Retracing the largest land mammal in the Philippines Keywords: Bubalus mindorensis, Tamaraw, critically endangered species, Mindoro, ocular observation Don Geoff E. Tabaranza Mindoro Biodiversity Conservation Foundation, Inc. (MBCFI) Muntinlupa City Email: djop.tabaranza@gmail.com Elyza Hazel P. Tan MBCFI Ma. Teresita Pineda-David Jr. Department of Environment and Natural Resources-Tamaraw Conservation Program (DENR-TCP) Virtito C. Natural Jr. MBCFI Eduardo B. Bata John Ramer G. Casuncad DENR-TCP The Mindoro endemic Tamaraw ( Bubalus mindorensis), the largest Philippine native land mammal, is critically endangered as its population has declined severely over the last century due to hunting and habitat loss. For more than two decades, Tamaraws were thought to occur in only three sites of Occidental Mindoro. New feld surveys were conducted to locate additional remaining populations on the island, to infer the range of the number of individuals, and to augment the current information on the Tamaraw ecology. Expeditions in Upper Amnay Watershed (January to February, June, and August 2018) between the provincial border, and in Mt. Calavite Wildlife Sanctuary (June 2019) of Occidental Mindoro reconfrmed the presence of Tamaraw with estimated ranges of 141–169 and 4–6 individuals, respectively. Through trained ocular observation, signs were classifed into direct and indirect signs. Habitat assessments demonstrate that the Tamaraw occupies various habitats with a wide range of elevation and is not limited to grassland habitats. Sylvatrop, The Technical Journal of Philippine Ecosystems and Natural Resources 32 (2): 33–52 Jackie M. Belmonte Jr. d'Aboville Foundation and Demo Farm, Inc. (DAF) Kathy Lene S. Cielo MBCFI Leticia E. Afuang Institute of Biological Sciences University of the Philippines Los Baños MBCFI Grace C. Diamante Elvin M. Madamba MBCFI Emmanuel Schütz DAF