NATURE — When Birds Of A Feather Flock Together
THE next time you step outside on a still morning, take a minute to listen for starlings, those ubiquitous birds that make chimneys, television aerials and telegraph wires their domain in autumn and winter, writes David Carnduff.
Their chattering and whistles tend to blend in with traffic noise and other urban distractions but they frequently draw attention to themselves with impressive mimicry of other birds.
Often I have looked up expecting to see a curlew flying over, only to discover a starling perched on my neighbour’s chimney giving a very credible impersonation of the long-beaked wading bird’s haunting call.
Just what drives a starling to sit aloft for ages throwing its burbling song to the wind has been the subject of recent research which has shown the starling to be a bit of a cool dude: a jazz singer, no less.
The scientists found that starlings practise different songs by ordering, reordering and repeating song sequences.
One researcher said: “It sounds a bit like free-form jazz and it is quite distinct from the structured songs that male songbirds produce when trying to attract mates.”
Another fascinating aspect of the starling’s behaviour is its winter pre-roost gatherings known as murmurations, when hundreds — sometimes even thousands — flock together to perform amazing aerial acrobatics which are mesmerising to watch.
As far as I know, Inverclyde has no large murmurations, but I have seen flocks of a few dozen swirling over waterfront sites in Greenock where cranes or buildings may provide shelter for the night.
Apparently, huge murmurations were common in ancient Rome, where the aerial patterns made by the birds were scrutinised for signs of how the gods were feeling on any given day. Some flock patterns were interpreted as omens, warning the city fathers of imminent battles or political unrest.
There are other accounts from history of enormous bird flocks that darkened the sky. For example, today’s starling murmurations are minuscule compared to flocks of what was America’s most abundant bird — the passenger pigeon — which migrated across the USA in huge numbers.
Alexander Wilson, the Paisley-born pioneer who became the father of American ornithology in the early 19th century, would have been familiar with flocks of starlings in his homeland but what he saw in the USA during his travels was, by today’s standards, truly amazing.
While travelling in Kentucky he saw a passenger pigeon roost of more than 40 miles in extent and, later, a flight of pigeons passed overhead which he calculated to number a mind-boggling two thousand million birds.
Meanwhile, back in 21st century Britain, starling numbers — far from matching the passenger pigeon — are actually in decline.
Long-term monitoring by the British Trust for Ornithology shows that starling numbers have fallen by 66 per cent in the UK since the mid-1970s. Because of this decline, the species is red-listed as a bird of high conservation concern.
And what became of the passenger pigeon? Lamentably, the entire species was driven to extinction, with hunting and habitat loss blamed for its cataclysmic demise. The last surviving individual, a female named Martha, died in Cincinnati zoo in 1914.
