Day 3: A Sack Full of Bats

Several of us woke at 5:30 in the morning to look for and document the variety of bird species that lived in the area. We ate our usual sardines and tomato stew with rice, then several of us, including Noerdjito, an ornithologist with the Indonesia Institute of Sciences, climbed into a small boat and motored upstream.

After about 20 minutes we banked on a stony beach area, pulled out binoculars and began our search for birds. We spotted a brahminy kite, a blue-winged leafbird, and an oriental darter with its sleek dark body and long neck. Several times we looked up to see a variety of hornbills, their massive wings making a distinctive deep whooshing sound as they flew above our heads. We also heard the melodic call of a greater racket-tailed drongo. We never saw the bird, but a book Noerdjito carried with him showed the bird – it is a deep midnight blue with a small crest of black feathers protruding from the top of his beak and a long, forked tail that hangs twice the length of the bird’s body.

As we sat on the rocky beach, we noticed the footprints of a monitor lizard that can grow to be more than three feet long. On our trip back down the river, we slowly approached a large colony of gibbons – called “woop woops” by the local Indonesians because of their calls. The hoots grew louder as we approached a towering tree to our left, but we could not see the gibbons through the thick foliage. We later floated past a group of proboscis monkeys perched in a tree immediately next to another tree filled with macaques whose long tails dangled below them as they pulled their breakfast of leaves from the high branches.
Bats hanging on the ceiling of a cave of Borneo. © Cahyo Rachmadi

We also saw the most beautiful bird I had ever seen - a stork-billed kingfisher which has a yellow body, orange bill and vibrant blue wings. During his four weeks with the expedition, Noerdjito documented a total of 124 bird species living in the Sangkulirang karst areas, nearly one-third of all the non-migratory, non-wetland birds found in Borneo.

That evening, Matt and Leo ventured into the dark jungle to erect traps to catch bats as they flew out of the caves. They returned several hours later, drenched in sweat and smelling of guano and carrying several canvas sacks holding live bats. Among his captures was a gold-tipped tube-nosed bat, documented only once before in Indonesia, about 50 years ago.

In all, Matt documented 34 species of bats in the Sangkulirang area, more than one-third of all the known bat species in Borneo and more than any other known site in Kalimantan, including protected areas. Several of the species he collected had never before been seen in Kalimantan.