Clay Model Reveals the Difference in Day and Night Predation Rates on Vietnam Warty Newt (Caudata: Salamandridae)

Abstract

Studying the relationships between predators and their prey is generally complex but provides valuable knowledge into the process of evolution. The clay model method is a technique that has been widely used to assess prey-predator interaction. In the study, we used clay models of the Vietnam warty newt (Paramesotriton deloustali) to evaluate its predator pressures in Tam Dao National Park (NP), northern Vietnam. We also employed camera traps to detect specific predators of the newt in nature. Our camera trap results showed that northern treeshrew (Tupaia belangeri), rats (Rattus sp.), and greater coucal (Centropus sinensis) are predators of the newt in Tam Dao NP. For the clay model experiment observed attacks on the head of clay models were triple those expected by chance, indicating that predators perceived the clay model as actual prey items. The proportions on the models predated upon differed in three habitat types: broadleaf evergreen forests, mixed broadleaf evergreen and bamboo forests, and bamboo forests. We also detected that the attacks on the models were mainly made by mammals. Attack rates at nighttime were three times higher than during the daytime.