The plumage of birds comes in a variety of colours and tones, from exotic rain forest species to our rather plain dunnock.

All plumage has evolved for a purpose. Male and female of many species but not all, differ,with males sporting more flamboyant feathers for display and courtship whereas females are of necessity duller as they need to remain concealed on their nests.

Members of the crow family exhibit almost identical plumage as do male and female robins for example. At the wonderful London Wetland Centre our powers of observation are tested to the limit. 

For there, are two species whose cryptically marked plumage renders them almost invisible when not moving.The first is the most secretive bittern. The bird stands stock still at the edge of a reedbed often with head and dagger-like bill pointing skywards. Its quite amusing to sit in one of the hides and see keen birdwatchers training their telescopes on what appears to be a mottled brown blob in the far distance, but we are assured that the blob is a bittern!

The second bird is the common snipe with an outrageously long bill which has a flexible sensitive tip with which it 'feels' for worms and invertebrates in the mud.

With plumage delicately barred and streaked it remains motionless at the edge of the reeds defying us to spot it.

When feeding, it moves to open water (see photo) when its handsome plumage can be admired.

The snipe also performs a sensational courtship display, climbing rapidly to height then diving, its stiff outer tail feathers emitting a 'drumming' sound.

The Wetland Centre, voted by readers of countryfile magazine Britains favourite nature reserve is the place to see these and other fascinating birds.