Sunday, November 19, 2000		Nature

FEMALES among lyrebirds are very particular about the cleanliness of their dwellings. Unlike many other birds, there is no permanent bond between the male and female. The male may have several mates who immediately after mating go off to their nests in their own territories, where they perform all the duties, from laying egg to raising young single handedly.

Females regularly remove their nestling’s droppings from the nest which is thrown in the nearby stream or pond or into a hole in the ground so they do not attract predators, besides keeping their nest clean. Droppings are easy to remove because they are enclosed in a transparent membrane.

There are two species of lyrebirds which are found only in Eastern Australia. These large, brown birds inhabit forests and scrub, feeding on small invertebrates. They build large, domed nests on the ground and usually lay a single grey or brown egg which is unusually resistant to cold and even during the initial days of incubation, it can be left unattended for several hours without being harmed. This enables the female to leave the nest to feed herself.

Lyrebirds are most accomplished mimics and they incorporate into their repertoire songs of other birds and any other sound which catches their imagination. Their song incorporates locomotive hoots, automobile honks, bell chimes, dog barks, horse neighs, laughter-like call of kookaburra (member of kingfisher family) and various other crashing and rumbling sounds, but they are interwoven so cleverly and beautifully that they sound melodious.

These birds have been given the name of lyrebirds because of one of their species, superb lyrebird, whose tail-feathers resemble an ancient Greek musical instrument ‘lyre’. This bird is not particularly beautiful, resembling a rather drab hen pheasant, but its beauty lies in its tail, which consists of two long delicately curved feathers which curve out and round so they resemble an ancient lyre. To add to the illusion, the area between these two immense lyre-shaped feathers is criss-crossed with a delicate tracing of fine white feathers that resemble the strings of the lyre.

Besides its tail, the bird’s courtship displays are too one of the most spectacular displays in the world to birds. When the mating season starts, the males choose an area in the forest which they then convert into a dance stage. They clear the area with the help of their strong feet and pile up the leaves in the centre of the clearing as a sort of stage. When everything is ready the male starts his displays. He sings and uses his tail to seduce every female within hearing range and even if the females are able to resist his tail, it is doubtful that they can remain unmoved by his song.

Males in these birds have a life span of about 15 years and their characteristic tail feathers grow during the first five to seven years. Other species of this bird, Prince Albert’s lyrebird does not possesses an attractive tail, it lacks two broad outermost feathers.