The park has 24 recorded species of
mammals, including
primates such as
gibbons,
banded langurs, and
long-tailed macaques. A total of 185
species have been identified in the park including
hornbills and
migratory water birds like the
Storm's stork. There are 8 species of
hornbill recorded in Sarawak including the
rhinoceros hornbill and the
black hornbill, which can be found in the park. Occasionally,
green sea turtles come ashore to lay their eggs. 12 out of the 20 marine mammals recorded in
Malaysia can be found in Sarawak. These include
whales,
dugongs, and
dolphins. Five species of dolphin have been recorded in Bintulu waters: the
Irrawaddy dolphin,
bottlenose dolphin,
Indo-Pacific humpback dolphin,
finless porpoise, and
pantropical spotted dolphin. Dolphins can be seen in the park from March to September every year. They are often spotted in groups of four or more during the early morning. The crocodiles in the Likau River consist of two species of riverine
crocodiles in the park: the
false gharial and
saltwater crocodile. The saltwater crocodile is very dangerous and has been responsible for many fatal
attack in Sarawak. The false gharial is generally shy and passive, but on rare occasions fatal attacks have been confirmed in
Central Kalimantan and
Sumatra. The
horseshoe crab often appears during the dry season from early May to October. They usually appear in pairs. The males are smaller in size compared to the females, who come to the shore to lay eggs. During the breeding season,
Sagor catfishesSagor Catfishes can be seen feeding on the eggs. ==Main attractions==