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.

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