BV-09: MANGROVE RIVER CRUISE, GORGEOUS MONKEYS AND GLOW BEETLES

13.00 Meeting with the guide at the hotel reception.  

15.30 Arrival at the base, where we will be greeted with tea, coffee and fried bananas. Proboscis monkeys and long-nosed macaques can often be seen from the pier.

16.00 After rest, we will go along the river with motorboats to see the animals. Proboscis monkeys are endemic to the island of Borneo, they are old world monkeys, so they can feed on mangrove leaves, the tail is only for balance unlike the new world monkeys which have a tusk. Their main food is mangrove leaves. The large bloated bellies contain special digestive bacteria that break down food by fermentation. The digestive system is very specific, so the menu is very limited. Foods high in sugar, such as ripe fruit, cause bloating and can be fatal. This specialized diet is the main cause of death of monkeys in zoos, so they are difficult to maintain and should not be kept in captivity. They live in two groups: a family of up to 20 females and one male, and a bachelor pack of only males. They are excellent swimmers and are skilled tree-to-tree jumpers. But they are shy.

18.00 Back at the base, we have a local style dinner of chicken curry, rice, vegetables and fruits.

18.30 After dark we will go back down the river to see the speed beetles. Five species are found in the state of Sabah (there are 200 species in the world): p. tener, p. gelasina, p. similar, p. malaccae, p. validates. To communicate with each other, they flash at different intensities. Males flash to attract females of the right species. Artificial light interferes with communication, so they live far from cities where there is no light pollution. The best time to see speed beetles is between 19:00 and 22:00. The beetle’s light source is “cold” light: 2% heat and 98% light, otherwise they would die. Beetles live less than one month. Contains a chemical called luciferin, which makes them unpalatable. When luciferin combines with oxygen and an enzyme (luciferase), a chemical reaction occurs that causes the belly to glow.

19.00 Departure to hotel.

21.30 Estimated arrival time at the hotel.