XR's fieldwork short notes

This page's purpose is to keep everyone updated on my fieldwork progress.

1 June 2013

Went to the site in Chestnut. Google maps was not functioning properly. Wasted a decent amount of time trying to locate the GPS coordinates of the central tree in both sites. Setup transect lines of the two grids with some hassle. Total time spent in the field was 5 hours. Longest ever. D:

3 June 2013

Went to the site in Bukit Timah, near Catchment Path. Site was easily accessed. No transect lines were done in one grid due to the frequent visits of researchers to this area.

4 June 2013

Went to the site in Bukit Batok. Both grid transects were located quite far apart and accessed via two different entrances. Terrain was quite hilly in the site near Meralodge. Illegal squatters were since but unoccupied. No fishing lines were done in both sites due to the presence of squatters.

6 June 2013

Went to the site along BKE (i.e. Bukit Timah East). Very easily accessible via the entrance near the army gate along the BKE (requires a vehicle). Terrain relatively flat. Good forest to work in.

13 June 2013

First ever setup of pitfall traps in Chestnut. Was done with very little hassle.

15 June 2013

Collected specimens from Chestnut's pitfall traps. Estimated to have about 5 species from this site. Pitfall traps that were baited with Sambar deer dung had no dung beetles at all. One pitfall trap baited with python dung had no dung beetles as well.

18 June 2013

BTNR Site. Slightly hazy conditions. Might affect the number of dung beetles captured in the traps.

20 June 2013

Relatively lesser dung beetles in BTNR site as compared to previous site in Chestnut. Possibly due to the haze. Requires comparison with second sampling round to prove this. Yet again, no dung beetles in Sambar deer dung baited traps.

27 June 2013

Bukit Batok Site. Pretty tough working on a slope and setting up the traps. Not to mention the mossies that are not deterred by any amount of repellent. Lots of bites and body aches. Good fun nonetheless. :)

29 June 2013

Collected specimens from the pitfall traps in Bukit Batok. Very low diversity of dung beetles in this site. Expected.

4 July 2013

BKE Site. The best site to work in due to its relatively open understory and flat terrain. Finished setting up traps with little hassle.

6 July 2013

Collected specimens from the BKE site. Lots of dung beetles captured but no Catharsius molossus at all. Perhaps they are just not common there. Hmm. One dung beetle in reticulated python trap and once again, no dung beetles in Sambar deer trap.

11 July 2013

First ever trip to the site in MacRitchie. Really dense forest with visibility of less than 5m (maybe even 2.. hmm). Flat terrain makes life much easier in the presence of spiny rattan and nibong palms. Did both transect setting and pitfall trap setup with the help of many great assistants. Barely escaped the thunderstorm. Thank God~ :D

13 July 2013
Collected specimens from MacRitchie. Pretty difficult to find the traps. Interesting finds from this plot. And there are finally dung beetles in the Sambar deer trap! :)

25 July 2013
Returned back to Bukit Timah Site to start my second round of sampling. Fieldwork was postpone for 30 min due to the heavy rain in the area. Had trouble finding the first plot. Blame it on my own poor navigation skills. Haha.

27 July 2013

Collected specimens from Bukit Timah. Got caught in the rain but it was alright. Good find from the site.

1 Aug 2013

Headed back to the site in Chestnut with many helpers! Had fun "bossing" people around. Saw the Giant millipede! Very cooling weather right after the rain. (:

3 Aug 2013

Fast and quick collection of specimens from Chestnut. Great weather.

8 Aug 2013

Back to BKE site to setup pitfall traps. Was slightly delayed due to the morning thundery showers.

11 Aug 2013

Lots of dung beetles collected from the BKE Site. (:

17 Aug 2013

Back to Bukit Batok to feed the mossies and setup pitfall traps. Saw a some animal paw prints along the stream. Cat? Dog? Always tough to setup traps on a hilly terrain.

19 Aug 2013

Forgot to bring covers along for one transect in Bukit Batok (dang). Had to improvise and use my latex gloves as temporary covers. As expected, very little dung beetles AGAIN. Saw a stray dog which is most likely responsible for those paw prints. One data logger had bite marks. -.-

24 Aug 2013

Back to MacRitchie. Although the forest is very dense with all the rattans n shrubs, it still beats working in Bukit Batok. :D

26 Aug 2013

Much lesser dung beetles as compared to the very first time I sampled this area. Could be due to the weather as there was no rain throughout the 48 hour sampling period. LAST SITE OF ROUND 2! HOORAY!!

(1 June 2013 to 26 Aug 2013... That's almost 3 months of fieldwork!!)

Singapore dungabee fact #2

Paragymnopleurus maurus

Paragymnopleurus maurus is perhaps the only dung beetle species in Singapore that rolls dung balls away from the dung source. Such rollers are also referred to as telocoprids, whereas the tunnelers are known as paracoprids [1].

Check out these long hind legs!

Rollers can be identified by their longer hind legs, which they use to roll dung balls away from its main source and bury them in another location for nesting purposes [1]. P. maurus is about 15mm in length, making it the second largest dung beetle in Singapore thus far.

Finally, please enjoy this short video (shot by Dave Ng) of this cool rolling "dungabee".

References:

[1] Hanski, I. & Cambefort, Y.  (1991) Dung Beetle Ecology. Princeton: Princeton University Press.

Photos by Zestin Soh

Ants of Singapore #08 - Strumigenys (cf. koningsbergi)

Strumigenys

Species accounts

Strumigenys cf. koningsbergi

Strumigenys c.f. koningsbergeri

Strumigenys (Myrmicinae : Dacetini) is a small, cryptic, leaf-litter dwelling ant; they are otherwise known as Trap Jaw ants as well.

They are pretty numerous in the leaf litter and also nest in the crevices of dead logs. They are move slowly most of the time, unless when disturbed.

It is said that some species are specialist predators of springtails (Coembolla, which are arthropods with six legs but do not have wings [Entognatha]). Perhaps that is why they require trap-jaw like mandibles as well, to 'capture' these fast moving Coembollas!

Ants of Singapore #07 - Cerapachys (undet.)

Cerapachys

Species accounts

sp. 1

Old World Army Ants Cerapachys sp.

The Old World Army Ants, Cerapachys are a diverse group of ants. Some of these ants are blind (i.e. they have no eye facets), while others are not. The one as shown above has only one eye facet (look at picture below), suggesting a subterranean or nocturnal lifestyle. It was actually seen attacking an earthworm at night, though no photographs to document that.


Cerapachys biroi, one of the species within the genus, is said to be very widespread and is considered a tramp ant [1] and was first described in Singapore by Forel in 1907, suggesting its origins in Asia as well. They are said to practice parthenogenesis [2] because workers can produce diploid eggs. They are also entirely subterranean which also suggests dispersal by exported soil perhaps. This might be an interesting article for those who wish to read more.

Alright, good day ahead.


References

[1] Wetterer et al.. 2012. Worldwide spread of Cerapachys biroi (Hymenoptera: Formicidae: Cerpachyinae). Myrmecological News 17: 1-4.
[2] Kronaeur et al.. 2012. Asexual reproduction in introduced and native populations of Cerapachys biroi. Molecular Ecology 21(21): 5221-5225.

Ants of Singapore #06 - Pheidologeton (diversus)

Pheidologeton

Species accounts

Pheidologeton diversus 

Recently Pheidologeton was synonymised under Carebara (Fisher, 2014). I will still recognize Pheidologeton for the sake of this blog.

Pheidologeton diversus, otherwise known as the Maurauder Ant. 

These ants are commonly seen, in the day and in the night, where there is a dead carcass. They are quick to recruit, and are the dominant insects at a particular dead carcass, often excluding other competitors. Maybe that's why they're relatively common insects.

Dominating at a carcass

They are polymorphic (come in various sizes), and sometimes the minor ants can be seen to be riding on the major ants, a behaviour similar to the leaf cutter ants whose minors ride on the leaves carried by the major workers. Not many are sure why this behaviour is so, but it has been hypothesized that perhaps it prevents phorid flies from laying eggs on their head.

They look similar to the Pheidole ant, another genus but can be distinguished based on the number of antennal clubs (Pheidologeton has 2, Pheidole has 3).

Ants of Singapore #05 - Camponotus (gigas)

Camponotus

Species accounts

Camponotus gigas

Camponotus gigas Latreille, 1802, the Giant Forest Ant in Singapore

The ant above, is none other than the famous Giant Forest Ant (Camponotus gigas), one of the largest species of ants possibly in the world. The Camponotus genus ("Carpenter Ants"), is also a hyperdiverse genus, meaning that there are many species within the genera. Fortunately, these Giant Forest Ants are easily distinguished from the other Camponotus species by their (large) size and red gaster.

They are polymorphic and have majors which are generally larger with a head which is more heart-shaped rather than ovate. They are said to have intraspecific territorial fights at night. They also nest in the base of trees.

Generally though, these ants are docile and they cannot sting (they have no stinging apparatus). It is personally therapeutic to look at them forage ;)

[As a side note, there are many other Camponotus species in Singapore, but am likely to be highlighting only this one for now. It would be interesting to study the temporal niche differentiation for certain species, because some are observed in the night, while others are observed foraging in the day.]

Giant Forest Ant Camponotus gigas female alate in Singapore.

C. gigas worker, found at Kubah National Park, Sarawak with slight variation in the legs (yellow) as compared to the ones in Singapore.

Ants of Singapore #04 - Oecophylla (smaragdina)

Oecophylla

Species accounts

Oecophylla smaragdina

The Weaver Ant, Oecophylla smaragdina

In the Singaporean context, the Asian Weaver Ant Oecophylla smaragdina Fabricius 1775 (subfamily Formicinae) is one of the more conspicuous ants around. These ants are able to bite and inflict some pain on one, if you step on their tiny "toes". Further, the formic acid they spray exacerbates that pain.

They are found mainly in the Indo-Australian region. The subspecies we have in Singapore is orange in colour but there is a green subspecies present in Australia, too. This is what makes their biogeography interesting as well (species independent of the Wallace and Weber lines).

These Weaver ants weave nests with leaves, using their larvae to produce silk thread. They are so adapatable, they can use almost any kind of leaves to build their nests -- even long, palm leaves. I have never witnessed the nest construction but it is said that they form chains extending to the next leaves. A satellite nests can be found in the vicinity of the 'main' nest, which houses the queen.

They are probably scavengers and food-generalists. In addition, they are seen to have an association with honey-dew producing insects, such as treehoppers, planthoppers and even some caterpillars. Perhaps their generalistic behaviour allows them to thrive in various conditions, at forest fringes and even at urban areas. They are able to utilize metal bars as passage ways.

In certain cultures (such as the Thai culture), people eat the Weaver Ants and their larvae fried with egg. It is said to be very delicious!

There are only two extant species, Oecophylla smaragdina and Oecophylla longinoda that are currently extant, with other species that are currently extinct.

I think I can go on and on about them because they are rather well-studied. A good read here.



The Weaver ant is not to be confused with the Yellow Crazy Ant. Here is a photograph of an alate Weaver Ant, with a couple of Yellow Crazy Ant (Anoplolepis gracilipes).