Sunday, 12 July 2015

Superb camouflage

Superb camouflage

While studying waders in northern Norway I was repeatedly impressed by the adaptation of these birds in their use of camouflage as their main defense from predators. Camouflage only works well if an animal does not move, relying on their cryptic plumage patterns to conceal them until the very last moment as potential predators, including humans pass by. This tends to make them rather difficult to study.

A Broad-billed Sandpiper hides amongst sedges

One species of wader which breeds in mires on the tundra is the Broad-billed Sandpiper Limicola falcinellus and they are very easily overlooked. These birds, about Starling-size, forage on mats of sphagnum moss on the edge of mire pools, creeping through the sedges. Their plumage has a background of dark browns like those of the muddy surface, with pale stripes that resemble the blades of the sedges. They match their habitat exactly.

Easier to see if you can pick out an eye

And if you think these are difficult to see, try to find the bird in the next photograph.

A Jack Snipe lies quiet amongst the sedges
Another species that lives in these mires is the Jack Snipe  Lymnocryptes minimus. Their plumage is like that of the Broad-billed Sandpipers, and the birds are of similar size. These two unrelated species have adapted similar plumages and behaviour, and they breed successfully, so their convergent evolution is evidence of the effectiveness of their survival strategy.

Even when seen close up they are not easy to discern

As I look down on these birds and admire their adaptation to their habitat, I often think to myself, how many have I walked past?

From above, the stripes on the Jack Snipe resemble the pale old leaves of the sedge

I study many cryptic species, but these waders are some of the the trickiest birds to find, they are true masters of the art of camouflage.

Once again, if it weren't for the eye....

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