observations of their feeding behavior revealed that they exploit a variety of terrestrial vertebrates from frogs, lizards, birds, to mammals, and even snakes, along with some invertebrates, such as ants, termites, and centipedes. Some snake species are dietary generalists, feeding on various terrestrial vertebrates including reptile eggs, whereas others are specialists relying on a limited ecomorph or group of animals, such as fossorial/semi-fossorial lizards or frogs. Snakes use different foraging modes from typical ambushing to widely foraging, often depending on species of snakes. Widely foragers would either directly pursue prey animals in activity, sneak up on resting prey animals in shelter, or rob eggs and vulnerable infants and chicks in nests. Lizards are important predators especially of small invertebrates, and some of the lizards are considered to compete with insectivorous avian species in the same guild. Some lizards are omnivorous, eating both animals and plant material, and a recent study showed that these lizards would play an essential role as unique seed dispersers of some plant species. In addition, we experimentally demonstrated the occurrence of eavesdropping of avian alarm calls by three species of lizards, which indicates the hidden presence of another ecological relationship between reptiles and birds through their common predators. In my talk, I will briefly introduce reptile fauna in the Ampijoroa dry forest and summarize the above ecological statuses of reptiles, particularly focusing on foraging habits of snakes.

日本生態学会