Sambar

Sri Lanka's sambar is the subspecies Rusa unicolor unicolor. At Horton Plains National Park it is a grazer of the wet patana grasslands, and there were over 1,000 animals there at the start of an 18-month study in 2018 (Weerasekera et al. 2020). Counts over 2018 to 2020 on 9.4 km² of grassland peaked each November and December at roughly 180 to 213 animals per km² (Weerasekera et al. 2023).

Horton Plains herds are unusually large, averaging about 20 animals against the usual two to four in India and Sri Lanka, and up to 52 between September and December (Weerasekera et al. 2020, 2023). Calving peaks in July and August, and hard antlers are carried through the September to January breeding season, a seasonality the authors compare to temperate deer. In Wilpattu, sambar are far sparser, at 8.26 ± 4.48 deer per km², in a mix of solitary animals and small groups (Gunawardhana et al. 2025). Nationally Near Threatened (Sri Lanka National Red List 2012).