11 September 2010

Collared Doves

The practice of keeping dovecots is now largely a thing of the past, which is rather a shame, because a few white doves add greatly to the charm of a garden or courtyard. Better than domestic doves, though, are those born and bred to the wild. They make ideal “pets”, because they are free to leave at any time, and there is none of the compulsion which to my mind mars the usual relationship of human with animal.

Unless you are very unlucky, you will have your own wild doves – Collared Doves – not too far away: slender, stone-coloured birds with a distinctive cooing song. They are fond of suburban back gardens, smallholdings, farmyards, and similar places, and where unmolested can become quite tame.

At a distance a Collared Dove looks almost uniformly greyish brown, but seen close to, especially in sunshine, it is a most elegant and attractive bird. The plumage is very delicately contoured and shaded, and a softly vinous flush on the breast harmonizes perfectly with the claret-coloured legs and feet. The eye, too, is in this register of red: when the sun catches it at a certain angle, it looks exactly like a ruby.

In its flight and habits the Collared Dove is a gentle, fastidious creature; the partial black collar, edged with white, is reminiscent of the velvet chokers once worn by dowager duchesses. The impression is completed by one of the bird’s often-used calls, a loud uhrrr, uhrrr! uttered as if in horror at the violation of its genteel sensibilities by the appearance of some unspeakably uncouth ruffian – perhaps even a flasher.

The Collared Dove has become so much a part of the local scene that it is hard to believe it bred in this district no earlier than 1966. The first arrivals were the subject of a series of excited notes on a brand-new card in my index box. The magic date was 25 May 1966, when a male was seen – studied at 30x through my telescope! – and heard singing on the roof of the house. By 4 June it had a mate and both birds remained in the area till the end of the year. Definitely not a domesticated form. Very good views frequently obtained when seen drinking from gutter 15’ from window. Wary and unapproachable.

Few bird-watchers now would bother to record “very good views” of the Collared Dove. But how and why has this bird become so common where previously it was unknown?

Nothing is ever static in the living world. Even the most apparently stable community of plants and animals is in perpetual flux, brought about by changes in climate or other environmental factors, or by changes in their own genetics and evolution. Change is in fact one of the chief characteristics of living things.

Normally this change is quite slow, taking the span of many human lifetimes to become obvious. Sometimes, though, it can be quite rapid, and occasionally, as in the case of the Collared Dove, it can be spectacular.

The most sudden changes come in the wake of some catastrophe, a natural disaster such as a forest fire, an earthquake, or volcano, which wipes out one community and gives a clean slate for the formation of another. Or the natural disaster may simply destroy one part of the community and alter its balance, allowing certain new forms to invade.

Man’s influence on the environment can be seen as a series of natural disasters, both large and small, of this second type. Many species have lost out; some have gained from the opportunities inadvertently put in their way. When a species not only has a new set of opportunities put before it, but simultaneously undergoes a genetic or behavioural change enabling it to exploit new territory, then you can expect some fireworks.

The Collared Dove was originally a bird of the Indian sub-continent. Its principal food is grain, which pre-adapted it to benefit from Man’s increasing use of agriculture. As farming slowly became more successful the Collared Dove began to spread slowly north and west, reaching Asia Minor in the 16th century. By 1925 it was well established in the Balkans.

Then, suddenly, something happened. It may have been a slight genetic change enabling some individuals to breed more successfully; it may have been a behavioural change making the Collared Dove even more tolerant of Man. Whatever did happen, the slow northward expansion of the previous few centuries became a full-scale invasion.

A record of its progress across Europe looks like one of those animated maps showing the advance of the Nazis: from Belgrade it reached Hungary in 1928 and Czechoslovakia in 1935. Austria fell in 1938, Poland in 1940. It reached Germany and Italy in 1944, Holland in 1947, Switzerland and Sweden in 1949. By 1950 it was breeding in France: the first (unofficial) British sighting was in 1952, the first breeding record in Norfolk in 1955. It first bred in the London area in 1962, and in our own district, as already mentioned, in 1966.

The earliest colonists were often to be found in the vicinity of chicken-runs, or at zoos or other places where spilled or otherwise free grain was to be picked up. This opportunism in feeding is one key to the Collared Dove’s success. Another is its liking for conifers in which to nest – almost to order we busily planted our suburbs with Lawson’s Cypress, ready for its arrival.

But the main key to its success is its fecundity. In mild weather the breeding season may begin as early as January and go on till October. It can tend the young of one brood while incubating the eggs of the next, and will tolerate levels of disturbance that would make most other birds desert.

The increase is still going on. In Britain it is extending its range into other habitats, especially farmland. Abroad it is still moving north and west, having reached Iceland, where this gentle invader may even be readying itself for the final, really big challenge, the one that even the Nazis couldn’t get near: Canada, the USA, and all points south.

(Introduction to these pieces; see all)

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