Barrydale Online

Winter is assuredly upon us, with its frequent frosty mornings and golden, sunny days. In the Western Cape, winter is (supposed to be) the rainy season, the time when many of our songbirds start making nests and breeding. Prominent among these is the Cape Robin, and the Barrydale members of this species are already getting quite flirty and singing with increasing virtuosity from every vantage point around their territories.  The robin that owns our garden incorporates imitations of several other birds’ songs into his repertoire, including that of the Didric Cuckoo (which is absent at this time of year).  As a general rule, Cape Robin-Chats are not as given to mimicry as are the other African robin-chats, so it is more of an individual talent. The late Dr C.J. Skead, famed ornithologist of the Eastern Cape, made a list in his bedside notebook of all the species calls imitated in dawn song by his local Cape Robin in Grahamstown. The list reached a total of 74 different birdcalls before, sadly, the bird fell victim to a hit-and-run driver in the street outside.

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Why do some birds mimic the calls of other species?  This question has engendered a fair amount of debate, and various hypotheses have been put forward.  Robin-chats often imitate eagles such as the Crowned Eagle or African Fish Eagle, probably because the calls of these birds fall within the frequency range most favoured by the robin, not because the robin is pretending to be an eagle in order to scare rivals out of its territory. Effective vocal advertisement is a vital part of life for a songbird, ensuring that it can defend a territory and attract mate. So how does one maximise effectiveness? One theory maintains that if a bird sings exactly the same ‘song’ all the time it runs the risk of becoming boring (the author of that hypothesis had obviously never listened to an African tinker-barbet!). If there is some truth in this idea, however, how does one avoid becoming boring? The answer is to have a big repertoire.  There are two ways to achieve this; one must either be a talented composer, or one can pirate parts of other composers’ songs.

There are quite a few bird mimics living in the village, including Common Starling and Fiscal Shrike for example, so if you hear a nightjar calling in the middle of the day, chances are that it is just a starling rehearsing his repertoire.