Into the forest at Lubuk Baji – Part 2: Monkeys and Apes

The real temperature was not so great, perhaps 83°F (28°C), but the humidity and the still air in the forest made it seem hotter.  I took large, slow strides, my toes instinctively trying to grip the slippery, steep slope through my sandals, my sleeves rolled down to keep the constant flow of sweat from dripping down my arms onto my camera bag.  A bandanna looped around my neck served as a towel to mop sweat from my face, sweat that stung my eyes, sweat that was so prodigious that it felt like the inside of my mouth was sweating.

Bird calls, the occasional ululating call of a gibbon, and the clicks and whirrs of numerous insects surrounded us.  Despite the fecund richness of the forest around us the only animal life to be seen were insects, most obviously large butterflies, predominately black in color, some with large yellow patches, others with cerulean blue patches, many with white polka-dots scattered over their wings.  In the warm air they rarely stood still, preferring to dance in the solitary shafts of sunlight and flit erratically through the trees.

Large butterflies were common in the forest, many about the size of an open hand

Large butterflies were common in the forest, many about the size of an open hand

On the forest floor, amongst the leaf litter crawled the occasional giant woodlouse, relatives of common pillbug but far larger.  They would curl at the slightest provocation, looking like painted ping-pong balls.

Giant woodlouse curled up on the forest floor

Giant woodlouse curled up on the forest floor

We were looking for wild orangutan in the hills of Lubuk Baji.  We knew they were in the area, abandoned sleeping nests in the trees and their pungent scent attested to their recent presence but they remained hidden in the forest.

Lubik Baji is a small hill on the west side of Gunung Palung National Park in West Kalimantan, Indonesia.  This large park is one of the last remaining protected lowland forests and contains nearly 10% of the world’s remaining orangutan.  The nearby town of Sukadana is partially surrounded by the park and a large number of people live nearby, many of them relying on resources found within the park for their livelihoods, especially timber resources.

Gunung Palung NP wraps around Sukadana, to the east is a small hill names Lubuk Baji

Gunung Palung NP wraps around Sukadana, to the east is a small hill names Lubuk Baji

We had seemingly missed our chance to see these large forest dwelling primates, perhaps arriving too late in the day.  Our guide kept a close eye out and several times pulled us off  the trail through small tangles of spiky rattan palm to follow up on potential sightings and sounds.  Each turned out to be a false alarm.

Wandering off the trail brought its own rewards though.

Large ground orchid in the Borneo rainforest

Large ground orchid in the Borneo rainforest

Where the ground was a bit more damp large white ground orchids grew, the broad, soft leaves looking more lilly-like than orchid like.

Unknown red & blue fruit (if you know, please let me know).

Unknown red & blue fruit (if you know, please let me know).  Each blue fruit was only about 1 to 1.5cm long.  EDIT: possibly Baccaurea odoratissima

The tree above was fruiting directly from the trunk.  This is a trait called cauliflory.  Plants that exhibit cauliflory flower and fruit directly from their stems and trunks.  It is relatively common in tropical environments and rare to non-existent elsewhere.  I have seen it on many plants in the Amazon, but the fruit growing in this manner that most people will be familiar with is papaya.  I think it is one of the most striking and beautiful ways for a tree to flower, in part because it is so unexpected.

I have heard several hypotheses for why tropical trees do this; one has to do with sun protection for delicate flowers and fruits.  Tropical sun is intense and the trees may be protecting their fruits under a dark canopy.  Another thought is that it makes the fruit easier for large animals to reach as they do not have to rick precarious trips onto thin branches that may not hold their weight.  One side effect of this growth form is that trees can produce fruits of immense size.  Jackfruit (Artocarpus spp), a delicious fruit of which there are many species, produces some of the largest fruits of any tree, the largest fruits weighing up to 80 pounds (36 kilos).

Failing to see any wild primates we continued our hike along the ridge to an overlook of bare granite shaded by a grove of tall bamboo.

Looking East-Northeast over Gunung Palung National Park and parts north from the Sukadana Hills

Looking East-Northeast over Gunung Palung National Park and parts north from the Sukadana Hills

From here we finally got an overview of the surrounding countryside.  Views like this can be surprisingly rare in forested lands, even when there are hills and mountains.  Below us rice paddies infringed on the edge of the national park, then faded into a shaggy carpet of greenery.  Here and there eskers of logging tracks could be seen following stream courses and through binoculars it was clear that all the tall trees had been cleared from the lower slopes of the distant hills.

We sat enjoying the breeze and view for a time, then headed back to the stream and park building for lunch.

I grew restless and maybe 15 minutes before we were to set out I told the guide that I would go first and wait for the rest of the group later on.  Walking in nature in large groups always bothers me a bit, too many people talk too loudly, make too much noise moving through the forest, and scare off the wildlife.  I tend to walk slowly and quietly with frequent pauses to listen, look, and smell the air.

As it has so many times in the past my slow approach to nature paid off in spades.  Just downhill from the honey gathering tree I saw a large branch move across the stream and head a loud rustle, clearly not from the wind.  I froze and waited, watching the closely.  Large dark shapes clambered about, difficult to see, sometimes in deep shade, other times so strongly backlit by the sun that all I could see was a dark blob.

I waited with my camera out.  After a few minutes of quiet waiting the orangutan began moving about, foraging and breaking off large dead limbs.  I waited until they seemed accustomed to my presence, then slipped back up the trail to wait for the rest of my hiking group.  Five minutes later they came down the trail, talking and breaking dead branches on the ground.  “Shhh, tiga orangutan,” I said holding up 3 fingers.  Everyone fell silent and we crept down the hill.

The orangutan watched us for a few minutes, then returned to foraging.  One adolescent clambered directly over us, occasionally peering down through the sheltering leaves, then moving on again.

Very curious adolescent orangutan

Very curious adolescent Bornean orangutan (Pongo pygmaeus)

Most of my photos did not turn out well, the contrast was too great and the apes moved too quickly.  After much post processing one image revealed that there were at least 4 orangutan, possibly more nearby.

After about 20 minutes we continued on our way down the hill, pausing to swim in a deliciously refreshing pool at the base of a waterfall.

The trail was paralleled by a series of lovely waterfalls

The trail was paralleled by a series of lovely waterfalls

Regretfully donning our clothes once more we continued our hike out of the forest, happy at seeing the orangutan and thinking that out wildlife sights were at an end.

Just inside the margin of the forest we found that we were unexpectedly and happily wrong.

Red leaf Monkey (Presbytis rubicunda), aka Maroon Leaf Monkey

Red leaf Monkey (Presbytis rubicunda), aka Maroon Leaf Monkey

Several Red Leaf Monkeys were foraging for fruit in the semi-wild durian orchard.  They made long, graceful leaps between the trees, their tails streaming out behind them, accenting the arc of their flight.

People often think we need to protect the forest in order to protect species like the orangutan, various monkey species, birds, and other forest inhabitants.  While this is indeed true, it is only part of the picture.  The forest denizens must be protected as well because without them the forest changes, sometimes radically, becoming a completely different environment.

Many species of plants require their seeds to be consumed along with their fruit and carried far off as part of their dispersal strategy.  Many seeds must pass through the digestive tracts of specific animals before they will germinate.  The extinction of one animal species can have repercussions that are slow to manifest, are difficult to reverse, and may have a wider impact through the ecosystem.

We often talk of specific species as being keystone species.  It may be wiser to think of all species as being keystone species.

Red Leaf Monkey watching me

Red Leaf Monkey watching me