First Documentation of Hypogaeic Ant, Dorylus orientalis, Predation on Olive Ridley Turtle Nests from the West Coast of India with a Note on Eco-friendly Mitigation in Hatchery Management
Sumedha A. Korgaonkar *
Department of Endangered Species Management, Wildlife Institute of India, Dehradun, Uttarakhand, 248001, India.
Anuja M. Vartak
Annasaheb Kulkarni Department of Biodiversity, MES Abasaheb Garware College, Pune, Maharashtra, 411004, India.
Sivakumar Kuppusamy
Department of Endangered Species Management, Wildlife Institute of India, Dehradun, Uttarakhand, 248001, India and Department of Ecology and Environmental Science, Pondicherry Central University, Kalapet, Puducherry, 605014, India.
*Author to whom correspondence should be addressed.
Abstract
The terrestrial developmental stage of sea turtles is highly vulnerable to multiple environmental and biological threats, including rising sea levels, elevated temperatures, and predation. Predation is one of the major factors reducing hatching and emergence success, thereby affecting population recruitment. During routine monitoring of protected nests in a hatchery on the west coast of India, severe infestations by hypogaeic ants were observed, resulting in damage to 35-50% of the relocated nests and causing 0% hatchling emergence in several cases, thereby compromising conservation efforts. The present study was undertaken to identify the ant species involved and to document its predatory behaviour on olive ridley turtle (Lepidochelys olivacea) eggs, with the objective of developing an effective management strategy to control the infestation. The ants were identified as Dorylus orientalis, which were found attacking protected nests and feeding on eggs during both early and late stages of incubation. The ants were also observed preying upon newly hatched hatchlings within the nest cavity. Neem cake, derived from the seeds of the native plant Azadirachta indica, was evaluated for its repellent properties. Application of neem cake to the nest at different stages of incubation effectively repelled the ants without causing mortality and ensured the successful emergence of hatchlings. The study provides the first direct record from India of predation on olive ridley turtle eggs by the hypogaeic ant Dorylus orientalis, demonstrating a simple and eco-friendly method for managing ant infestations in sea turtle hatcheries.
Keywords: Predation, conservation, ecology, ants, sea turtle, Asia