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PALAWAN
FACT SHEET APPENDIX- A MORE SCIENTIFIC VIEW FROM GREENVIEWS GUESTS
BLAIR AND GEOFF BROWNE
Palawan
is a beautiful island. Some 400 kilometres long, with a mountainous
spine along its length, but only narrow in width - varying
from about 12 to 65 kilometres. Logging has been forbidden
by law since 1989 and the island is forested from mountain
top down to sea level. It is peaceful, remote, relatively
unspoiled and its wildlife is in many ways unique. For example,
remarkably for an island this size, there are 445 recorded
species of butterfly, of which 32 are endemic to Palawan -
not to be found anywhere else. The majestic birdwing Trogonoptera
trojana (pictured right) alone is worth going to see!
Who knows how many species of moths there are, including the
micros? And what about all the beetles, flies, dragonflies,
mantids, ants, cockroaches, etc.? Then there are all the plants,
from trees to algae! |
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The sea is another world again; coral reefs teeming with fish
(pictured left), and a bewildering array of other
marine life, including dolphins, larger whales, turtles, sea
snakes and countless invertebrates! No doubt there is much
yet to be recorded. How and why is all this so? That is a
question that has been considered since Victorian times.
Alfred Russel Wallace, the great Victorian biologist and friendly
rival of Charles Darwin, travelled the islands of South East
Asia during the 1850's and observed that the many islands
could be divided into those that had typically Asian wildlife
and those that had typically Australasian life; so he separated
them on the map with a line - known to this day as The Wallace
Line. The island of Palawan is on the Asian side of the line,
along with the rest of the 7,200 or so Philippine islands.
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What
Wallace seems to have recognised we now know to be the eastern
edge of the Sunda Shelf, an ice age continent that existed
as an extension of the asian continent when sea levels fell
dramatically during the coldest part of the ice ages, 18 -
10 thousand years ago. As the ice retreated sea levels rose
again, and biologists call this now submerged continent Sunderland
- lying today under the shallow South China Sea. However,
Wallace did not get it quite right. The Philippine islands
have moved north along with China, Tibet and the many islands
of Indonesia, due to continental drift - including Australia
which separated from the continent of Antarctica about 50
million years ago. All of these were once part of the great
ancient continent of Gondwana. We also know now that Palawan
broke away from the Asian plate and drifted south, isolated
for some 40 million years, and reaching its present position
about 5 million years ago. When sea levels fell during the
ice ages it was connected to Asia again via Borneo, separating
once more when sea levels rose as the ice melted.
In 1868 Thomas Henry Huxley modified Wallace's line, separating
Palawan island from the rest of the Philippines by turning
it north at the Makasser Strait. Wallace never accepted Huxley's
modification, but our present day knowledge of continental
drift supports the modificaton because we now know that Palawan
and the rest of the Philippine islands have different origins.
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Visitors
to Greenviews Resort can see some of these wonders for themselves.
At night a mercury vapour light, running off a generator,
brings moths to a white sheet, and sometimes skipper butterflies.
The large Saturniid moths are a delight; the huge atlas moth
(Attacus atlas) being a special treat!
A nearby river mouth has a fine mangrove swamp forest which
can be visited in a small banca. ('Boat' in the Tagalog language,
widely spoken in the Philippines). Mangrove swamp is characteristic
of tropical tidal river mouths where the water is shallow
and loaded with suspended sediment. The resulting silt is
trapped by the aerial roots of the trees, resulting in the
slow seaward extension of the land. Mangrove trees (Rhizophora
sp.) are all resistant to sea water, and the stilt and
aerial roots can extend into salt water further than any other
land plant.
Interestingly, the seeds begin to germinate while the fruits
are still attached to the mother-plant. Each seedling resembles
an arrow hanging downwards and, in the case of the east asiatic
species Rhizophora mucronata, can reach 60cm (nearly
2 feet) in length by the time they fall to the ground, stabbing
into the silty mud that collects around the dense tree roots.
Here they quickly grow roots and produce leaves.
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Mangrove snakes (pictured right) can be seen in the
branches overhanging the water, and Palawan has its own endemic
subspecies - Boiga dendrophila multicincta. Sea snakes
can sometimes be glimpsed in the river as they surface to
breathe, and monitor lizards (Varanus salvator) can
be seen on the mud or swimming in the river. In the trees
you may see long-tailed macaques (Macaca fascicularis),
and a variety of birds - woodpeckers, kingfishers, herons
and egrets. Colourful crabs make their burrows in the mud
on the river banks, and clams cluster on the mangrove roots.
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Port Barton is situated in a shallow, sheltered bay which
is a marine reserve area with its own coral reef, only just
below the surface in places. This is just right for snorkellers,
or those with a clear bottomed bucket who wish to stay dry
in the boat! A local dive master can provide excellent diving
facilities for those qualified to aqualung dive in open water,
and this can be arranged through Greenviews Resort.
About 2 hours away by boat is the Puerto Princesa Subterranean
National Park (Underground River), a World Heritage Site.
A guided boat trip into the cave is enjoyable not only because
it is said to be the longest navigable underground river in
the world, but also because of the splendid stalactite and
stalagmite formations to be seen there, and the swiftlets
and eight species of bats that roost in the cave in hundreds.
(If not thousands). Outside the cave the beach and forest
scenery is wonderful, with marked trails, trees identified
with labels, and signs bearing information about the Site
and its wildlife. You can get close to really big monitor
lizards, and long-tailed macaques - who will steal your sandwiches
if you are not vigilant!
A visit to the El Nido area by boat, stopping at some of the
many uninhabited islands and lagoons is a breath taking experience,
they really are straight out of a paradise island holiday
catalogue! For the naturalist interested in seashore life,
snorkelling or just beachcombing for shells, etc., this is
a highlight of the trip to Palawan.
Greenviews Resort is the gateway to a naturalist's paradise
- a photographer's too!
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