Tag Archives: Hugh Cott

Camouflage Talk, Camouflaged Cakes

Today I gave my ‘Camouflage without Spots’ talk at Gunnersbury Triangle nature reserve. It was very hot, and having helped the RSPB local group set up their stall at the Bedford Park Festival on the common, I cooled off and picked up the materials for the talk.

Amazing Camouflaged Cakes
Amazing Camouflaged Cakes

Helen had set out the tables and baked some amazing Camouflage Cakes – someone joked they couldn’t see them – and we all had lemonade in the heat.

2 legs good, 4 legs better
2 legs good, 4 legs better: Tadpole Metamorphosis before our eyes

Once I had run through the talk and arranged the talk table with books and materials, I had a quick walk around the reserve. The tadpoles are just at the moment of growing legs – some have none, some two, some four: it’s very beautiful and touching.

A keen entomologist came running, a Clouded Yellow presumably blown in on the warm southerly wind had breezed across the reserve in front of the hut! They are only occasional visitors here, common enough in France, but they hardly ever perch when the weather is warm.

A Pompilid Spider-Hunting Wasp with prey ... on a sheet of paper in the hut
A Pompilid Spider-Hunting Wasp with prey … on a sheet of paper in the hut

A second entomological excitement: a Pompilid spider-hunting wasp was running rapidly about on some papers in the hut, dragging something white below her body. The photo shows what the naked eye could hardly perceive: she had a paralysed spider as big as herself in her jaws (a leg has broken off). She was presumably running about to find a suitable hole to bury the unlucky spider in, complete with one of her own eggs which will hatch and eat the spider as a supply of fresh, living food, enough to keep it going until it pupates.

Masked Hunter Bug, camouflaged with sand grains
Masked Hunter Bug, camouflaged with sand grains

A surprisingly large audience congregated for the talk, which looked at tricks that animals use to conceal themselves, often in plain sight. I demonstrated using painted cylinders in the fortunately bright sunlight how countershading works and why it is necessary; and how some animals like skunks and honey badgers use it in reverse to make themselves as conspicuous as possible. We all marvelled together at the wonderful camouflage of the Masked Hunter Bug, the Flat-tail Horned Lizard, and perhaps best of all the Potoo, beloved of Hugh Cott, motionless with its astonishing disruptive markings in the fork of a tree. I risked bringing out my copy of Abbott Thayer’s Concealing-Coloration in the Animal Kingdom, complete with his fine but sadly misguided paintings of camouflaged Peacock, Roseate Spoonbills and Wood Duck. He was right about the principle of countershading, and the superb disruptive plumage of gamebirds, though.

Then we had more lemonade and ate the camouflaged cakes!

See also the blog article that trailed the talk.

Book Review: Dazzled and Deceived, by Peter Forbes

Dazzled and Deceived: Mimicry and Camouflage, by Peter Forbes
Dazzled and Deceived: Mimicry and Camouflage, by Peter Forbes

The effect of natural selection on how animals look has attracted the
attention of naturalists from the birth of modern natural history, starting even before Darwin’s Origin of Species.

Visual appearance can affect an animal’s survival in numerous ways.
Camouflage makes it hard for predators to find a prey animal; warning coloration advertises that a potential prey is poisonous or distasteful; Batesian mimicry allows an edible species to pretend to be distasteful; and Müllerian mimicry allows a distasteful species to be sampled less often by young inexperienced predators, by resembling a more common distasteful species. And within these areas, there are infinite possibilities.

Butterfly Mimicry: mimics on the right, the imitated 'models' on the left
Butterfly Mimicry: mimics on the right, the imitated ‘models’ on the left

But as the cover art suggests, Forbes does not stop there.  Camouflage has military uses; and the history of two World Wars reveals extraordinary interactions between naturalists like Hugh Cott (author of the greatest twentieth-century book on camouflage, Adaptive Coloration in Animals, 1940) and Peter Scott with the military – Scott was a naval captain, so he had a foot in both camps.

Much of the book concerns the natural history and biology of butterflies – they include many of nature’s best mimics, and provide incredibly complex examples of visual evolution at work, as the mimic species adapts to each of the many geographic variants of the host or model species. It’s even possible for multiple forms to appear in a single brood. Forbes describes the research workers, their controversies and their heated opinions, right or wrong. Truth wins in the end, but that doesn’t prevent a messy process along the way, just as in evolution.

Today, new light is being shed on the mechanisms of mimicry and coloration in general by evolutionary developmental biology, which Forbes insists on calling “evo devo”. The result of such inquiry will one day be an explanation of the observed, very complex, natural history at multiple levels – genetics, developmental biology, visual appearance, and natural selection, all of which will have to fit together exactly. Pieces of the puzzle are becoming clear, as in the genetic and developmental mechanisms for producing eye-spots. These can be “impressionistic” – they do not have to mimic a cat’s face, as long as a wing-flash gives a bird predator an illusion of eyes-suddenly-jumping-out-at-me; for we suppose that birds have
an escape reaction triggered in some such way. Thus the explanation must take into account ecology too – the behaviours of both predator and prey are needed to explain why eyespots evolved.

Forbes can’t resist putting an artistic and literary take on the natural
history and science: Sir Ernst Gombrich the art historian was deeply
fascinated by visual illusion, while novelists like Vladimir Nabokov (a keen naturalist) were intrigued by truth and lies. Sometimes the analogies go rather far from natural history (electronic warfare is a case in point: it may be deception but it certainly isn’t visual). But Forbes is always precise, and invariably entertaining.

Buy it from Amazon.com  (commission paid)
Buy it from Amazon.co.uk (commission paid)