Spiders defence defence strategies strategies

ByCheong Ah Kwan

BEFORE the advent of online Spiderman games, little boys used to hunt down the real McCoys, put them carefully in small matchboxes and primed them for sport.

These ‘fighting spiders’, known to display aggressive behaviour when put together with another of its species, were trophies by themselves to be flashed at potential opponents in contests. A champion spider

could elevate a young boy’s status more than a few notches.

Joseph Koh, the current High Commissioner of Singapore to Brunei, was one of those little boys who carried around matchboxes with a prized spider in each of them.

What began as a simple hobby turned into a life-long passion.

His book on the spiders of Singapore has gained him recognition as the authority in the region.

The Malaysian Nature Society Kuching Branch has never had an expert talk about spiders and it was indeed a rare treat to have the mysteries of some of these spectacular web sites unravelled.

Spiders have an array of predators ranging from birds, frogs, wasps and other spiders.

As a result, these arachnids have evolved a host of defence strategies to protect themselves.

Some of these strategies to escape predation are ingenious and include camouflage, the building of shelters, intimidation with threat posture and the use of mimicry.

Camouflage is a very common defence strategy and we are not unfamiliar with animals that can blend into their surroundings to render themselves invisible to potential enemies. In fact, this is such an effective strategy that human beings have exploited the technique in warfare.

Spiders that resemble tree nodes are often found sitting on the bark or branch of a tree.

The wraparound spider simply ‘vanishes’ by wrapping itself around a twig during the day.

Instead of constructing webs, some spiders build shelters or burrows on the ground.

The entrance to such contraptions is often plugged with leaves and pebbles during the rainy season to protect against flood waters.

The waterproof trapdoor also keeps uninvited guests at bay.Most spiders possess great agility that enables them to escape with speed when danger lurks. Some slower moving spiders do play dead when they feel threatened.

CAMOUFLAGE: The bird-dropping spider takes mimicry to a whole new level.

The use of intimidation as a defence strategy is relatively common.As a deterrence to their enemies, many spiders are armed with thorny projections and may be colourful in their appearance in an effort to present themselves as unpalatable.

Defensive stances and threat postures such as the spreading open of legs, raising the body and exposing fangs are used to intimidate potential enemies.

Of all the defence strategies employed by spiders, the most fascinating one has to be that of mimicry.

Spiders have fantastic mimicry that they employ for protection as well as hunting.

To escape predation, several species of spiders have resorted to ant mimicry.

Ants are known to be unpalatable because of the formic acid they contain, and it is therefore advantageous to look like them.

In protective mimicry, these eight-legged creatures wave their forelegs in the air to fake antennae reducing the number of functional legs to six. In addition, their bodies also seem appropriately segmented to look like an insect.

Very often, protective mimicry extends into aggressive mimicry whereby the spiders use anatomical and behavioural ant mimicry to hunt ants.

Their stunning deception gets them accepted into ant colonies which they willlater destroy. The bird-dropping spider

takes disguise to a whole new level. It not only looks like bird dropping on a leaf, but comes complete with a wafting odour of dung. Such a devious strategy is effective against birds and wasps.

The smell is a plus as it attracts flies which are devoured.

The macro photographs of the spiders projected onto the big screen during Koh’s talk were a feast for the eyes. Certainly the Spiderman weaved us into his multi-dimensional web.

As we queued to sign up for the night walk to hunt for spiders, he promised a session on the feeding strategies of our eight-legged friends when he returns.

Meanwhile, to all the Miss Muffets out there, do stock up on curds and whey.

How Snakes Can "Fly"

http://news.nationalgeographic.com/news/2010/11/101124-flying-snakes-fly-science-darpa-dod-socha/?source=link_fb20101123howsnakesfly

ANNOUNCEMENT – BIRDING TRIP / Time: Sunday 28 November 4 P.M. at Chupak

 Pictures taken by Collin Cheong

ANNOUNCEMENT – BIRDING TRIP

The MNS Kuching Branch Bird Group is organizing a birding trip to Chupak!

It will be a perfect time to visit Chupak again as the paddy fields have just been planted and are in great condition to showcase the birds found there. 

Previous sightings at Chupak have been more than rewarding.  The Buff-banded Rail, a first sighting record for Kuching, was spotted in Chupak.  More recent sightings include the Black-winged Stilt and Gargarney.

The trip will be led by our expert birders, Daniel Kong and Yeo Siew Teck.  Unlike the usual early morning birding trips, the Sunday afternoon trip will give us a chance to see birds which are more active in the evening. 

Meeting Point:              By the road at Tapah Village

                                     Taman Rekresis Tapah (Town Park) Please be there by 3.45pm 

Time:                            Sunday 28 November 4pm

For those who prefer to sleep in on Sunday you still can join us!

One of the nearest and most extensive rice fields around Kuching area, Kg. Chupak/Skudup attract great number of migratory and wetland birds.   A number of interesting sightings have come out of the area including Sand Martin (1^st record for Borneo for nearly a century), Greater Painted-Snipe (1^st for Sarawak), Red-necked Phalarope, Blue-breasted Quail, Black-winged Stilt and Chinese Pond Heron. 

HOW TO GET THERE  Drive up the Kuching/Serian road, passing Siburan town, 18 mils (Jong’s Crocodile Farm) and Beratok town, 22 miles (limestone quarry is opposite the town).  Drive further along the road for 2 more miles and you will pass a Shell petrol station on your left.  Tapah town is just a kilometer along the road from Shell station.  So slow down!  Turn into Tapah town and meet at the road side in front of Taman Rekresis Tapah (Town Park) which is next to the Tapah Chinese Primary School.  Please be there on time - Those who are late will have to find their way to Chupak themselves.

TO BRING Please bring along your binocular, bird guides, pocket-size note pad, hat, and umbrella.  Please also remember to wear dull-coloured clothes.

FEES MNS Members and Students: FREE.  Non Members: RM5/-

 REGISTRATION/INFORMATION

For registration please contact Susan Teal at 012-8874401  or sueteal2006@gmail.com'

For more information about the trip please contact Anthony Wong at 013-8333163 (antwong@sareaga.com)or Susan Teal – 0128874401 or Kwan – 0198349499

The Chinese crested tern

RARE SIGHTING: An adult and juvenile Chinese crested tern are seen at the Min Jiang Estuary, China. — Photo by Zhang Hao (Fujian Birdwatching Society)

By Cheong Ah Kwan

“So, this is the place, eh?”, he half-murmured to himself.

When Adrian Long from BirdLife International visited Buntal last November, he could not be persuaded to get off the beach despite the searing mid-day heat.  It was low tide and the shorebirds were sitting too far out to be seen.  He scanned the coastline with his binoculars, now and then turning to our local guide to ask the same question, “and you have seen it; Chinese?” 

I did not catch the significance of his questions then.  A growling stomach did not help and playing over and over through my mind was …. “Mad Dogs and Englishmen Go Out in the Mid-day Sun”.

Last week, after a scrumptious steamboat dinner in honour of Simba Chan, Senior Conservation Officer of BirdLife International Asia Division, we gathered around a table to listen to the exciting news our guest had to share with the Malaysian Nature Society Kuching Branch.  That was when I put the two separate visits from our BirdLife partners together, and the penny dropped.

The Chinese Crested Tern (Thalasseus bernsteini) is a globally threatened seabird and has been designated by the IUCN Red Data Book as Critically Endangered.  In layman’s term, the bird is extremely rare and in grave danger of becoming extinct.  In fact the entire population in the world today is estimated to be not more than 50 birds!

The Chinese Crested Tern was first described in the early 1860s.  Very little is known about the species since sightings were few and far between.  Identification is made more difficult as there is another bird very similar to it in appearance. 

It is generally assumed that the bird breeds in north eastern China because of the breeding plumage it displayed during the sightings there.  However, breeding grounds have never been discovered.  In 1937, on the islands near Tsingtao on the Shandong Peninsula, 21 Chinese Crested Terns in breeding condition were collected for specimens.  After that insanely tragic massacre of 21 there was no more confirmed sighting of the bird and it was thought to be extinct. 

In the year 2000, a photographer made a chance re-discovery of the Chinese Crested Tern while carrying out a survey in the Matsu Islands.  These tiny islands, designated as nature reserves, are just a short distance off the coast of Fuzhou mainland China but are administered by Taiwan.  Politically, the islands are of strategic importance.  They are, hence, under military regulation and have been off limits to the public for many years.  Security measures put in place for political reasons appear to have offered the seabird protection from poaching.  The highest count of the species in the year 2000 was 12 birds consisting of 8 adults and 4 chicks.

Poaching and the collection of eggs continue to threaten the Chinese Crested Tern. The Taiwanese Government gives strong support to projects that increase public awareness on this rare tern.  Taiwanese Coast Guards intercept and inform fishermen that poaching and egg collections are not permitted.  Both the marine and agriculture departments work closely to protect the birds even though the two departments are known to have little communication.

DOING THEIR PART: Student volunteer groups increase public awareness in Huangqi Town, Fujian Province. The town is very close to the Matsu Islands.

Simba updated us on his work with the Chinese Crested Tern.  He talked about concentrating efforts on where it is most needed which is information on the distribution and population size of the birds. The BirdLife International China Programme together with local birding communities in China is organizing a series of educational student workshops in areas where breeding colonies have been sighted.  The focus is on students from fishing families. It is hoped that these children will take the urgent message home to their parents who are often out at sea and might come into contact with the Chinese Crested Tern.  Posters and booklets are printed for distribution in restaurants and parks to get people to familiarize with the bird so that chances of it being identified are increased.  It is akin to the milk carton campaign in search of missing children.

While the breeding grounds of these birds have never been confirmed, a greater enigma hung in the air.  Where do they go during the non-breeding season? 

Non-breeding range of the Chinese Crested Tern is thought to include southern China, Thailand, Indonesia, the Philippines and Malaysia.  There are three winter records from Sarawak; in 1890, 1891 and 1913.  The last confirmed sighting in 1913 was from the Bako Buntal Bay.  Yes, here in our very own backyard!  Since then the Chinese Crested Tern has not been reliably recorded from Borneo.

“….and you are sure you have seen it, the Chinese Crested Tern?”

Imagine an ocean without fish. Imagine your meals without seafood. Imagine the global consequences. This is the future if we do not stop, think and act.

http://www.saveourseafood.my/

FROM SARAWAK TO SHEEPSTOR, DARTMOOR, IN DEVON

                                             GRANITE SCENERY: A view of Sheepstor in Dartmoor, England.

By 

Alan Rogers

Only six weeks ago I just finished reading “The White Rajahs of Sarawak” by Professor Bob Reece of Murdoch University, W. Australia when my sister phoned and invited me for a walk to Sheepstor on SW Dartmoor in Devon. Yes, I immediately took off to explore the Brookes family graves at St. Leonard’s Church only 100 kms from my house. Alas, alack, in my impetuosity, I neglected to bring my camera!

A few weeks later on holiday in Kuching I read two articles in the Borneo Post, one derived from the local SW England newspaper – The Western Morning News –on the final resting place of the Brookes family. The following day, in the Borneo Post, Dato Sri Dr James Masing explained how just before the downturn of the economy in 1997 the Sarawak Government tried to purchase land in that area of SW Dartmoor to promote Sarawak tourism. Had that happened the vicar of this beautifully built granite church in the 1400’s would be rubbing his hands in glee today. Actually the origins of the church date back to 1240 AD when a chapelry was built on that very site.

Rising majestically, above the graves of the First Rajah, James (d.1865), the Second Rajah, Charles (d.1917) and Charles Vyner (d.1963) and other members of the Family Brookes, is Sheepstor – a granite monolith. Interestingly inside St. Leonard’s Church one of the upper leaded light windows displays a Nepenthes Rajah (pitcher plant), a butterfly and a moth as a living memorial to those valiant Sarawakians who lost their lives during the occupation in World War 2. They will always be remembered.

Buried in the shadow of the imposing Sheepstor (altitude 369 metres) the Brookes family rest in peace surrounded by rugged granite scenery in an environment which was once moulded in geological times by a tropical climate almost identical to that which the Brookes family experienced here in Sarawak!

The word “tor” comes from Celtic meaning a hill. As a pure Celt of Cornish and Welsh parentage I was born only 15 kilometres from the castellated, famous granite cliffs of Land’s End. Only 4 kilometres away from my parents’ house I took my five year old son on his first abseil down a granite escarpment tor! Granite scenery has haunted me throughout my life be it in Cornwall, on Dartmoor or at Shap Fell in the Lake District – all in the UK but also on Mt.Kinabalu and at Praslin in the Seychelles in the Indian Ocean.

Granite is a molten plutonic rock intruded into the overlying country rocks at Cornish and Dartmoor as two continental tectonic plates converged. As the molten granite meets the country rocks it bakes those rocks into metamorphic rocks thus changing their form. Various elements at different cooling stages in the molten rock were deposited as ores in the country rock – arsenic, copper, lead, tin and tungsten. The Cornish and Dartmoor tin mining industries continued into the early 20^th Century when alluvial deposits of tin were exploited in a more economically viable form in Ipoh.

Granite magma was intruded at both high temperature and pressure and upon cooling it contracted producing vertical cracks or joints. In time the overlying country rocks were eroded and gradually the granite appeared nearer to the surface. Thus the granite mass experienced a reduction in pressure and ltemperatures! It responded by developing pseudo (false) bedding planes or horizontal pressure release joints. However as the granite cooled and crystallized water was released, which attacked the feldspars (brown crystals) to produce kaolin or china clay. Two other minerals in this granite are quartz – white or pink – (SiO2) and mica (black) the crystals of which occur at different sizes according to the rate of cooling.

Returning to Sheepstor, where the granite was injected some 290 million years BP (Before Present time) it was only in early Tertiary times (65 million years BP) that Dartmoor experienced a tropical climate with very high annual rainfall and temperatures and evergreen and semi-evergreen forests almost identical to Sarawak!

Consequently the rainfall percolated down through the soil overlying the country rocks into the granite thereby rotting the granite through its joints and pseudo bedding planes decomposing the quartz crystals into sand and the feldspar and mica crystals into clays.

The chemically rotted rock around the least affected parts of the was washed away by the high annual rainfall or by solifluction (litterally: soil flow) as a result of soil thaw at the end of the Ice Ages 10000 years BP. This exposed (exhumed) the solid granite core stones, which are now precariously balanced on each other. (See Diagram). Thus the granite tors were eventually revealed in the landscape. The processes of exhumation are still highly debateable and will continue to be, as each granite mass is studied in depth. However, Mt. Kinabalu with its ice cap which melted only 3000 years BP and subsequent exposure to freeze-thaw conditions meant that some chemically rotted granite was sludged downslope to reveal small granite boulders parly embedded in clays as on the Pinosuk Plateau in Kinabalu National Park. On the road up to the mountain one can see granite boulders embedded in clays where landslides or excavations have occurred. Its jagged skyline and peaks suggest as some geomorphologists believe that the ice cap protected some of its features.

Sheepstor in SW England never experienced the ice sheets and glaciers that sculpted the Northern areas of the UK and interestingly near Sheepstor remains of Prehistoric animals that migrated south from the advancing ice sheet have been found.

Whatever the continuing debate on the origins of granite scenery Sheepstor and Mt.Kinabalu weekly attract hundreds of hikers/climbers yet the Brookes family are buried in a geological time capsule. I just wonder what Rajah James would have made of Burrator Reservoir (the water supply to the city of Plymouth) in a flooded granite valley near his last residence at Burrator House.

For further information please refer to:

Professor Bob Reece, Murdoch University, Australia.  The White Rajahs of Sarawak – A Borneo Dynasty. 2004 Archipelago Press.

htpp:// www.dartmoor-npa.gov.uk/lab-geologylandforms