Dazzled and deceived

Thanks to a recent British library membership acquisition, I got hold of this book by Peter Forbes – Dazzled and deceived: Mimicry and Camouflage. The book effortlessly leads the reader through a journey that begins in earnest with the comma butterfly flying across a garden and slowly winding its way through personal lives of luminaries in biology, through the private struggles and public lives of the proponents of various sorts of camouflage for both sides in the two world wars, artists and naturalists. There has been much talk about the role of camouflage nets in the winning of the Second battle of El Alamein in World War II. The battle was quite important – it got Churchill to apparently ring bells all over Britan, signifying the impending end to the war.

Tanks disguised as trucks in the Battle of El Alamein. Camouflage inspired by animal models were big during WW2.

Some of these people are very well-known, at least to biologists. The correspondence between Henry Walter Bates and Alfred Russel Wallace and their journey together and apart in the Amazons, and their pre-occupation with trying to explain why among such a diversity of butterflies (over 700 species), there were uncanny similarities between apparently unrelated species of butterflies makes for interesting reading.

The Viceroy butterfly (above) which is non-poisonous and “bland tasting” and potentially a prey is also avoided because it is similar to the toxic and bitter tasting Monarch butterfly (below) – one of the best known examples of Batesian mimicry

Here begins an interesting question that fascinated biologists on one side and inspired artists on the other. Many such models of mimicry are found in nature and our own Kallima is perhaps the best example, often unspottable among the leaf litter. Darwin and Bates had hypothesised based on their observations that the “odourless and palatable” Leptalis might be mimicking the boldly patterned and brightly coloured Heliconius, which advertises its bad taste with bright colours and patterns. Much before genes were known of, or even named such, the explanations and experiments to understand the evolution of mimicry progressed fast. Tempers ran high in those days – biologists even tasted a few Heliconius to prove their point, with a bitter taste in their mouth(!). One of these was Thayer, to whom Forbes dedicates at least two chapters to. Apparently, Thayer is the only(?) artist to have a law named after him – Thayer’s law of countershading. Thayer turns out to be a very interesting character. Suffering from what he himself called “Abbott’s pendulum”, he had terrible mood swings (because of his bipolar disorder) and the fact that these moods often caught him in the middle of passionate wartime advocacy did not help matters. His passion for countershading became so severe that he was publicly rubbished by (among others) Theodore Roosevelt. Here’s one such response to Roosevelt by Thayer.

The underside of the Orange Oakleaf, found in many parts of India is a superb example of disguise

 For my assertion that white on objects’ upper slopes, under an open starry sky without the moon or any artificial light far or near, is an absolute match for the sky, Col. Roosevelt can hardly find words to express his contempt, saying many things which must some day look very funny to him when he finds out his error.

It turns out that Thayer was extremely convinced that white upper coloration is one of the best camouflages to provide to anything in the sun. Roosevelt brought to this debate, his own hunting experience from African trips and indeed was invoking sexual selection arguments in days when it was out of fashion – as summarised by Norman Johnson here.

A photograph of two model ducks, the right countershaded and camouflaged and the left just camouflaged.

The two world wars provided plenty of opportunity for biologists and artists to cross swords at war offices, where they invoked various laws and rules of nature to help hide ships or disguise buildings. A British artist, Norman Wilkinson has been credited with being the first to show how to hide ships using dazzle camouflage, although he had to win this recognition after a legal battle. His painting Plymouth harbour sank with the Titanic. Initially, devised to decrease ship damage from torpedo attacks from German U-boats, the coloration was inspired by the sort of patterns seen on zebras. Apparently, the discuption caused by the lines and patterns which breaks the shape of the object makes it very difficult to even predict which direction the object is moving making it difficult to target during wars. See this boat from Arnhem for example.  More recent work by marine biologists has confirmed similar observations in cuttlefish and other marine fauna.

The book has so many other colourful descriptions of colourful characters – people included. Peter Scott, John Cott, Jonathan Kerr and of course the “other” mimicry scientist (other than Bates), Fritz Muller, of the Mullerian mimicry fame. Interesting accounts of Vladamir Nabokov and his early history are also provided, as are the details of letter exchanges between Bates and Darwin. Hugh Bamford Cott is credited with coining the term “arms race” to denote the adaptations and counter adaptations such as in predator-prey who are engaged in a continuous shruggle of “bettering” the other. Cott’s explanation of mimicry and camouflage is indeed simple and elegant. He saw three main categories – concealment, disguise and advertisement. His application of these categories to explain a lot of observations across diverse species is apparently still the best available book on the topic – Adaptive cooluration in animals. The work of Miriam Rothschild, a code breaker for the top secret German Enigma code, based out of Bletchley Park, in unravelling the origin of the toxicity of many of the butterflies through exploring which plants they got it from in the first place. She found that the imperviousness of butterflies to the toxins they imbibe from plants, is species-specific; she found this through rather difficult experiments of feeding some plant substances to unsuspecting starlings. Madam Rothschild’s contributions are many – finding out the mechanism of jumping among flies, setting up Schizophrenia research fund, and campaigning for the legalisation of homosexuality – and in the meanwhile writing 350 papers on entomology and zoology!

All in all, an amazing book that sends the reader in multiple directions – there are many I did not pursue – the cubists and their role in this discourse for example. Amazing research and scholarship and no surprises in the book bagging many awards and good reviews. Peter Forbes’ Warwick memorial lecture “Science morphing into Art” is a good teaser if you are considering the book.

And on a lighter note, if you want to try some dazzle for your scooter, here’s how it will look. As one of the comments says, this could be one perhaps to “confuse the navel artillery”. :p

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