The species occurs in grasslands, open woodlands and second-growth forest (Hoogstraal, 1951). It has a gestation length of approximately 180 days, with typically one young, and rarely twins. Age at sexual maturity is 8-12 months, with a life span of 12-20 years. This species is diurnal, browses on leaves, and lives in small herds (Wemmer, 1998). This species has a group size up to 27 individuals, but usually 7–14 (with much smaller groups reported in heavily hunted areas; Oliver and Villamor, 1992).

Red List Category

Red List Criteria

Version

2008

Oliver, W., Widmann, P. & Lastica, E.

Black, P.A. & Gonzalez, S. (Deer Red List Authority)

Justification

History

• 1996
  Endangered
  (Baillie and Groombridge 1996)
• 1994
  Endangered
  (Groombridge 1994)
• 1990
  Vulnerable
  (IUCN 1990)
• 1988
  Vulnerable
  (IUCN Conservation Monitoring Centre 1988)
• 1986
  Vulnerable
  (IUCN Conservation Monitoring Centre 1986)

The species was reputedly common in all suitable localities throughout the main islands islands of Busuanga and Culion in the 1940s, but to have drastically declined in numbers on all parts of these islands, except in the extreme south of Culion, by the mid-1970s (Grimwood, 1976). A small population of deer surviving on Calauit Island at that time was supplemented by a further 30 translocated individuals in 1977 (J. Gapuz pers. comm.), following the creation of the ‘Calauit Island Game Preserve and Wildlife Sanctuary’ in 1976, and the eviction and resettlement of the islands former residents (Oliver, 1993; Oliver and Villamor, 1993). By April 1994, Calauit was reported to hold an estimated population of 1,123 ± 236 individuals (Orig and Rosell, 1994); though more recent estimates indicate significant reductions in the numbers of these animals numbers following resettlement of the island by former residents and resurgence of hunting pressure. A survey in 2006 (Rico and Oliver, in prep.) showed the species still to be widespread on Calauit, Busuanga and Culion. though densities remain low in many areas (W. Oliver pers. comm.). It was also found still to be present on the islands of Marily and Dimaquiat.

Decreasing

The species is threatened due to hunting pressure and human settlement and agricultural expansion over its very limited range, coupled by the evident lack of effective and sustained enforcement of the strong local protective legislation (W. Oliver pers. comm. and unpubl.). Hunting was particularly severe during the mid-1970s (Grimwood, 1976), but seemingly declined in most areas during the 1980’ and 1990’s, except on Calauit where hunting pressure increased dramatically following the resettlement of the island by former residents under the auspices of the ‘Balik (Back to) Calauit Movement’. In 1986, 51 out of the 256 families evicted from the island ten years earlier had re-settled on the island, and by 1992 the settlers numbered nearly 500 people (Oliver, 1993; pers. comm.). Much of the hunting of the species is recreational, and also to provide venison to the local markets (W. Oliver pers. comm.). On Calauit, introduced African ungulate populations are increasing but are probably not competing with Calamian deer. A presidential proclamation that precluded removal or control of exotic species, and the movement or management of Calamian deer on Calauit Island was recently amended, thereby also potentially enabling the better future control of the exotic ungulate populations, though in fact many of these populations have also been seriously reduced by poaching. While relatively large parts of Busuanga and Culion Islands are still undeveloped and sparsely inhabited, there are no proper reserves on either.

It occurs in the Calauit Island Game Preserve and Wildlife Sanctuary (37.4 km²), which was established in 1976 to protect a collection of free-ranging African ungulates. Protection is inadequate and there are no management plans (Oliver, 1993). Several hundred local people were evicted at that time it was established, but many of these have since returned to settle illegally (Oliver and Villamor, 1993). Thirty animals were introduced to Calauit in 1977 to supplement a small relict population (Orig and Rosell, 1994).

The following conservation actions are recommended:
1. Monitor current status on all the three islands and determine population trends. Evaluate levels of hunting and habitat loss.
2. Strengthen existing protected area system via establishment of new (additional) reserves and development and implementation of properly structured conservation management plan for Calauit that includes improved infrastructure, and measures to combat poaching.
3. Agree and establish a zoning system within Calauit in collaboration with all relevant stakeholders, which enforces strict protection of the core area.
4. Establish protected areas on Culion and Busuanga, based on habitat and deer status surveys.
5. Undertake behavioral and ecological research of Calauit deer to determine management requirements. Conduct
more detailed studies in selected areas.
6. Initiate a conservation education program using Calamian deer as a flagship species to promote a wide variety of related conservation activities, including combatting the bushmeat trade.

This species is listed on CITES Appendix I. There is a captive population of 54 individuals in the San Diego Zoo (as of March 2008).