Wednesday, October 31, 2007

The doves of NUS

Siyang has been very efficient on reporting the birds spotted in NUS and through him, I'm able to better appreciate that within the school, there is so much wonder we can fascinate with.

Can't resist but also to share some photos of the peaceful or zebra doves found. The last time we went the hatchings were small. Shuyi and I went to check out the nest this morning and guess what they have grown up and are about to fly anytime soon, judging from how I see them flapping their wings.

Wanted to update and follow up on SY's post and after a quick cherck, wow he has actually done the update. Cool.

Nevertheless, here you go, my photos.


The one on the right should be either their mother or father.


A closer look at the parent.






Flapping and getting ready for the launch.

And here's the video taken of the birds :-)


Saturday, October 13, 2007

Sunbird at my corridor



A boring day was brightened a bit by this common Olive-backed Sunbird (Nectarina jugularis) that decidedly flew up 11 storeys high to a plant along my corridor. Since I managed to take a couple photos, thus, also looked up more about this bird from Ria's Sungei Buloh page.

From the webpage, it mentioned,

"The Olive-backed Sunbird is very bold and often builds nests close to and even in human habitation (balconies, porches, corridors). Not surprisingly then, it is among the most common Sunbirds in this region.

Sunbirds survive mainly on nectar, although they may snack on the occasional insect. Their nectar extraction equipment include: a long, slender, decurved bill with fine serration along the margins of both mandibles; and a tubular, deeply cleft tongue. Males are particularly territorial and may defend a good feeding site from other Sunbirds.

Although it is said that they cannot hover like true hummingbirds (which are found only in tropical Americas), Sunbirds can hover briefly. But they do prefer to cling to a nearby stem or vegetation as they sip nectar. They may "steal" the nectar by piercing through the base of the flower than going through the front of the flower (thus avoiding payment of pollinating services in exchange for the nectar reward).

They forage both at tree tops and among lower bushes. Like other Sunbirds, the Olive-backed male is more colourful than the female. In fact, females of most species of Sunbirds look very similar."



Status in Singapore: Very common resident throughout the island, including North and South offshore islands.

Though its a very common bird, I still like you :-)

Friday, October 5, 2007

Studying Ecology of Bukit Timah Nature Reserve

On a fine Thursday afternoon, "ecologists-to-be" from our ecology module had a field trip to Bukit Timah Nature Reserve (BTNR). Thanks to Siva for preparing this trip, though I did not see him throughout, he was somewhere else with another group I think.

Bukit Timah NR though has plant species more than even the whole of North America which deserved to be celebrated, it is also named as a patient under intensive care because of many reasons, mainly due to human impacts like fragmentation, edge effects etc. This was the topic of our graded essay at the end of the trip which there was not enough time to write down all I wanted, sigh.


Climbing up the steep slopes can also be a joyful thing. Look at the cheery smile from Su Wen.


Panting, up we go to higher grounds where we can find Shorea trees which is significant of lowland evergreen rainforest or coastal hill dipterocarp forest. People might have the misconception that BTNR has 100% primary forest. This is wrong, there is now only about 40% fragments of primary forest in the BTNR and the rest is secondary forest. BTNR was literally disturbed in many ways before and now.


I will always remember to watch out for this rock that probably no usual passerby will peer into the forest and ask why. Can you see a white circular patch on the rock?

I learnt about this when Dr Wang YC from Geography Department shared it with us during our Terrestrial and Coastal Environments module field trip. Mosses on the rocks need light to survive and grow on. The whitish patch might show that they are no moss there. Why?? Reason might be because a smaller rock beside it might have just fallen away or that this big rock was slightly shifted from the ground. Over time, let's watch the covering of moss back to the rock.


Back from rocks to trees. This is Shorea tree (Shorea curtisii) which is an emergent tree. From aerial photos, their canopies look like caulifowers with slightly greyish shades. They grow very tall in BTNR and also have wing-structures on their seeds for better wind dispersals. Are you reminded of it from your primary or secondary school science classes?


Canopy of Shorea from the ground bottom up level.


And everyone of got an A3 map of BTNR to shade the different boundaries and human interventions around the area to better understand how fragmented is our precious rainforest. So small yet highly impacted.

---------
Update: Nature reserves may be reunited by eco-passage on Straits Time 11 Oct 07

I'm not too sure if this is going to be effective, but remember of the concept of biogeography, or put it simply, think about why a flying insect stuck in your bedroom won't escape by itself though you open the window ledge, hoping it will get out.
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A study from a Geography honours student (shared with us by Prof Lu Xi Xi from Geography Department) on the trails in BTNR shows 51 big and small trails of over 8 kms within the reserve. The density of trails was so bad that it was a 26 km per km square. Just imagine!

There was another paper written by Chatterjea K., 2007 studying the effects of trails in BTNR this year, as recommended by Siva. That was also very insightful.

Chatterjea K. (2007) Assessment and demarcation of trail degradation in a nature reserve, using GIS: case of Bukit Timah Nature Reserve. Land Degradation and Develop., 18: 1–19.

Abstract here.

The orange highlighted portion of BKE shows how Bukit Timah NR was fragmented away from the larger Central Catchment area, and this caused a lot of roadkills when animals try to cross over.


Glad National Parks Board is doing something, which is closures of small trails.


Big trees within the forest sometimes have huge buttress roots. To prevent damage from trails, boardwalks were built across some of it. Nice.


Thanks to our teaching assistant, Stanley, we learnt quite a lot about the ecology in BTNR. And many of the students are not concentrating in Biology. What they learn now will be of great impact as someone might turn out to be an influential person in Singapore making important decisions to conserve nature.


I discovered something along the way, some red labels of the paths on the side of the trails, slightly covered by leaf litters.


These must be a bit historical I guess, judging from how much it has worn out.

More plants and descriptions below :-) Happy reading.


Leaf litter plant.




Terentang tree.




Leaves of Terentang seedlings.

Update: These "Terentang seedlings" are obviously something else(Sapotaceae/Fagaceae/Lauraceae). The "ears" of Terentang are even more pronounced in the seedlings/saplings and clasping twigs, making the leaves look sessile.

Thanks MS!


Sepui, Red Dhup tree. This is an uncommon tree.


At the end of the trip, as mentioned, we had a essay test which was tiring as writing very fast is not my cup of tea. Need to organise thoughts as well. I'm really glad Siva made everyone understood all the challenges of this tiny patch of remaining primary forest in Singapore. A heritage we have to treasure.

There are other challenges like do we need to have human intervention in order to ensure the survival of forest trees with big fruits as larger-beak birds like hornbills are extinct in BTNR as dispersers. Many many questions.

Next time when you visit BTNR, let's appreciate it and look at it with a new perspective.

Thursday, October 4, 2007

Field trip to Botanic Garden

On Tuesday, NUS students of a biology module on life forms and function went for a field trip to Singapore Botanic Gardens to examine some example of plant structures in nature and relate these to functions.

We had to examine plants from three main categories: mesophytes (plants growing with moderate amounts of moisture), xerophytes (with small amount of moisture) and hydrophytes (growing with abundant moisture).


First stop for mesophyte plants, from a short walk from the visitor centre, will be this strangler Johor fig (Ficus kerkhovenii). Their long contractile roots is for anchorage, uptake of water and minerals and also also, to crush their host trees. These roots are very taut!


The other mesophyte will be this super huge and tall Pandan plant (Pandanus species). This plant has very long and narrow leaves that are pleated, so as to increase rigidity from mechanical damages. There are also spines on the leaves so as to reduce herbivory.


If you look closer on the stems of this plant, there are something growing, like bunch of grapes in green.


And a closer look will let one discover caulifory: production of inflorescences on the trunk, probably to increase presentation to pollinators and/or fruit dispersers. Some birds do not fly as high as some canpoies you see.


This is the famous tembusu tree you may find behind a five dollar note. And these trees are precious in Botanic Gardens, they are protected from lightnings. Can you spot the lightning conductors along the trunk of the tree?


Botanic Garden is a popular spot for wedding photos, we saw at least 3 couples! Ngan Kee, our teaching assistant, speculated they are teachers having time out to do the photo shots since it was Children's day. Anyway, isn't they a sweet looking couple? Nice ah.. on the buttress roots.


This is Vanda Miss Joaquim or also Singapore's national flower. It is actually a cultivated variety of a hybrid. They must be vegetatively propagated or clonally propagated. If you allow these flowers to grow from seeds, different color combinations will arise according to Mendelian's Law. Imagine a Singapore national flower in different colour.


Now over to xerophytes we see Optunia species with fleshy water storage leaves.


Agave species of xerophyte are interesting. They are being planting on Taiwan slopes facing China along the borders. Take a guess why. Clue: they have spines or prickles on their leaves so as to reduce herbivory from herbivores. But the reason for planting in Taiwan is not due to herbivores.


This interesting tree is called the Monkey pot tree. This is not a xerophyte though.


And this is the description, saves me from typing :-)


Back to xerophytes, this bottle tree (Brachychiton rupestris) stores water not in the leaves, and obviously in their trunks. A few of these trees were previous planted and I saw them during my previous trip with the church. However, most died.


Now over to the symphony lake to check out the hydrophytes.


Side distraction: cute duck....


More cute ducks... ok time to move on to the plants.


This is the papyrus plant (Cyperus papyrus) with petioles filled with spaces for better floating in the water.


This papyrus plant is interesting as it was mentioned in the Bible and also was used by the Egyptians to make paper. Look at this part that was already torn when we approached.


When we ended our session, another group was still in discussions. What a wonderful and serene environment to learn things, somemore in front of a lake.


Before we left, this banana-looking plant which is not banana caught some of our attention.

Thanks to Prof Hugh Tan for arranging this and all the TAs for working hard to share so much invaluable informations with us.

Friday, September 14, 2007

Mangrove Ecology at Sungei Buloh

Thursday afternoon, a big bunch of learning "ecologists" from NUS went to Sungei Buloh Nature Reserve for a field trip to study mangrove ecology. And believe me, everytime you go, there is something new for you to be marvelled at.


If you enter through Kranji, you might come across this railway crossing which has only one lane for a two-way traffic. Therefore, traffic jam always occurs near here though this place is not every populated.

Upon reaching the nature reserve, we were introduced to zonations based more on topography than species since our "compressed" mangroves are more heterogenous as compared to other undisturbed mangroves elsewhere from Singapore. From landward to seaward, the zonation goes like this: Back mangrove, mud lobster mound system, main forest, sandbank and then mudflat. One thing about the diversity of mangrove plants as compared to that from tropical rainforest is that species diversity is low as few plants can tolerate low oxygen, high salinity conditions.

Our first station is the back mangroves where it is found at tidal heights beyond where the highest water spring tide occur. What dominates the back mangrove will be Sea Hibiscus.


The next zonation will be the mud lobster mound and pool system.


Over here, the mud lobsters dig mud and unknowingly, they create huge mounds which are analogous to condominiums, even with swimming pool, in the forms of water pool. The height of the mound is advantageous to those plant which cannot tolerate salt because these plants can grow on the sides or on top of these mounds and be higher up from the salty water of the incoming tides. Growing on these mounds are mangrove ferns...


and sea holly. These plants can be identified by its jagged edges.


The main forest zone of Sungei Buloh is highly disturbed and therefore has more species of plants in a small area as compared to undisturbed mangroves. The common mangrove trees include the Rhizophora tree with stilt aerial roots, Bruguiera with knee like roots (as shown above) , and Avicennia with thin pencil-like roots.


And this is the flower of one of the Bruguiera species.

Even the huts along the boardwalk is so cute, with all the collages of drawings.

And hey, we saw this monitor lizard basking under the sun. Monitor lizards are the cleaners of the shores as they can feed on almost anything they catch. They also can "smell" the air with their tongue to track down prey. In Chek Jawa, we even saw one swimming and they are known to even swim underwater for half an hour.

Here is a fly on a leaf that has gotten my attention to take a snapshot before moving on as the teaching assistant shows us the different parts of mangroves.

This is a giant mudskipper which is actually a fish that can stay on land. How do they do it? They have hold water in their mouth and also breathe through moist skin. These fearsome predators even have two rows of teeth in their upper jaw, feeding on small fishes and crabs.

Talking about crabs, we have the tree climbing crabs. Why? Because they climb on trees! Duh. They climb high up during high tide to avoid being preyed upon. These guys eat mangrove leaves and seedlings and sometimes scavenge for meat.


The furthest seaward zone is where you can find the sandbank, as shown here. You can see many herons resting and feeding on the sandbank and also have a great view of Johor from here.


A close-up of the birds on the sandbank.

We then proceeded to the bridge over Sungei Buloh Besar and this photo shows the upstream portion where nutrients input into the mangrove ecosystem. There is a big name to explain this: allochthonous nutrient input.

And downstream, we find the river leading to the Straits of Johor.


Across again, another view of Johor. Sadly, we did not see natural shores along, but with modifications.

Here again we chanced upon this resident monitor lizard at the side of Sungei Buloh Besar. It is evident that there are the pencil-like thin roots which mainly belonged to the Avicennia trees.

Archer fish is interesting because they can feed on insects near the water surface by pumping out forceful jets of water to knock insects off leaves.

Our last stop was the main hide where we were told that many telescopium Rodongs can be found on the flat when the sluice gate drains the water out.

The whole trip was summarized with a short test and we were of course stressed over it for that short moment. Other than that, was a great trip. Thank God for wonderful weather despite nasty forecast from meterological station.

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