The Bawean deer, Hyelaphus kuhlii, also known as Kuhl's hog deer or Bawean hog deer, is a highly threatened species of deer found only in the island of Bawean (Gresik Regency) in Indonesia. A typical height for males of 60–70cm has been reported. Males have three-tined antlers. Their fawns are spotted at birth, which separates them from the best known western population of the hog deer (H. porcinus). Due to ongoing habitat loss, small population size and limited range, the Bawean deer is evaluated as critically endangered on the IUCN Red List of Threatened Species. It is listed on Appendix I of CITES. It has few natural enemies except for birds of prey and large snakes such as pythons.
Their past extinction was due to the Balinese tiger, and humans hunting them for their antlers and pelts. Their main predators now are humans, but also leopards, the golden jackal, dholes (the Asiatic wild dog), the Indian wolf, pythons, and crocodiles. Another reason for population decline is from habitat deterioration to build bigger cities, and more places to live and build crops.
The World Wildlife Fund, has said that one of the factors for the reason of the declining of this species, as well as other species found in Indonesia is from climate changes such as warming ocean temperatures, rising sea levels, prolong droughts, and increased flooding. The current conservation efforts which is being done is the Government of Indonesia has the Bawean deer protected against being hunted which was passed in 1977. With the help of this law that has been passed the reproductive success has gone up over the years. International Union for Conservation of Nature (IUCN) has listed the Kuhl's hog deer as being critically endangered, meaning that the species is facing an extremely high risk of extinction in the wild.
