One of the most remarkable animals in the animal
kingdom is the Superb Lyrebird (Menura
novaehollandiae). Its ability to mimic the sounds of a variety of species
is nothing short of astonishing. The males use their vocal ability, along with
their flashy tail, to attract potential mates. In fact, up to 70% of their
vocalisations consist of imitations from up to 20 local species of bird.
It has been thought that females are impressed by
the repertoire of sounds that a male can produce. This hypothesis does seem
plausible in the case of M. novaehollandiae
as his repertoire is quite extensive however, for other species of bird, this
is not the case. A new hypothesis is not how large a repertoire is but how
accurate the mimicry of the sounds is.
A study from 2012 set out to test just how accurate
the mimicry of M. novaehollandiae
is. They assessed the accuracy with which the lyrebird was able to imitate the
complex song of the Grey shrike-thrush, Colluricincla
harmonica. The accuracy of the imitation was found to be extremely strong
and the only deviation came from the fewer amount of repetitions that were
produced by the lyrebird. It was so accurate that it was able to fool the grey
shrike-thrush itself.
This idea of accuracy being driven from female
preferences has also been examined specifically and with the use of
spectrograph cross-correlations, they were able to provide ample evidence to
support this alternative hypothesis to the previous repertoire idea.
References
Coleman S. W, Patricelli G. L,
Coyle B, Siani J & Borgia G. (2007). Female preferences drive the evolution
of mimetic accuracy in male sexual displays. Biology
Letters, 3(5),
463-466.
Dalziell A. H & Magrath R. D.
(2012). Fooling the experts: accurate vocal mimicry in the song of the superb
lyrebird, Menura novaehollandiae. .Animal
Behaviour, 83(6),
1401-1410.
Hey Dave! Super interesting post. I've always wanted to see one of these in the wild, whereabouts are they found?
ReplyDeleteLyrebirds are brilliant! I love the fact that they can also imitate human sounds (cameras and chainsaws). It’s very interesting that it is rather the accuracy of mimicry and not the repertoire. I do wonder though, if the accuracy is good enough to fool the model (grey shrike-thrush) does this mean that female lyrebirds actually have to visually locate a mate first, before they can assess him on his vocal ability? Otherwise, how does the female know he is a lyrebird and not a shrike-thrush? Cool!
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