Mohamed bin Zayed Species project number 220529130

Understanding the distribution, population and spatial ecology of Critically Endangered brown tortoise in Sumatra, Indonesia

Asian giant tortoise (Manouria emys) is listed as critically endangered in IUCN Redlist. The major drivers of declining of the tortoises population are the harvesting of animals for food, pet trade, and habitat fragmentation. In Indonesia, Asian giant tortoise is under presented and no conservation actions have been implemented until now. There are only few efforts conducted, behaviour study (Høybye-Mortensen, 2004; Mo, 2020), distribution records (Platt et al. 2018), and morphometric study (Kundu et al. 2018). However, the knowledge of ecological impact of the Asian giant tortoise is still limited while the population of this keystone species is dramatically declining.

Meanwhile we have very well ecological knowledge of other tortoise species (Chelonoidis niger).Previous studies suggest they promote the distribution of cactus plant and move the seeds over a long distance (Gibbs et al, 2010; Blake et al, 2012). A study from amazon noted that tortoises could disperse the seeds about 276.7 m (Jerozolimski et al, 2009). As very little is known about the ecological role & distributional range of Asian giant tortoise in the tropical area, the objectives of this proposed study will cover the research gap in Asian tortoises. All the information collected during the study will be original and significantly add to the limited knowledge of this species.

Objectives:
1. To study the habitat selection of Asian giant tortoise at a small scale.
2. To study activity, movement and home range of Asian giant tortoise by using low-cost GPS tracker.
3. To observe the diet of Asian giant tortoise, how they forage and what plant seed they can disperse.
4. To understand the distribution in island scale area using species distribution models.

Reference:
Blake, S., Wikelski, M., Cabrera, F., Guezou, A., Silva, M., Sadeghayobi, E., ... & Jaramillo, P. (2012). Seed dispersal by Galápagos tortoises. Journal of Biogeography, 39(11), 1961-1972.
Gibbs, J. P., Sterling, E. J., & Zabala, F. J. (2010). Giant tortoises as ecological engineers: a long‐term quasi‐experiment in the Galápagos Islands. Biotropica, 42(2), 208-214.
Høybye-Mortensen, K. (2004). The tortoise Manouria emys emys: behaviour and habitat in the wild (Doctoral dissertation, Syddansk Universitet).
Jerozolimski, A., Ribeiro, M. B. N., & Martins, M. (2009). Are tortoises important seed dispersers in Amazonian forests?. Oecologia, 161(3), 517-528.
Kundu, S., Kumar, V., Laskar, B. A., Tyagi, K., & Chandra, K. (2018). Morphology and genetic variation in the endangered tortoise Manouria emys: distinct lineages or plastron anomalies?. Mitochondrial DNA Part B, 3(1), 166-170.
Platt, S., Platt, K., Myo, K. M., Soe, M. M., & Rainwater, T. (2018). Distribution records and conservation status of the Burmese Black Giant Tortoise (Manouria emys phayrei Blyth 1853) in western Myanmar. Herpetology Notes, 11, 847-852.
Mo, Matthew. "Only in captivity?: An interaction between two threatened chelonians, an Asian Giant Tortoise (Manouria emys) and a Malaysian Giant Turtle (Orlitia borneensis)." Reptiles & Amphibians 27.1 (2020): 89-90.