Explorations of an Ecologist: Borneo 2018: Part 8 (Tabin Wildlife Reserve)

Part 1: Fly to Borneo, Kota Kinabalu (September 30 - October 2, 2018)
Part 2: Kota Kinabalu to Mount Kinabalu (October 3, 2018)
Part 3: Full day at Mount Kinabalu (October 4, 2018)
Part 4: Mount Kinabalu to Sepilok (October 5, 2018)
Part 5: Sepilok (October 6, 2018)
Part 6: Kinabatangan River (October 6-7, 2018)
Part 7: Kinabatangan River, Gomantong Caves (October 7-8, 2018)
Part 8: Tabin Wildlife Reserve (October 8-9, 2018)
Part 9: Tabin Wildlife Reserve (October 9-10, 2018)
Part 10: Danum Valley (October 11-12, 2018)
Part 11: Danum Valley (October 13-14, 2018)

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October 8, 2019 (continued)

The Tabin Wildlife Reserve is one of the largest protected areas in Sabah province, and by extension, Borneo. The reserve was established in 1984 and protects a large swath of lowland dipterocarp forest. Perhaps the reserve is most famous for housing and attempting to breed Sumatran Rhinoceroses on site. Unfortunately the last male Sumatran Rhino in Borneo, which was housed at the reserve, passed away earlier this year leaving just one female remaining, and she is not reproductively viable. Occasional sightings of Sumatran Rhinos occurs in the Indonesian province of Kalimantan in southern Borneo, but it is thought that less than 10 individuals exist and it is likely only a matter of time until the species is extirpated from Borneo. Fewer than 100 remain in Sumatra and that is after the population has dropped about 70% in the last two decades. As is so often the case with large mammal species, poaching and habitat loss are the primary drivers of the Sumatran Rhinoceros' inevitable extinction in the upcoming decades.

The Tabin Wildlife Reserve is an incredible area with impressive diversity, and it is the location for a lot of research about tropical ecology. I was particularly thrilled to visit this place for the first time. Our group would be here for three nights and would explore the reserve both on foot, and from the bed of a large truck outfitted with rows of seats.

To reach Tabin, we rumbled along a dirt road that traversed countless tracts of oil palm plantation. While the protected areas in Sabah are utterly spectacular, travelling by vehicle between reserves provides a sobering view of the rest of the landscape. Fortunately there are quite a few protected areas in Sabah for now and we can only hope it stays that way.

We finally reached a wall of trees, signalling the beginning of the Tabin Wildlife Reserve. The main entrance road passes by right along the edge of the forest with oil palm plantation on one side and mature tropical forest on the other side. Later that day we would be going on a dusk drive along this road.

Tabin Wildlife Reserve, Sabah, Malaysia

Around lunchtime we arrived at the lodge, tucked just inside the forest edge with each of the cabins overlooking a beautiful creek. Welcome drinks were in order, followed by a brief orientation with Rafael, a local guide from Tabin who would be with us for the duration of our stay. Lunch was next, then a break for a couple of hours before we would reconvene for our dusk drive.

I went out for a short walk on the lodge grounds, seeing what birds I could drum up during the middle of the day. A nice little flock contained Black-winged Flycatcher-Shrike, Ruby-cheeked Sunbird, Greater Green Leafbird and several other species.

Black-winged Flycatcher-Shrike - Tabin Wildlife Reserve, Sabah, Malaysia

Around 4:30 we loaded ourselves into the back of the truck and began our dusk drive. Excitement was high and anything would be possible. Often, crepuscular and nocturnal mammals will come out to the edge of the forest at dusk and in the evening to feed on the abundant oil palm fruit in the nearby plantation.

Bird sightings were frequent as we began our drive - Blue-throated Bee-eaters, Dusky and Chestnut Munias, Dollarbirds and Fiery Minivets - but it was the mammals that stole the show. Rafael spotted a large stick "nest" in a roadside tree that materialized as an Orangutan! But even better, she had a youngster in tow. Mom wasn't visible as she was in the stick shelter and only occasionally a hairy arm would reach out to re-position a stick. But the youngster was happy to play in the trees and eat a few figs in the last hour before sunset. Orangutans make these shelters each evening for protection.

Bornean Orangutan - Tabin Wildlife Reserve, Sabah, Malaysia

Young Bornean Orangutans will remain with their mothers for the first six or eight years of their life, a necessity so that they can learn the ways of the forest.

Bornean Orangutan - Tabin Wildlife Reserve, Sabah, Malaysia

It was a pretty incredible experience to witness. Finally around dusk, mom coaxed the little guy into the nest, and we continued on.

Bornean Orangutan - Tabin Wildlife Reserve, Sabah, Malaysia

Orangutans are just one of many species in the Borneo rainforests that require a high percentage of figs in their diet. Various pigeons and doves also specialize on this food source with certain species favoring particular figs. Unlike fruit-doves which are vital in dispersing fig seeds, green pigeons have muscular gizzards which crush up the fig seeds. The Large Green Pigeon is the least common of the green pigeons and it specializes on large figs. We were fortunate to have a pair fly past while we were oggling the orangutans.

Large Green Pigeons - Tabin Wildlife Reserve, Sabah, Malaysia

Around dusk several new bird species could be heard calling from deep within the forest. We had two new species - several Great Argus (a seriously impressive pheasant) and a White-crowned Hornbill. The White-crowned is one of the rarer hornbills in Borneo but it is relatively common at Tabin, as are all seven other species of Bornean hornbills.

Eventually all residual sunlight was gone and we rumbled along under an incredible night sky. Rafael spotted eyeshine on a few occasions - usually, the culprit was a Common Palm Civet gorging itself on the oil palm fruits. This one particular individual was particularly "cooperative" with our group. A nice way to finish off a great dusk drive.

Common Palm Civet - Tabin Wildlife Reserve, Sabah, Malaysia

October 9, 2018

Before dawn I was awakened by some strange calls that I had never heard before. I got myself ready for the day and was pleasantly surprised to find that the culprits were a family group of North Bornean Gray Gibbons. The four extant genera and eighteen species of gibbons in the world are classified as "lesser apes", while the "great apes" include orangutans, gorillas, chimpanzees and of course, humans. My group was not fortunate enough to see gibbons in 2017 so this was a nice bit of redemption.

North Bornean Gray Gibbon - Tabin Wildlife Reserve, Sabah, Malaysia

According to Rafael, this family group of gibbons is often seen in the lodge environs, and Rafael pointed out each of the family members and what their names were. While gibbons and orangutans are both apes, there are some major differences in their habits. Gibbons will travel in these small groups while orangutans are generally solitary. Gibbons are also able to swing ("brachiate") effortlessly through the forest using their long limbs, while Orangutans move much more slowly. Gibbons are shown to be the most important dispersers of many fruit species in lowland dipterocarp forests. Gibbons also occur in higher densities than orangutans, partly because they are better suited at accessing all fruits, even those on small trees that Orangutans cannot climb.

North Bornean Gray Gibbon - Tabin Wildlife Reserve, Sabah, Malaysia

Our morning excursion was a hike to a "mud volcano", that is, an area where water is pushed up to the earth's surface through a fault and it mixes with soil to create a slurry. However the hike to the mud volcano was through a beautiful section of forest meaning that wildlife sightings would be frequent.

Rhinoceros Hornbill - Tabin Wildlife Reserve, Sabah, Malaysia

The above Rhinoceros Hornbill was perched in a roadside tree, while the Banded Broadbill pictured below was the first one of the trip for our group.

Banded Broadbill - Tabin Wildlife Reserve, Sabah, Malaysia

We moved slowly through the forest, in part because it maximized our chances at seeing wildlife, but also due to the stifling heat and humidity. Among the many avian highlights were sightings of Crimson-winged Woodpecker, Borean Crested Fireback and Black-crowned Pitta. We also heard Blue-headed Pitta, a rare Jambu Fruit-Dove and the spectacular call of a Helmeted Hornbill. This species' vocalizations last for upwards of several minutes. It starts as single, resonant "hoot" note every 20 seconds or so; eventually, the gap between calls narrows over time, until the notes are right after each other. The call eventually climaxes with a maniacal laugh that reverberates through the whole forest. Hearing a full rendition can send chills down your spine!

Broad-headed Carpenter Bee - Tabin Wildlife Reserve, Sabah, Malaysia

Eventually we emerged into the open area where the mud volcano was located. Unfortunately the "volcano" was inactive at this time, appearing as just a big field of crusty mud that one can walk over. But we lucked out with some wildlife sightings including the Helmeted Hornbill which flew into view and called from the edge of the clearing. We also lucked out with flyovers of two raptors - an Oriental Honey-Buzzard and a Black Eagle, both of them new species for me.

Black Eagle - Tabin Wildlife Reserve, Sabah, Malaysia

Oriental Honey Buzzard - Tabin Wildlife Reserve, Sabah, Malaysia

The hike was a resounding success and we finished with great views of a Black-crowned Pitta near the start of the trail. Soon we were rumbling back to the lodge in the truck, the breeze feeling incredible against our sweat-soaked field clothes.

We enjoyed a tasty buffet lunch at the lodge followed by a few hours of down time. Some took advantage of this by relaxing on their back porches overlooking the river which proved to be a prudent decision. A due of young Oriental Small-clawed Otters slowly ambled along, flipped rocks in the shallows in search of crustaceans and fish. Fortunately most of the group was able to assemble to watch the antics of the otters.

Small-clawed Otters - Tabin Wildlife Reserve, Sabah, Malaysia

The two individuals were very easy to tell apart, since one was lacking a tail!

Small-clawed Otters - Tabin Wildlife Reserve, Sabah, Malaysia

Small-clawed Otters are one of four otter species that inhabit Bornean rivers. Obviously if each of these species utilized the same habitats and foraging technique, there would be too much competition and one species would likely dominate eventually. However, Small-clawed Otters specialize by working smaller rivers and especially by consuming small morsels found in the shallows and under rocks. The similar looking Smooth Otters usually stick to the big rivers, where they eat mostly fish.

Small-clawed Otters - Tabin Wildlife Reserve, Sabah, Malaysia

That afternoon we loaded back into the truck to head to a different part of the reserve. Here we accessed a track that cut through secondary forest and which eventually reached nice primary forest. We explored on foot in hopes of coming across across some different species than what is expected in the primary forest.

Birding was a little slow, though we did add a few things including a nice view of two Rufous Piculets, a Scarlet-rumped Trogon, several babblers and bulbuls and a heard only Asian Emerald Dove. A few Bornean Bearded Pigs appeared too, though they quickly disappeared into the forest.

Bornean Bearded Pig - Tabin Wildlife Reserve, Sabah, Malaysia

That evening we went for a nice long night drive, but that will be included in the next post.

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Thursday, 18 July 2019

Borneo 2018: Part 8 (Tabin Wildlife Reserve)

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