Urban: Filling the skies

Birds capable of flight travel wherever and whenever they please. Compared to the land space humans have populated, there is still extensive air space within and above urban areas for birds to roam, making them one of the most noticeable aspect of nature in cities aside from insects and flora. Some flight birds also roost in elevated places much like how Singaporeans live in high-rise buildings. Might urban areas be a suitable habitat for both humans and birds?

Adapting to urban life

The broad environmental tolerance of urban bird species may allow them to adapt to human environments more easily then rural bird species (Bonier et al., 2007). Sol et al.(2005) finds that birds with larger relative brain size are able to respond better to new environmental conditions with their enhanced cognitive skills. Check out the crows in the video.

Some urban birds have been observed incorporating cigarette butts into their nests. Suárez-Rodríguez et al. (2013) finds that this reduces the number of nest-dwelling ectoparasites. However, potentially toxic chemicals in cigarette butts could harm the birds too.

Møller (2008) found that the relative flight distance of urban bird populations was lower than their rural counterparts and was positively related to the number of generations of the urban population since urbanization, “suggesting that as time has passed, urban and rural populations have diverged in terms of flight distance.”. This means species found in urban environments are not inherently adaptive but individuals of a species that can adapt to urban life are selected for. In other words, the mynas and pigeons in Singapore can tolerate close distances with humans might not be because it they are an adaptive species but because they are the descendants of individuals who can.

Change in the songs of urban birds are also observed. Patricelli & Blickley (2006) discussed the changes in the frequency, amplitude, temporal and timing aspects of urban bird songs. Birds can adjust the frequency of their songs in response to the low frequency urban noise and/or increase the amplitude or loudness of their songs but this could be limited by the size of the bird and the energetic costs of singing louder. Temporal structure refers to the timing of modulations, notes and syllables in a vocalisation which can affect ability of other birds to detect the call while timing refers to the time of the day the birds sing.

Bonier (2012) reviewed findings regarding endocrine ecology of urban birds and concluded that “The current urban endocrine ecology literature does not reveal any consistent patterns, but has demonstrated that populations of birds in urban habitat often exhibit differences in endocrine traits, particularly hormone concentrations, when compared to conspecifics in nonurban habitat.”. This shows even more changes that the urban environment can inflict on birds.

Bird in black

The common myna is considered a feral species in Australia and was declared among “100 of the World’s Worst Invasive Species” by the International Union for Conservation of Nature (IUCN) in 2000. Introduced to Canberra in 1968, they have become one of the most common feral birds in Canberra with increasing concern over their impacts on local biodiversity such as competing with native species for nesting hollows (Tidemann, 2001). In Singapore, mynas are also considered as pests mostly due to it being a nuisance to humans but locals are quite tolerant of them. After all, we do not have to clean up after them and most are not aware of the threats to local biodiversity by exotic species.

There are 2 species of mynas found in Singapore. The Javan myna prefers green patches among residential areas while the common myna prefers the rural landscape (Lim et al., 2003).

8512585881_493d7d92f0_o Common myna or Indian myna Acridotheres tristis
Javan Myna or White-vented myna                            Common myna or Indian myna
Acridotheres javanicus                                                                Acridotheres tristis
Photo credit: Sergey Pisarevskiy                                 Photo credit: Sergey Yeliseev

Mynas can be kept as pets and they are able to imitate sounds too. Most of us take little notice of these very abundant birds in Singapore but they are being admired and demanded in other countries.

The common hill myna (Gracula religiosa) does a way better job.

Not all benefit

In a study by Lim & Sodhi (2004) in Singapore, generally the number of native species decreases with increasing levels of urbanisation while the number of exotic species increases. Insectivorous species, shrub nester and primary excavator abundance decreased with increasing urbanisation due to the lack of food and nesting sites. Meanwhile, granivourous, frugivorous, tree nesters and secondary cavity nesters increase in abundance due to availability of food from anthropogenic sources and nest sites in tall shade trees and human structures.

Chong et al. (2012) reveals increasing abundance of bird species in Singapore over the past 10 years but many of them are exotic. This study investigated the change in bird abundance over the past decade and compared their results to another survey done in 2000-2001. The Javan myna in the study area was found to have (status: exotic) increased from 1955 to 3238. You see them everywhere in Singapore.

Some birds are able to adapt well to our urban environment and provide a tiny slice of nature for us to see. However, they are also considered pests by humans when they make too much noise, dirty places with their droppings and threaten local biodiversity. I have noticed huge numbers of mynas crowding around one or two trees making so much noise and the pavement below the tree will be covered in their droppings. Meanwhile, urban areas do not provide suitable nesting sites or proper food for many other bird species especially native species who are adapted to forests and mangroves in Singapore. With increasing urbanisation, many bird species will still be threatened as they cannot adapt to live alongside us in our cities.

Perhaps more emphasis should be placed on creating specific habitats for different bird species rather than simply greening urban areas. Birds are able to move around freely and choose places most suitable for them but in Singapore, we are only made up of islands. The mainland has mostly been urbanised and since birds do not recognise country boundaries, if they do not find a suitable habitat here, they have no other places to go except to leave the country entirely. Furthermore, urban environments can act as a force of selection that causes phenotypic and genetic divergence within bird species resulting in a sort of urban subspecies different from that of the rural population. This means we would not exactly be preserving the species in their natural or original form.

Bonier, F. (2012). Hormones in the city: Endocrine ecology of urban birds.Hormones and behavior, 61(5), 763-772.

Bonier, F., Martin, P. R., & Wingfield, J. C. (2007). Urban birds have broader environmental tolerance. Biology letters, 3(6), 670-673.

Chong, K.Y., Teo, S., Kurukulasuriya, B., Chung, Y.F., Rajathurai, S., Lim, H.C., Tan, H.T.W. (2012). Decadal changes in urban bird abundance in Singapore. Raffles Bulletin of Zoology. Suppl. 25: 181-188.

Lim, H. C., & Sodhi, N. S. (2004). Responses of avian guilds to urbanisation in a tropical city. Landscape and Urban Planning, 66(4), 199-215.

Lim, H. C., Sodhi, N. S., Brook, B. W., & Soh, M. C. (2003). Undesirable aliens: factors determining the distribution of three invasive bird species in Singapore. Journal of Tropical Ecology, 19(06), 685-695.

Møller, A. P. (2008). Flight distance of urban birds, predation, and selection for urban life. Behavioral Ecology and Sociobiology, 63(1), 63-75.

Patricelli, G. L., & Blickley, J. L. (2006). Avian communication in urban noise: causes and consequences of vocal adjustment. The Auk, 123(3), 639-649.

Slabbekoorn, H., & Ripmeester, E. A. (2008). Birdsong and anthropogenic noise: implications and applications for conservation. Molecular Ecology, 17(1), 72-83.

Sol, D., Duncan, R. P., Blackburn, T. M., Cassey, P., & Lefebvre, L. (2005). Big brains, enhanced cognition, and response of birds to novel environments.Proceedings of the National Academy of Sciences of the United States of America, 102(15), 5460-5465.

Suárez-Rodríguez, M., López-Rull, I., & Garcia, C. M. (2013). Incorporation of cigarette butts into nests reduces nest ectoparasite load in urban birds: new ingredients for an old recipe?. Biology letters, 9(1), 20120931.

Tidemann, C. R. (2001). Mitigation of the impact of mynas on biodiversity and public amenity. School of Resources, Environment & Society, the Australian National University.

Running thoughts: We decide

Where they live

Plans to move the Jurong Bird Park to the Mandai area were mentioned during the “Ask the Prime Minister” forum on Channel NewsAsia recently. This is to move it closer to the other three parks run by Wildlife Reserves Singapore to make it more convenient for visitors to get from the Singapore Zoo, Night Safari and River Safari to the bird park. This move has had me thinking of the amount of control we have over animals. We decide where they live and what they eat. The birds have no say in the move and we have no way to ask them.

Zoos and marine parks are surrounded by controversy which I will cautiously touch on in the future. On one hand they provide education to the public and play a role in conservation either by taking in injured and sick animals or carrying out breeding programmes for endangered species. On the other hand these animals are also exhibited for entertainment purposes and live under human care and in an artificial restricted space. Are the animals better off in guaranteed safety or happier in their natural habitats? Or rather, which is better for us humans?

How they look

The shade trees along side our roads did not grow there naturally nor did the shrubs and bushes around our buildings. They are almost all planted by NParks with many considerations. Singapore did not build buildings around plants, we plant plants around our buildings and we decide what plants to plant. Primary forests patches are rare in Singapore with the two largest being in Bukit Timah Nature Reserve and the Central Catchment Nature Reserve.

We are truly a city in a garden for a garden is man-made. During the 2014 national day rally, Prime Minister Lee Hsien Loong announced plans to change the layout of the Jurong Lake District. He said “On the west side of the lake, there is Jurong Lake Gardens or Jurong Lake Park and they are really three different pieces. But if we bring them all together, we can redesign the whole area. You can change the islands, you might merge them. You can change the shape of the lake, which is right now a little bit awkward. You can create one beautiful set of gardens in our heartlands and that can be Jurong Lake Gardens and can be something really special.”. It is truly amazing the control we have over our space.

What nature is

When we say ‘nature’ we expect some untouched by man but ‘true nature’ is hard to find in Singapore. The biggest challenge Singapore faces is space. A forest and a residential building cannot occupy the same space. Animals like us require space to live and roam. I think it will be impossible for the malayan tiger or asian elephant to ever return to mainland Singapore for there simply is no space for them to roam.

We can also decide what animals and plants we do not want. Mosquitoes are something Singaporeans do not want in Singapore’s environment and so are large carnivorous animals like the tiger. The website STOMP has many images of snakes and monitor lizards (almost all are native species) and even monkeys which we all know are found in Singapore. Every few months my own home would be overrun by ants. I thought I had eradicated them with ant bait/poison but it appears that they never left so every few months they would return in droves, haunting their old ant trials and eventually disappear again as I start cleaning up the house and sealing all the food containers. 

I was watching the news on Mediacorp Channel 5 a few days ago and they discussed about the setting up the Municiple Services Office which will coordinate all the government agencies. They interviewed a lady and the issue was related to monkeys. She had spotted monkeys in her neighbourhood and first called the police but the police said it was not their responsibility and she had to call someone else. In the end the monkeys left on their own. It is not the lack of coordination of the agencies that I want to focus on but the fact that before the lady could find the right agency, the monkeys already left by themselves. It was not mentioned if the monkeys were being a nuisance.

The lives of most Singaporeans would continue on undisturbed by the lack of native animals. Flora is much easier to control and require less space than animals and also provide the beauty of nature. I guess ‘nature’ in Singapore is largely defined by the flora and birds while monkeys and reptiles are better off (for us) contained in nature reserves and parks. Insects appear to be the least appreciated by majority of the locals and I have never come across any ‘shocking’ insects in STOMP compared to the endless pictures of snakes. 

Unless we instill a sense of wonder for nature and appreciation for both fauna and flora in all Singaporeans, it is unlikely that we would get a unified move to protect the local environment. However, much of Singapore’s environment is controlled and shaped to our needs. Is it already too late? Should we just keep the ‘nature’ we want, ignore the less desirable fauna or flora and contain ‘nature’ in specific areas for our convenience?

The answer that comes to me is one that I do not want. My first thoughts were ‘yes’ to both questions but I find it sad to control nature for our convenience. It seems really lonely for us humans to only recognize ourselves as beings who have needs.



Domestic: Our best (selectively bred) friend


When Wild Dog reached the mouth of the Cave he lifted up the dried horse-skin with his nose and sniffed the beautiful smell of the roast mutton, and the Woman, looking at the blade-bone, heard him, and laughed, and said, ‘Here comes the first. Wild Thing out of the Wild Woods, what do you want?’

Wild Dog said, ‘O my Enemy and Wife of my Enemy, what is this that smells so good in the Wild Woods?’

Then the Woman picked up a roasted mutton-bone and threw it to Wild Dog, and said, ‘Wild Thing out of the Wild Woods, taste and try.’ Wild Dog gnawed the bone, and it was more delicious than anything he had ever tasted, and he said, ‘O my Enemy and Wife of my Enemy, give me another.’

The Woman said, ‘Wild Thing out of the Wild Woods, help my Man to hunt through the day and guard this Cave at night, and I will give you as many roast bones as you need.’

Wild Dog crawled into the Cave and laid his head on the Woman’s lap, and said, ‘O my Friend and Wife of my Friend, I will help Your Man to hunt through the day, and at night I will guard your Cave.’

When the Man waked up he said, ‘What is Wild Dog doing here?’ And the Woman said, ‘His name is not Wild Dog any more, but the First Friend, because he will be our friend for always and always and always. Take him with you when you go hunting.’

-Excerpt from Just So Stories by Rudyard Kipling

Dogs were domesticated 9000-34000 years ago. Recent research has suggested that dogs and grey wolves share a common ancestor rather than the idea that modern dogs descended from a group of grey wolves. How dogs were domesticated is still debated. One claim suggests that humans captured wolf pups and selectively bred them by allowing tamer captured wolves to breed. Another claim is self-domestication where wild wolves less afraid of humans would approach human camps and feed on the leftovers. These wolves survive better as they are able to easily obtain food and their numbers increase via natural selection. Perhaps the latter claim suggesting natural selection might better explain the divergence of wolves and dogs from their common ancestor. I might suggest that appearance of permanent human settlements triggered the diversifying selection for tamer wolves, which thrive better with humans, and more human-independent wolves, which thrive better in the wild.

Dogs are evident of animals having close relationships and in some cases highly dependent on humans as seen in bulldogs which usually require artificial insemination and cesarean section due to their body shape. They mostly rely on humans for food and shelter while both sides benefit from each others companionship.

The Bond

Being able to read human signals is what makes dogs so special. Dorey et al. (2010), in a study to investigate at what age do dogs become able to follow human points, showed that puppies become better at following momentary proximal points to find hidden food as they get older. This shows the ability of dogs to learn to read human social cues as they age. There is still some debate over whether dogs are born with this ability or acquire it as they age but the presence of the ability is proven.

In a study done by Miklósi (2003), dogs when faced with an insoluble problem are much more likely and quicker then socialised wolves to look back at the human experimenter and gaze for longer periods of time. He suggests that this communicative contact with humans seem to be genetically predisposed as this behavior was difficult to be induced in socialised wolves. 

Topál et al. (2005) stated that “…dogs have evolved a capacity for attachment to humans that is functionally analogous to that present in human infants.” and Prato-Previde (2003) “Our observations during separation episodes (ep. 3, 6, 5 and 8) show that the dogs’ search behaviours closely resembled those described in human infants and chimpanzees and included following the owner to the door, scratching at and jumping up on the door, puling on the door handle with the forelegs or mouth, remaining oriented to the door, going to the owner’s empty chair or looking at it from a distance.”

Both studies used the Strange Situation procedure which was originally used by psychologist Mary Ainsworth to study human infant-mother relationship. The following video shows the procedure. Simply replace the baby with the dog and you will get the general gist of the experiments.

You might have thought that the dog-human relationship was similar to that of a wolf pack in which the human is the “alpha” but it turns out that is not really true. It must be reminded that dogs are NOT wolves despite being the same species under Canis lupus. There are still many people trying to assert dominance on their dogs during training which might be excessive or even pointless.

The narrator mentions how humans can control dogs with our superior minds. This is much less stranger then having humans resort to dog behaviors and actions to communicate with dogs. Afterall, we have no tails to wag and certainly do not often growl or whine to communicate with fellow humans.

Selectively bred

Selective breeding is the process where a characteristic (physical and/or behavioral) is selected for in a species. The mating pair with the desired characteristic or the lack of an undesired characteristic is allowed to breed and hopefully pass the genes of the selected characteristic to their offspring. This has given rise to dogs with unique characteristics such as the size of chihuahuas and the face of pugs. Strangely enough, some of the oldest dog breeds look quite different from modern wolves such as the saluki and the chinese shar pei as one would expect.

Selective breeding occurrs all the time. Pure breed dog lines are strictly monitored to prevent any cross-breeding while new breeds are still being created and refined. The Dire Wolf Project started in 1987 hopes to create a breed that physically resembles the extinct dire wolf but with a gentle and mellow temperament. Known as the American Alastian, it is essentially a mix of Alaskan Malamute and German Shepherd with a few other mastiff breeds in the mix. Breeding dogs back to wolves, a process known as “breeding back”, and other extinct species is controversial although this project is not attempting to do so. It seems possible in theory but genetics is extremely complex. Some claim that cross breeding all existing dog breeds will give you a wolf.

Watching through many Animal Planet Dog 101 videos on YouTube, I realise that certain breeds are susceptible to specific health problems. This is a result of selective breeding done without regard for the health of the breed. The short legs and long back of Dachshunds often causes them to suffer from ruptured vertebral disks while deep-chested breeds such as the Great Dane commonly suffer from gastric torsion.

Dogs have also been selectively bred for behavior to carry out different jobs ranging from herding, hunting and simply being a lap buddy. The extent of physical and behavioral differences in dogs show how much impact humans can have on a species. This video just shows how amazing a sheepdog (in this case a border collie) can respond to commands of its owner.

The relationship humans have with dogs is wonderful and unique. Communication goes both ways although the extent of understanding from the dog is questionable. The compliance of the dog has allowed intelligent humans to domesticate and teach them various commands such that a dog acts as an extension of its owner. This is certainly a win-win relationship with both sides benefiting. Is this the kind of relationship we should aim for with nature?   

Non-academic sources

Academic sources
Dorey, N. R., Udell, M. A., & Wynne, C. D., 2010. When do domestic dogs,Canis familiaris, start to understand human pointing? The role of ontogeny in the development of interspecies communication. Animal Behaviour,79(1): 37-41.

Miklósi, Á., Kubinyi, E., Topál, J., Gácsi, M., Virányi, Z., & Csányi, V., 2003. A simple reason for a big difference: wolves do not look back at humans, but dogs do. Current Biology, 13(9): 763-766.

Prato-Previde, E., Custance, D. M., Spiezio, C., & Sabatini, F., 2003. Is the dog-human relationship an attachment bond?   An observational study using Ainsworth’s Strange Situation. Behaviour, 140(2): 225-254.

Topál, J., Gácsi, M., Miklósi, Á., Virányi, Z., Kubinyi, E., & Csányi, V., 2005. Attachment to humans: a comparative study on hand-reared wolves and differently socialized dog puppies. Animal behaviour, 70(6): 1367-1375.

Running thoughts: The dilemma

During a cold winter day, the hedgehogs decided to huddle together for warmth. However, their spines pricked each other as they huddled close. They began to separate but the cold drives them closer and their spines once again got in the way. This repeated until they finally settled on remaining a little distance from each other.

The above  scenario was created by philosopher Arthur Schopenhauer in Parerga und Paralipomena which was published in 1851. It is known as the Hedgehog’s (or Porcupine’s) Dilemma. Originally used to explain human psychology, Hugh Warwick, author of the book ‘The Hedgehog’s Dilemma’, applies it to the relationship between humans and hedgehogs. Inspired by this thought, I began to realise the many ways in which humans and nature have come close and in some cases have hurt each other.

The hedgehogs decided on remaining enough distance away such that their spines do not prick each other yet they are still able to receive some degree of warmth in the cold. Is there a certain distance in which humans and nature should be apart such that we do not harm each other?

There are so many degrees of closeness that have occurred or are currently occurring between humans and nature. From physical closeness of domestic animals and plants to the extent of communication between humans and animals, each living being has “spines” of a different length.

I hope to be able to uncover the “length” of as many “spines” as possible and the perfect distance, if it exists, between all the “hedgehogs” such that although we all do not get the most warmth, we are not hurting each other too.