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Thursday, January 27, 2011

Flying in the face

God in his wisdom made the fly
And then forgot to tell us why.
- Ogden Nash


Bengalia looking out for a victim
One of my favourite flies was a species of Bengalia found especially during the rainy season. You will find him or her beside ant columns, watching stealthily and then making a quick dash and stealing a pupa or snatching food out of the mandibles of a passing worker. It was actually years between my first observation and finding the identity of the fly. The identity incidentally was made possible thanks to the Internet, on an email group, at a time when the web was still in its infancy. I posted a description of the behaviour and was entirely surprised when it was identified to genus by Dr D P Wijesinghe. Apparently the food-stealing or kleptoparasitic behaviour has been documented from early times. I later learnt that hardly anything is known about the life-history of this fly, which got me wondering how could anyone find more information about something like this. Perhaps one should build a large glass case and use some kind of passive marker with some detection apparatus on it to see where it goes. For all the spy gizmos and nano-technology, there does not seem to be any way. The only way to find out seems to be look out for it and to be prepared for surprise.
Ochthera - probably males at a lek

Lots of times, it is so hard to see what's happening. During the last rains I noticed a swarm of tiny silvery flies that seemed to like sunbeams under shaded trees. They are so alert and swift that they cannot even be captured. And no they are not hoverflies (Syrphidae). I asked my entomologist friends but they too have not figured a way to capture a specimen ! 

Another time I found this large aggregation of flies on a leaf. They have their forelegs raised and it looks a bit like a hand holding a sword. The structure is actually even closer to a pen-knife with a groove and the flies are actually capable of grasping prey - midges and indeed, the scientific name means midge-hunter. Now what this large aggregation is about is hard to tell, I suspect they are mostly males.

There are a couple of spectacular Internet gatherings of entomologists and the two that stand out at the moment are diptera.info and hymis.de - one on flies and the other on hymenoptera. These sites gather information, photographs and reassemble them into very interesting nuggets.  They are the kind of system that brings together taxonomists, photographers and amateur entomologists. You can login, ask questions, obtain papers, identifications and so on. Today, I came across this entirely curious case of what can only be called "fly falconry" - check it out !

Postscript

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Monday, January 17, 2011

Bedazzled

I am interested in a little mystery - the origin of the term "Jatinga bird mystery". It would be unpardonable if a scientist coined that term, for there is hardly any mystery in the entire matter nor is it specific to that location. It might of course have been a way of getting tourists or obtaining funds for misguided research.

The first time I heard the phrase was when still at school. One evening there was a documentary screening  at  the Indian Institute of Science Gymkhana and the question was asked by a student and posed to an old man named Salim Ali who had just woken up from a nap for the entire duration of the screening of  a documentary  (about Bharatpur - and remember that it was a time when TV penetration was low and Doordarshan was dull) and I do not remember hearing a cogent answer. One interpretation was that the birds were "committing suicide" in Jatinga (that was also a time when there were Disney films  with Lemmings committing suicide and neither Snopes nor Dawkinism existed) !  Fortunately the government website today seems to be slightly more enlightened and points out that the locals kill the birds after confusing them with lights on foggy nights. There is still some mystery mongering, perhaps aimed at tourists, as a last word on their page though.

Punch. January 11, 1879. p. 11

All this came to mind, strangely enough, while browsing through some ancient digitized versions of Punch Magazine (thanks as always to the Internet Archive). It is quite a challenge to imagine the conditions of that time and identify the humour  in those brilliant cartoons. Some of them can still be thought provoking, for instance - how does one evaluate the consequences of new technology. It is easy to dismiss cautions when  the predictions such as those of the early Luddites and technophobes are hyped. So exactly how did lights affect birds? It seems like very little is known in the Indian context. The numerous lighthouses around the country must be trapping a range of birds during their migration and numerous birds must be dying there. Perhaps some qualified organization will find a way to communicate with the  government bodies that control lighthouses and actually find out how many birds are disoriented or killed. Jones and Francis (2003) note deaths of up to 2000 birds in a night at a single lighthouse. There are a number of factors that contribute to increased mortality, including cloud cover, bad weather and phase of the moon. Apparently fewer mortalities occur towards the full moon. Birds are also attracted and killed at flares on offshore oil rigs. The use of green and blue coloured lights may reduce the number of bird mortalities. (More here )

Luminous fungal colonies (via Earth3D 1.0.5)
What could an excess of light at night do to humans? Probably hard to do controlled experiments but work on mice shows that they can become obese. Anyway the people who have been most affected by light are the astronomers. The only country in the world to apparently have an advanced light pollution law is Chile and this is led mainly by the large number of astronomical observatories in the region. Light pollution standards may also exist in Australia and the Czech Republic includes light pollution prevention in its law on protection of the air ! (Teikari 2007) The picture of the world by night makes it clear that many countries need better management of their lights. Like sound and noise, light pollution is probably a lot tougher to control as its effects are not obvious or readily visible. Worse still is that almost everyone is an offender.

So make sure you switch off those lights early tonight. Good night.

Further reading

Postscript
Since writing this, I have found some rather old references to the use of lights in trapping birds.
Lanciatoia, an Italian hunting method
"In the south of Spain the practice of taking Larks and other little birds with bell and lantern supplies the markets with myriads of small fry. Mr Abel Chapman has referred me to his charming work, "Wild Spain", in which he says that the engines of the fowler are the "Cencerro" or cattle-bell and the dark lantern. "As most cattle carry the ' Cencerro' around their necks, the sound of the bells at close quarters by night causes no alarm to the ground birds. The bird-catcher, with his bright candle gleaming before its reflector and the cattle-bell jingling at his wrist, prowls nightly over the stubbles and wastes in search of the roosting birds. Any number of bewildered victims can thus be gathered, for Larks and such like birds fall into a helpless state of panic when once focussed in the bright rays of the lantern". There was a time in "Merrie England" when the right of catching Larks by such means was so highly valued as to be restricted in practice to the owners of land. The title of "Low-belling" was employed to distinguish this variety of fowling from other methods. (Macpherson HA (1897). A history of fowling. Edinburgh: David Douglas. p. 60)
Fowling at night from a book edited by A. Philippo Gallaeo with art by Jan Van der Straet [=Joannes Stradanus] (1596) Venationes   Ferarum,   Avium, Piscium. A copy of this treatise on hunting can be found on the wonderful French digital library. 

Post-postscript (20 February 2011)
While reading a book on the origins of phrases, I discovered that the phrase "beating about the bush" comes from the old practice of bat-fowling. The trappers who went at night were accompanied by those with long sticks who beat about the bushes to put the birds to flight.

19 September 2018 - larks were apparently also captured with mirrors!
Forty thousand larks are delivered in London every day for table purposes. Quite as many more are sacrificed for the sake of their feathers. And how are they caught? Smearing the branches of trees with lime, if slow, is an easy way of catching birds. A revolving mirror worked in the sunlight from behind a thick bush attracts all birds. They fly against it, are stunned, go to rest on neighbouring trees, the branches of which are limed; and the rest is easy. Another trick is to release a bird with a long limed rope attached to it. When others approach this birds (says the London Mail) they also become captives. This stuffed owl is thickly limed all over, and small birds that come to mock it cannot detach themselves from its feathers. - Dundee Evening Post 20 January 1903 p. 6

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    Saturday, December 25, 2010

    Itchy backs and tickly toons

    Robert William Wood
    Some years ago, I had been to the Brahmagiris in Coorg. The rolling sholas are spectacular and it has a way of bursting into view with special effect that is enhanced by the climb that one has to make. Anyway in the weeks after  my return returned, I developed an itch on my back with eruptions on the skin that kept made me miserable for almost two months. The dermatologist I went to tried out antifungals, antibacterials and when the right remedy was found it quickly subsided but it did raise doubts about the quality of medical diagnostics. When I mentioned this to my birding  physician friend Dr. NS Prashanth, he mentioned that it should have been quite easy to identify a fungal infection using a Wood's lamp, something that every doctor would apparently have in their kit. A Wood's lamp essentially produces ultraviolet light and some fungi glow in UV. The process is termed fluorescence - the fungi convert light in the UV range into light in the visible wavelengths - and should not be confused with bioluminescence which is also seen in some fungi. Wood's lamp is just like our everyday "tubelight" (technically a fluorescent tube - a glass tube internally lined with a fluorescent chemical) but made of a special glass called Wood's glass. Wood's glass is made of Barium silicate with nickel oxide - which makes it very opaque to visible light but letting UV through.
    First published in 1907 the introduction reads:

    For some are guided by tradition.
    While others use their intuition,
    And  even I make no pretense
    Of having more than common sense
    Indeed these strange homologies
    Are in most flornithologies,
    And I have freely drawn upon
    The works of Gray and Audubon,
    Avoiding though the frequent blunders
    Of those who study Nature's wonders.

    Looking up, thanks to Wikipedia for showing the connectedness of things , I found that this Wood was  Robert William Wood (May 2, 1868 – August 11, 1955), a physicist who had a keen interest in UV and IR photography. He also apparently was debunker of frauds and when the journal Nature sent him to investigate something called N-rays he did the little trick of removing a vital prism in the experiment and the discoverer of the rays was still able to produce unaltered results demonstrating plainly that the setup was fake.  Wood liked to amuse people and one trick was to carefully toss sodium into a pond and act as if he was spitting to shock onlookers with explosive  effect ! H L Mencken apparently called him the "wild man of Baltimore" ! Strangely however I had already bumped into his Lear-esque verse and cartoons, long before learning about his other achievements. Pure entertainment that he created to amuse his children, but may well reflect to some extent the poor opinion that physicists in that era tended to have of biology. Indeed one physicist famously compared biology of that time to stamp-collecting. Wikipedia has an article on the "Nature fakers controversy" where this work has been pointed out as a parody of a long controversy at around that time in the United States of America that arose from the conflict between science and sentiment in popular nature writing. The controversy was due to a large number of nature writers of the time conflating fact and fiction. For instance one writer talked about birds applying a mud cast to their legs and another wrote about wolves hunting caribou by tearing their hearts out. This was finally settled and even involved Theodore Roosevelt, their hunting President, who decided that such fake writing should not be included as part of the compulsory reading for children. One protester even wrote a letter to Roosevelt to remove other "fake natural history" such as that written by Charles Darwin !

    A pick below of some of the pages (thanks  to the Internet Archive) from Wood's satirical book follows.





















    References
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    Tuesday, December 21, 2010

    Great observers - Ernest Hanbury Hankin

    Never heard of E H Hankin? You can be excused, for neither had I, until this morning when Colonel Ashwin Baindur dropped his name. Searching around, looking up some bits and pieces at the end of the day I have to decided that he belongs on a pedestal along with so many other lesser known greats.

    To start with Ernest Hanbury Hankin (February 4, 1865 – March 29, 1939) studied medicine and came to India to work in the United Provinces (now still UP) and was perhaps among the first to detect the activity of bacteriophages - he noted (in 1896) that there was something in the river waters of the Ganges and Jamuna that passed through filters but was destroyed by boiling and seemed to kill Vibrio cholerae . He suggested that these may have been responsible in reducing the ravages of Cholera in that area. Phages were finally "officially" discovered by Felix D'Herelle in 1917.

    Anyway, Hankin did not work further on that front and phages continue to be a field that has a lot of promise but is perhaps supressed by legal frameworks which in turn are perhaps supported by the pharmaceutical industry. Imagine having a drop of water with a few viruses instead of buying antibiotics ! If you have heard about the practice of adding Potassium permanaganate into wells, that was a technique popularized by Hankin to manage cholera and typhoid.This practice led to the emergence of an Anglo-Indian term of everyday usage "pinky pani".

    Around 1911 Hankin took an interest in observing birds and the detail of his observation can be found in his careful illustrations. These were first published in Flight - the first aviation magazine and in 1914 he published a book on Animal Flight. He restricted himself to making insightful observations and comparing notes with what he knew on anatomy and noted that he was handicapped by his lack of knowledge on various aspects. He looked up specimens at the Bombay Natural History Society (that was in an era when that organization did allow interested people to study their collections!)

    He begins his 1914 book with a quotation from someone who signs as A.O.H. (easily determined as A O Hume - and this was perhaps at a time when he was under the sway of the theosophists - although later separating himself after exposing Madame Blavatsky)

    A writer who signs himself A. O. H. watched vultures in Simla at a height of about 7000ft. in the Himalaya Mountains. He states that these birds start their flight in summer between six and seven o'clock in the morning, but in winter not till nearly nine o'clock. Their usual speed of flight he estimates to be from twelve to fifteen  miles  an   hour, the  lowest speed of gliding to be seven to eight miles an hour, and the highest twenty-six to twenty-seven miles an hour. The species observed was Gyps himalayensis, a vulture of 9ft span. When gliding in a straight line for miles the only movement shown by this vulture was an occasional and gradual "shift " of the tail. He says that crows can soar rising in circles without flapping, but that they do so only when the air is quite calm. He states that soaring flight is due to "levitation." This is a miracle or conjuring trick in virtue of which a man can remain unsupported in the air. He says that it consists in "so altering the magnetic polarity of the physical frame that in lieu of being attracted it is repelled by the earth." This power is achieved by "living an absolutely pure life and intense religious concentration." Birds are endowed with this power, apart from such mental exercises, unless, it may be suggested, the hill crow finds it helpful to indulge in irreligious sentiments when trying to descend to earth without  the help of gravity.

    Others, having a clearer idea of causation, have attempted to show mathematically how soaring flight could he explained if the wind has a certain upward trend, or if the air is subject to horizontal pulsations. Such theories have been put forward as possibilities. They are admittedly not based on facts of observation, although, by some, they have been mistaken for established doctrines. But, as will be seen, the study of soaring flight brings us face to face with an extremely complicated series of phenomena, and there it room for doubt how far these simple mathematical conceptions carry us towards an explanation.
    A selection of illustrations
    What captures ones attention is the careful attention, observation and illustrations that he made of soaring birds. He then goes on to compare certain actions and postures with the musculature involved. He notes for instance that there are no muscles in birds that allow the phalanges to be pressed down to enhance the camber. He notes that this is present in flying foxes. His area of research seems to be the exploration of what is today called dynamic soaring and is presumably much better understood. Indeed hang-gliding enthusiasts today have a feel for the subject that would be have been much the envy of Dr. Hankin. In March 1923 Time magazine noted:
    People on a London common saw a strange sight—an elderly gentleman playing with a toy aeroplane. He was Dr. E. H. Hankin, M. A., D. Sc., author of Animal Flight (a book dealing with the science of living flight), and he was experimenting with a model glider.
    A vulture coming in for landing - at the final stage the flapping is directed forward to brake

    When Hankin returned to England, he was also amusing himself with geometrical patterns. He was especially interested in the patterns in the trellis work of Fatehpur-Sikri and Sikandra. And so this multifaceted doctor turned his attention to tesselations comparing Mughal, Arab and Saracen patterns. He especially seems to have taken an interest in non-repeating tile patterns (Penrose tilings) !

    Hankin's works are not very well known, but it is clear that he had a lot of time to think. He seems to have spent a lot of time on thinking about education. In one study he noted the upbringing of Quakers and suggested that their emphasis on intuition rather than excessive conscious logic helped them in making scientific advances. His statistics for that time period indicated that one had a 46 times greater chance of being elected Fellow of the Royal Society if one came from a Quaker upbringing ! He later wrote several books :
    The first I can only find a reference to (PS July 2014: now online and linked above) is referred to in a 1926 issue of the "Proceedings of the Stanford Conference on Business Education" where the author notes:
    There is a little book which I think every business teacher ought to read, by a man named Hankin, in England. It is entitled The Mental Limitations of the Expert. A revision and enlargement of this book has just been published by E. P. Dutton, with the title Common Sense and Its Cultivation. Mr. Hankin is an expert himself, an expert chemist in the British foreign service in India. To have a thinking Englishman live in India is significant. He has time to sit down and think, and some excellent work by Englishmen has come out of India. Among the illustrations that Mr. Hankin gives of expert limitations is this.

    He says that, in a certain section of India, a certain caste had developed a high degree of financial ability. The people of this caste had handled banking and financial affairs of that region continuously and almost exclusively. For many years it had been one of the standards of this caste that their children should not attend school. They learned the multiplication tables by units and quarters up to 50—as 49% times 23%. They had most accurate memories for this most complicated of multiplication tables. Everything else they got by intuition and apprenticeship.

    Then the English came in, and English education became the vogue. About fifty years ago this tribe began to take to English education, formal education.  Today, Mr. Hankin says. they have almost entirely lost their place of dominance in finance, and it has been taken by another caste, which adheres to the old type of education. By their English education the former controllers of the financial situation lost their intimate contact with things, the intimate try-outs of experience, through which they had been getting something which had made them dominant; and when they lost it they lost their dominance.
    Fortunately for us, Hankin died more than 70 years ago and so his works are now in public domain under most jurisdictions.

    References
    • Alexander Sulakvelidze, Zemphira Alavidze, and J. Glenn Morris, Jr. (2001) Bacteriophage Therapy. Antimicrobial Agents and Chemotherapy. 45(3): 649–659. doi: 10.1128/AAC.45.3.649-659.2001.
    Postscript
    Anyone lucky enough to have access to the Cambridge archives might be able to find a portrait of the man  (H62) and perhaps someone will be able to persuade them to release at least a low resolution version into the public domain.
    Hankin aged 35
    February 2014 - an email to the Cambridge Antiquarian Society received a very prompt response and thanks to Dr John D. Pickles, Honorary Librarian, we now have a copy of perhaps the only portrait of the man. Here it is in full glory. A crop is available on the Wikipedia article.


    Additional 
    Apparently some people make use of this bacteriophage story to add "scientific" weight to the idea of the purity of the Ganga. This, naturally is a bit of a misrepresentation, and it may dismay them to note that  most bacteriophage hunters today find the choicest phages in hospital sewage (often including phages that kill antiobiotic resistant bacteria). This inappropriate understanding of research findings encourages the status quo attitude of governments and people to assume that it is fine to dump garbage and sewage into these undoubtedly wonderful rivers because of their "miraculous" ability to recover from such abuse.
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    Saturday, December 11, 2010

    Life on a raft

    A friend recently approached me for some mapping help and this led me to rediscover some old tools (DIVA-GIS is one of the best free map tools that I know of) and forced me to look back at some recent thoughts. Generating a false-colour altitude map of the Indian Subcontinent heightened my appreciation of some observations and recent readings.
    Elevations of India (click to see detail and legend)

    Most people, even birdwatchers, often do not appreciate the peculiarities of species distribution and those that do not have the fortune of having a training in biology miss out entirely on the joy of mental stimulation that one gets when one tries to ask more questions.

    On the border between northern Bengal (Jaigaon) and Bhutan (Phuntsholing) one can see an interesting phenomenon. Just walk into Bhutan and you see (apart from fewer humans and orderly traffic) that there is a lot of grass and vegetation and after walking up the first bend of the road you will find the commonest sparrow to be the Tree Sparrow, a species that simply refuses to accept life in India a few 100 metres away ! Along the busy roads of Jaigaon, only the House Sparrow may be seen, although it is also found on the Bhutan side. There is a difference in their habitat preferences and the Tree Sparrow seems to be the more picky species. Tree Sparrow do not have the marked sexual dimorphism that is found in the House Sparrow. When the two species occur in the same place, there is little confusion, but hybrids are known although they perhaps need further study. For instance, the only place where they are said to hybridize in India is not in the main distribution area but in the Eastern Ghats of Andhra Pradesh. The hill forests here are perhaps the least studied of the numerous biogeographical islands within India. The evidence for this supposed hybridization is not even well known - P. C. Rasmussen in her Birds of South Asia (2005) mentions this (presumably based on a specimen that shows hybrid characters) while Clement et al. (1993) (full references can be found on the Wikipedia articles) suggests that the species was introduced by ship to this part of India !

    A painting by Bhawani Das (c. 1777)

    Looking at the false-colour altitude map one can see a sharply delineated region in the Gangetic plains of Bihar in the altitude range of 50-100 m which corresponds to the region with the most records of the most-likely-extinct Pink-headed Duck. Now we do not really know much about that species, it may have lived in dense swampy wetlands and may even have been crepuscular in habit. Now we do not know about the habitat choice, behavioural or ecological adaptations evolved by this species and sadly perhaps, we will never know.

    Considering this, one would imagine that we are better off when it comes to species that are not endangered but this just is not the case. Indeed, few have even really looked at the information available, not so much because they cannot, but because much of the information is scattered and it involves considerable work and trouble to bring together the data in a single location to even begin to examine for patterns. Often the tools required can only be handled by specialists and getting them to work across disciplines can be  daunting given the splintered scholarly ecosystem where academics carve niches outside of which they fear to step. Like mixed-species flocks of birds, interdisciplinary associations must be a tricky balance. A pleasant surprise however comes in the recent work on the  isolation and speciation of two high altitude birds from Southern India - the Rufous-bellied Shortwing and the White-bellied Shortwing. - these birds, whose exact higher level relationships are still shrouded (the genus placement remains questionable with scientists merely guessing that it should be close to the Himalayan Myiomela),  appears to have had ancestors that were widespread when the climate was a lot cooler. With changes in climate, populations were pushed up into the higher reaches of the hills of Peninsular India. Not being strong fliers , these birds were restricted into breeding locally within their own little pools (or beanbags )  and over time, these populations diverged in form, shaped by accident and selective forces into forms that are very different in plumage.

    Disjunct distribution of Nephenthes

    Now this is not an isolated incident, it is the norm although the isolation mechanisms and forces are harder to identify in other cases. Looking at the islands formed by just plotting altitudes, it is clear that that numerous other studies of this kind could be made within India and naturally "islands" can be created by any kind of barrier. The effects depend on the mobility and the evolutionary history of the species under consideration. Look at this distribution of pitcher plants in the genus Nephenthes for instance. It is well accepted that the Indian Plate rafted away from Gondwana into Asia but lots of debate exist on the timing and presence of bridges. These debates are largely raised by fossil evidence or surprising discoveries like the Purple frog. A recent talk (and paper) at IISc by Prof. Ashok Sahni was particularly interesting - working in an isolated island of scholarship in northern India, his team has looked at insects in Indian amber dating to the Eocene  - apparently there are tons of these fossils in lignite mines and they are usually just destroyed. And the wealth of information trapped there is being looked at - by the worlds leading  paleo-entomologists including David Grimaldi . Apparently the endemism levels in insect are high for India as most of  the insect fauna got onto the raft from Gondwanaland. These fossils come from after the K-T incident (65 million years ago).

    Coming back to thoughts of Bhutan - the White-bellied Herons, 36 or so individuals - that live on the edge in the lower valleys of the Himalayan rivers surely have an interesting specialization, found only on the  lower elevations on rivers running southwards along the edge of the Himalayas  they are seriously threatened by dams that are needed mainly to power the growing populations of India. The world population has been optimistically estimated at 200 and as the bird-folks in Bhutan say - one hopes that the supposed 150 more birds in Burma are safer. And Burma is also the the last hope for the Pink-headed Duck.

    Further reading

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