The strait is about 50 kilometres (31 mi) wide with a maximum depth of around 100 metres (330 ft).[3] It was therefore likely to have been below sea level before the last ice age and archaelogica; records indicate that there was an exchange of flora and fauna such as the Bornean tiger#Archaeological records between Borneo and the Palawans.[4][5][6][7][8]
^Piper, P. J.; Ochoa, J.; Lewis, H.; Paz, V.; Ronquillo, W. P. (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. Bibcode:2008PPP...264..123P. doi:10.1016/j.palaeo.2008.04.003.