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Most of us walk past a babbler or a garden lizard without a second look. M. Krishnan spent his life looking, then writing down exactly what he saw. This post covers who he was, what his observations added to Indian natural history, and how a student can practise the same habits.
Who was M. Krishnan?
Madhaviah Krishnan lived from 1912 to 1996. A Madras Musings article on his Tamil writings says he began writing in Tamil in the 1930s, while working in Madras and later at the court of the princely state of Sandur in present-day Karnataka. After Independence he turned down a government post to make a living from writing and photography, and switched to English. Until 1957 he also wrote regularly on birds, animals and the monsoon for Tamil magazines, illustrating each piece with his own line drawing.
The Government of India's Gazette notification of Padma awards for 1970 lists "Shri M. Krishnan, Naturalist, Madras, Tamil Nadu" among that year's Padma Shri recipients.
What made his observations scientific?
A centenary article in Madras Musings describes two kinds of work. One was technical: notes in the Journal of the Bombay Natural History Society on centipedes, the migration of the bar-headed goose, elephants and gaur in Mudumalai, saltwater crocodiles of Bhitarkanika, wild dogs hunting chital and more. With a fellowship from the Jawaharlal Nehru Memorial Fund, he completed an ecological survey of the larger mammals of peninsular India and published the results in the same journal.
The other was popular writing for newspapers and magazines. The article notes that many of these pieces held records valuable enough for technical journals, including what may be the first account of a mass migration of butterflies in India.
What did he notice before scientists measured it?
A review of the anthology of his writings, by ecologist M. D. Madhusudan (2001), points to a 1957 piece called "Cat Fight". Krishnan saw that kittens were safe with their resident father but that an unfamiliar tom killed two of them. Madhusudan observes that this described infanticide in animal societies years before it received formal scientific attention.
The centenary article adds that Ramachandra Guha credited Krishnan with anticipating "high-tech science" when he reported that elephants communicate with very low-frequency sound. That was later measured. In 1986, Payne, Langbauer and Thomas recorded calls from captive Asian elephants mostly between 14 and 24 hertz, lasting 10 to 15 seconds, and called elephants the first land mammals reported to produce infrasound.
Why can't we hear those elephant calls?
Here is a short worked example. Human hearing is usually taken to start at about 20 Hz, so much of the 14 to 24 Hz range sits at or below it. The wavelength of a sound wave is λ = v ÷ f. Taking the speed of sound in air as about 343 m/s:
At 14 Hz: λ = 343 ÷ 14 ≈ 24.5 m.
At 24 Hz: λ = 343 ÷ 24 ≈ 14.3 m.
Waves this long bend around trees and hills easily, which fits the paper's suggestion that such calls help elephants coordinate in thick vegetation or across separated groups. A common slip is to divide f by v instead of v by f. Check your units: (m/s) ÷ (1/s) gives metres.
What did he think was missing from education?
Madhusudan's review quotes a 1947 essay in which Krishnan wrote that "the average educated adult knows little or nothing of the teeming plant and animal life of the country," and blamed school education. Twenty years later, the review says, he asked a group of graduates to name two red-flowered trees or an animal found only in India, and nobody could.
You can take that as a challenge rather than a complaint.
How can a student build Krishnan's habits?
Keep a field notebook. Date, time, place, weather, and what the animal did. Sketch even if you cannot draw well.
Watch one species for a week. Crows, mynas, squirrels or ants at the same spot each day. Record what changes.
Ask one why. Krishnan suggested, in passing, that toads inflate to push out a repellent from their skin, not just to look bigger. Write a "maybe because" for each behaviour, then look it up.
Read the people who did this well. Compare Krishnan with Jim Corbett, who tracked tigers in Kumaon, and George Schaller, who studied tigers in Kanha.
When the physics behind something you observe, such as sound waves and wavelength, needs a clearer picture, the Fermi Simulation Lab has interactive simulations for ideas that are easier to see than read.
Start a notebook page today: one animal, ten minutes of watching, and three things it did that you did not expect.
