The male superb lyrebird (Menura novaehollandiae) uses vocal displays when encountering rival males or
before mating. 70% of the superb lyrebirds repertoire consists of imitations
from approximately 20 different species of neighbouring birds (Dalziell &
Magrath, 2012). As the receivers are either rival males or potential mates,
Dalziell & Magrath (2012) strongly suggest that the mimetic vocalizations
are a sexually selected trait.
Because of this, large repertoires may be more favourable by
selection than mimicry, as a wider variety of songs give the superb lyrebird
increased mate choice and territorial defence. However, obtaining a large
repertoire would require mimicry as a shortcut (Dalziell & Magrath, 2012).
As I’ve already mentioned in my previous post (Vocal Mimicry: Accuracy vs Versatility) superb lyrebirds are highly accurate mimics. Coleman and
colleagues (2007), in their study of satin bowerbirds (Ptilonorhynchus
violaceus), suggest that high accuracy is driven by female preferences in
complex mating displays. A correlation can be made about mating success and
accuracy, as modification of vocal motor patterns, and learning and refinement
of displays as a juvenile is required for mimetic accuracy (Coleman et al. 2007).
To date, only two studies
have been successfully conducted on the mimetic accuracy of this species, so
conclusive information is limited, but not unknown.
Dalziell & Magrath (2012) found that there is strong
selection favouring accuracy rather than large repertoires in order for mating
success, and that a species can decipher signal structure and contextual learning
to distinguish between the model and imitations.
Quality over quantity.
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, vol. 3, no. 5, pp. 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, vol. 83, no.
6, pp. 1401-1410.
I think I’m getting confused – you say that these birds can mimic approximately 20 different species of birds, so this suggests that they are highly versatile in their vocal production. However, you say that they are highly accurate, but in your previous post, you seemed to suggest that they did make mistakes. So, surely these lyrebirds are favouring quantity over quality? Please can you comment.
ReplyDeleteSorry for the confusion! In the (limited) research I have done on this topic, I believed that the lyrebirds weren't highly versatile when in comparison to other species for example, brown thrashers (Toxostoma rufum) which have over 1000 distinct song types in their repertoire.
ReplyDeleteThe lyrebirds made mistakes in relation to repetition of certain elements in the song, but were highly accurate (and successful) in matching the complexity and structure of the song - enough to fool the receiver.
The study cited in this and previous posts by Dalziell & Magrath (2012) found that selection strongly favours accuracy in mimicry of male song choices.
It's important to keep in mind that this is only one of a very few published studies done on this species so conclusive evidence is somewhat limited.