Biology Reference
In-Depth Information
the one-horned rhino a relatively recent phenomenon, triggered by habitat loss and poaching
for the mythical qualities of the rhino's horn?
My ecological study took an unexpected turn when I asked Gyan to maneuver Kirti Kali
into an ideal spot for a photograph. I raised my camera to capture an exquisite panorama: the
rhino cow and calf in the foreground, perfectly framed by the Annapurna range and Mount
Dhaulagiri to the north. Then I noticed some clumps of low trees that spoiled the picture's
composition. Copses of a species called
bhellur
(
Trewia nudiflora
) stood out like archipela-
goes in the midst of the grassland. I asked Gyan why the trees had assumed this pattern. He
took a break from smoking a cigarette rolled in a jungle-leaf wrapper to answer my silly ques-
tion. “Oh, it's the work of
gaida
,” he said matter-of-factly, using the Nepali word for “rhino”
and gesturing toward the tree islands. “Those are old rhino latrines.”
Rhinoceroses return to the same places time after time to deposit their dung—not out of
tidiness but because these communal latrines allow solitary animals living in dense vegeta-
tion to exchange vital data, via scents within the dung, about their whereabouts and sexual
activity. The sheer size of the dung piles, sometimes dozens of meters long, and the dense
stands of
Trewia
trees that sprang from them were a revelation to me. All the more so be-
cause when I first arrived in Chitwan, I had wondered how this giant herbivore could have
even a minor influence in cropping the lush vegetation—the wall of green grass surrounding
me—which was recharged each year by the summer monsoon.
The answer lay buried in the dung. By voraciously consuming
Trewia
fruit and defecating
intact seeds in latrines scattered throughout the floodplain, the rhinos could rapidly convert
the world's tallest grasslands into
Trewia
forests. Countervailing the rhino-dispersal effect
were the annual floods, which wash away and bury
Trewia
seedlings, and the annual natural
fires, which incinerate much of the previous year's crop. But some of these seedlings obvi-
ously survived to become tree islands. What remained as an indelible imprint for me was the
staggering potential of rhinos to reshape their surroundings, implying, in this case, that eco-
logical impact does not always reflect numerical abundance.
It would be a stretch to say that sifting through rhino dung or musing while on elephant-
back triggered my fascination with rarity. But my observations of these rhinos, and observa-
tions that I and others had recorded of another globally rare denizen of their neighborhood,
the tiger, made me wonder: What if more biologists fanned out to study in depth not the com-
mon mongoose or the ubiquitous spotted deer but members of Chitwan's uncommon mena-
gerie—great hornbills, Gangetic dolphins, gharial crocodiles, sloth bears, and Indian bison?
How might one's perspective on the natural world change? What novelties, complexities, and
even counterintuitive elements might emerge, and what adventures lay in store for the pur-
suer of these rarities?
As a scientist, I knew that the interplay of rarity and abundance is central to understanding
patterns of nature as well as understanding the idea of dynamic ecological balance. What do
