The Mitsui & Co. Environment Fund

Introduction to Grant Projects

University of the Ryukyus Faculty of Science    Professor: Masako Izawa

Establishment of methods to evaluate the habitat of the endangered Iriomote mountain cat, with a focus on the aquatic environment of Iriomote Island.

Research grant

Project Description

Okinawa's Iriomote island is home to a large number of native species. What makes this possible is the unique and plentiful river systems. What role do the rivers have in the habitats of the island's endangered species? This will be clarified by using aerial laser surveying to map the waterways of the island, and by analyzing the habitats of the Iriomote cat—positioned at the top of the ecosystem, and the rare frog species living in and around the waterways. Based on the results of the findings, we will aim to develop an environmental map or establish methods to develop such a map. Additionally, in relation to an increase in human activity due to an increase in tourists on the island, we will create a guideline which will help to protect the ecosystem on Iriomote island. [No. R16-0035]

Ecosystems and the Symbiotic Society
Grant year
FY2016 Research Grants
Grant term
2 years
From April 2017 to March 2019
Grant amount
4.498 million yen
Activity region
Iriomote Island, Yaeyama District, Okinawa Prefecture
The Iriomote Cat

Overview of the Organization

Professor: Masako Izawa
Professor: Masako Izawa
Faculty of Science
University of the Ryukyus
Area of specialty: Animal ecology
Academic affiliation: The Mammal Society of Japan, The Ecological Society of Japan, The Biological Society of Okinawa
CV (work history, academic qualifications): After withdrawing from the second half of her Doctorate in Scientific Research at the Kyushu University Graduate School in 1984, she acquired a Doctorate in Science in the same year. Following work as a grants-in-aid researcher and special researcher for the Japan Society for the Promotion of Science, in 1990 she joined the Kitakyushu Museum of Natural History & Human History as a curator. In She became an assistant professor at The University of the Ryukyus in 1991, and a Professor from 2006, and currently retains that position.
Recent Activities
  • Nakanishi, N., M. Izawa et al. (2005) The effect of home range size in the Iriomote cat Prionailurus bengalensis iriomotensis Mammal Study, 30:1-10.
  • Watanabe, S., N. Nakanishi, & M. Izawa (2005) Seasonal abundance of the floor-dwelling frog fauna on Iriomote Island of the Ryukyu Archipelago, Japan. Journal of Tropical Ecology 21: 85-91.
  • Masako Date·Nozomi Nakanishi 2008 I drive an Iriomote wild cat to the subtropical forest. "Soft south study and thought" (University of the Ryukyus), pp.252-261, The Okinawa Times, Okinawa.
  • Izawa, M., N. Nakanishi et al. (2009) Ecology and conservation of two endangered subspecies of the leopard cat (Prionailurus bengalensis) on Japanese islands. Biological Conservation, 142: 1884-1890.
  • Masako Date·Nozomi Nakanishi (2010) Wonder of the creature [Iriomote wild cat—wildcat of the island of the water] heredity, 64(1): 2-7.
  • Izawa, M. and Nakanishi, N. 2015 The Iriomote cat: a discussion. In "Nature in the Ryukyu Archipelago" (eds. fujita, K., Arakaki, T., Denda, T., Hidaka, M., Hirose, E. and Reimer J. D.) pp.70-75.