Red-capped robin-chat: Master mimics.

Red-capped robin-chat

Mimicry can be defined as the habit of some birds to copy the calls of other species. By far the best mimic in the St Lucia area is the beautiful Red-capped robin-chat (formerly Natal Robin). I have personally heard them mimic the calls of African emerald cuckoo; Orange-breasted bush-shrike; Brown-hooded kingfisher; Gorgeous bush-shrike; Green malkoha; African fish-eagle; Red-chested cuckoo; Klaas’ cuckoo and Fiery-necked nightjar. For the most part it is easy to differentiate between the call of a 'real' bird and their mimic due to discrepancies in tone, tune or pitch but some individual’s calls (possibly the older, more experienced birds) are uncannily similar to that of the bird being mimicked.
 
So why do birds mimic?.....
 
One reason, such as in the case of the Fork-tailed drongo, is to gain access a food source. Fork-tailed drongo mimic the alarm calls of other species (such as Meerkats) to send them running for cover and thereafter take advantage of the abandoned food source.
 
Similarly, some bird species mimic the call of predators to send other species scattering, thereby gaining sole access to a food source. The Square-tailed drongo’s in St Lucia regularly use this tactic. I have heard them on countless occasions mimicking the call of African goshawk (the most common predatory bird in forests around St Lucia), thereby chasing other species away from a food source such as a swarm of flies, termite alates etc and thereby gaining sole access to feeding.

 
Finally, another possible reason for mimicry- and more likely the case with the Red-capped robin-chat- is to impress potential mates. Possessing a diverse repertoire of songs may indicate to potential mates that a male bird is an older, more experienced individual who has had plenty time to practice and refine his mimicry skills. This will indicate to female birds that, firstly, he has good genetics and, secondly, that he has good survival skills and intelligence – both of which are desirable traits to pass on to offspring. 

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