Super Perigee




On Friday morning, while biking to work alongside a couple of Garden Street joggers, the sweet sound of a cardinal’s song made me take notice. It was the first cardinal song I had heard in 2011. When I drove through Mt. Auburn cemetery today, most cardinals were silent, but a couple did sing in anticipation of spring. In March and April, I go to the cemetery oftener than usual because the birds start singing and the warblers arrive, and they are easier to find because there are no leaves on the branches yet.

But, this post is about the black-capped chickadee, Massachusetts’s tiny state bird, about which I’ve been reading lately in Birdsong: A Natural History, a lovely book by Don Stap. Chickadees are named after their call “chick-a-dee-dee-dee” , made by males and females and easily heard in many wooded areas in the US. Less well-known is the song of the black-capped chickadee, a whistled “fee-bee-ee”.

Nearly all songbirds learn a song with a basic structure and some small variations. These variations tend to be peculiar to the area in which the bird is found. For example, song sparrows in California make a slightly different sound from those in Massachusetts – a sort of avian dialectic variation. There is probably an evolutionary explanation to this – a bird with a slightly different song, or a larger vocabulary of songs is more likely to find a mate. Now, it so happens that chickadees are unique among songbirds in one aspect of their song. Male chickadees all over North America have the same song! The same whistled “fee-bee-ee”, also referred to as “hey-sweetie”. This is striking because it is so rare: a black-capped chickadee in Montana sings the same pattern of notes as that of a chickadee in Massachusetts.

That was the conventional wisdom, until Prof. Don Kroodsma of the University of Massachusetts found exceptions to the rule. Kroodsma is the author of The Singing Life of Birds: The Art and Science of Listening to Birdsong. He noticed that, on the island habitats of Nantucket and Martha’s Vineyard, some black-capped chickadees sing the inverted “sweetie-hey” or “sweetie-sweetie” instead of “hey-sweetie”. I’m not far enough into Stap’s book to know why this is the case, but was intrigued enough to pay closer attention to a chickadee song the next time I heard it. Indeed, today, as I stood observing chickadees, cardinals, titmice, nuthatches, sparrows and red-winged blackbirds partake of a feeder’s bountiful supply of birdseed, I perked up my ears as sounds of “hey-sweetie” punctuated the numerous “chip”s and “chuck”s made by the various birds.

[Link to “hey-sweetie” sound from Audubon Magazine’s website]

Then, from a tree behind me, came a different chickadee song. I am sure that, if I hadn’t been reading that particular chapter from Birdsong, I’d have clubbed it with all other chickadee songs that I was hearing. To make sure that my mind wasn’t playing tricks on me, I (fumblingly) tried to record the sound on my phone. And since the WordPress mercenaries will not let me add the audio unless I pay them, I have to link to a  horribly jerky video that I’ve put up on Youtube. To prevent vertigo, I urge you to close your eyes and listen only to the sound :). You may need to turn up the volume.

Does it not sound unmistakably like “sweetieeee-hey”?! Now, the funny thing is, even though I hear it as “sweetie-hey” and sometimes “sweetieee-sweetie”, it is quite different from the Martha’s Vineyard chickadee recording that Audubon Magazine has on its website. For my chickadee from Mt. Auburn, there are two distinctly audible kinks in the sound while the recording from Martha’s Vineyard has one audible kink and one extremely subtle kink that would only be discernible in a sonogram.

[Link to “sweetie-hey” sound from Audubon Magazine’s website, and the accompanying sonogram.]

All this begs the question: Was I listening to a chickadee that has wandered over from one of the islands? But Don Stap writes that they don’t like water crossings and will try to avoid them when necessary. Or is the first kink in the audio just an aberration? Or, have I just been over-excited by this particular sound, which is one of the known versions of the mainland US black-capped chickadee song that I am unaware of because my experience with birdsong is so limited? I’m wondering: should I send this to Mass Audubon for clarification?

Happy Birthday, Carl: A personal tribute

The Cosmos is all that is or ever was or ever will be. Our feeblest contemplations of the Cosmos stir us— there is a tingling in the spine, a catch in the voice, a faint sensation, as if a distant memory, of falling from a height. We know we are approaching the greatest of mysteries.

-Carl Sagan.

In 1980, Carl Sagan created a TV series for a general audience about the universe and how it came to be. Made at a time when special effects were feeble compared with what is possible today, Cosmos aired on PBS and became an enduring classic, thanks largely to Sagan’s extraordinary gift for explaining science to the layman.

To my knowledge, Cosmos – the TV series – did not make it to India’s national network. The book, however, became available in bigger cities in the early 90s. I remember going to a bookstore in Pune’s Cantonment Area with my pockets stuffed with the money that my parents had given us to buy books. I think it was the largest sum of money I had ever carried in my pocket, and remember feeling that I had better spend it on something good. We bought many books that day, only two of which I remember. One was Gone with the Wind; the other was Cosmos. It took a lot of effort for me to read Gone with the Wind, and I don’t think I finished it entirely. But I read Cosmos from cover to cover. Then, I read it again.

Many times, I would read the passages aloud at home to share them with my mother and we would both shake our heads in happy disbelief. How could someone explain science so beautifully and eloquently? It was one of those times when one is galvanized and desperate to do something. While preparing for the pivotal Grade XII exams, I made up my own English Composition titles just so that I could write essays extolling the “immensity” and the “eternity” that Sagan spoke of. These were strange pieces, much longer than the minimum word limits, giddy with exhilaration, drunk on Sagan; raging with all the arcane facts that came gushing to me from my middle-school experience of writing and illustrating a personal astronomy book that couldn’t go beyond Saturn.

With Cosmos, I embarked on a meandering, somewhat arbitrary but extremely satisfying journey in scientific non-fiction. I read almost all of Sagan’s books, relishing The Dragons of Eden, Broca’s Brain, and Shadows of Forgotten Ancestors. With each book, I discovered more and more of what Sagan called “the romance of science.” I like to think that I imbibed a little bit of it, that it played a part when I decided to pursue graduate research. Later, in my own personal voyage, I would discover Russell and Feynman and Dawkins – all debts that I owe to Carl Sagan.

It was only in graduate school that I finally found out that Cosmos was actually based on a TV series. One day, deflated by the grueling midterms that I never got used to no matter how many courses I took, I went to the university library to unwind, and on a whim, asked for a video cassette of the first episode of Cosmos. Since I didn’t have a TV, I had to watch it in the library, so I asked for headphones and went to a room in the back where you could pick a TV set with a VCR and privately watch your video in the comfort of a well-worn sofa-chair. This was how the series began; this was how I heard Carl Sagan speak for the first time.

The room was very dark and and people were separated from each other by a dozen feet of space and by the virtual worlds on their screens. It was just as well; nobody saw me wipe away a silent tear.

Two years after the heady winter of 1994 when I first read Cosmos, Carl Sagan would die of an uncommon disease of the bone marrow. He would have been 74 years old on November 9.

[Note: The video preview linked above was uploaded by threedotsdead, a youtube user.]

A Truly Fascinating History

When a friend recommended that I read Guns, Germs and Steel, I commented cavalierly, without having read a single word, that the book seemed like an oversimplification: How can one possibly account for all the twists and turns and blind alleys of human history? Now, as I race through the pages of Jared Diamond’s monumental work, I could not be more ashamed of myself. Subtitled “The Fates of Human Societies”, this large, and often dense book describes, through the lens of an evolutionary biologist and biogeographer, the fascinating journey of man on earth. Its claimed objective is to try to explain how today’s world came to be, with its glaringly unequal divisions of haves and have-nots. Diamond explains, painstakingly and precisely, why some societies became overlords while others remained primitive or vanished; why some people preferentially reaped the benefits of Guns (conquest), Germs (disease) and Steel (technology).

Jared Diamond is a professor of geography at UCLA. His first love, however, is ornithology. It was the study of bird evolution that took him to Papua New Guinea, where a local politician put to him the question that was to germinate into his Pulitzer Prize-winning book: “Why is it that you white people developed so much cargo, and brought it to New Guinea, but we black people had little cargo of our own?”

The first step that Diamond takes in answering this question is to explain why he thinks it is necessary to answer it at all. Having explained this with a nuanced, delicate perspective that is increasingly lacking in much of the scientific nonfiction today, the writer proceeds to dispense with simpler explanations such as “X had superior technology and superior weapons” or “X developed education and language and trade”. These explanations, Diamond says, are only proximate, and a scientific inquiry into history must ask the question “Why is it that  X developed technology and Y didn’t?”

As one reads more and more of this book, it seems ludicrous that anyone can attribute the unequal distribution of wealth, technology, language, etc. to genetics. Yet, rationalizations such as “People from continent A have higher IQs than those from continent B, and this correlates with differences in their genes” abound in people’s minds. These thoughts are not often expressed because they would be considered indecent. One does not have to be a post-modernist (though it would certainly help in this case) to point out that an IQ test in society A is designed to test intelligence according to the conventions and culture of society A, and therefore said IQ test is not a good metric for society B. Recently, James Watson got into hot water when he made comments about Africans having inferior intelligence than Europeans. It is presumptuous to conclude that Watson was motivated by the racist sentiments that many people accused him of, but it is clear that if the difference in IQ test scores is not a good indication of a difference in innate intelligence, then the point about causative genetic differences is moot.

The method of Guns, Germs and Steel is to keep asking the “How and why” questions until they lead to one answer: The difference between the fates of human societies was caused by a difference in the environment in which those societies lived. This thesis seems simple and anti-climactic, but reading about the details is truly fascinating. I have read half of the book so far, and have been completely enthralled by Diamond’s explanations of the change in lifestyle from hunting-gathering to farming and the domestication of herbivores. How did man, at first unconsciously and later deliberately, influence the evolution of certain plants? Why is it that man took so long to farm apples? Why is it that over 13000 years, humankind has succeeded in domesticating only 14 large mammals? How did previously detrimental mutations turn into blessings for some crops, aided by the human hand, while previously beneficial mutations became excuses for extinction? Diamond answers these and other questions while being careful to evaluate the strength of the scientific evidence for those answers. One of the most intellectually rewarding consequences of doing science – or reading about it – is that a discovery (whether firsthand or not) causes something to “click into place,” that mental “light-bulb-going-on” effect. Reading Guns, Germs and Steel is akin to walking the road of history and discovering markers and lights – not too many, but just tantalizingly enough to enable us to connect the dots.

A book that attempts to compress 13000 years into less than 500 pages is bound to favor broad patterns over spatially and temporally specific threads of human history. Some of these hypothesized broad patterns, such as the role of the orientations of continental axes, are likely to be very speculative. Experts in modern (recorded) human history can easily give specific examples from the past 5000 years which point, not to the environment but to the role of culture and politics in the unequal distribution of wealth and power, and in this they are right. However, I feel that, if one is interested in the basic framework underlying the elaborate tapestry of history since the Pleistocene Era, Jared Diamond’s book is a superb accomplishment that is definitely worth reading.

If you are strapped for time, you might consider watching National Geographic’s TV series on the book. I wouldn’t judge the book from the TV series, but it would be a good first approximation. As of this writing, the program is available in 18 parts on YouTube.