Borneo, October 2022

Borneo, the third largest island in the world behind Greenland and New Guinea, is home to some of the planet’s oldest rainforests, containing a stunning array of biodiversity. The conditions in Borneo forests have stimulated the evolution of many different organisms that are capable of gliding between the tall trees, and there are “flying” squirrels, frogs, Draco lizards, geckos, colugos, even snakes and ants! 

While Borneo is currently manifested as an island, over geological time this is usually not the case. The waters between the Malay Peninsula, Java, Sumatra and Borneo are all quite shallow, and during periods of low water levels (such as during glacial maxima) these areas are connected by land, which is the case about 80% of the time.  Collectively, this part of the world is known as the Sundaic shelf and many species are shared between the land masses in this region.   

A number of Borneo’s species are found nowhere else in the world, meaning that they are endemic to Borneo. Many of Borneo’s endemic species are resident to the highland areas of the island where they have adapted to the cooler conditions and unique habitats. The iconic Bornean Bristlehead is a highly distinctive bird which is the only member of its family, and is endemic to the lowland forests of Borneo. Mammals are well-represented in Borneo and we were hoping to encounter many of the iconic species during our tour: the Sunda Colugo, Proboscis Monkey, Horsfield’s Tarsier and of course, the Bornean Orangutan. 

Bornean Orangutan - Tabin Wildlife Sanctuary, Sabah, Malaysia

This was my third Borneo tour for Worldwide Quest and I was looking forward to experiencing its biodiversity with a keen group of travelers. On October 6 we met in the city of Kota Kinabalu, located in the northwestern corner of the island within the Malaysian state of Sabah. During our first day, we visited sites near our hotel where we found many lowland coastal bird species that we would not see again on the tour. These included Pied Triller, Collared Kingfisher, the range-restricted Blue-naped Parrot and a great variety of terns, shorebirds and wading birds.

Chestnut Munia - Likas Lagoon, Sabah, Malaysia

Little, Intermediate and Great Egrets - Likas Lagoon, Sabah, Malaysia

Pied Triller - Likas Lagoon, Kota Kinabalu, Sabah, Malaysia

Ashy Tailorbird - Kota Kinabalu Wetland Center, Sabah, Malaysia

Periophthalmus sp. - Kota Kinabalu Wetland Center, Sabah, Malaysia

Mangrove Skink (Emoia atrocostata) - Kota Kinabalu Wetland Center, Sabah, Malaysia

Blue-naped Parrot - Tanjung Aru, Kota Kinabalu, Sabah, Malaysia

Green Imperial Pigeon - Tanjung Aru, Kota Kinabalu, Sabah, Malaysia

Dollarbird - Tanjung Aru, Kota Kinabalu, Sabah, Malaysia

Eurasian Tree Sparrow - Nabalu Viewpoint, Sabah, Malaysia

We left the city behind and drove up to the lower flanks of Mount Kinabalu, vegetated with beautiful chestnut and oak forest and home to an impressive array of endemic birds, treeshrews, pitcher plants, orchids and much more. Luck was on our side because one of the first birds that we discovered upon arrival was a rare Everett’s Thrush, an endemic species to Borneo’s highlands which was even a new species for yours truly.

Everett's Thrush - Mount Kinabalu, Sabah, Malaysia

As dawn broke each morning, the peak of Mount Kinabalu loomed above us, illuminated by the sun. We discovered an impressive variety of birds near our lodging in the forest during the early mornings – Bornean Green-Magpies, Bornean Treepies, Whitehead’s Spiderhunter, even a glistening Whitehead’s Broadbill. One morning, we found an endemic snake (Lined Reed Snake), while a night hike produced an adorable Balu Bow-fingered Gecko and many frogs. The epicenter of squirrel diversity is the island of Borneo and we found a variety of species here on Mount Kinabalu, including one of the smallest squirrels in the world: Whitehead’s Pygmy Squirrel. During a lull one afternoon, we visited a site further down the mountain where we observed blooming Rafflesia keithii. 

Matang Creek Frog (Limnonectes conspicillatus) - Mount Kinabalu, Sabah, Malaysia

Unidentified translucent cicada (subfamily Cicadinae) - Mount Kinabalu, Sabah, Malaysia

Borboropactus sp. - Mount Kinabalu, Sabah, Malaysia

Bornean Green-Magpie - Mount Kinabalu, Sabah, Malaysia

Borneo Black-banded Squirrel - Mount Kinabalu, Sabah, Malaysia

Snowy-browed Flycatcher - Mount Kinabalu, Sabah, Malaysia

Bornean Forktail - Mount Kinabalu, Sabah, Malaysia

Tufted Pygmy Squirrel - Mount Kinabalu, Sabah, Malaysia

Rafflesia keithii - Poring, Sabah, Malaysia

The rest of the tour took place in lowland rainforest in the northeastern region of the island. In the Sepilok area we spent an evening and a morning on a canopy walkway through primary rainforest, and while we struck out with Bornean Bristleheads, we had our first encounter with Bornean Orangutans here, found several gliding species (Draco lizards and Red Giant Flying Squirrels), and enjoyed many different birds. A night walk produced highlights such as the almost unbelievably-coloured Rufous-backed Dwarf-Kingfisher and a lucky find: a Horsfield’s Tarsier! We rounded out our time at Sepilok by visiting the Orangutan and Sun Bear rehabilitation centers. 

Borneo Skink (Dasia vittata) - Sepilok, Sabah, Malaysia

Bornean Orangutan - Sepilok, Sabah, Malaysia

Bartlett's Flying Dragon (Draco cornutus) - Sepilok, Sabah, Malaysia

Brown-backed Needletail - Sepilok, Sabah, Malaysia

Rufous-backed Dwarf-Kingfisher - Sepilok, Sabah, Malaysia

Horsfield's Tarsier - Sepilok, Sabah, Malaysia

Inger's Wart Frog (Limnonectes ingeri) - Sepilok, Sabah, Malaysia

Greater Racket-tailed Drongo - Sepilok, Sabah, Malaysia

Cinnamon-headed Green-Pigeons - Sepilok, Sabah, Malaysia

Pale Giant Squirrel - Sepilok, Sabah, Malaysia

North Philippine Temple Pitviper (Tropidolaemus subannulatus) - Sepilok, Sabah, Malaysia

Sun Bear (captive) - Sepilok, Sabah, Malaysia

The next leg of the trip was spent along the Kinabatangan River in a wide swath of riverine forest. The rivers and tributaries provide access to the forest; indeed, all of our travel was done by boat. It felt like a scene out of The Jungle Book as we slowly drifted down the tributaries, watching hornbills fly over and four species of monkeys feeding in the riverside trees. We found many endemic Proboscis Monkeys and spent time observing their group dynamics. A small population of the Endangered Storm’s Stork lives in this area and we lucked out with two sightings of this rare species. We found a Bat Hawk nest, three species of kingfishers, Black-and-red Broadbills and endemic Brown Barbets. A Small-toothed Palm Civet feeding on figs during the day was a lucky find as well. 

Small-toothed Palm Civet (Arctogalidia trivirgata) - Kinabatangan River, Sabah, Malaysia

Common Kingfisher - Kinabatangan River, Sabah, Malaysia

Bat Hawk (and nest) - Kinabatangan River, Sabah, Malaysia

Storm's Stork - Kinabatangan River, Sabah, Malaysia

Malayan Birdwing (Troides amphrysus) - Kinabatangan River, Sabah, Malaysia

Paradise Flying Snake (Chrysopelea paradisi) - Kinabatangan River, Sabah, Malaysia

Proboscis Monkey - Kinabatangan River, Sabah, Malaysia

Blue-eared Kingfisher - Kinabatangan River, Sabah, Malaysia

Yellow-bellied Prinia - Kinabatangan River, Sabah, Malaysia

For the next three nights we stayed in a beautiful lodge next to a small river in the Tabin Wildlife Sanctuary, the largest protected forest in Borneo. Afternoon and evening wildlife drives provided many highlights here: Buffy Fish Owls, several species of flying squirrel, all eight species of Borneo’s hornbills, a flanged male Bornean Orangutan and even two Leopard Cats. Birding hikes were quite successful and a memorable moment for many was the walk-away view afforded by a Blue-headed Pitta one afternoon, followed shortly by a pair of Bornean Crested Fireback pheasants. We spent quality time with a family group of North Bornean Gibbons near the lodge, and we found a rare Sabah Grizzled Langur. Our “birdiest” morning of the tour occurred during a visit to the interior forests of Tabin. Amongst our 65+ bird species that morning, some of the highlights included a Wallace’s Hawk-Eagle, White-bellied Munia, Pale Blue Flycatcher, great looks at a Black-crowned Pitta, a rare group of Swinhoe’s White-eyes and even a pair of Barred Eagle-Owls. 

Rhinoceros Hornbill - Tabin Wildlife Sanctuary, Sabah, Malaysia

Crested Serpent-Eagle - Tabin Wildlife Sanctuary, Sabah, Malaysia

Buffy Fish-Owl - Tabin Wildlife Sanctuary, Sabah, Malaysia

Common Parasol (Neurothemis fluctuans) - Tabin Wildlife Sanctuary, Sabah, Malaysia

Gray-rumped Treeswift - Tabin Wildlife Sanctuary, Sabah, Malaysia

Nisitrus vittatus - Tabin Wildlife Sanctuary, Sabah, Malaysia

Purple-naped Spiderhunter - Tabin Wildlife Sanctuary, Sabah, Malaysia

Lesser Green Leafbird - Tabin Wildlife Sanctuary, Sabah, Malaysia

Black Hornbill - Tabin Wildlife Sanctuary, Sabah, Malaysia

Blue-headed Pitta - Tabin Wildlife Sanctuary, Sabah, Malaysia

Barred Eagle-Owl - Tabin Wildlife Sanctuary, Sabah, Malaysia

Sunda Scimitar-Babbler - Tabin Wildlife Sanctuary, Sabah, Malaysia

Black-and-yellow Broadbill - Tabin Wildlife Sanctuary, Sabah, Malaysia

Pale Blue Flycatcher - Tabin Wildlife Sanctuary, Sabah, Malaysia

Swinhoe's White-eye - Tabin Wildlife Sanctuary, Sabah, Malaysia

Saban Grizzled Langur - Tabin Wildlife Sanctuary, Sabah, Malaysia

Blue-throated Bee-eater - Tabin Wildlife Sanctuary, Sabah, Malaysia

White-crowned Hornbill - Tabin Wildlife Sanctuary, Sabah, Malaysia

We finished the main tour by visiting the decadent Borneo Rainforest Lodge. These world class accommodations are situated deep in the Danum Valley, one of the largest expanses of protected primary rainforest in Sabah. Our days were filled with exploration along the trails and on the extensive canopy walkway, while after dark we embarked on night drives and short hikes in search of mammals, frogmouths and more. 

We finally connected with a couple of Bornean Bristleheads, while other memorable birds here included Helmeted Hornbill, Red-bearded Bee-eater, Crested Shrikejay, Chestnut-naped Forktail, Bornean Banded Pitta and Dusky Broadbill among many others. We lucked out with sightings of Sunda Colugo, Maroon Leaf Monkey, Lesser Mousedeer and Least Pygmy Squirrel, as well as a couple of rare rodents in Margaret's Ranee Mouse and Gray Tree Rat. The biodiversity in the Danum Valley is impressive and no two trips are the same. 

Lesser Mousedeer - Danum Valley, Sabah, Malaysia

Cyano sp. - Danum Valley, Sabah, Malaysia

Arthroschista hilaralis - Danum Valley, Sabah, Malaysia

Miltochrista synestramena - Danum Valley, Sabah, Malaysia

Hairy-backed Bulbul - Danum Valley, Sabah, Malaysia

Helmeted Hornbill - Danum Valley, Sabah, Malaysia

Phormingochilus sp. - Danum Valley, Sabah, Malaysia

Margaret's Ranee Mouse (Haeromys margarettae)

The main tour ended after the Danum Valley, but eight of the travellers continued on with me to peninsular Malaysia where we met up with Laura for the tour extension. That will be the focus of my next blog post.