Sleep deprived, he ran into this group of birders camped out around a particularly productive spot where several migrating warbler species were hanging out.

During the ensuing conversation, David mentioned he hailed from Singapore. One amongst the group mentioned that he knew several people from the Malaysian Nature Society – this didn’t ring any bells initially, until he introduced himself by his first name.

Then it all clicked, David says, because John Ascher, soon to be at the department in Singapore, had mentioned to David several months ago that Ben King was in the area and based at the AMNH.

An excited David announced this in all caps on Facebook page and his Facebook page was peppered with congratulatory (and facetious) posts.

Ben’s book (Ben King, Martin Woodcock & Dickinson, 1975. The Collin’s Field Guide to Birds of South East Asia. 480p.) was a bible for many naturalists starting out with birds in the 1980′s and 1990′s.

I asked David for the photo he thankfully took – and I am sure it will bring warm memories to many a biologist in this corner of the globe.

David Tan and Ben King chatted about the work which still needs to be done for the Southeast Asian birds, especially with little brown birds like flycatchers and babblers. This work is closely related to Frank Rheindt’s interests and to a lesser extent to David’s thesis work to come.

Buried in marking, I was really pleased to hear this news.

I have relied on birders for over three decades for the finer points. Ben King’s book was amongst the first bird book I referred to, and David is the latest of many birders I have consulted – before leaving for his stint abroad, he produced The Birds of NUS, a resource for undergrads.

A chance meeting with Ben King in Central Park? Well, you know what they say about birds of a feather.

The National University of Singapore’s (NUS) Faculty of Science received a $1 million donation which will help it boost life sciences research and education at the university. The donation came from developer SingHaiyi Group and its parent company, Haiyi Holdings.

NUS said the gift will attract a matching grant from the Government, and a portion will be used to fund scholarships for some 50 graduate students at the Department of Biological Sciences over a period of two to three years, starting from this August.

From 2014, the gift will also fund up to 150 undergraduates who are pursuing an honours degree in life sciences annually, for their research projects.

Part of the $1 million gift will also support the Xiamen Winter Symposium, an annual life sciences conference jointly organised by the NUS Department of Biological Sciences and Xiamen University.

Thankfully, when I joined the department last July, my environmentally-conscious office mates and fellow Full-Time Teaching Assistants (FTTAs) already had a system worked out for recycling.

The FTTAs are green tea and milk tea junkies, and often, a bottle purchased from the canteen during lunch helps us through a tiring afternoon! A quick rinse is all the bottles need and they are left to dry at the sink.

The bottles will pile up in about three weeks, and are then packed away in reusable bags and the bottles are dropped off at the recycling bins in the Science Canteen during lunch.

Small and simple steps make for painless habits! Do you have a recycling strategy?

FTTAs Amanda and Hongxia bring washed and dried plastic bottles
to the recycling bins. Photos by Weiting.

Message from Life Sciences Undergraduate Program Committee, 22 April 2013:

“Dear students,

Registration is now open for LSM4263 – Field Studies in Biodiversity, Special Term IV.

Registration ends 07 June 2013.

This 4MC module will be conducted in Semester IV, AY2012-13. Though a detailed timetable will be available later, class begins Tuesday 25 June and ends Fri 26 July 2013.

To qualify, students must be:

continuing into their Honours year in AY2013/14

concentrating in Environmental Biology and

possess a CAP of 3.5 or above

expected to cover part of the module cost (not amounting more than SGD400).

The field trip is scheduled to be on Thurs 11 July to Wed 17 July 2013.

Class size is limited to 30 students and preference given to students with Biodiversity (LSM1103) and Ecology (LSM2251).

To register, complete the form at 

http://tinyurl.com/LSM4263-June2013-Registration

The list of successful applicants will be announced after the release of final examination results.

Best wishes,
Life Sciences Undergraduate Program Committee
http://www.lifesciences.nus.edu.sg“

Discus fish by niomix2008

Anita’s project aims to determine the different attributes and drivers associated with market demand for discus and its variation within and between discus strains for the ornamental trade. Such attributes include color, patternation, overall fish shape, bred type and price.

Potential differences in consumer preferences will be evaluated by conducting choice experiments and card sorting exercises, targeting towards actors involved at different levels of the market chain, including exporters, importers, retailers, breeders and end-buyers such as hobbyists from the general public.

Volunteers are required to act as surveyors and conduct consumer questionnaires and preference ranking exercises to both trade and public visitors from 30th May –  2nd June 2013 at Aquarama 2013 which is being held at Sands Expo & Convention Center, Marina Bay Sands.

If interested, please email Anita at anitawan.11@gmail.com.

OED is taking this opportunity to repair and improve the conditions of the roads that are shown in the map below.

Road resurfacing works will be carried out from 11 May 2013 to 15 June 2013, from 8.00pm to 7.00am the next morning, every day of the week (including public holidays).

These roads will remain accessible by motorists as the contractor will work on a single lane of the two-lane road at any one time before progressing to adjacent lane.

Signages and road marshallers will guide motorists in the affected locations.

If there are issues during the period, let OED know through their 24/7 Maintenance Hotline (6516-1515) or email oedhelp@nus.edu.sg

“Origin and spread of the German cockroach, Blattella germanica (Blattodea: Blattellidae)“

TANG Qian
Graduate Student
Dept. of Biological Sciences, NUS

Fri, 3 May 2013: 3.00pm
@ S1A, #02-17
Supervisor: Assoc Prof Evans, Theodore Alfred

All are welcome

Abstract:

“The German cockroach (Blattella germanica) is likely to be the world’s most widespread domestic pest, from large cities to rural areas, on all continents (except Antarctica) and across most latitudes.

How this situation transpired is unknown, even the origin of this species is unknown; the name indicates where it was named, as an invasive species. Historical records and morphological phylogeny suggest that the German cockroach is of African or Asian origin.

Considering the evidence from both sources, I hypothesize that the German cockroach and its Asian relatives share a common ancestor out of Africa, and that the ancestors of the German cockroach was brought to Europe and domesticated there.

Adaptation to buildings allowed for transportation by humans, and thus spread to the rest of the world.

I will test my hypothesis using different genetic markers on cockroach samples collected from over 100 cities or regions.  I will use various genetic analyses to trace the history of the Genus Blattella (ribosomal DNA, mitochondrial DNA) and the species B. germanica (microsatellites). 

This study may also provide evidence for the expansion of B. germanica and suggest processes of domestication by pest species in the urban environment.”

One or more part-time assistant(s) are required to help with experiments, sampling  and sample processing in Singapore reservoirs from April to Dec 2013.

PUB: Local Catchment Water

Project description: Sampling and processing of samples from Singapore’s reservoirs as well as subculturing and aiding in experimental work on cyanobacteria in the laboratory.

Job Scope

1. Work when needed on experimental days (every 2 days) and one full day for filtration of reservoir samples.
2. Most work will be conducted on weekdays, but some experimental collection days may be on weekends and public holidays
3. Filter water samples, record and weigh freeze dried water samples
4. Assist in collection of samples for experimental work in the laboratory as well as filtration of samples on weekdays or weekends.

Requirements

Candidates should be:

1. Meticulous and careful with samples
2. Be able to come into the lab on a need to basis.
3. Knowledgeable about phytoplankton and sterile techniques is useful, but candidates with no prior knowledge can also apply as training will be provided.

Salary

S$8.74/hour

Contact

Please contact Maxine Mowe, Graduate student, Freshwater and Invasion Biology Laboratory, Department of Biological Sciences, National University of Singapore. Email: maxinemowe@gmail.com or call 6516-4255.

At the recent department retreat, Theo Evans put up some slides for analysis which provide a quick idea of the research interests in this group.

Data source: department webpage.

Here they are:

The FTTA’s, Sylvia Law, Cai Hongxia, Xu Weiting and Amanda Tan, are enjoying a teaching break during Reading Week and used the time to sign up for John’s classes.

He was escorted to class today by my Mac buddies Laurence and Kenneth who sent me this photo after the first session:

L-R: Sylvia, Hongxia, John, Laurence, Weiting and Amanda.

Teaching staff including the FTTAs are always learning, seeking new ideas for implementation into lessons, skills which we think undergrads would find useful, techniques for more interesting lesson delivery or admin techniques which free up time for everyone.

We’re not trigger happy about implementation though. Each idea needs to be evaluated and tried out. So even as semester ends, we are sniffing out new ideas to wrestle with in the months ahead, before the tough Semester I begins.

And not all this learning is over formal sessions. Some of the best learning takes place informally over a meal!

We kick off with a state of the department review by the head.

Sometimes the news is good, sometimes it can be gloomy. As with everything in Singapore, it’s interesting to observe the influence of the economy on the status of the department and projections for the future.

It’s an intense schedule of short presentations and discussions so its impossible for anyone not to be clued into reality, defying the ability to be isolated in an ivory tower.

Science in a modern era is tiring this way but the exposure is unavoidable. Some of that reality should trickle down to students who ultimately do feel the effects.

It’s not all gloomy though. We tend to compare with the best objectively and the department is not half bad. And when comparative metrics are produced, debate invariably emerges as far as time allows. And then you get to observe personalities.

Which is the bonus when sitting through long meetings!

Paul Matsudaira starting with the state of the department review
 

The NUS Biology Crew at their breakout session at the department retreat.

She is one of several students who wish to contribute to regional efforts to protect and conserve. Since a job is not immediately available, getting involved as a volunteer is an excellent way to learn the ropes and be at the right place when an opportunity presents itself.

Chloe has been looking since she graduated last semester and thanks to Ng Bee Choo, wrote me recently with some wonderful news:

“Hi Siva,

I’ll be a volunteer on the Philippines Biodiversity Conservation Programme (PBCP) under the Philippines Biodiversity Conservation Foundation Inc. (PBCFI).

For this three month stint (22 Apr to 22 Jul), I’ll be in the field helping out with biodiversity surveys, working in breeding and rescue centers in Negros and Panay, and possibly assisting with threatened species reintroduction projects on Negros, Panay and Cebu Islands.

Negros, Panay and Cebu, together with Masbate, make up the West Visayas – a region of PBCFI considers a conservation priority. The long-term goal of the PBCP is to establish a continuously developing network of Local Conservation Areas (LCAs) in the country.

For the first week in the Philippines, I’ll be helping [Ng] Bee Choo at the 6th International Hornbill Conference in Manila. During which I will meet the PBCP field personnel and firm up my itinerary, then tag along as they return to the field sites.

Thanks Siva!”

Happy Earth Day Chloe! Thanks for helping to make the world a better place!

Qualifying  Examination

“Population Structure and Gut Flora Diversity in Coptotermes gestroi in Southeast Asia”

Zhang Manping
Graduate Student
Dept. of Biological Sciences, NUS

Tues, 23 April 2013: 1.00pm
@ DBS Conference Room ii (S1 Level 3, Mezzanine)
Supervisor: Assoc Prof Evans, Theodore Alfred

All are welcome

Abstract:

“Coptotermes gestroi (Wasmann) (Insecta: Isoptera: Rhinotermitidae), commonly known as the house termite, is one of the most destructive urban pests in Southeast Asia.  This species has gut microorganisms (protists, bacteria and archea) to aid wood digestion and nutrient intake. 

It appears to be an urban adaptor or exploiter, as it rare in natural forests, but common in urban centres; it has been found to infest up to 80% of buildings in Malaysia.

The species is invasive as well, and had spread though human trade to other geographic regions, including east and south Asia, North and South America, Europe and several islands in the Pacific, Caribbean and India Oceans. 

Although C. gestroi is an important pest species, little is known about its origins, endemic distribution, geographic spread, and adaptation to urban life. Indeed it is only in the last decade its taxonomy was resolved.

My project aims at uncover some of this unknown information, by elucidating the population structure and genetic diversity of C. gestroi across Southeast Asia and invasive populations using microsatellite markers.  A better sampling strategy (sampling in cities, countrysides and forest) and comparative Copototermes species would be adopted. 

Pyrosequencing survey of the gut flora diversity will be used as a facilitated method to reveal the dispersal pattern, and help understand adaptation to urban life.

A laboratory experiment that tests the effect of food types on gut flora diversity of C. gestroi will complement the pyrosequencing. 

My project intends to shed some light on

1. The origin and dispersal pattern of C. gestroi.
2. The underlying mechanism for wide distribution of the species.
3. The adaptive strategy of C. gestroi to urbanization.”

“Investigating the introduction and impacts of gastropods in Singapore’s fresh waters”

Ng Ting Hui
Graduate Student
Dept. of Biological Sciences, NUS

Friday, 19 April 2013: 10.30am
@ DBS Conference Room (S3 L5)
Supervisor: Asst. Prof. Darren Yeo, Dr. Tan Heok Hui

All are welcome

Abstract:

“Introduction of freshwater gastropods are a concern globally owing to negative impacts like habitat-modification, competition with native species, and the spread of zoonotic parasites. In contrast to other native aquatic fauna in Singapore, which are usually found in unmodified habitats, freshwater molluscs here are almost exclusively found in human-impacted habitats, e.g., reservoirs and canals. Hence, it is suspected that many species may have been introduced. The lack of comprehensive information regarding native freshwater molluscs has made it difficult to determine the true status of many species found here. My inspection of museum collections and unpublished data found that only six species of gastropods were found here half a century ago, while the current malacofauna consists of 33 species, including freshwater bivalves. Preliminary data from a review of freshwater mollusc introductions to Southeast Asia shows that the aquarium trade has been most often proposed as a source for introductions, including in Singapore. A survey of the aquarium trade here revealed 58 species. While the results indicate that the trade is a likely introduction pathway, it is also implied that there are other potential pathways.

I also aim to investigate if the genetic diversity of local freshwater molluscs can resolve the status of cryptogenic species, and to examine the factors facilitating the spread of freshwater molluscs by investigating physico-chemical parameters and life history traits that may influence their distribution in canals. Finally, preliminary data indicates that the decline in distributions of native apple snail Pila scutata coincides with the introduction and spread of the confamilial golden apple snail Pomacea canaliculata. Potential ecological overlap between these two species will thus be investigated. The results of the genetic and ecological studies will be used to determine the management measures necessary to control introduced freshwater gastropods in Singapore.”

“Morphological and Chemical Evolution in Sepsidae: An Evolutionary Approach to Phenomics and Shape Analysis”

Pitta de Araujo, Diego
Graduate Student
Dept. of Biological Sciences, NUS

Tues, 23 April 2013: 10.00am
@ DBS Conference Room (S3 Level 5)

Supervisor: Prof. Rudolf Meier
Co-Supervisor: Dr. Joanne Yew

All are welcome

Abstract:

“New advancements in morphological and chemical analysis are promoting a renaissance of the studies of phenotypes in the era of genomics. Here I propose to use a “phenomics” approach to fully explore the morphology and chemistry of Sepsidae flies. These flies have very complex and variable morphological structures most of which are used in sexual behaviour and serve as a model clade to study phenotypic evolution. I am combining several morphological imaging techniques (Visionary Digital, Light Microscopy, Confocal Microscopy and Scanning Electron Microscopy) and chemical imaging (Ultra-Violet Laser Desorption Ionization Mass Spectrometry) to understand key changes during sepsid evolution. The three main questions that be addressed in this research are: How much morphological and chemical change happened in the evolution of Sepsidae? Is there a phylogenetic pattern and correlation among different phenotypes? How to quantify morphological change in an evolutionary context?

I carried out a detailed morphological and chemical study of the mysterious osmeterium, a gland that is located on the hind tibia of males. I use UV-LDI Mass Spectrometry to solve the identity of its secretion, the time of secretion, and the secretion’s fate when it is transferred to the female’s body during mating. My preliminary morphological results pertain to the morphology of the head capsule and mouthparts and indicate variation among species, mainly with regard to the structure of the head capsule. For this part of the flies’ body there is little evidence for sexual dimorphism. The thorax morphology of sepsids varies among species with regard to the shape of thoracic plates and patches of micropilosity. I am also the first entomologist studying the male intromittent organ in sepsids and document its variation across the species.

Lastly, I propose to explore new tools in 3D design to create representations of morphological structures. I propose to use new techniques in shape analysis for advanced 3D visualization and shape measurement: evolutionary morphing, shape similarity and shape complexity. With these tools I hope to quantify and visualize how sepsid morphology changed over evolutionary time.”

Kathy Su obtained her Honours and Masters degrees at NUS has successfully completed her Ph.D. in France and is now back in Singapore to pursue her post-doctoral research at the Evolutionary Biology Lab.

Her doctoral research on the evolution of wing spot patterns in Drosophilid flies was recently published in the journal Science.

The study illustrated how the appearance of darkened wing spots within a group of closely related flies was orchestrated by the assembly of a gene regulatory network involving several pigmentation genes under the regulation of at least one shared transcription factor.

This study has broad implications and provides insights into the emergence of novel morphological traits and their subsequent diversification. Her study was also featured recently in the French press, Le Monde.

Congratulations Kathy on your recent publication!

“Ecology and Restocking of Giant Clams”

William Eckman
Graduate Student,
Dept. Biological Sciences, NUS

Tue 16 April 2013: 3.00pm
@ DBS Meeting Room
(S3 Level 5,General Office #05-010)

Supervisor: Asst Prof Peter Alan, Todd

All are welcome

Abstract:

“As giant clams inhabit shallow waters, primarily in developing nations, many of their species are in danger of becoming directly extirpated by human activity, or of being unable to reproduce due to falling population densities. Over their long lifespans, giant clams produce large numbers of offspring, which have low survival rates at the larval and juvenile level. This is a successful reproductive strategy in the absence of human intervention.

Archaeologists know that humans have been harvesting clams for thousands of years, but modern technologies such as commercial fishing boats and SCUBA gear are depriving clams of refugia from which to repopulate other reefs. Increasing water turbidity due to coastal development, eutrophication, and dredging can make deeper water uninhabitable to giant clams, forcing their populations to reestablish in areas where they are more vulnerable to harvesting, tropical storms, and increasing water temperatures.

There is a significant amount of scientific literature regarding giant clams, particularly regarding their anatomy, physiology, and their symbiotic relationship with zooxanthellae. However, there are major gaps in the areas of their general ecology, reproductive behavior, and larval stages.

I will present the results of my experiments to determine giant clam larval tolerances to elevated water temperature, reduced light penetration, and reduced salinity.

I will also outline a proposed general ecology paper which will highlight and attempt to quantify the role that giant clams play in maintaining healthy reef ecosystems. There have been attempts in many countries to restock reefs with giant clams, although success rates have been low. Those efforts have not documented their strategy for placing clams in order to achieve high rates of survival and reproductive success.

I have carried out some preliminary investigations into giant clam reproductive behavior, and will continue and expand that work into a model resulting in guidelines for optimal clam placement. Clams in restocking efforts are initially placed in anti-predator cages, but their design is haphazard. I will experimentally compare several designs, including intertidal, benthic, and floating models, to determine which is most suitable for clam protection and growth in Singapore’s waters.

Finally, I plan to investigate the impacts of sediments on giant clams, using machinery which is capable of varying the timing and intensity of sediments to simulate various environmental or anthropogenic events.”

Application details at NParks webpage.

Responsibilities

The Biodiversity Information and Policy branch under the National Biodiversity Centre is responsible for developing biodiversity information products and services, coordinating and promoting collaboration and partnerships in enhancing urban biodiversity and ecology in Singapore, driving the implementation of policies and guidelines pertaining to biodiversity conservation and managing the implementation of the National Biodiversity Strategy and Action Plan.

Key responsibilities

The successful applicant is required to facilitate and steer biodiversity research towards conservation priorities in support of Singapore’s National Biodiversity Strategy and Action Plan, manage the research application and approval process, organize biodiversity research presentations and workshops and to regularly review the kind of biodiversity research being conducted in Singapore.

Requirements

• Degree from a recognized university and at least 3 years of work experience
• Have at minimum a first degree in a relevant discipline
• Keen interest and passion in biodiversity conservation
• Strong organization and analytical skills
• Good writing and interpersonal / communication skills
• Competence in database management and experience in using Global Information Systems (GIS) will be an advantage
• Some experience in doing scientific research work

Only shortlisted candidates will be notified.

See also other jobs at the NParks webpage.

A paper published in the Biological Journal of the Linnean Society about ghost crab camouflage arose from a collaboration between Martin Stevens, Peter Todd and his hons student Cheo Pei Rong. BBC Nature News picked up the story on 5th April 2013:

This was picked up by WildSingapore when it first came out .and circulated in the local naturalists community. To find out more about this crab on our shores, Wild Singapore which has a page on Ocypode ceratophthalmus here.

Abstract – Species that change colour present an ideal opportunity to study the control and tuning of camouflage with regards to the background. However, most research on colour-pattern change and camouflage has been undertaken with species that rapidly alter appearance (in seconds), despite the fact that most species change appearance over longer time periods (e.g. minutes, hours, or days).

We investigated whether individuals of the horned ghost crab (Ocypode ceratophthalmus) from Singapore can change colour, when this occurs, and how it influences camouflage.

Individuals showed a clear daily rhythm of colour change, becoming lighter during the day and darker at night, and this significantly improved their camouflage to the sand substrate upon which they live. Individuals did not change colour when put into dark conditions, but they did become brighter when placed on a white versus a black substrate.

Our findings show that ghost crabs have a circadian rhythm of colour change mediating camouflage, which is fine-tuned by adaptation to the background brightness. These types of colour change can enable individuals to achieve effective camouflage under a range of environmental conditions, substrates, and time periods, and may be widespread in other species.

“Comparative and experiment approaches to understanding  sexual selection of sepsid flies”

Speaker: Mindy Tuan 
Graduate Student,
Dept. of Biological Sciences, NUS
Wednesday, 17th April 2013: 10.00am
At the S1A Seminar Room, S1A- 02-17
(Next to the S1A Car Park/CBIS)
Supervisor: Prof Rudolf Meier

All are welcome

Abstract:

“Males often differ from females by having exaggerated ornaments and/or performing complex behaviours. Such sexually dimorphic traits are usually the product of sexual selection and can be morphological, behavioural, chemical or tactile in nature.

Here I use sepsid flies to study the evolution of such sexual dimorphisms to test whether they evolve faster and make a more significant contribution to speciation when compared with non-sexual traits.

Sepsid flies occur worldwide and comprise over 300 species. They possess a fascinating array of sexually dimorphic morphological and behavioural traits that are used during mating. In my research, I use sepsid flies to quantify the amount of correlated evolution between morphology and behaviour, study the evolution of copulation duration, and compare character change in pairs of closely related species and distantly related, allopatric populations.

My comparative work on 30 species already shows that sepsid fly mating behaviour varies tremendously, with flies assuming static positions and performing dynamic actions that are largely sex-specific. Furthermore, my data clarifies the relationship between morphology and behaviour by indicating instances in which morphological change is linked to behavioural change, and instances in which there is no such correlation.

I also studied the evolution of copulation duration across the 29 taxa and demonstrate that it evolves quickly although there is a significant phylogenetic effect with “basal” species having longer copulation times. I am currently testing whether this pattern correlates with the complexity of behaviour and morphology.

Moreover, I will look for traits that are influential in speciation, by studying morphological, behavioural and chemical traits in groups of closely related sister species (genetic distance for COI: 0-3%), as well as distantly related populations of a species (genetic distance for COI: 1.5% to 3%). Preliminary data suggest that behavior and morphology may evolve the fastest while the chemicals in a sexually dimorphic male gland evolve slowly.”

Congratulations to Matthew Lim and Li Daiqin for their recently published PLoS One paper, “UV-Green Iridescence Predicts Male Quality during Jumping Spider Contests” – see PLoS One

“This paper primarily investigates the correlations of a salticid’s structural colours (i.e., UV-green iridescence) with individual quality (i.e. physical endurance during male-male competition), providing insights into the role of ‘pure’ structural colours during animal contests.”

Abstract – “Animal colour signals used in intraspecies communications can generally be attributed to a composite effect of structural and pigmentary colours. Notably, the functional role of iridescent coloration that is ‘purely’ structural (i.e., absence of pigments) is poorly understood.

Recent studies reveal that iridescent colorations can reliably indicate individual quality, but evidence of iridescence as a pure structural coloration indicative of male quality during contests and relating to an individual’s resource-holding potential (RHP) is lacking.

In age- and size-controlled pairwise male-male contests that escalate from visual displays of aggression to more costly physical fights, we demonstrate that the ultraviolet-green iridescence of Cosmophasis umbratica predicts individual persistence and relates to RHP.

Contest initiating males exhibited significantly narrower carapace band separation (i.e., relative spectral positions of UV and green hues) than non-initiators. Asymmetries in carapace and abdomen brightness influenced overall contest duration and escalation.

As losers retreated upon having reached their own persistence limits in contests that escalated to physical fights, losers with narrower carapace band separation were significantly more persistence.

We propose that the carapace UV-green iridescence of C. umbratica predicts individual persistence and is indicative of a male’s RHP.

As the observed UV-green hues of C. umbratica are ‘pure’ optical products of a multilayer reflector system, we suggest that intrasexual variations in the optical properties of the scales’ chitin-air-chitin microstructures are responsible for the observed differences in carapace band separations.

Photo of male Cosmophasis umbratica by Matthew Lim

“The Effects of Urban Greenery on Biodiversity”

Chong Kwek Yan
Graduate Student
Dept. of Biological Sciences, NUS
19 April 2013, Friday
4:00PM
DBS Conference Room (S3, Level 5)
Supervisor: Assoc Prof Hugh Tan T W

All are welcome

Abstract – “The world’s growing urban population and urbanized areas have occurred in areas with high biodiversity value. Frontiers of urbanization are also approaching protected areas and encroaching upon habitats of threatened or endemic species. Urbanization usually involves the destruction of habitat when natural vegetation is cleared to make way for buildings and roads, but cultivated greenery and open green spaces such as parks are also created. Such greenery and green spaces have been used as urban planning tools to improve the quality of life for human residents in cities, but have also been thought to be able to improve habitat quality for urban wildlife.

Using data from surveys of birds and butterflies, and satellite imagery in Singapore, my analyses show that cultivated tree cover and natural vegetation both promoted alpha diversity, while traffic density reduced alpha diversity. However, after controlling for the confounding effects of alpha diversity on community dissimilarity, cultivated vegetation was found to produce homogeneous bird and butterfly communities compared to natural vegetation. In addition, there was evidence of interactions between traffic density and tree cover.

In addition, I explored how abundances of 20 most common bird species in a subset of transects that were surveyed a decade ago (from 2000 to 2001) have changed, and if changes in abundance were related to changes in the urban landscape, or attributable to species interactions. The brood parasitic Asian koel (Eudynamys scolopaceus), which is known to prefer house crow (Corvus splendens) as hosts, has increased in abundance even though the house crow has declined from culling. There was also no evidence that the decline in house crow abundances through culling had resulted in release from competition for its co-invading alien, the Javan myna (Acridotheres javanicus). Instead, increased urbanization was correlated with the increase in abundance of the Javan myna.

In conclusion, cultivated greenery has not been a good substitute for natural greenery in terms of providing for biodiversity. This poses problems for maintaining truly urban biodiversity in compact cities such as Singapore, where future urbanization will necessarily involve the loss of remnant or regenerating natural vegetation within the built-up areas.”

“Enhancing biodiversity on tropical seawalls: the role of habitat complexity in regulating the diversity and composition of intertidal communities”

Loke Hui Ling, Lynette
Graduate Student,
Dept. of Biological Sciences, NUS
Supervisor: Asst Prof. Peter A. Todd

Thu 04 Apr 2013: 2.00pm
DBS Conference Room (S3, Level 5)

All are welcome

Abstract – “Increasing coastal urbanisation has resulted in widespread replacement of natural habitats with large-scale artificial structures, such as seawalls, which tend to support less diverse biological communities. With the realization that such infrastructure cannot be removed, there is now a call for more research into ways seawalls can be built to increase their value as a habitat while meeting engineering criteria.

To understand how seawalls can be better designed, I first focused on improving their structural complexity. Habitat complexity has been hypothesized to be one of the primary drivers of biodiversity, however, the mechanism(s) by which it does this remains unclear. One of the greatest impediments to advancing this critical area is the ambiguity regarding the definition of ‘complexity’.

In addition to making comparisons of ‘complexity studies’ highly problematic, this lack of terminological clarity and precision has undermined attempts to standardise the measurement of habitat complexity or to develop indices that can be used to create artificial habitats with different levels of complexity—an essential first step for both systematically studying the relationship between habitat complexity and biodiversity and for creating artificial habitats for restoration efforts.

I address these issues by describing a new framework for conceptualising ecological complexity and then introduce a novel software program that enables users to visualize static, physical complexity. My program also provides output files that can be used to create artificial substrates at any scale and level of complexity for experimental and/or restoration and reconciliation studies. With it, I built concrete tiles to test for the effects of complexity and different component types (while controlling for area) and subsequently, the effects of scale and water-retention.

With the knowledge gained from these experimental studies, I plan to design and fabricate a composite tile (BioBoss). Using this new tile, I will investigate the effects of other processes, including hydrodynamics, fragmentation and population dynamics.