Philip Piper et al reported the discovery of the presence of Panthera tigris in the island of Palawan, Philippines. The team of archaeologists who were excavating Ille Cave near El Nido found the tiger bones in a “large human-derived animal bone assemblage dating to at least the early 11th millennium BP that included the remains of macaques, deer, pigs and a variety of small mammals and reptiles.” They found a complete set of toe bones: a complete basal phalanx of the 2nd digit of the left manus and the distal portion of a subterminal phalanx of the 2nd digit of the left manus (see picture below).
According to the authors, the tiger was in Palawan during the late stages of the Pleistocene. The probability that the tiger was from animal bone trading in 10th and 12th century Philippines is nil, considering that the bones were articulated and with no evidence of human modification. They suggest that “the skeletal elements found in Ille represent the remains of an individual either hunted or scavenged in the environments around the cave.” They explained that “the remains of large mammals, particularly top predators that are naturally scarce in ecological communities are generally (but not always) rare in Late Pleistocene archaeozoological accumulations.”
The tiger, P. tigris, was “a member of the Middle Pleistocene ‘megafauna’ which once roamed the open woodland and savanna environments of the Sunda shelf about 900,000 yr ago and still inhabits the island of Sumatra today.” Piper et al said that the tigers may have “first entered Palawan from Borneo and established a population in the Middle Pleistocene some 620 ka or 420 ka during periods when the expansion of the polar ice sheets
reduced relative sea levels to their lowest at ca. −130 m.” The authors suggest that the tigers might have swam from Borneo to Palawan across the Balabac Strait when the distance between the islands was reduced to a few kilometers. Similar migrations might have happened to the other terrestrial animals as well since “92% of Palawan’s non-volant mammal community have close relatives in Borneo or on other islands of the Sunda shelf.”
The authors further explained that the tiger populations in Palawan were isolated when the Balabac Strait widened due to climatic amelioration and sea level rise at the end of the Pleistocene. From an estimated landmass of 100,000 square meters, the sea level rise reduced Palawan to 12,000 sq meters, reducing the available habitat for the tigers and the deers (an important resource for the tigers). The authors concluded that
The eventual extinction of the tiger on Palawan was probably a consequence of the isolation of a small population, vast reduction in habitat, diminishing food resources and possibly predation by people. The combination of these factors is not dissimilar to contemporary pressures confronting remnant tiger populations across Asia. The fate of the tiger on Palawan is a cautionary tale that demonstrates the vulnerability of small isolated populations of large mammals to extinction.
Piper, P., Ochoa, J., Lewis, H., Paz, V., & Ronquillo, W. (2008). The first evidence for the past presence of the tiger Panthera tigris (L.) on the island of Palawan, Philippines: Extinction in an island population Palaeogeography, Palaeoclimatology, Palaeoecology, 264 (1-2), 123-127 DOI: 10.1016/j.palaeo.2008.04.003