| The Himalaya are not only the world's tallest mountains, they're
also the youngest - and still growing. Because of them, most of Tibet
and parts of northern Nepal are high-altitude deserts, hidden in the
Himalayan rain shadow, while many southern slopes, which bear the full
brunt of the monsoon, are rainforest: nowhere in the world is there a
transition of flora and fauna so abrupt as the one between the Tarai and
the Himalayan crest, a distance of as little as 60km. As a result, Nepal
can boast an astounding diversity of life, from rhinos to snow leopards
Geology
The Himalaya provide graphic evidence for the plate tectonics (formerly
known as continental drift) theory of mountain-building. According to
this theory, the earth's crust is divided into a dozen or so massive
plates which collide, separate and grind against each other with
unimaginable force. The Himalaya are the result of the Indian
subcontinental plate ramming northwards with particular force into the
Asian plate - something like a car smashing into the side of a truck. It
has been estimated that a 2000-kilometre cross-section of land along the
collision zone has been compressed into 1000km, doubling the thickness
of the crust and producing not only the Himalaya but also the vast
Tibetan Plateau.
The shallow Tethys Sea , which once covered the entire region, was the
main casualty in the process; its sedimentary deposits, now contorted
and metamorphosed, can be seen at all elevations of the Himalaya. The
first phase of mountain-building began around 45 million years ago, as
the edge of the Asian plate, buckling under pressure from the advancing
Indian plate, rose out of the sea to a height of about 2000m. Although
it has since been lifted much higher, this Tibetan Marginal Range ,
which parallels the main Himalayan chain to the north, still stands as
the divide between the Ganges and Tsangpo/Brahmaputra rivers. Unique
among the world's major mountain ranges, the Himalaya don't form a
watershed: rivers like the Kali Gandaki, Bhote Koshi (there are several
by that name) and Arun cut right through the Himalaya because their
courses were established by this earlier Tibetan Marginal Range.
The next major uplift occurred between 10 and 25 million years ago, when
great chunks of the Asian plate were thrust southwards on top of the
Indian plate, creating a low-altitude forerunner of the Himalayan range.
Things appear to have remained more or less unchanged until just 600,000
years ago - practically yesterday, in geological time - when what is now
the Tibetan Plateau was suddenly jacked up to an average elevation of
5000m, and the Tibetan Marginal Range to about 7000m. From this point on,
monsoonal rains became an important erosive force on the south (Nepalese)
side of the mountains, while the north, left in the rain shadow, turned
into a high desert. Southward-flowing rivers, fuelled by phenomenal
gradients of up to 6000m in 100km, further eroded the landscape.
Most of Nepal's present features were created at the geological last
minute. Beginning around 500,000 years ago, the Tibetan rim lunged
forward along numerous separate fronts to form the modern Himalaya .
Averaging 8000m, Nepal's himal (massifs) show a freeze-frame of the
current state of play.
But mountain-building produces downs as well as ups: around 200,000
years ago, a broad belt of foothills subsided, creating Nepal's midland
valleys , while the southern edge of this zone curled up to form the
Mahabharat Lek and, still further south, the Chure Hills (called the
Siwaliks in India). These ridges rose so rapidly that they forced many
southbound rivers to make lengthy east-west detours and permitted only
three principal outlets to the Tarai; the Bagmati and Seti rivers were
initially dammed up by the Mahabharat Lek, flooding the Kathmandu and
Pokhara valleys respectively.
The Himalaya are rising still, albeit at a slower rate than previously.
Periodic and severe earthquakes demonstrate that the earth continues to
rearrange itself - one in eastern Nepal in 1988 killed 700 people -
while hot springs , sometimes found near streams along trekking trails,
are indicators of tectonic faultlines. Erosion is a particular problem
in the Himalaya, where the mountains are continually sloughing off their
skins, and landslides occur regularly during the monsoon. While glaciers
play a part in shaping the terrain above about 5000m, the Himalaya
aren't highly glaciated due to their sheer slopes (which can't support
glacier-breeding snowfields) and relatively low precipitation at high
elevations. On the whole, Himalayan glaciers are in a retreating phase,
as they are in most parts of the world, and old moraines (piles of
rubble left behind by melting glaciers) are commonly seen above 4000m.
Nepal's valleys are like vast cutaway diagrams of geological history,
and trekking or rafting in them you'll be able to imagine the forces
that have shaped the Himalaya. Igneous intrusions (usually granite) are
common, but most outcrops consist of metamorphic rocks (schist, gneiss,
limestone and dolomite), deposited as underwater sediments and later
mashed and contorted under tremendous pressure; the wavy light and dark
bands of the Lhotse-Nuptse Wall, in the Everest region, illustrate this.
Fossils found in many of these layers have helped geologists date the
phases of Himalayan mountain-building. The famous shaligram stones of
Muktinath in the Annapurna region contain fossilized ammonites (spiral-shaped
molluscs) dating from 150-200 million years ago. Of a much more recent
origin, the bones of Peking Man and primitive stone tools have been
found in the Chure Hills - proving that the Himalaya are so young that
early humans were present during their creation.
Flora
Nepal's vegetation is largely determined by altitude and can be
conveniently grouped into three main divisions. The lowlands include the
Tarai, Chure Hills and valleys up to about 1000m; the midlands extend
roughly from 1000m to 3000m; and the Himalaya from 3000m to the upper
limit of vegetation (typically about 5000m). Conditions vary
tremendously within these zones, however: south-facing slopes usually
receive more moisture, but also more sun in their lower reaches, while
certain areas that are less protected from the summer monsoon - notably
around Pokhara - are especially wet. In general, rainfall is higher in
the east, and a greater diversity of plants can be found there.
Mammals
Most of Nepal's rich animal life inhabits the Tarai and, despite dense
vegetation, is most easily observed there. In the hill regions, wildlife
is much harder to spot due to population pressure - along trekking
trails, at least - while very few mammals live above tree line. The
following overview progresses generally from Tarai to Himalayan species.
The Asian one-horned rhino ( gaida) is one of five species found in Asia
and Africa, all endangered. In Nepal, about 500 rhinos - a quarter of
the species total - live in Chitwan, and about 40 have been introduced
to Bardia; they graze singly or in small groups in the marshy elephant
grass, where they can remain surprisingly well hidden.
Although trained elephants ( hatti) are a lingering part of Nepali
culture, their wild relatives are seen only rarely in Nepal. Since they
require vast territory for their seasonal migrations, the settling of
the Tarai is putting them in increasing conflict with man, and the few
that survive tend to spend much of their time in India.
Koshi Tappu is the only remaining habitat in Nepal for another species
better known as a domestic breed, wild buffalo ( arnaa), which graze the
wet grasslands in small herds. Majestic and powerful, the gaur ( gauri
gaai), or Indian bison, spends most of its time in the dry lower
foothills, but descends to the Tarai in spring for water.
Perhaps the Tarai's most unlikely mammals, gangetic dolphins - one of
four freshwater species in the world - are present in small numbers in
the Karnali and Sapt Koshi rivers. Curious and gregarious, dolphins tend
to congregate in deep channels where they feed on fish and crustaceans;
they may betray their presence with a puffing sound which they make
through their blow-holes when surfacing. They're considered sacrosanct
by Nepali Tharus, but are cruelly hunted in India.
The most abundant mammals of the Tarai, chital, or spotted deer , are
often seen in herds around the boundary between riverine forest and
grassland. Hog deer - so called because of their porky little bodies and
head-down trot - take shelter in wet grassland, while the aptly named
barking deer, measuring less than two feet high at the shoulder, are
found throughout lowland and midland forests. Swamp deer gather in vast
herds in Sukla Phanta, and males of the species carry impressive sets of
antlers (their Nepali name, barasingha, means "twelve points"). Sambar,
heavy-set animals standing five feet at the shoulder, are more widely
distributed, but elusive. Two species of antelope, the graceful,
corkscrew-horned blackbuck and the ungainly nilgai (blue bull), may be
seen at Bardia and Koshi Tappu respectively; the latter was once assumed
to be a form of cattle, and thus spared by Hindu hunters, but no longer.
Areas of greatest deer and antelope concentrations are usually prime
territory for tiger ( bagh), their main predator. However, your chances
of spotting one of Nepal's endangered Bengal tigers are slim: they're
mainly nocturnal, never very numerous, and incredibly stealthy. In the
deep shade and mottled sunlight of dense riverine forest, a tiger's
orange- and black-striped coat provides almost total camouflage. A male
may weigh 250kg and measure 3m from nose to tail. Tigers are solitary
hunters; some have been known to consume up to 20 percent of their body
weight after a kill, but they may go several days between feeds. Males
and females maintain separate but overlapping territories, regularly
patrolling them, marking the boundaries with scent and driving off
interlopers. Some Nepalis believe tigers to be the unquiet souls of the
deceased.
Leopards are equally elusive, but much more widely distributed: they may
be found in any deep forest from the Tarai to the timber line. As a
consequence, leopards account for many more maulings than tigers in
Nepal, and are more feared. A smaller animal (males weigh about 45kg),
they prey on monkeys, dogs and livestock. Other cats - such as the
fishing cat, leopard cat and the splendid clouded leopard - are known to
exist in the more remote lowlands and midlands, but are very rarely
sighted. Hyenas and wild dogs are scavengers of the Tarai, and jackals ,
though seldom seen (they're nocturnal), produce an eerie howling that is
one of the most common night sounds in the Tarai and hills.
While it isn't carnivorous, the dangerously unpredictable sloth bear , a
Tarai species, is liable to turn on you and should be approached with
extreme caution. Its powerful front claws are designed for unearthing
termite nests, and its long snout for extracting the insects. The
Himalayan black bear roams midland forests up to tree line and is, if
anything, more dangerous. Wild boars can be seen rooting and scurrying
through forest anywhere in Nepal.
Monkeys, a common sight in the Tarai and hills, come in two varieties in
Nepal. Comical langurs have silver fur, black faces and long, ropelike
tails; you'll sometimes see them sitting on stumps like Rodin's Thinker.
Brown rhesus macaques are more shy in the wild, but around temples are
tame to the point of being nuisances. Many other small mammals may be
spotted in the hills, among them porcupines, flying squirrels, foxes,
civets, otters, mongooses and martens. The red panda , with its rust
coat and bushy, ringed tail, almost resembles a tree-dwelling fox; like
its Chinese relative, it's partial to bamboo, and is very occasionally
glimpsed in the cloud forest of northern Helambu.
Elusive animals of the rhododendron and birch forests, musk deer are
readily identified by their tusk-like canine teeth; males are hunted for
their musk pod, which can fetch $200 an ounce on the international
market. Though by no means common, Himalayan tahr is the most frequently
observed large mammal of the high country; a goat-like animal with long,
wiry fur and short horns, it browses along steep cliffs below the tree
line. Serow , another goat relative, inhabits remote canyons and
forested areas, while goral , sometimes likened to chamois, occurs from
middle elevations up to the tree line.
The Himalaya's highest residents are blue sheep , who graze the barren
grasslands above the tree line year-round. Normally tan, males go a
slaty colour in winter, accounting for their name. Herds have been
sighted around the Thorung La in the Annapurna region, but they occur in
greater numbers north of Dhorpatan and in She-Phoksundo National Park.
Their chief predator is the snow leopard , a secretive cat whose habits
are still little understood.
Amphibians and reptiles
Native to the Tarai's wetlands, crocodiles are most easily seen in
winter, when they sun themselves on muddy banks to warm up their
cold-blooded bodies. The endangered mugger crocodile favours marshes and
oxbow lakes, where it may lie motionless for hours on end until its prey
comes within snapping distance. Muggers mainly pursue fish, but will eat
just about anything they can get their jaws around - including human
corpses thrown into the river by relatives unable to afford wood for a
cremation. The even more endangered gharial crocodile lives exclusively
in rivers and feeds on fish.
Nepal has many kinds of snakes , but they are rarely encountered: most
hibernate in winter, even in the Tarai, and shy away from humans at
other times of year. Common cobras - snake charmers' favourites -
inhabit low elevations near villages; they aren't found in the Kathmandu
Valley, despite their abundance in religious imagery there. Kraits and
pit vipers, both highly poisonous, have been reported, as have pythons
up to twenty feet long. However, the commonest species aren't poisonous
and are typically less than two feet long.
Chances are you'll run into a gecko or two, probably clinging to a
guest-house wall. Helpful insect-eaters, these lizard-like creatures are
able to climb almost any surface with the aid of amazing suction pads on
their feet. About fifty species of fish have been recorded in Nepal, but
only mahseer, a sporty relative of carp that attains its greatest size
in the lower Karnali River, is of much interest; most ponds are stocked
with carp and catfish.
Birds
Over 800 bird species - one tenth of the earth's total - have been
sighted in Nepal. The country receives a high number of birds migrating
between India and central Asia in spring and autumn and, because it
spans so many ecosystems, provides habitats for a wide range of
year-round residents. The greatest diversity of species is found in the
Tarai wildlife parks, but even the Kathmandu Valley is remarkably rich
in birdlife. The following is only a listing of the major categories -
for the complete picture, get hold of Birds of Nepal.
In the Tarai and lower hills, raptors (birds of prey) such as ospreys,
cormorants, darters, gulls and kingfishers patrol streams and rivers for
food; herons and storks can also be seen fishing, while cranes, ducks
and moorhens wade in or float on the water. Many of these migratory
species are particularly well represented at Koshi Tappu, which is
located along the important Arun Valley corridor to Tibet. Peafowl make
their meowing mating call - and peacocks occasionally deign to unfurl
their plumage - while many species of woodpeckers can be heard, if not
seen, high up in the sal canopy. Cuckoos and "brain fever" birds repeat
their idiotic two- or four-note songs in an almost demented fashion.
Parakeets swoop in formation; bee-eaters, swifts, drongos, swallows and
rollers flit and dive for insects, while jungle fowl look like chickens
as Monet might have painted them. Other oddities of the Tarai include
the paradise flycatcher, with its lavish white tailfeathers and
dragonfly-like flight; the lanky great adjutant stork, resembling a
prehistoric reptile in flight; and the giant hornbill, whose beak
supports an appendage that looks like an upturned welder's mask.
Many of the above birds are found in the midlands as well as the Tarai -
as are mynas, egrets, crows and magpies, which tend to scavenge near
areas of human habitation. Birds of prey - falcons, kestrels, harriers,
eagles, kites, hawks and vultures - may also be seen at almost any
elevation. Owls are common, but not much liked by Nepalis. Babblers and
laughing thrushes populate the oak-rhododendron forest and are as noisy
as their names suggest. Over twenty species of flycatchers are present
in the Kathmandu Valley alone.
Nepal's national bird, the iridescent, multicoloured danphe (impeyan
pheasant), can often be spotted scuttling through the undergrowth in the
Everest region; a range of house paints has been named after it. Kalij
and monal, two other native pheasants, also inhabit the higher hills and
lower Himalaya . Migrating waterfowl often stop over at high-altitude
lakes -ruddy shelducks are a trekking-season attraction at Gokyo - and
snow pigeons, grebes, finches and choughs may all be seen at or above
the tree line. Mountaineers have reported seeing choughs at up to 8200m
on Everest.
Invertebrates and insects
Perhaps no other creature in Nepal arouses such squeamishness as the
leech ( jukha). Fortunately, these segmented, caterpillar-sized annelids
remain dormant underground during the trekking seasons; during the
monsoon, however, they come out in force everywhere in the Tarai and
hills, making any hike a bloody business. Leeches are attracted to body
heat, and will inch up legs or drop from branches to reach their
victims. The bite is completely painless - the bloodsucker injects a
local anesthetic and anticoagulant - and often goes unnoticed until the
leech drops off of its own accord. To dislodge one, apply salt or burn
it with a cigarette; don't pull it off or the wound could get infected.
Over 600 species of butterflies have been recorded in Nepal, with more
being discovered all the time. Although the monsoon is the best time to
view butterflies, many varieties can be seen before and especially just
after the rains - look beside moist, sandy banks or atop ridges;
Phulchoki is an excellent place to start in the Kathmandu Valley.
Notable hill varieties include the intriguing orange oakleaf, whose
markings enable it to vanish into forest litter, and the golden
birdwing, a large, angular species with a loping wingbeat. Moths are
even more numerous - around 5000 species are believed to exist in Nepal,
including the world's largest, the giant atlas, which has a wingspan of
almost a foot.
Termites are Nepal's most conspicuous social insects, constructing
towering, fluted mounds up to eight feet tall in the western Tarai.
Organized in colonies much the same as ants and bees, legions of termite
workers and "reproductives" serve a single king and queen. The mounds
function as cooling towers for the busy nest below; monuments to insect
industry, they're made from tailings excavated from the colony's
galleries and bonded with saliva for a wood-hard finish. Honey bees
create huge, drooping nests in the Tarai and especially in the lush
cliff country north of Pokhara. Spiders aren't very numerous in Nepal,
although one notable species grows to be six inches across and nets
birds (it's not poisonous to humans). Fireflies , with orange and black
bodies, give off a greenish glow at dusk in the Tarai. For many
travellers, however, the extent of their involvement with the insect
kingdom will be in swatting mosquitoes : two genera are prevalent in the
lowlands, one of them Anopheles, the infamous vector of malaria
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