Apr 17 2010

The Singapore ‘Sakura’

Published by under Uncategorized and tagged:

Ever wanted to experience the blooming of cherry blossoms? Fret not as you need not travel all the way to Japan to see and immerse yourself in such an environment.

During the period of late March to early April, students of the National University of Singapore were treated to a sight along the stretch of Heng Mui Keng Terrace leading towards the Energy Studies Institute. The flowers of the Trumpet Tree (Tabebuia rosea) blossomed in massive numbers, presenting a sight of tranquil colour mix of nature’s green and brown with its light touches of pink.

Street showered with flowers of the Trumpet Tree

Street showered with flowers of the Trumpet Tree (Photo from triplecorrelation.com)

 

The mass flower blooming coincided with the Cherry Blossom bloom period in Japan, leading some students in the university to term the sight as the ‘Singapore Sakura’.

The Tabebuia Rosea is a common tree planted along the streets of Singapore. The similarity in the flower colour often led to individuals unable to differentiate between the Trumpet Tree and the Pink Mempat (Cratoxylum formosum). A preliminary search was done on the internet to identify the species of the tree that was responsible for such flowering. Substantiated by newspaper reports of sightings of massive flower blooming across different parts of the island, I was led into believing that the tree that was found along the stretch of Heng Mui Keng Terrace was that of the Pink Mempat. Upon closer observations of the flowers that dropped on the ground against pictures provided by internet users, I realised that the pictorial description of the flower of the Pink Mempat was different from that of the flowers seen at Heng Mui Keng Terrace.

Pink Membat Flower Bloom (Photo from Stomp.com.sg)

Pink Membat Flower Bloom (Photo from Stomp.com.sg)

The most distinct morphology that differentiates between the two flowers of the species is their length of the pistil. The flower of theTrumpet Tree has a longer pistil as compared to the flower of the Pink Mempat.

Flower of Trumpet Tree (Photo from Flikr)

Flower of Trumpet Tree (Photo from Flikr)

 

Flowers of Pink Mempat (Photo from Flikr)

Flowers of Pink Mempat (Photo from Flikr)

 

The mass flowering is especially rare for a country like Singapore. The local climate of uniformly wet without prolonged period of dry spell does not cause such mass flowering to occur. However, the prolonged dry spell in the recent month followed by a sudden heavy rain triggered the intense mass flowering of the Trumpet Tree and thus bringing the ‘Singapore Sakura’ into NUS. (Borchert, 1983)

References:

Borchert R., (1983). Phenology and Control of Flowering in Tropical Trees. Biotropica, Vol. 15, No. 2 (Jun., 1983), pp. 81-89 .

“Know 10 Trees”, National Parks Singapore. URL: http://www.nparks.gov.sg/cms/index.php?option=com_content&view=article&id=182&Itemid=161 (accessed on 13 April 2010)

” ‘Sakura’ season in Singpaore too”, by Huang Lijie. The Straits Times, 21 March 2010. Hosted on WildSingapore: http://wildsingaporenews.blogspot.com/2010/03/sakura-season-in-singapore-too.html (accessed on 13 April 2010)

8 responses so far

Apr 16 2010

the perfect symbionts?

Published by under Uncategorized and tagged: ,

The sea anemones and the clown fish are well known to be a mutualistic pair and lot of research have been done about this pair of symbionts. We can also say that this relationship is a near perfect one in all aspects. Mutualism is an ecological interaction between two organisms in which both gain increased survivorship as a result of the interaction.

The mutualism between the clown fish and the sea anemones is one such example. The 26 species of clown fishes from two genuses; 25 from the genus Amphiprion and 1 from the genus Premnas, are obligate symbionts of the 10 species of sea anemones which belong to two main genera Stichodactyla and Heteractis. Usually only fish of one species occurs within one actinian but there are also cases where 2 of them share a host which will usually be a large one with different territories for the 2 species.

Clown fishes and sea anemones are under an obligate mutualism. This means that their range both ecologically and geographically does not really extend beyond their host. The stinging tentacles of the anemone protects the clown fish from the predator fishes. The clown fish is the only one which does not get stung by the tentacles since it has a mucus covering for protection. It was discovered that the clown fish do not really attach themselves to the tentacles but swim among them and huddle inside them for protection. Since the sea anemones pretty much fixated to the area they are in and are not very mobile, the clown fish helps to defend their territory and also eats the left overs from fish on the tentacles. The clown fish is provided with food by the anemone and in turn the clown fish give a better circulation of water to the anemones since they fan their fins while swimming about. The feces of the clown fish is also used as fertiliser by the anemone.

References:

1)      Fautin, D.G, 1991. The AnemoneFish Symbiosis: What is Known and What is Not. Symbiosis 10: 23-46

2)      “Please use captive raised Clown Fish hosts” by Trevor. Anemones and Clown Fish, 7 Sep 2003. URL: http://www.garf.org/trever/anem/anenome.html  (accessed on 16 Apr 2010).

3)      “An exploration of the Clownfish” Author Unknown. Clownfish Biology, Oct 2005. URL: http://tolweb.org/treehouses/?treehouse_id=3390 (accessed on 16 Apr 2010).

2 responses so far

Apr 16 2010

Neighbourhood Bully in a Size of a Crow

Published by under Uncategorized and tagged:

The House Crow (Corvus splendens) has been reportedly seen attacking Singaporeans and even other animals. Some people suffered from scratches on their faces or head when the crows dive at them. In the most recent case, STOMPer Ong witnessed a series of crow attacks on passerby along Choa Chu Kang Street 1 on 1st April 2010 . ( see video at http://tinyurl.com/whats-going-on-crows-attack) House crows were caught harassing other birds too. Allan Teo and Tang Hung Bun observed a House crow harassing Black-Shouldered Kites (Elanus caeruleus) and White-Bellied Sea Eagles (Haliaeetus leucogaster).  Other small animals may also be attacked by these aggressive House Crows. Gloria Seow witnessed a Common Fruit Bat (Cynopterus brachyotis) being attacked by about six House Crows.
 
A Common Fruit Bat attacked by six House Crows http://besgroup.blogspot.com/2006/04/house-crow-and-bat.html

A Common Fruit Bat attacked by six House Crows http://besgroup.blogspot.com/2006/04/house-crow-and-bat.html

 
 
A House Crow harassing three juvenile Black-Shouldered Kites http://besgroup.blogspot.com/2007/01/harassment-of-black-shouldered-kites.html

A House Crow harassing three juvenile Black-Shouldered Kites http://besgroup.blogspot.com/2007/01/harassment-of-black-shouldered-kites.html

According to most studies, this display of aggressiveness from the House Crows is usually associated to food or nest-defense. However, being in an urban habitat with a dense human population, the House Crow should have be habituated with humans already. So what makes them aggressive and thus publicly labeled as pests or bullies?
 
Bird study in J.D Lockie regarding aggressive behaviour of crows indicated that crows may fight with each other over food. It is stated that during winter there is usually an increase in crow fights because of shortage of food. However, in Singapore where food is abundant and climate is always hot and humid, it does not really account for the House Crows’ aggressive behaviour.
It is most likely due to nest-defense.  A research comparing between rural and urban crows by Department Wildlife Ecology, University of Wisconsin shows that urban crows do display higher aggressiveness when threatened as rural crows are more afraid of humans. So crows may attack Singaporeans out of defense because their nests are nearby.
However, in the same research, it also show that urban crows have higher tolerance to humans than rural crows. Urban crows will not feel threaten easily when humans are near their nests.
This contradicts the reason behind crow attacks. One theory could be that the House Crows are becoming more daring as they become less afraid of humans. Thus, they might pester human for food instead. 
 
 Reference cited:
“What’s going on? Crows attack passerby at Choa Chu Kang” by STOMPer Ong. STOMP-Singapore Seen, 1st April 2010.
” Harassment of Black- shouldered Kites” by A. Teo and Tang H.B. Bird Ecology Study Group, Nature Society (Singapore). 6th January 2007.
“The House Crow and the Bat” by G. Seow. Bird Ecology Study Group, Nature Society (Singapore). 20 APril 2006
 

 

Lockie, J. D.(1956) ‘Winter Fighting in Feeding Flocks of Rooks, Jackdaws and Carrion Crows’, Bird

 
 

 

 

Study, 3: 3, 180 — 19o

 

 

 

Knight, R.L. (1987). Nest Defense Behavior of the American Crow in the Urban and Rural Areas. The Condor. 89: 175-177

One response so far

Apr 16 2010

Mangroves: More To It Than Meets The Eye…

You may have seen mangroves somewhere along the coastal area of Singapore but what are the significances of those mangroves? Just after doing some research before writing this blog that I realized mangroves have profound significances to coastal ecosystems in Singapore. For instance, along the coast of Chek Jawa, you can observe mangroves , e.g. Bakau minyak (Rhizopora apiculata) and api-api bulu (Avicennia rumphiana) growing at the intertidal zone.

Bakau Minyak

Bakau Minyak (photos from WildSingapore, Flickr)

Api-api bulu

Api-api bulu, another common mangrove species found at Chek Jawa (photos by WildSingapore, Flickr)

Mangroves support over 150 species of fish in Singapore (Lim K.P. Kelvin et al., 1999). Estuarine catfish (Mystus gulio) is a common example.

Estuarine catfish

Estuarine catfish (Retrieved from "A Guide to Mangroves of Singapore" by Peter Kelvin K.P.Lim et al., 1999)

One of the most important roles of mangroves is nursery habitats for juvenile fish. You may ask why mangroves are so attractive to fish, especially juvenile fish. The reasons for this question include 2 major factors,i.e. food abundance and protection from predators. The epiphytic  algae on mangroves pneumatophores accumulate an assemblage of invertebrate species, thus providing ample food supply to fish (Low and Chou, 1994). The structure of mangrove habitats also provides protection and shelter from predators to juvenile fish.

Another important role of mangroves is that mangroves bind soft sediments, facilitating coral reef development in areas that might otherwise have too much silt for coral growth. In turn, coral reefs buffer wave impacts, helping to minimize erosion of soft sediments that mangroves need to grow (Mumby et al., 2004). 

References:

Low, J.K.Y, Chou, L.M.1994. Fish diversity of Singapore mangroves and the effect of habitat management. Research Paper, Third ASEAN-Australia symposium on living coastal resources Vol.2 (pp.465-470). Bangkok: Chulalungkorn University.

Lim, K.P. Kelvin et al. 1999. A Guide to Mangroves of Singapore. Singapore Science Centre.

Second sources:

Mumby, P.J. et al. 2004. Mangroves enhance the biomass of coral reef fish communities in the Carribean. Nature 427: 533-536.

3 responses so far

Apr 16 2010

Spare this tree some mercy

Published by under plants and tagged: , ,

Currently, there are five Bodhi Trees (Ficus Religiosa) in Singapore registered under the list of Singapore’s heritage tree register. However, one that is especially worth mentioning is the latest addition to the list, and that would be the Bodhi tree located within the premise of a temple located off Bartley road.

JLS_Bodhi_Tree

The tree is over 120 years old and has a height of approximately 30 metres, girth of 8.5 metres, which is considered to be ” the most ancient and largest Bodhi tree in Singapore according to the NSS (Nature Society Singapore) and Nparks.” (Wikipedia.com, 2007)

The Bodhi tree has a symbiotic relationship with the temple as its roots are deeply intertwined with the building’s foundation. Hence, development of the land at the proximity of the tree’s location will have an adverse effect on the tree, thus causing soil movement and stresses to the roots.

Alas, as part of the plan for redevelopment, the temple was acquired to make way for the construction of Circle line despite the immense effort and appeals from the public though the tree was conserved as in response to the public’s petition.

However, it looks like this is not the end to the tree’s sufferings. In 2009, URA has put up a site for application for likely development of homes on the land where the tree is occupying. Although it is under the protection of heritage trees, one can wonder what sort damage will be caused onto the tree when the land is developed for the building of fancy condominiums?bartley_landparcel02

References:

1. Wikipedia.com. Singapore oldest Bodhi Tree estimated at 120 year old at Jin Long Si Temple on 21 Jan, 2007. Credits: Aldwin Teo. Retrieved April 16, 2010, from http://en.wikipedia.org/wiki/File:JLS_Bodhi_Tree.jpg

2. H88.com.sg (n.d). The Bartley Road land parcel and a Bodhi tree. The homepage for homes. Retrieved April 16, 2010, from http://www.h88.com.sg/article/The+Bartley+Road+land+parcel+and+a+Bodhi+tree/

3. Singapore’s Heritage Tree Register (January, 2010). Retrieved April 16, 2010, from http://www.nparks.gov.sg/cms/docs/CIB/Heritage_Tree_Register_NOV2009.pdf

One response so far

Apr 16 2010

Not your usual Puss in Boots..

Published by under Uncategorized

Recently adopted kitten, affectionately named Flea.

Recently adopted kitten, affectionately named Flea.

Going about our daily activities in Science Faculty, some of us may have taken time to ogle, point and pet the occasional stray cat (Felis catus) we meet. Do not be deceived by their contented looks, for life as a stray cat here is not as laid back and purr-fect as it seems. While the urban environment appears to be safe and stable for us, it is difficult to imagine that these cats face a host of challenges for survival, not unlike their feral/wild relatives.

Mother cat White Sockes with litter of kittens. (last semester)

Mother cat White Socks with litter of kittens. (last semester)

Food: These cats rely on us humans as their chief source of food, either by intentional feeding or scraps. (Dards, 1980) However, their human sources are very much ‘seasonal’, mimicking a famine during school holidays. Fortunately, anyone with a pet cat can vouch how intact their innate predatory instincts still are. The observed prowling behaviours occasionally result in piles of feathers found in the vicinity, possible remnants of the Javan Minah (Acridotheres javanicus).

Remnants of a successful hunt. Possible Javan Minah (Acridotheres javanicus).

Remnants of a successful hunt. Possible Javan Minah (Acridotheres javanicus).

Environment: Construction sites nearby present both physical and biological hazards. Kittens are most vulnerable to unhygienic conditions, with an average of 50% mortality. The population density of stray cats in Science is the highest in NUS, thus the easy spread of diseases such as FIV(Feline Immunodeficiency Virus) and parasites like flea mites.

Inter/Intra-Specific Interactions: These cats display social dynamics amongst themselves. Not many males are found in the same area due to their territorial nature (Natoli, Sept, 1985). A particular black adult is the distinct alpha male, suspected to be responsible for most of the kittens born. There have also been instances of stray dogs (Canis lupus familiaris) preying on the weaker cats in the area.

Alpah male affectionately named CaoCao by volunteer feeders

Alpha male named CaoCao by volunteer feeders.

Selection: NUS Cat Cafe is currently attempting to systematically sterilise the cats. It is inevitable that only the relatively tamed ones are sterilised. It is ironic that this selection process results in the illusive and flighty cats to continue to propagate, an outcome ‘unfavourable’ to efforts aimed at controlling the cat population, assuming such behaviours are heritable.

References:

-Dards, J. (1980). Habitat Utilisation by Feral Cats in Portsmouth Dockyard. The Ecology and Control of Feral Cats (p. 6). Hertfordshire: The Universities Federation for Animal Welfare.

-Natoli, E. (Sept, 1985). Behavioural Responses of Urban Feral Cats to Different Types of Urine Marks. Behaviour , Vol. 94, pg 234-243.

*Information also from work done by NUS Cat Cafe. Please contact directly if interested in adopting kittens.

No responses yet

Apr 16 2010

Tales of the roaming dead – in your backyard.

Published by under Uncategorized and tagged: ,

Warning: Not safe for work – you wouldn’t want to feel nauseous in the office, do you?

Themes of zombies and the living dead have never failed to capture people’s imagination. Zombie-genre films such as Night of the Living Dead and 28 Days Later are continuously churned out by Hollywood producers to feed the insatiable appetites of consumers for thrill and excitement. One might think that zombies are restricted only to the big screens and science fictions; they are terribly wrong. In reality, zombies do roam the earth, and they might just be in your backyard.

The zombie and the parasites

The zombie and the parasites

Parasitic wasps have always been a fascinating research area for scientists. These wasp injects its eggs into the caterpillar host and the newborn larvae will feed on the caterpillar’s body fluids and grow inside the host. Think of it as a mobile food van with all-you-can-eat buffet for these hungry young maggots.  Wasp Glyptapanteles can inject up to eighty eggs into the caterpillar host. (Brahic, 2008) When the larvae are fully grown, they emerge out of the caterpillar’s skin to spin their cocoons and undergo pupae stage. It might be every caterpillar’s dream to become a beautiful butterfly, but alas, this unfortunate one will never be. In addition to inject her eggs, the parasitic wasp also injects a plethora of virus particles into the host, hay-wiring its immune system, causing it to fail to pupate and dies as a caterpillar. (Beckage, 1997)

What’s even more intriguing, however, is that the wasp larvae appears to have manipulative control over its host. Once the larvae emerged out of the caterpillar and become cocoons, the caterpillar stays stationary and does not move or feed, as if it is watching over these vulnerable cocoons.

Click the link to see zombie caterpillar in action : Zombie caterpillar controlled by voodoo wasps

As seen in the video, if the caterpillar is infected by parasitic wasp, its behavior drastically changes and will actually defend the wasp cocoons vigorously if a predator approaches. The caterpillar will stay alive until the adult wasp hatches.

This is no mere coincidence: in an experiment conducted by Ame Janssen of University of Amsterdam, it is discovered that the majority of the parasitic caterpillars will defend the cocoons by thrashing their head vigorously to knock the incoming predators off the branch while uninfected caterpillars are totally oblivious to the predators. Furthermore, the cocoons guarded by the parasitic caterpillars have double the survival rate of its unguarded counterparts. (Brahic, 2009) This further proves that the wasps have a profound manipulative influence on its caterpillar host.

If you think such atrocious acts of parasitism does not occur in our area, think again. A species of parasitic moth of family Ichneumonidae has been spotted in Bukit Timah Nature Reserve, parasiting its host Pergesa Acteus (Leong, 2009)

So next time when you walk through the forested areas in Singapore, be extra cautious. Who knows, you might be stepping into a zone of zombie caterpillars and their parasitic hosts.

References:

  1. “Zombie caterpillars controlled by voodoo wasps”, Catherine Brahic, NewScientist, 04 June 2008. URL: http://www.newscientist.com/article/dn14053 (accessed on 14 April 2010)
  2. “Zombie caterpillar controlled by voodoo wasps”, NewScientistVideo, Youtube, 03 June 2008. URL: http://www.youtube.com/watch?v=7UkDMrG6tog&feature=player_embedded (accessed on 14 April 2010)
  3. Beckage, N.E, The Parasitic Wasp’s Secret Weapon, Scientific American, Nov 1997, 277(5):  82-87.
  4. Caterpillars Beware: Parasitic Wasps Come in a Wide Variety”, Andrew Moseman, Discover Magazine, 02 Sep 2008. URL: http://blogs.discovermagazine.com/discoblog/2008/09/02/caterpillars-beware-parasitic-wasps-come-in-a-wide-variety/ (accessed on 14 April 2010)
  5. “Parasitized and Expired Hornworm”, Wormwould. Flickr. URL: http://www.flickr.com/photos/onthespiral/1245492578/ (accessed on 14 April 2010)
  6. Leong, T.M, Rozario, V.D, Larval development and metamorphosis of the hawkmoth, Pergesa Acteus in Singapore, Nature in Singapore, 2009 (2): 329-338

No responses yet

Apr 16 2010

The Dragonflies fly!

Published by under Uncategorized and tagged: ,

It is not uncommon for a dragonfly to be trapped in our home. Recently, a relatively large dragonfly flew into our living room and set the house in pandemonium! Moreover, we live on the tenth floor which reflects on how high the dragonfly can fly. It was trying to escape and it was interesting to observe its flight pattern while trying to shun it. It flew (with a slight buzzing sound) forwards and backwards suddenly and sometimes it just hung in midair. Ignoring the innate fear of large insects, it was actually quite fascinating! Interestingly enough, the method dragonflies employ for flight has been applied to various fields such as “robotics, aviation, and the military” (Beale, 2003). I found out that the method employed by these highly-skilled fliers is referred to as “active motion camouflage” which creates an illusion that they are not moving when they actually are (Beale, 2003).

The presence of dragonflies in an urban area is analogous to the presence of lichens in forests. While the latter is very sensitive to air pollution and thus can be used as an indicator for air pollution levels (Nash et. Al), dragonflies are indicators of water pollution. Their presence indicates relatively unpolluted water bodies and they play a key role in the freshwater ecosystem (“NParks”).  Dragonflies generally eat small insects, including mosquitoes! And frogs in the pond ecosystem feed in these dragonflies (see Aside and Youtube video Dragonfly and Frog!)

It came as a surprise to discover that the dragonfly population in Singapore is indeed flourishing and increasing! According to a study done by NParks over a two-year period (2008-2010), the total number of dragonfly species have reached over 120 (as compared to 117 in 2008 (Norma et. Al, 2008)) ! This is nearly as large as the number of species in the whole of Europe, which only has 130 species (Wasscher, 2003)!!

So the next time you see the humble dragonfly, remember it reflects on how the freshwater pond community is thriving!

Aside:  Above are some pictures of the lagoon area in my condominium(I meant to put them below but i can’t seem to format it right). It used to be teeming with dragonflies and frogs everyday at around 1800. It was a freshwater ecosystem right at our doorstep, literally! Unfortunately, due to the high cost of maintaining the freshwater fish pond (also because many children including myself took the liberty to go pond fishing ;)), the fishes were removed and the water chlorinated about a year ago. Consequently, the dragonflies and frogs disappeared!

References

Beale, Bob. “Putting the Buzz in Navigation.” Scientist 17.19 (2003): 28. Web. 14 Apr 2010. <http://www.the-scientist.com.libproxy1.nus.edu.sg/article/display/14150/>.

Norma-Rashid, Y., L.F.Cheong, H.K.Lua & D.H. Murphy, 2008. The Dragonflies (Odonata) of Singapore: Current Status Records and Collections of the Raffles Museum of Biodiversity Research. Raffles Museum of Biodiversity Research, Singapore. 21 pp. Uploaded 7 Nov. 2008.   <http://rmbr.nus.edu.sg/raffles_museum_pub/Dragonfly_of_Singapore.pdf>

Nash, Thomas, and Unione italiana. Lichen Biology. 3rd ed. United Kingdom: Cambridge Univ Pr, 1996. 240-41. Print.

“NParks’ Dragonfly Project Unveils One Third of Total Species Existing in Singapore Sighted at Urban Parks and Gardens.” National Parks. Singapore Government, 30 03 2010. Web. 14 Apr 2010. <http://www.nparks.gov.sg/cms/index.php?option=com_news&task=view&id=188&Itemid=50>.

Wasscher, MT. “The European dragonflies: Notes on the checklist and on species diversity .” CSA Illumina 29.1 (2000): 31-43. Web. 14 Apr 2010. <http://md1.csa.com/partners/viewrecord.php?requester=gs&collection=ENV&recid=4699809&q=dragonfly+number+europe&uid=1015501&setcookie=yes>.

7 responses so far

Apr 16 2010

Fig Tree and Fig Wasp = Babysitter and Matchmaker

Published by under species interactions and tagged: ,

Figs fruiting from trunk. (Photograph © Nick Baker)

Figs fruiting from trunk. (Photograph © Nick Baker)

Fig trees (Ficus sp.) are considered as a keystone species in Singapore rainforest. This is because they flower and fruit frequently, offering frugivorous animals a year-round supply of food. The figs are actually an enclosed inflorescence known as syconium, within which a unique mutualistic relationship between the plants and fig wasps take place. Fig wasp is a tiny insect from the Agaonidae family which lays its eggs in the syconium.  

 

Upon hatching, the larvae will grow and develop inside the syconium with protection and immediate food provided by the fig. It is also within this small syconium, the grown up wasps mate. The female wasps carrying fertilized eggs will then leave the syconium with the assistance of the wingless male wasps which chew a hole through the syconium wall and subsequently die without leaving the syconium (Cook & Rasplus, 2003).

 

In return for the shelter and food, the female wasps act as pollinators for the fig tree. This is because a female wasp often picks up pollen from the male flowers in its home syconium. After leaving its home syconium, the female wasp will look for another syconium to lay its eggs and eventually they pollinate the female flower within (Tan, Chou, Yeo & Ng, 2010).

 

Figure 1: Life cycle of fig wasp (Agaonid)

Figure 1: Life cycle of fig wasp (Photograph © Encyclopædia Britannica)

 

The mutualistic relationship between figs tree and fig wasp is co-evolutional and highly obligated. Each fig species generally has its own agaonid symbiont as pollinator; the wasp on the other side is host-specific. This can be revealed by the inability of a fig species to colonize a new habitat without its specific pollinator wasp species being established (Ramirez, 1970). The specificity is advantageous to both fig trees and fig wasps. This is because it reduces inter-species competition for syconia while increase the chance of successful pollination of fig trees.

 

 

References:

 

  1. William Ramirez B., 1970. Host Specificity of Fig Wasps (Agaonidae). Evolution, 24(4): 680-691.
  2. Cook, J.M., Rasplus, J.Y., 2003. Mutualists with attitude: coevolving fig wasps and figs. Trends in Ecology and Evolution. 18: 241-248
  3. Hugh Tan T.W., Chou L. M., Darren Yeo C. J, Peter Ng K. L., 2010. Primary Vegetation. The Natural Heritage of Singapore. Singapore: Pearson Education South Asia Pte Ltd.
  4. “Fig Wasp” by Encyclopædia Britannica, 1999. URL: http://www.britannica.com/EBchecked/topic-art/206044/19378/The-life-cycle-of-the-fig-wasp (accessed on 15 Apr 2010)
  5. “Bukit Timah Nature Reseve- a precious remnant of primary rainforest” by Nick Baker. Ecology Asia, 2010. URL: http://www.ecologyasia.com/html-loc/bukit-timah.htm (accessed on 14 Apr 2010)

 

Second Sources:

  1. Wiebes, J. T., 1979. Co-Evolution of Figs and their Insect Pollinators. Annual Review of Ecology and Systematics, 10: 1-12

7 responses so far

Apr 16 2010

The Invasion of Yellow Crazy Ants

As one of the world’s top 100 worst invasive species (Lowe et al., 2000), the yellow crazy ants (Anoplolepis gracilipes) have now invaded Singapore! This species of ants are notorious of forming multi-queen supercolonies and invading large areas, which is one of the leading factors for its disastrous impact (Abbott, 2006). However, not many of us actually know about this particular “invasion”. In a quick survey around NUS, these ants are found in high densities at the patch of adinandra belukar secondary forest just behind NUH!

A close up picture of a yellow crazy ant.

A close up picture of a yellow crazy ant.

The yellow crazy ants got their name from their pale yellow colour and their frenetic or “crazy” movement when disturbed. Their extremely long legs allow them to move rapidly, which may give them an advantage over other ants when foraging the leaf litter for food. They are rather aggressive and sometimes also spray formic acid into other competing ants. Luckily, these ants does not seem to bite humans.

It’s hard not to wonder how creatures this small a size can actually cause a significant impact. However, this species of ants received worldwide attention for its devastating impact on endemic birds of Seychelles (Hill et al., 2003) and the red land crabs of Christmas Island (Abbott, 2006). In a recent study, these ants have shown high degree of exploitative and interference competition, and have successfully establish several colonies in Kent Ridge Forest and Bukit Timah Nature Reserve (Cedric et al., unpublished data). It is really hard to imagine what will happen if the population of these ants suddenly explodes. And for the current time being, the invasion progress of the yellow crazy ants have to be minitored.

REFERENCES

Abbott K.L. (2006). Spatial dynamics of supercolonies of the invasive yellow crazy ant, Anoplolepis gracilipes, on Christmas Island, Indian Ocean. Diversity and Distributions. Vol. 12. pp.101-110.

Cedric K.W.T., Teh H.Y., Lee G., Corlett R.T. (unpublished data). Invasion of the Yellow Crazy Ant in Singapore.

Hill M., Holm K., Vel T., Shah N.J., Matyot P. (2003). Impact of the introduced yellow crazy ant Anoplolepis gracilipes on Bird Island, Seychelles. Biodiversity and Conservation. Vol. 12.  pp.1969-1984.

Lowe S., Browne M., Boudjelas S., De Poorter M. (2000). 100 of the world’s worst invasive alien species. Invasive Species Specialist Group.

No responses yet

Apr 16 2010

Singapore’s Drainage system, a highway for snakes to our residential estates

Published by under Uncategorized and tagged:

When I was serving in the national service as a neighbourhood police officer in the year 2007, I attended three cases in response to calls by residents after spotting pythons. All the three pythons were found within residential areas, two in drains while the other near a drain. One managed to escape through the covered drain when we arrived, while the other two managed to be caught.
The Singapore police receive calls from residents two to three times a week reporting a visit by one of Singapore’s many snakes.(Arnold, 2004) The Singapore Zoological Gardens collects 100 pythons a year from the police.(Arnold, 2004)
Pythons commonly spotted in Singapore are the Reticulated Pythons (Broghammerus reticulatus). They are known to be either the largest or second-largest species of snake in the world, with reliable records of specimens exceeding 9 m in length and 150 kg in mass (Pope, 1975).
So what are they doing in our residential estates?
Wayne Arnold, a journalist for The New York Times suggest that these pythons end up in the urban as they tire the usual forest fare of monkeys and birds, in search of rats, cats and dogs.(Arnold, 2004)
I am rather sceptical of his claims. Instead, my question is do these pythons end up in the residential areas by chance (considering the small size of Singapore and the proximity of residential areas with the forests) or due to the insufficient prey for them to hunt in the forests such that they had to search them beyond their habitat?
Singapore’s vast sewer system, which is vital for preventing torrential tropical storms from flooding the city, has been used by these snakes as their own subway network. (Arnold, 2004) These snakes are versatile due to their diversified nature of being able to swim, and or climb in trees. (Shine and Madson, 2006)
Much of the rivers in Singapore have been replaced by drains and canals. Pythons, now unable to travel via rivers use these “highways” instead. Therefore I think that these lost snakes probably have taken the wrong route since drains are covered and the snakes will not know where they are heading to.
Second source: Shine R, Madsen T., 1997 Prey abundance and predator reproduction: Rats and pythons on a tropical Australian floodplain. ECOLOGY 78(4) pp.1078-1086 http://cat.inist.fr/?aModele=afficheN&cpsidt=2767856
References
Pope, C.H., 1975. The Giant Snakes. Alfred A. Knopf, New York.

Shine R, Madsen T, 2006. Is Thermoregulation Unimportant for Most Reptiles? An example Using Water Pythons Physiological Zoology, Vol. 69(2), pp. 252-269

“Wildlife’s revenge : Even in urban Singapore, it can sometimes be a jungle,” by Wayne Arnold. The New York Times, 25 September 2004. http://www.nytimes.com/2004/09/25/news/25iht-rtropics_ed3_.html (accessed on 25 April 2010).

One response so far

Apr 16 2010

Spotted: Weaver ants trying to tear apart a live Honey Bee

black dwarf honey bees

Figure 1: Black honey dwarf bees.

Black dwarf honey bees (Apis andreniformis) were spotted collecting nectar in a Powderpuff tree (Calliandra emarginata). On a closer look, the bees also shared the tree with some Weaver red ants (Oecophylla smaragdina), as well as other small black pollinating midges (c.f. Family Ceratopogonidae or Cecidomyiidae).

Firgure 1: Weaver ants hoisting motionless bees back to their arboreal nests.ants: "yummy. another dead bee."

Figures 2 and 3: In two other nearby trees: Weaver ants hoisting motionless bees back to their arboreal nests.

I had assumed that although these  ants look intimidating, they play a vital role in helping to speed up the decomposition of dead matter (i.e. nature’s clean-up crew as seen above), and are therefore mostly scavengers. Little did I know that these ants we commonly see outdoors can be very voracious predators. They may just be on the lookout for their next sizable prey, whether dead or alive.

Weaver ants each holding onto a different point of the bee. They seem to be pulling and trying to contort the bee.

Figure 4: Weaver ants each holding onto a different point of the bee. They seem to be pulling and trying to contort the bee. (Black arrow: Was that a part of the bee?)

As I took a closer look at the first tree which was busiest with bees (as in Figure 1), I spotted a commotion on one of the branches (Figure 4 on the left). I thought the bee was dead — but it buzzed briefly and was held down by the weaver ants.

Weaver ants have been documented to kill prey by stretching it, and simultaneously concealing them with twigs and leaves, or retrieving them back to their arboreal nests, to prevent other predators from snatching their prey (Rastogi 2000).

I was appalled, but it also puzzled me how these light-weight ants could hold onto a bee attempting to escape. It turns out that the limb ends of these ants are specialized to resist detachment up to 150 times their own weight  (Federle et. al. 2002):

Light micrographs of how a weaver ant’s pre-tarsus (limb end) grabs onto a surface. As the limb is pulled downwards, the adhesive cuticle pad (between the pre-tarsal claws) expands automatically, creating a suction-adhesion force. (Figure 2 in: Federle et. al. 2002)

Light micrographs of how a weaver ant’s pre-tarsus (limb end) grabs onto a surface. The cuticle pad (between the pre-tarsal claws) creates a suction-adhesion force. This adaptation enables them to forcefully pull in neighbouring leaves while standing on smooth leaf surfaces (can be seen in action in Figure 4). (Figure 2 in: Federle et. al. 2002)

tree trunk crawling with weaver ants

Figure 5.

Out of the several Powerpuff Powderpuff trees present, only that one tree was busiest with bees. Bees being endotherms, perhaps they preferentially extract nectar from trees receiving the most sunlight (Young 1985). However on closer inspection of the adjacent tree ( with visibly less bee activity) — I found another possible reason — the branches were colonised by weaver ants (see Figure 5).

Witnessing how a weakened bee had been held captive by the weaver ants in a case of power in numbers, it’s no wonder that the tree barely had any bee visitors (refer to: Ritter and Akratanakul 2006, Junker et. al. 2006 ).

A weaver ant showing aggression at the honey bee.

A Weaver ant showing aggression at a Black dwarf honey bee (seen by exposing its mandibles).

Seems like these ants not only deter herbivores in a mutualistic relationship with its host tree (as mentioned in fellow course-mate u0805142’s blogpost), they also deter pollinators (Ness 2006, Tsuji et. al. 2004). These ants have certainly more to them than meets the eye.

ants

Weaver ants standing gaurd, and on the lookout.

References:

  • Young, A. M., 1985, Pollen-collecting by stingless bees on cacao flowers, Cellular and Molecular Life Sciences, 41(6):760-762
  • Rastogi, N. 2000, Prey concealment and spatiotemporal patrolling behavior of the Indian tree ant Oecophylla smaragdina (Fabricius), Insectes Sociaux, 47(1):92-93
  • Federle, W., Riehle, M., Curtis, A. S. G., Full, R.J., 2002, An Integrative Study of Insect Adhesion: Mechanics and Wet Adhesion of Pretarsal Pads in Ants, Integrative and Comparative Biology 42(6): 1100-1106.
  • Ness, J. H., 2006, A mutualism’s indirect costs: the most aggressive plant bodyguards also deter pollinators, Oikos, 113(3): 506-514
  • Tsuji, K., Hasyim, A., Harlion & Nakamura, K. ,2004, Asian weaver ants, Oecophylla smaragdina, and their repelling of pollinators. Ecological Research, 19(6): 669-673
  • Ritter, W. & Akratanakul, P., 2006, Honey bee diseases and pests:a practical guide, FAO (Food and Agriculture Organization of the United Nations) agricultural and food engineering technical reports, p20. Retrieved April 12, 2010 from : http://www.fao.org/AG/ags/subjects/en/industFoodAg/pdf/AGST_techrep_4.pdf
  • Junker, R., Chung, A. Y. C., Blüthgen, N., 2006, Interaction between flowers, ants and pollinators: additional evidence for floral repellence against ants. Ecological Research,22(4):665–670.

( Coloured photographs used in this post are taken by the author on 11th and 12th April 2010)

3 responses so far

Apr 16 2010

An Unusual Anti-Predatory Response

Published by under Uncategorized and tagged:

The behaviour of sacrificing body parts as a defense strategy is not uncommon in the marine habitat. An encounter with Stichopus horrens during a survey at Pulau Semakau gave me a personal experience of the unique defense responses displayed by the Holothurian (sea cucumber).

Stichopus horrens taken before the shedding of its body wall

Stichopus horrens taken before the shedding of its body wall. (Photo taken at Pulau Semakau, 3 April 2010)

Holothurians have seven main types of anti-predatory mechanisms to defend themselves from potential predators, which include (Bingham & Braithwaite, 1986; Francour, 1997): (1) having thickened body wall, (2) toxic and noxious skin and organs, (3) body welling or stiffening, (4) swimming, (5) nocturnal activity, (6) cryptic or burrowing, and (7) autotomy or evisceration.

Pink spotted sea cucumber ejecting Cuvierian tubules as a form of defense response. "Pink sea cucumber," by Ria Tan. Wildsingapore, June 2009. URL: http://www.wildsingapore.com/wildfacts/echinodermata/holothuroidea/pinkspot.htm (accessed on 16 April 2010)

Pink spotted sea cucumber ejecting Cuvierian tubules as a form of defense response. "Pink sea cucumber," by Ria Tan. Wildsingapore, June 2009. URL: http://www.wildsingapore.com/wildfacts/echinodermata/holothuroidea/pinkspot.htm (accessed on 16 April 2010)

While evisceration and ejection is more common, where Holothurians discharge their guts or Cuvierian Tubules to ensnare and distract their enemies (National Geographic Society), the S. horrens protects itself from predation in a more unusual manner. When I removed it from the water to take photographs, the S. horrens surprised me by detaching a piece of its body wall within a few seconds, after arching into a “U” shape.

Stichopus horrens with its shed body wall after returning it into the water. (Photo taken at Pualau Semakau, April 2010)

Stichopus horrens with its shed body wall after returning it into the water. (Photo taken at Pualau Semakau, April 2010)

After placing it back into the water immediately, the usually slow S. horrens moved much faster away from the spot where I left it. These observations were consistent with a study done, where S. horrens were observed to contract the body into a “U” shape, followed by shedding of a piece of body wall and down current bounding locomotion when attacked, which was proven to be rather successful for escape (Kropp, 1982). It is also said that members of this genus if removed from the water too long, can “melt”, become limp and even disintegrate all together (Hauter & Hauter). Thankfully, if they are not too badly “melted”, they can reverse this process and recover.

Handle sea cucumbers with care the next time you see one. After all, we are their potential predators.

References:

Bingham, B. L., & Braithwaite, L. F. (1986). Defense adaptations of the dendrochirote holothurian Psolus chitonoides Clark. Journal of Experimental Marine Biology and Ecology , 98 (3), 311-322.

Francour, P. (1997). Predation on holothurians: a literature review. Invertebrate Biology , 116 (1), 52-60 .

Hauter, D., & Hauter, S. (n.d.). Sea Cucumber Family Profile. Retrieved April 15, 2010, from About.com.: Saltwater Aquariums: http://saltaquarium.about.com/blcucumberfam_stichopodiae.htm

Kropp, R. K. (1982). Responses of five holothurian species to attacks by a predatory gastropod, Tonna perdix. Pacific Science , 36 (4), 445-452.

National Geographic Society. (n.d.). Sea Cucumber Holothuroidea. Retrieved April 15, 2010, from National Geographic: http://animals.nationalgeographic.com/animals/invertebrates/sea-cucumber

Image:

“Pink sea cucumber,” by Ria Tan. Wildsingapore, June 2009. URL: http://www.wildsingapore.com/wildfacts/echinodermata/holothuroidea/pinkspot.htm (accessed on 16 April 2010)

2 responses so far

Apr 16 2010

Crab eat Crab

Published by under species interactions and tagged: , , , ,

Who would have thought that a crab could devour another crab more than half its size? Certainly not a largely algivorous Purple Climber Crab!

Picture taken in Pulau Semakau

Picture taken in Pulau Semakau, 28th March 2010

Being an opportunistic predator inhabiting the sea-ward mangrove fringe, the Purple Climber Crab, Metopograpsus spp., is occasionally known to incorporate smaller crabs as part of their diet (Poon & Chan, 2009). Shown in the picture below is an example of such an occurrence. What is thought to be a soldier crab (Mictyris brevidactylus) was struggling in the grip of the distinct purple pincers of the climber crab, a vice of which is known to be better suited to scrap off algae (Ng & Sivasothi, 2001).

This crab’s dietary pattern is shaped by the interplay between its biology and physical environment (Poon & Chan, 2009). Having spoon-shaped chelae efficient for browsing filamentous macroalgae or scraping off biofilm from substrates, it is little wonder than its diet is dominated by algae. However, the purple climbing crab will attack any prey it can overcome given its highly opportunistic nature.

Habitats with a four-seasonal variation also influence the crab’s diet. An example would be in Hong Kong, where winters reduce the wandering activity of the soldier crab and winter bloom of ephemeral macroalgae, result in the consumption of more algal material. Summers see the opposite happening (Poon & Chan, 2009).

The opportunistic nature of the crab can be likened to that of other animals such as humans, leopards or dogs, which are able to kill and eat almost anything. It is thus little wonder that the crab can survive well on the dynamic shores of Pulau Semakau!

References

Ng, P. K., & Sivasothi, N. (2001). purple climber crabs. Retrieved from Guide to Mangroves of Singapore: http://mangrove.nus.edu.sg/guidebooks/text/2047.htm

Poon, D. Y., & Chan, B. K. (2009). Spatial and temporal variation in diets of the crabs. Springer Science , Hydrobiologia (2010) 638:29–40.

Second Source

Poon, D. Y., & Chan, B. K. (2009). Spatial and temporal variation in diets of the crabs. Springer Science , Hydrobiologia (2010) 638:29–40.

No responses yet

Apr 16 2010

The natural “pesticides” against mosquitoes

Published by under Uncategorized and tagged:

NParks has conducted dragonfly studies for over 2 years and they have found that a considerable number of species of dragonflies are able to thrive in an urban environment like Toa Payoh Town Park, when previously they are more commonly found in the reserves and rural areas. The news may not be appealing at first but the ecological role of dragonflies might be beneficial to human race in the case of fighting dengue.

Often, the use of chemicals during mosquito control like the water based fogging as shown pollutes the canal and drains and this affects the quality of the drinking water which in turn may affect our health in the long run. YUCKS!

Introducing the dragonflies which are the predators into the ecosystem might bring about biological control of the mosquito populations. From the ecology perspective, this provides insights to the prey and predator relationship between dragonflies and mosquitoes. The dragonflies are active and aggressive carnivores adapted with strong biting mouthparts which often target insects on the wings.

There is a video to look at how the dragonfly devours its prey

To substantiate the finding, I have found a review article on the perspective of mosquito biological control. An experiment was done in Myanmar and the result showed that mosquito larva disappeared rapidly after dragonfly larvae have been introduced into the containers. This is provided by the diagram representing the interactions of mosuito larva and its predators as shown from the link as shown here.

Of course, there are various predators such as the mosquitofish targeting at the mosquito larvae as well. But what makes dragonflies special predators is that they are able to predate both the adult mosquito and the mosquito larva, hence ensuring there is little replacement for the adult mosquitoes and to eliminate the dengue carrying mosquitoes directly! Therefore, the presence of dragonflies found in urban landscapes means good news for the human population.

With such natural pesticides available, it is not surprising that the authorities are now racking their brains to create habitats in national parks for the dragonflies to thrive well.

Reference

“Celebrating Singapore’s BioDiversity! International year of biodiversity 2010,” by Ria. Iyb2010singapore, 31 March 2010. Hosted on Iyb2010singapore:http://iyb2010singapore.blogspot.com/2010/03/dazzling-dragonflies-of-singapore.html (accessed on 13 April 2010)

“Dragonfly Eating Mosquito,” by kpe12375, 07 July, 2009.URL:http://www.youtube.com/watchv=B13ZKO8LWRg&feature=player_embedded(accessed on 13 April 2010)

“Fog the foggers,” by Quah Seng-Sun. Anything Goes, 17 April 2009. Hosted on Ssquah: http://ssquah.blogspot.com/2009_04_01_archive.html(accessed on April 14 April 2010)

“Larvicidal Efficiency of Aquatic Predators: A Perspective for Mosquito Biocontrol,” by Ram Kumar and Jiang-Shiou Hwang. Sinica, 30 November 2005. URL:http://www.sinica.edu.tw/zool/zoolstud/45.4OnlineFirst/940607.pdf (accessed on 14 April)

“Nettings,” by Ivan Ang. SingaporeTreasures: unusual stories, extraordinary memories, special encounters, just another unique day in Singapore. URL: http://www.singaporetreasures.com/html/fiction.html (accessed on 13 April 2010)

“NParks’ Dragonfly Project Unveils One Third of Total Species Existing in Singapore Sighted at Urban Parks and Gardens,” by Nparks. Nparks 30 Mar 2010. URL:http://www.nparks.gov.sg/cms/index.phpoption=com_news&task=view&id=188&Itemid=50(accessed on 13 April)

One response so far

Apr 16 2010

Human’s love-hate relationship with Excoecaria agallocha

Published by under Uncategorized

One of the plants that may be noticed in Singapore mangroves are the Blind Your Eye (Excoecaria agallocha).

Picture of Excoecaria agallocha taken from www.wildsingapore.com

Picture of Excoecaria agallocha taken from www.wildsingapore.com

These plants come from the Euphorbiaceae family. While most of the plants in this family are herbs, Blind Your Eye, as the name suggested, has milky sap that will cause irritation to skin and causes temporary blindness if it enters the eye (Wang et al., 2006).

Due to its toxicity, these plants are traditionally used as poisons for fishes (Ng, P. K. L., 1999). The milky sap is also applied to arrowheads as a form of defense.

This toxicity of the sap discouraged most animals from eating their fruits. Hence, these plants disperse their seeds by explosion of their fruits. Their seeds are then brought further by water where they germinate far away from the parent plant. One type of insect that are found of these plants are the shield bug (Calliphara nobilis) (Ng, P. K. L., 1999). The larva of these bugs feed on the seeds of Excoecaria agallocha.

Picture of the Excoecaria aggalloca seeds with Stink bug feeding on it. Taken from http://mangrove.nus.edu.sg/guidebooks/text/2012.htm

Picture of the Excoecaria aggalloca seeds with Stink bug feeding on it. Taken from http://mangrove.nus.edu.sg/guidebooks/text/2012.htm

However, despite being a toxin plant, this plant also has many medicinal uses. The bark and wood of this plant can be used against flatulence (Karalai et al., 1994) while the roots are mixed with ginger to be used as a lotion for swollen limps (Jayaweea, 1980).

It was found that certain chemicals found in these plants actually have tumor suppressing effect (Konoshima et al., 2001). It is also anti-HIV, anti-cancer, anti-bacterial and anti-viral properties.

So if you are thinking of getting a medical certificate to skip exam, try rubbing the sap these plants into your eyes. You will be too blind for an exam and at the same time, you might be even save yourself from HIV!

Reference

Wang, J. D., Zhang W., Li Z. Y., Xiang W. S., Guo Y. W., Krohn K, 2006. Elucidation of excogallochaols A–D, four unusual diterpenoids from the Chinese mangrove Excoecaria agallocha. Phytochemistry 68: 2426–2431

Konoshima T., Konishi T., Takasaki M., Yamazie K. and Tokuda H., 2001. Anti-tumor-Promoting Activity of the Diterpene from Excoecaria agallocha. II, Biol. Pharm. Bull., Vol. 24, 1440-1442

Karalai, C., Wiriyachitra, P., Operkuch, H.J., Hecker, E., 1994. Cryptic and free skin irritants of the daphnane and tigliane in latex of Excoecaria agallocha. Planta Med. 60, 351–355.

Ng, P. K. L. & Sivasothi, N. 1999. A Guide to the Mangroves of Singapore I (Plant Diversity). Singapore Science Centre. 168 pp.

One response so far

Apr 16 2010

Figs can be parasites too!

Published by under Uncategorized and tagged: , , , ,

Fig wasps

(Picture from van Noort and Rasplus, depicting fig-wasps emerging from the gall flowers)

 

It is rather well-known that figs (Ficus sp.) serve as keystone species in Singapore’s forests. These plants fruit year-round and serve as important sources of food for frugivores, especially when other trees are not fruiting. They also display mutualistic relationships with fig-wasps (family Agaonidae), providing fig-wasps with food and a place to grow. In return, the fig-wasps serve as sole fig-pollinators. This relationship is specific to a pair of fig species and the fig-wasps it depends on. (www.figwebs.org gives a detailed description of this relationship.)

 

 Fig tree covers rotting trunk of host tree

(Picture from http://www.loxahatcheefriends.com)

 

However, some fig species also engage in parasitism. One such example is the strangler fig, which includes Waringin (Ficus benjamina). This type of figs grows from a seed dropped on a tall host tree. From this seed, long roots grow and reach the ground. Then, they thicken and surround the whole tree. This eventually prevents the host tree from growth, thus “strangling” and killing it. This phenomenon has been examined in palm savannas in Venezuela (see study by Putz and Holbrook, 1989). In the following picture, we can see the roots of F. benjamina surrounding the trunk of another tree.

 

 Ficus benjamina

(Picture from Ria Tan – taken at Sungei Buloh Nature Reserve, Feb 2010)

 

I am amazed by how a single species can have different types of ecological interactions with other species. This reinforces the fact that ecosystems have complex relationships within and between them, and that everything is interlinked. As the song “Colours of the Wind” from Disney’s Pocohontas says, “We are all connected to each other in a circle, in a hoop that never ends”. Indeed, to successfully conserve these keystone species, we will need to have knowledge of all the different interactions that are occurring in the ecosystem.

 

References
Elisabethiella stuckenbergi females and males emerging from their galls inside a split open fig of Ficus thonningii,” by S. van Noort and J. Rasplus. Figweb, 2009. URL: http://www.figweb.org/Interaction/How_do_fig_wasps_pollinate/index.htm (accessed on 14 Apr 2010).

Ficus benjamina,” by Ria Tan. Wildfactsheets, 10 Mar 2008. URL: http://www.wildsingapore.com/wildfacts/plants/others/ficus/benjamina.htm (accessed on 13 Apr 2010).

“Figs,” by Ria Tan. Wildfactsheets, 10 Mar 2008. URL: http://www.wildsingapore.com/wildfacts/plants/others/ficus/ficus.htm (accessed on 13 Apr 2010).

“Figs and Fig Wasps,” by S. van Noort and J. Rasplus. Figweb, 2009. URL: www.figweb.org (accessed on 14 Apr 2010).

“Fig tree covers rotting trunk of host tree,” by Friends of the Loxahatchee Refuge. Friends of the Arthur R. Marshall Loxahatchee National Wildlife Refuge, Jun 2009. URL: http://www.loxahatcheefriends.com/Nature/0906%20Jun/vines.htm (accessed on 14 Apr 2010).

Putz, F. E. & Holbrook, N. M., 1989. Strangler Fig Rooting Habits and Nutrient Relations in the Llanos of Venezuela. American Journal of Botany, 76 (6): 781 – 788.

“Waringin,” by Ria Tan. Wildfactsheets, 10 Mar 2008. URL: http://www.wildsingapore.com/wildfacts/plants/others/ficus/benjamina.htm (accessed on 13 Apr 2010).

No responses yet

Apr 16 2010

The Lone Ranger: Lost, Exiled or proud Explorer?

Published by under Uncategorized and tagged:

Lost, exiled or proud explorer?

Long-tailed macaques.” ParaSites Project . Web . 15 Apr 2010.:http://www.stanford.edu/group/parasites/ParaSites2009/MaryamGarba_pasmodium/MaryamGarba_pasmodium.htm

As I was driving home about 2 months ago, I encountered a lone monkey, sitting in the middle of the road leading up to my house. I was both shocked and excited. I immediately recognised the monkey as a species that was similar to those that I often see in MacRitchie reservoir and Bukit Timah Area. It was a long-tailed Macaque also known as crab-eating Macaque, Macaca fascicularis (Family Cercopithecidae) , which is a species native to Singapore(Tan). My house is located in the eastern region of Singapore, Tanah Merah where monkey sightings are rare (in fact this is the first time I’ve seen a monkey in this area and I’ve been staying in the same estate for 20 years). The closest reserve-like places or reservoirs where these macaques or other monkeys can most probably be found in are, Bedok reservoir and East Coast Park. These places are about, 8.3km and 4.1km away respectively, from the estate, which seems pretty far to me and are also separated by many busy roads. Hence the question, how did this monkey get here and alone nonetheless? Lost perhaps?

The long-tailed Macaques normally live in groups of 10 to 48 individuals, and sometimes even bigger groups of around 100 individuals. It is uncommon for them to be found alone (“Visit the zoo – Primates”). Therefore, the mystery of the lone monkey. Monkeys are social animals and are generally thought to communicate through more visual means such as facial expressions and postures. Sitting in close contact is actually a form of ongoing communication. Huddling with a companion confirms and reinforces positive social relationships (Saint Louiis Zoo). Also, experiments have shown that macaques like the rhesus, are generally communal monkeys who would choose companionship over solitude (Reinhardt, and Reinhardt 1991). Moreover, travelling and living in a troop provides protection crucial for survival. Hence, did curiosity overpowered its survival instinct and urged this special monkey to leave its comfort zone and venture into a whole new habitat….to explore the world? Not so different from humans then…when Christopher Columbus first sailed around the world in the spirit of discovery and adventure. Or perhaps….the monkey was simply a terrible communal dweller and exiled by its troop!

References

  1. Tan, Ria. “Long-tailed macaque.” Wild Fact Sheets. WildSingapore, October 2009. Web. 14 Apr 2010
  2. “Crab-eating macaque.” Visit the zoo – Primates. World Association of Zoos and Aquariums WAZA – United for Conservation, n.d. Web. 14 Apr 2010.
  3. REINHARDT, V., and A. REINHARDT. “Impact of a privacy panel on the behavior of caged female rhesus monkeys living in pairs.” Journal of Experimental Animal Science 34 (1991): 55-58. Web. 14 Apr 2010
  4. Saint louiis Zoo, . “Monkeys facts and Trivia.” Indianchild.com, 2004. Web. 15 Apr 2010

2 responses so far

Apr 16 2010

Are you waving to me? : The waving fiddler crab

Published by under Uncategorized and tagged:

A visit to the shores of Pulau Semakau brought my attention to the tiny crabs scuttling about the muddy sea beaches (McLeod), appearing in and out of their burrows, waving their claws all the time.
Fiddler crabs (genus: Uca) (Orange fiddler crab Uca vocans Family Ocypodidae)were named with reference to the fiddle shaped large claw of the male crab, and the movement of the small claw from the ground to its mouth resembles the motion of someoneof someone moving a bow across a fiddle (the large claw). The over sized claw was used for displaying to attract females and to intimidate their opponents (Rosenberg, 2001). However, only the smaller claw is used for feeding as the size of the enlarged claw is too big.

Figure 1 in: Wild Fact Sheet (http://www.wildsingapore.com/wildfacts/crustacea/crab/ocypodoidea/vocans.htm), Orange fiddler crab, Uca vocans, Family Ocypodidae
Figure 1 in: Wild Fact Sheet (http://www.wildsingapore.com/wildfacts/crustacea/crab/ocypodoidea/vocans.htm), Orange fiddler crab, Uca vocans, Family Ocypodidae

The Fiddler Crab communicates through a sequence of waves and gestures unique to his own species. During courtship, the males would repeatedly raise and lower their oversize claws in an effort to attract females (How et al. 2007).

Figure 2 in: http://en.wikipedia.org/wiki/Fiddler_crabs
Untitled
Figure 3 in: (How et al. 2007)Movements during the three stages of the lateral claw waving display: stage 1, both the major and the minor claws are quickly unflexed; stage 2, the major claw is lifted slowly upwards and the body and second ambulatory legs are raised; stage 3, the major claw, body and legs are rapidly dropped back to resting position.

An interesting fact is that despite the intimidation of the large claw, some of the crabs were actually ‘bluffing’ their rival opponents. Certain males may lose their claws in the process of predation or combat, but they are able to regenerate a new claw. However, the regeneration of the new claw tends to emphasize more on the size instead of quality. Hence, new claws tend to be lighter, and less robust than the original claw. The ability to regenerate a large claw is essential, as males size each other up before fights, and displays of the enlarged claw is an important part of the combating process. Since other males were unable to distinguish between original and regenerated claws (British Ecology Society),Fiddler Crabs were able to ‘bluff’ their opponents in thinking that they have a large and powerful claw.
Do look out for fiddler crabs if you walk through sea beaches, swamps or mangroves, they might just happen to be waving to you.

References

MARTIN J. HOW, JAN M. HEMMI, JOCHEN ZEIL & RICHARD PETERS, 2007. Claw waving display changes with receiver distance in fiddler crabs, Uca perplexa, pp. 1015-1023
Michael S. Rosenberg, 2001. The Systematics and Taxonomy of Fiddler Crabs: A Phylogeny of the Genus Uca Source: Journal of Crustacean Biology, Vol. 21, No. 3, pp. 839-869

Simon P. Lailvaux , Leeann T. Reaney and Patricia R. Y. Backwell, 2007.
Dishonest signalling of fighting ability and multiple performance traits in the fiddler crab, Uca mjoebergi.

British Ecological Society (November 13, 2008). “Fiddler crabs reveal honesty is not always the best policy”. University of New South Wales. http://www.science.unsw.edu.au/news/fiddler-crabs-reveal-honesty-is-not-always-the-best-policy/. Retrieved November 19, 2008

“Fiddler crabs, Uca sp., Family Ocypodidae” by WildSingapore. URL: http://www.wildsingapore.com/wildfacts/crustacea/crab/ocypodoidea/uca.htm

Lianne McLeod. “How to Set Up a Tank for Fiddler Crabs”. About.com. http://exoticpets.about.com/cs/rarespecies/a/fiddlercrabs.htm (accessed on 13 Apr 2010)

One response so far

Apr 15 2010

Pied Fantails spotted on NUS Kent Ridge Campus

Published by under Uncategorized and tagged: ,

The Pied Fantail (Rhipidura javanica) is a small, energetic bird. It attracts attention with its long tail, which bobs and fans as it moves. Despite being a primarily mangrove bird, the Pied Fantail can also be found in secondary forests, coastal woodlands and gardens (Strange, 2002).

This fact makes the sighting of Fantails in NUS (Kent Ridge Campus) highly unexpected and unusual. The first sighting occurred on 1 April 2010, at 12pm. A Pied Fantail was spotted on a tree outside the Kuok Foundation House (see Fig. 2). Whistling calls were clearly heard. The second sighting occurred on 3 April 2010, at 8.10am. Two Pied Fantails were observed to be ‘dancing’ and chattering on a grass patch close to the area of the first sighting (see Fig. 2). It can be speculated that the ‘dancing’ and trilling were part of a courtship ritual (Higgins et al., 2006). This assumes that the Fantails were of different genders.

The areas indicated in Fig. 2 experience high human and vehicular traffic. It is possible that the Fantails came from the nearby Kent Ridge Park (see Fig. 3). But they do tend to stick to “natural coastal areas… (and) inland sites (like) Singapore Botanic Gardens, Bukit Batok Nature Park and many of the areas that support old abandoned farmland, particularly where there is water” (YC Wee, 2007). Thus this hypothesis is unlikely.

The relationship between Fantails and urbanisation is largely undocumented. However, the expansion of urbanisation subjects the remaining fragments of natural habitats to high stress and possible isolation. This may have forced the Fantails to enter urban areas in search of food, shelter and nesting sites. Further information on this topic can be found in an article by Stephens et al. (2004 – refer to link below).

References

“Antics of the Pied Fantail,” by YC Wee. Bird Ecology Study Group, Nature Society (Singapore), 19 January 2007. URL: http://besgroup.blogspot.com/2007/01/antics-of-pied-fantail.html (accessed on 12 April 2010)

Higgins, P.J., Peter, J.M. & Steele (2006) Handbook of Australian, New Zealand and Antarctic Birds Volume 7: Boatbill to Starlings, Melbourne: Oxford University Press, 8p.

Stephens, Scott E., Koons, David N., Rotella, Jay J. and David W. Willey (2004). Effects of habitat fragmentation on avian nesting success: a review of the evidence at multiple spatial scales, Biological Conservation, Volume 115, Issue 1, 101-110p. Direct link: http://www.demogr.mpg.de/publications/files/2367_1155283320_1_Stephens%20et%20al%202003.pdf

Strange, Morten (2002) A Photographic Guide to the Birds of Malaysia and Singapore, Periplus, 398p.

3 responses so far

Next »