Sunday, 19 August 2012


Ground feeding birds under the realm of opportunists

      Woke up in the morning listening to bird chirps, chuckles, gurgles and coos.Lying on the bed I fancied our Hibiscus tree studded with birds of blue, red, yellow, white and so on. After couple of minutes,finally making up my mind,picked myself up to reach the balcony and to my surprise, and slight disappointment, all I could see is a tree of noisy bunch of purplish brown birds, the Common Mynah1. The incident, though it wasn’t possible then to perceive ample scale of the phenomenon- phenomenon of Common Mynahs taking over other ground feeding birds, stayed on me as an image, a notion.

The Common Mynah 
       ‘Isn’t this the way nature goes about? Why should nature’s way of better species replacing weaker ones gain any importance scientifically?’ One might ask. The answer would be an ‘yes’, I must concur, but the emphasis here is on the fact that whatever prevails should be a better species, which is not the condition in the phenomenon we look upon here. Mynahs are clearly not better species, in terms of feeding adaptations, preying skills or survival adaptations like agile flight, camouflage,swiftness on land, than most of the species it is likely to replace.

It might sound paradoxical to declare a dominating species as weaker one in terms of evolutionary adaptations, but it must be understood, however, that all the adaptations above mentioned, that Mynahs seem incompetent in,are individual. Social adaptations of Mynahs afford an explanation for the phenomenon. Mynahs are highly social birds strutting haughtily in quarrelsome pairs often forming foraging groups ten to twenty strong. Before discussing Mynahs’ social adaptations and its evolutionary upshots, let’s look into the incentives behind any animal(including birds) being social.

Food and its distribution along with habitat of any animal, in effect, design their social pattern.As mentioned before animal’s social patterns, like being solitary, in pair, or groups of different sizes, is determined predominantly by their food and its distribution2. When the food is nutritious and bulky the animal need not spent much time feeding hence it is not vulnerable most of the time and can afford to be solitary, as they can watch out for themselves from their predators e.g. king fisher, weasel. For animals on top of the food chain vulnerability is not a concern, although it might have to defend its kill from other predators, here hunting technique contributes in deciding the social pattern3. This category does not include scavengers with, excepting the fact that it’s just putrid remains, similar food design. These animals work in groups to save energy spent in search of carcass through vast area.  

When the food is less nutritious the animal needs to spend much of its time feeding making it vulnerable hence they tend to form social groups so that they have more watchful eyes, this would also mean more mouths feeding, giving raise to social hierarchy, severity of which depends on the availability of food. Animals like sparrows, spotted deer, to name a few, fall under this category.Animals with rich cultural knowledge, for better survival, are bound to be social in two ways. One, their offspring inherit very less instincts, as they might act against cultural knowledge, and their growth period is prolonged so as to accommodate much learning, making them very vulnerable. Two pairs of watchful eyes often aren’t enough protect them, most of the primates for example. The other reason would be more individuals in a group would mean more exposure,therefore learning takes place faster.

A Spotted Dove, one of the victim belonging to second category 

      Those animals feeding on nutritious food available in small packages, groups of small sizes, preferably pairs are favoured. This enables them to share information either of food sources are of threats without much competition on food. These animals feed shorter time span than those of above category at the same time longer than those of the first category. Their alertness, therefore, is somewhere between that, which explain their social adaptations. Sunbirds and lorises would be best examples.  

A Magpie Robin, one of the victims belonging to third category 

Mynahs, peculiarly, have a diet which includes both of the last two categories i.e. they feed on both less nutritious food and small packed nutritious food. This makes up their specific social structure of having feeding pair welcome (really?) to form occasional foraging groups. Mynah’s natural diet ranges as invertebrates, fruits, nectar, grain and human garbage. This wide range of food habits prevented them from any possibility of specializing. They are designed to be opportunistic feeders and therefore, not surprisingly, supposed to be in large numbers, as they have always been (can be seen in the diagram). For such a widespread bird (more widespread than House Crow) found in such numbers any unusual favourable condition would result in drastic insurgence of population. This is where human garbage comes in.

An ideal population circle

Human garbage is an interesting combination of food source. It is a sea of less nutritious food dotted with bonus of nutritious food both in small packages and large chunks. Excepting bulky nutritious food, which House Crows4dominate, the rest forms a perfect menu for Mynahs. Mynah’s volatile social structure further supported them conquer this food resource. Thus what had previously been amateur opportunists then evolved to be garbage specialists. They eventually habituated human presence5, and, in fact, turned bold and aggressive. Thus human garbage, more than any, formed Mynah’s primary food, and with its consistent escalation has comforted huge population of the bird.

Mynahs with Rock Pigeons

This might seem perfect that, increase in food source naturally increasing the population of the consumer, therefore striking a natural balance. But the trouble arises from the fact that Mynahs are of persevering nature that they refuse to give up their other food habits. Thus it essentially comes out to be these bold, aggressive, confiding, social birds opposed, to comparatively less so, other birds. It is much in favour of Mynahs, but nevertheless the situation is completely man-made, that way what are basically just two selective forces (adaptability to human garbage and his presence) overcome all the natural selective pressures, which moulded other specialised birds, to favour Mynahs.

The situation is made further hostile to these specialised birds due to man-made fluctuation6 in their natural diet like nectar, grains, fruits, and invertebrates. Being specialised they cannot rely on any other back up food source whereas Mynah population is buffered by constant human garbage outputs. This phenomenon is more severe in urban environment with more human caused primary food source instability, his presence and garbage output. This phenomenon also affect some birds indirectly, for example; Cuckoos are basically canopy feeders and not competed by Mynahs directly but they brood-parasite Babblers and other small birds like Prinias which in turn suffer the phenomenon. Mynahs roost communally making them less vulnerable to their possible predators.

After human Interference

        All the birds depicted in the diagrams are common birds none rare or endangered. Notice the bigger food circle of Mynah and more overlapping. With more overlapping and selective pressures the food circles of other birds would eventually shrink.

As it is obvious now that the phenomenon is not natural let’s look at the consequences. It is mentioned at the beginning that Mynahs are not better species in terms of individual evolutionary adaptations. Their social adaptations come at the expense of their lack of specialisation. They, therefore, can be better survivors but not better feeders. They can never be an apt substitute of those specialised birds they are likely to replace from the food chain for example; Mynahs cannot prey on dry leaf floor dwelling insects as effectively as a Jungle Babbler. They dominate food web at the same time weaken its links.

Mynahs waiting for a Brahminy kite’s kill, a peculiar behaviour 

         Such a system can fall into ecological imbalance in at least two ways. Any depletion in human garbage or human activity directly affecting Mynah population, say a toxic breach in garbage output, would result in ecological imbalance which would have been prevented provided more specialised bird population i.e. when very conditions that favoured Mynahs turn unfavourable their population drastically falls leaving a gap which cannot be filled by other birds7 (as the diagram below illustrates) given the short time scale of the phenomenon.

       This gap left behind would result in complete collapse with an upsurge in invertebrate population, failure of pollination in certain species, uncontrolled burst in grass population etc. The cause might seem less likely in this case but in a man-made environment any such possibility can be anticipated and therefore should not be neglected.

        The second possibility is a more likely one. The food itself might evolve to be resistive, like developing an unpalatable husk in case of grain or distasteful chemical in the case of invertebrate, rendering it inaccessible to Mynahs. Mynahs cannot specialise to gain access to themas they rely on garbage as their primary food source, at the same time their population, social pattern and confiding nature would still be a threat to specialised or rather able-to-specialise birds. Moreover for bird with such wide range of food habit, loss of access to a few species may not be significant. The result would be similar to the former case though not to that extent.

        Given the extent of the phenomenon, one gets a mixed feeling seeing a Mynah. Should they be seen as a bullying pest of bird kingdom? Or as a human being, Should one identify with them as funny walking creatures representing man’s destructive power in bird kingdom?

 A friend knowing my interest in bird watching invited me to his place, some time back. I went there without much anticipation and it proved right again. I had a hard time explaining him that it’s just one species, Common Mynah communally roosting. There are not many species out there as it sounds like, I cried out. 


1.     It’s been six years since the incident and that was much before interest for bird watching grew on me. I now know that Common Mynahs are highly vocal, capable of producing wide range sounds ranging from chattering, chirping, whistling, to occasional mimicry.

2.     Food and its distribution, though are most important deciding factor, do not account for social behaviour solely. Sensory capabilities, energy efficiency, birth rate along with many other factors play a synergistic effect in deciding social pattern of an animal.   

3.     A Tiger can be solitary because it can sneak up to its prey closer than a savannah inhabiting lion would using much denser vegetation as a cover and can score a large kill, most of the time, with a single pounce. Whereas lions have lesser cover, and their prey is quite large requiring great muscular power to bring down, this comes at the expense of speed hence they need to hunt in pack.

4.     The adaptation of house crow to human garbage is another worrying phenomenon. Crows are inveterate robbers of bird nests, as their population increases with increasing garbage output
other birds might suffer severe mortality rates.

5.      Human garbage has been in to existence long enough for Mynahs to have evolved their confiding, inquisitive nature and gradually getting habituated to human presence.

6.      This phenomenon is much seen in aquatic environment, as the fluctuations in aquatic life increases more specialised aquatic birds like Ibises and open-billed storks are dominated by opportunistic feeders like Cattle Egrets.

7.     Birth rates are limited to generations and therefore often fail to cope up with sudden increase in death rates.

              I thank Thamarai.s.Elanthirayan my friend and an aspiring photographer for the pictures presented.

1.A photographic guide to birds of India-Bikram Grewal, Bill Harvey and Otto Pfister, Princeton                          University press,2002 periplus editions

After words:
                     By coincidence all my three articles so far are about one thing dominating over others. This article is inspired by the trivia that I recently read about Common Mynah being declared as one of the most invasive species. When I further read up I found some of the species it is said to threaten as an invasive species are found in India too. The article, though lacks any statistical data to back up and is solely based on observations, is presented with the confidence that arguments put forth here are substantial and defendable. I would be glad, therefore, to have my arguments discussed or to have data defying or supporting the arguments than being criticised for its lack of statistical data.

Some local Tamil names

Sparrows- chittukuruvi
Mynah-ur kuruvi or naganavai
Spotted Dove- mani pura 
Rock Pegions-mada pura
Bullbull- annan
Babblers-vannathi kuruvi 
Wagtails,Pippits- vaalaatti kuruvi 


  1. dear aji,
    that was a good read. i was shocked to know about your experience at your friend's house where you found only mynah's. now i thought that in and around my home there are more 5 species of birds. though i am not a bird watcher (havent tried to be the one) now i have to check. i think i mistook by the various sounds which i hear daily. the association with house crow and human population is one thing that is well known. but this association is something new and have to ponder about it.

  2. Ajithan, Its a good interpretation of human intervention in the birds food chain by the means of producing large organic garbage and how it can nurture selectively the quick adaptable bird species to out number the others.

    I am neither a bird watcher nor well read in this subject. As a layman I would like to put forth my observations which is very relevant to your article and contradict a bit in points concerning with the habitat domination of Mynas and Crows.

    Backyard of our home in the village is quite green with plenty of coconut trees, plantains, guava, citron and different flowering plants and climbers. There runs a small ditch that carries the waste from household (mostly vegetarian food wastes and water) and irrigates the waste water to trees. The wet banks of it is a good source of worms and small insects. This garden is equally inhabitated by crow, crow pheasant, sparrow, myna and squirrels, though ground feeding is dominated by sparrows and mynas.

    Also, I have lived in a house which was located just opposite to a busy big vegetable market in the city center. Rotten vegetable, fish and meat wastes are dumped outside the market. As one would expect crows dominate here.

    From these two localities my observation is, despite being omnivores Mynas totally avoid a busy market though rich in variety of food stuff and prefer more quiet and less 'fertile' backyards. So, I drive to a conclusion that Mynas (sparrows too) are still not adapted to move bravely amidst human beings. Therefore, in your observations -I hope they are mostly from calm home gardens, no wonder why you see a domination by Mynas. Can it be because of the reproductive rate of Mynas? ( like, how many eggs it lays when compared to crows or other birds, reproduction speed etc.,). Both common mynas and crows are indigenous to our land, hence I would say your point number 4 (in the notes)is more arguable in the Indian scenario of indigenous invasive species.

    1. Dear Prakash Shankaran,

      My observations are mainly from urban and sub-urban environment. The article is particular about ground feeding birds not any other levels of feeding. And it must be noted that the article nowhere mentions Mynahs dominate garbage, it says Mynahs dominate ground feeding birds. Mynahs are the most human garbage adapted groundfeeding birds but when it comes garbage feeding Mynahs have to give way to other birds and animals. That would include crows,black kites, stray dogs, cattle, rodents etc But not any other groundfeding birds more than mynahs(even sparrows). Mynahs have always lived on man made organic environment so I wouldn't blame that for the phenomenon, but garbage output rates are sorely high. And it must be noted that Mynahs are not scavengers so thier diet is limited to fresh organic matter unlike other garbage feeders. Although they can be seen rarely feeding onroten matter. finally Reproductive rate can never account for population. It is a false notion one gets from observing human population under consideration. Human beings, for better or worse, have the ability to alter the environment to accomodate themselves.wherein other orgainisms population is limited to how much the environment can sustain and increase in population obvously means suitably environment. reproductive rates are decided over evolution to match mortality rate.

  3. //more arguable in the Indian scenario of indigenous invasive species.// sorry. it should be MORE AGREEABLE

  4. Dear Aji,

    Happy to read such an interesting article. You are becoming a bird observer rather a bird watcher. would like to have few points shared here, discounting the factor that i dont have a systematic study on this subject.
    Crows are more socialized with humans and mynas are still keeping away from human. But, while reading some Sangam verses, few birds are repeatedly depicted as pet birds(parrot, Myna, peacock, Swan and Dove). Still these birds are with human. Crow has never been portrayed as a pet or friendly bird. I think , by default, they are natural human habitat scavengers. Other birds , though adapted with human , they still keep their habitat as natural as possible.
    The population of mynas are not as big as crows in Chennai. Probably, in some food junctions(!) we may see the packs of Mynas along with crows. But, the wide spread of crows are far better than Mynas. As prakash says, mynas in villages are different from mynas in Chennai. In my observation, mynas in chennai start sharing the food habits of crows. I have read Mynas are perfect mimic artists; Do they mimic the habits too?
    I feel it is only the food availability than food selection. Not only Mynas under this web. In same manner , i have seen some pictures (really forgot the source) where pelicans find food in garbage dump yard somewhere in Assam (Guwahati , i think). Certainly this will be a concern to raise. But, wont nature balance it? or Do human give problems too big to handle for mother nature?

    Pl do write more.


  5. Sri ajithan,

    It is interesting to read about my favorite subject in this site, and it is presented in a brilliant way .Thank you.

    It is true mynahs are slowly dominating our cities of Karnataka. We can see them more in Mysore and Mangalore . You explained the evolutionary pattern and ecological background of this situation with full details and logic. I appreciate the work behind it.

    Two things i noticed. One is mynahs are not thriving in dry northern Karnataka. Two they are not thriving at chemically polluted cities like Kanpur. But common crows becoming uncontrollable bird communities in these areas.

    So i came to a conclusion that mynahs can live on human garbage but can not survive the chemicals of it. And they can not survive the water scarcity found in many of our cities.

    Anyway the article is food for thought The poetic and symbolic opening and philosophical ending is enjoyable

  6. interesting article.New way to look our environment. Generally we feel happy to see lot of birds around us. this shows the other side. the reality scientifically


  7. The article i good in language a usual. But sorry again i want to give my penny.

    In today Hindu there is an interesting article about the cell phone towers.

    For long time our environmentalist creating a phobia on the cell phone towers- the effect of radiation they create. The author sarcastically says they said the cell phone radiation is the cause for all deceases including baldness and envy. )))

    Similar type of ideas are always created in the media by our environmentalists. They said cell waves are the cause for eradication of sparrows .But statistical studies showed there is no remarkable fall in their number.

    Nature is not a machine. It is a great flow of events, or a mega event, and it is operating through dialectics. Nature is doing its balancing at on every second. well, it is called dialectics. Our environmentalist look in to a single event and cries danger.

    1. Dear Kumaarasami perumaal,

      Again you've kept your arguements on an astract level far from the articles subject, I would have to stray out of the subject to answer them, as well. I have come across a lot of similiar comments and working on an article objecting.
      I would appreciate if next time you would touch upon the subject article discusses. like explaining how would nature balance the above phenomenon without losing its diversity and therefore stability.

  8. Good article.

    The photos are also good. I observed they were taken by an armature photographer. The photo of mynahs are waiting for kites food is really amazing.

  9. Good Article. Good analysis and fine readability


  10. i would like to see birds on the road ,once that like i saw one bird colour black,hight between 5to6 cm,its look like sun bird its has two lines on its body. Lince are not tuching. i am serching for its name i refered in salim ali book its not having .if u know its name please tell me

  11. This comment has been removed by a blog administrator.

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