Biology Reference
In-Depth Information
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 bark-
ing deer, portrayed in this topic. 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 abund-
ance. 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 com-
mon 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. Sud-
denly 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 nation-
al 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 bio-
logists estimate that as many as 1,200 species, or roughly 20 percent of all mammals, eat figs
