The Calamian deer (Axis calamianensis), also known as Calamian hog deer,  is an endangered species of deer found only in the Calamian Islands of Palawan province in the Philippines. It is one of three species of deer native to the Philippines, the other being the Philippine sambar (Rusa marianna) and the Visayan spotted deer (Rusa alfredi).
It is considered by some taxonomists to be in the genus Hyelaphus ; however, in 2021, the American Society of Mammalogists placed it in the genus Axis ,  a position the IUCN also uses. 
It is known as the "hog deer" because when it is fleeing from danger, it dashes through underbrush with its head down like a hog instead of jumping over barriers like other deer. These animals are crepuscular, meaning that they are active at sunrise and twilight. They rest during the warmer part of the day and then come out from the undergrowth to forage. Mainly solitary, they sometimes form small herds if left undisturbed. As with other deer species, Calamian deer are ruminants, meaning that they have four stomach chambers and chew cud. A soft, high-pitched, nasal call is their main vocalization. Their diet consist of shoots, twigs, and leaves. 
A typical height for males of 60–65 cm (24–26 in) has been reported. Weight can very usually from 79-110 pounds. Males have three-tined antlers.  Their fawns are not spotted at birth, which separates them from the best known western population of the Indian hog deer (A. porcinus). There are few natural predators except for birds of prey and pythons.
Fossils were found at Ille Cave near the village of New Ibajay in Palawan. They were ascribed to tigers, deer, macaques, bearded pigs, small mammals, lizards, snakes and turtles. From the stone tools, besides the evidence for cuts on the bones, and the use of fire, it would appear that early humans had accumulated the bones.   
Using the work of Von den Driesch,  all chosen anatomical features of appendicular elements' anatomical features which were chosen, besides molars, were measured to distinguish between taxa that had close relationships, and see morphometric changes over ages, though not for pigs or deer. For the latter two, cranial and mandibular elements, besides teeth of deer from Ille Cave were compared with samples of the Calamian hog deer, Philippine brown deer, and Visayan spotted deer, and thus two taxa of deer have been identified from the fossils: Axis and Cervus .  Throughout deposits of the Terminal Pleistocene and early Holocene and Terminal Pleistocene at Ille Cave, elements of deer skeletons are regular, gradually becoming less before vanishing in the Terminal Holocene. One 'large' and one 'small' taxon can be easily differentiated by the significant change in size observed in the postcranial elements and dentition.  From comparisons of the mesial-distal and labio-lingual measurements of individual fossil teeth and mandibular toothrows with those of surviving deer taxa in the Philippines and other Southeast Asian islands, it appears that the Calamian hog deer is most plausible candidate for the small taxon. The hog deer exists in forest edges and open grassland habitats on the islands of Culion and Busuanga, which during the Pleistocene were part of the landmass of Greater Palawan, but not on Palawan itself nowadays. 
Palawan, officially the Province of Palawan, is an archipelagic province of the Philippines that is located in the region of Mimaropa. It is the largest province in the country in terms of total area of 14,649.73 km2 (5,656.29 sq mi). The capital city is Puerto Princesa. Palawan is known as the Philippines' Last Frontier and as the Philippines' Best Island.
Palawan is the largest island of the province of Palawan in the Philippines and fifth-largest by area and tenth-most populous island of the country, with a total population of 994,101 as of 2020 census. The north west coast of the island is along the South China Sea, while the south east coast forms part of the northern limit of the Sulu Sea. Much of the island remains traditional and is considered by some as under-developed. Abundant wildlife, jungle mountains, and some white sandy beaches attract many tourists, as well as international companies looking for development opportunities.
The chital or cheetal, also known as the spotted deer, chital deer, and axis deer, is a deer species native to the Indian subcontinent. It was first described and given a binomial name by German naturalist Johann Christian Polycarp Erxleben in 1777. A moderate-sized deer, male chital reach 90 cm (35 in) and females 70 cm (28 in) at the shoulder. While males weigh 30–75 kg (66–165 lb), the lighter females weigh 25–45 kg (55–99 lb). It is sexually dimorphic; males are larger than females, and antlers are present only on males. The upper parts are golden to rufous, completely covered in white spots. The abdomen, rump, throat, insides of legs, ears, and tail are all white. The antlers, three-pronged, are nearly 1 m long.
The Visayan spotted deer, also known as the Visayan deer, the Philippine spotted deer or Prince Alfred's deer, is a nocturnal and endangered species of deer located primarily in the rainforests of the Visayan islands of Panay and Negros though it once roamed other islands such as Cebu, Guimaras, Leyte, Masbate, and Samar. It is one of three endemic deer species in the Philippines, although it was not recognized as a separate species until 1983. An estimated 2,500 mature individuals survived worldwide as of 1996, according to the IUCN, although it is uncertain of how many of them still survive in the wild. The diet of the deer, which consists of a variety of different types of grasses, leaves, and buds within the forest, is the primary indicator of its habitat. Since 1991 the range of the species has severely decreased and is now almost co-extensive with that of the Visayan warty pig.
The Cervinae or the Old World deer, are a subfamily of deer. Alternatively, they are known as the plesiometacarpal deer, due to their ankle structure being different from the telemetacarpal deer of the Capreolinae.
The Philippine deer, also known as the Philippine sambar or Philippine brown deer, is a vulnerable deer species endemic to the Philippines. It was first described from introduced populations in the Mariana Islands, hence the specific name.
The Philippine mouse-deer, also known as the Balabac chevrotain or pilandok, is a small, nocturnal ruminant, which is endemic to Balabac and nearby smaller islands southwest of Palawan in the Philippines. The genus Tragulus means 'little goat' and the Philippine mouse-deer has been named so due to the horizontal pupils of the eyes. This position of the pupil allows for an increase in peripheral depth perception. It has traditionally been considered a subspecies of the greater mouse-deer. In 2004, though, T. nigricans was separated from T. napu as its own species due to differences in skull morphology. Contrary to its common name, the Philippine mouse-deer does not belong to the deer family Cervidae, but is a member of the chevrotain family.
The Bawean deer, also known as Kuhl's hog deer or Bawean hog deer, is a highly threatened species of deer endemic to the island of Bawean in Indonesia. 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.
The Palawan bearded pig is a pig species in the genus Sus endemic to the Philippines, where it occurs on the archipelago of islands formed by Balabac, Palawan, and the Calamian Islands. It is 1 to 1.6 m in length, about 1 m (3.3 ft) tall and weigh up to 150 kg (330 lb).
The Philippine long-tailed macaque is a subspecies of the crab-eating macaque, known in various Philippine languages as matching/matsing or the more general term unggoy ("monkey"). It is endemic to the Philippine forests and woodlands, but especially in the mangrove forests of western central Philippines— particularly in Palawan, the Visayas, and Mindanao. The names M. f. philippinensis and M. f. philippinenesis have also been used, but arise from orthographical error.
The Palawan water monitor, Varanus palawanensis, is a quite large species of monitor lizard in the family Varanidae. The species is endemic to the Philippines.
Calamian Tagbanwa is spoken in the Calamian Islands just north of Palawan Island, Philippines. It is not mutually intelligible with the other languages of the Tagbanwa people. Ethnologue reports that it is spoken in Busuanga, Coron, Culion, and Linapacan municipalities.
Calauit Safari Park is a wildlife sanctuary in the Philippines which was originally created in 1976 as a game reserve featuring large African mammals, translocated there under the orders of the President Ferdinand Marcos during his 21-year rule of the country.
Dewil Valley, located in the northernmost part of Palawan, an island province of the Philippines that is located in the Mimaropa region, is an archaeological site composed of thousands of artifacts and features. According to the University of the Philippines Archaeological Studies Program, or UP-ASP, the closest settlement can be found in New Ibajay, which is covered by the town capital of El Nido, which is located around 9 km (5.6 mi) south-east of Dewil Valley. Physically it measures around 7 km (4.3 mi) long, and 4 km (2.5 mi) wide. It is in this place which the Ille Cave, one of the main archaeological sites, can be found. It is actually a network of 3 cave mouths located at its base. It has been discovered that this site in particular has been used and occupied by humans over multiple time periods.
Elephas beyeri is an extinct species of dwarf elephant belonging to the Elephantidae family of the Middle Pleistocene. It was named after the anthropologist H. Otley Beyer. The type specimen was discovered on Cabarruyan Island in The Philippines but has since been lost.
The Sunda leopard cat is a small wild cat species native to the Sundaland islands of Java, Bali, Borneo, Sumatra and the Philippines that is considered distinct from the leopard cat occurring in mainland South and Southeast Asia.
The Bornean tiger is possibly an extinct tiger population that may have lived on the island of Borneo in prehistoric times. A live Bornean tiger has not been conclusively recorded, but the indigenous Dayak people believe in its existence and report sightings on occasion.