The Kingdom of Rarities (38 page)

An appearance by the white-bellied heron would have completed our morning's rare bird quota, but it was not to be. This species is second only to the goliath heron in size but is much scarcer, although we were told that a pair had been seen using this area. Endemic to the Eastern Himalayas and with perhaps fewer than 250 individuals left, the white-bellied heron is listed as critically endangered in the IUCN Red List. The herons, like the eagles, roost in the tall pines along the river and depend on large, free-flowing rivers, a difficult ecosystem to protect, even in green Bhutan.

Some large herons nest in low vegetation in rookeries, so the white-bellied's propensity for nesting very high in the trees has yet to be explained, although other large herons, such as the great blue and grey, also nest high in trees. At least elsewhere in its range, habitat loss and poaching of adults and eggs are the apparent causes of decline. As a result, the species has been reduced to a few small populations in northeastern India, northern Myanmar, Bangladesh, and eastern Nepal. Extensive hydroelectric development in the region poses a major threat to recovery of these core populations.

As we walked past a bend in the road above the river, a group of Tibetan monks smiled at us as they ambled past and then returned to their chant, fingering their prayer beads. Monks are a common sight in Bhutan, where many young men enter monasteries as children. How different their early lives seemed from ours, I thought. Then I remembered a joke told by a Tibetan friend: “What is the difference between a Buddhist and a non-Buddhist?” The answer: “The non-Buddhist thinks there is one.” As the red-robed faithful faded from sight, we turned our attention again to the herons, which remained elusive.

Mincha Wangdi was waiting for us at the guesthouse in Punakha. The next day in the car, we kept up a steady interrogation of our hosts. Sherub and Nawang answered natural history inquiries and the loquacious Mincha handled every other subject, from Buddhism to Bhutanese politics. During a stop for lunch at an outdoor café, the stories rolled off his tongue. My gaze drifted from Mincha to a new sighting, a complement to the national sport of archery. Up the road, a group of young men were hurling what resembled small missiles—carved wooden rockets with nails on the tips—at a target about thirty meters away. This was
khuru
, a Bhutanese version of long-distance darts. As we strolled after lunch along a border of flowering pomegranate trees, the whistles and shouts of the cheerful missileers carried on the breeze.

We made for Trongsa, a tourist attraction because of its beautiful dzong. The highway wound through one of the most exquisite and diverse broad-leaved forests in the temperate regions of the world. Several of the common trees were still leafless but had exploded into flower—the white mimosa-like blossoms covering the
Albizia
, the deep red petals of the coral bean (
Erythrina
), the luscious pink of elephant ear (
Bauhinia
)—all of them accented by the vibrant new foliage of maple, oak, walnut, chestnut, laurel, and, everywhere, the leathery leaves of rhododendron and magnolia. Underneath lay a carpet of valerian, primrose, violet, and club moss dense enough to cushion a sleeping musk deer, or yeti. The forest seemed endless.
Our van snaked around one mountain valley draped in dense forest only to enter the next cove of deep woods. I kept waiting for signs of devastation, a denuded mountainside. Yet nowhere in sight was a mountain village, terraced field, or landslide scar, all inevitable features of the Nepalese and Indian Himalayas.

The mountainous road made us queasy and we had to stop periodically, but each time we were rewarded by the sight of some spectacularly colored birds. First, we admired powder-blue verditer flycatchers, then the shimmering iridescence of orange-bellied leafbirds. Next we saw and heard the blue-throated barbet, and then the most beautiful common bird on any continent—a male scarlet minivet, an elegant treetop inhabitant wearing blushing red and black feathers. But all thoughts of the minivet vanished when a male Mrs. Gould's sunbird landed on the crown of a nearby hemlock. In the brilliant mountain light, its burgundy mantle and back set off its bright yellow rump and belly, highlighted by a long blue tail. The Buddhists say that attachment to beauty is one of the false perceptions humans hold. We, however, suspended Mincha's Buddhist instruction at such moments and wallowed in our attachment.

Over dinner in Trongsa, our conversation ricocheted between natural history and the subject of karma and higher rebirth. I asked Mincha if he would like to be reincarnated as the beautiful scarlet minivet. Mincha paused for a moment and then pointed out how many insects a minivet consumes in its lifetime. “Killing other creatures causes pain in the world. So from a Buddhist perspective, we must say that the minivet is not to be envied.” Besides, he related, there are 500 rebirths separating birds and humans, so a bird rebirth would be a big setback from enlightenment.

Back in our room, I reached for a field guide and inadvertently knocked over the rucksack containing our portable library. Across the floor spilled natural history books as well as Ute's copy of
Radical Acceptance: Embracing Your Life with the Heart of a Buddha
, by Tara Brach, a clinical psychologist and respected teacher of Buddhist philosophy and meditation. I dipped into this other type of
field guide and soon came upon a passage describing how we live our lives in a mental trance, rarely seeing what is right in front of us. As I continued to read, my evening plan to learn to differentiate laughing thrush species switched to pondering Brach's challenging question to the reader: Is much of one's life spent inside a cocoon of our own making?

The next morning at dawn, we departed from Trongsa and headed south for the village of Zhemgang. As the road descended, we left the cool broad-leaved forest for the lowland warm broad-leaved forest, the richest habitat in Bhutan for birds and perhaps the richest remaining in the entire Himalayas. We quickly saw that this forest was also home to several species of primates. Troops of Assamese macaques crossed the road in front of our car as we scanned the hillsides for langur monkeys.

The golden langur was first reported in 1907. But it was neither photographed nor filmed until the great naturalist E. P. Gee encountered it during several expeditions he made along the Bhutan border in the 1950s. The Zoological Survey of India named the species
Presbytis geei
, or Gee's langur, in his honor (it has since been reclassified as (
Trachypithecus geei
).

A common question without an easy answer nagged at me. Why, in the same genus, do we find a ubiquitous species, such as the common or gray langur, which leaps across a wide range of forest canopies of the Indian subcontinent, as well as such rare species as the golden langur, which is confined to a tiny area, and the capped langur, confined to another? Did gray langurs outcompete their golden and capped cousins and limit the latter's range? Or did the common species members, the gray langurs, become isolated and over time evolve into a new species, sometimes with die-off of the parent species in this new locale? Of course, the same question could be posed for any species-rich genus or family, from babblers to barking deer, portrayed in this book. Each large taxonomic grouping in nature seems to have its commoners, adapted to exploit a wide range of habitats, elevations, and tolerance of human presence
and its rarities, those family or genus members with a limited range or low abundance. Perhaps for most of these rare members, it was a specialization of habitat or an inability to survive the presence of humans that kept their numbers low. Perhaps the commoners used the available resources in a more efficient fashion. Identifying the causes of rarity in these little-studied species is likely to be a topic of interest for generations of scientists to come.

Here in the lower broad-leaved forests of Bhutan, we were right in the center of the minute range of the magnificent golden lemur, a place where goldens were supposed to be the common species. We kept a close watch on the trees lining the road. Around a bend, we glimpsed the incongruous sight of some fluffy blond bath towels draped over the canopy to dry. Suddenly the towels came to life: black faces, long tails, and the fabled coat of creamy-white and yellow-gold became apparent. Delightedly, we watched the golden langurs jump between trees with wild abandon, tails raised to steady their balance. They appeared to glow, even through binoculars. We exulted as the troop moved across the canopy and down the mountain valley, and then we moved on to a spartan guesthouse in Zhemgang.

The peregrine falcon that flew over the guesthouse as we were leaving Zhemgang the next morning seemed like a good omen. The forest between Zhemgang and our next stop, Tingtibi, lay on the edge of a wildlife corridor connecting Manas, Bhutan's premier lowland national park, and Jigme Singye Wangchuck National Park (formerly known as Black Mountains National Park). The forest was remarkably intact. Young golden langurs frolicked through the treetops while an older animal paused and sat, contemplating an
Albizia
blossom before eating it. The sighting made me rack my brain: where else in the world could one see such a wondrous rarity from the vantage of a paved major thoroughfare?

From the road, we scanned the forest canopy for fruiting fig trees. Ripe figs attract not just monkeys, as noted in the preceding chapter, but other mammals as well. In fact, tropical biologists
estimate that as many as 1,200 species, or roughly 20 percent of all mammals, eat figs for a living. But birds relish them, too, especially large fig eaters such as a bird high on my hope-to-see list for the day, the great hornbill.

Golden langur (
Trachypithecus geei
) about to feed on an
Albizia
blossom

On the outskirts of Tingtibi, we parked the truck and made straight for the woods. The trail along the tributary of the great Manas River led through a magnificent unbroken stretch of lowland forest. For the first time in Bhutan, we were sweating in the heat. Resident breeding birds were vocalizing everywhere, as this was the peak of the mating season. Along the trail's border we spied several chestnut-bellied nuthatches trilling away. Nuthatches are
a delight to watch feeding, as they are capable of what in humans would be the ultimate party stunt: walking on the ceiling. Nuthatches may forage comfortably all day long while upside down. The riparian forest was brimming with chestnut-bellied nuthatches, right-side-up babblers, and cuckoos, but sadly, no sign of the rare
Sitta formosa
, or beautiful nuthatch. Around noon, the heat of the day quieted the chorus and we split up for the afternoon. Ute and I would drive back with Mincha and his friend in his pickup to spend more time with the langurs and perhaps encounter a beautiful nuthatch at a slightly higher elevation. Sherub and Nawang remained behind to try again along the river. We would all regroup that evening up the mountain in Trongsa.

We didn't drive far before meeting the golden langurs. As we came around a bend, on a rock face bordering the road sat a large troop of mothers with infants, subadults, and an adult male. Dynamite blasting during road construction between Zhemgang and the southern border had exposed a mineral lick where the sharpfeatured langurs could restore their electrolyte balance, oblivious to their audience. I was able to sit so close to a troop of one of the rarest monkeys on Earth that I practically could have reached over and brushed their golden fur. Mincha's camera clicked away from the pickup's backseat as the langurs calmly posed for one portrait after another. I could imagine how an ancestral bird similar to the tree creeper could evolve into the beautiful nuthatch, the difference of a brighter blue on top and a warmer orange on the belly. The more highly pigmented body plan of a beautiful nuthatch over that of a more “plain” nuthatch seemed like an easy result of natural selection. But to go from the sooty color of the gray leaf monkey to the brilliant pelage of the golden langur seemed like the alchemy of evolution.

Our driver stopped abruptly at a turnout and pointed to two giant birds sailing like hang gliders over the forest far below. Great hornbills! The birds traversed the entire four-kilometer-long valley, and then moments later a third individual, perhaps an offspring,
joined the pair. Through my binoculars, the birds' giant goldenyellow casques, helmetlike protuberances on the bill, and white and black markings stood out against the green blanket of forest. Elsewhere in Asia hornbills are rare, heavily persecuted for their body parts by dealers in traditional medicines. In Bhutan they were still common. The Bhutanese tradition of preserving and respecting life, rather than consuming every last individual of a species, seemed like a natural antidote to the bushmeat trade so pervasive in many countries around the world.

The beautiful nuthatch remained elusive on this leg. But such is often the case in the search for rarities. A pattern we first observed in the Foja Mountains of New Guinea and then saw repeated in the Peruvian Amazon and now in Bhutan is that even in the most intact habitats, many species will always be rare. Birding karma, or even compassion for wild creatures, was not going to trump natural selection and make the beautiful nuthatch any more common or easy to see. Why it has such a spotty distribution over its range is not yet known. Greater clarity on the reasons for such rarity will come when devices such as the TrackTags placed on jaguars become miniaturized to fit smaller rarities, or other new technologies are developed that allow us to gather the data needed to unlock the mysteries of uncommon creatures. This is one of many topics in conservation biology in which theory needs to be bolstered by innovative technologies. Only then will we better understand the more particular conservation needs of many rare species. In the meantime, providing adequate habitat and protection is still the wisest preventive to extinction.