There is currently a lack of detailed information about the life history of the Philippine brown deer. It is known that breeding most commonly occurs from September to January, with females giving birth to a single fawn marked with light coloured spots, which disappear after a few weeks. During the rut, females may form small groups of up to eight individuals, but the males remain solitary and are aggressive (7).
Resting during the day, hidden in dense vegetation, the Philippine brown deer commences activity in the evenings which continues throughout the night until dawn. This species generally favours the edges of forests or forest clearings, browsing upon a variety of vegetation such as grasses, leaves, fallen fruit and berries (7). In the regions where it has been introduced, the Philippine brown deer has caused significant damage to indigenous ecosystems, preventing forest regeneration as well as eating large amounts of crops (6) (8) (9).