Collared Dove (Streptopelia decaocto)
In not one of these areas has it been forced back seriously. Instead the Collared Dove has consolidated its position wherever it has gone, going from being a complete stranger one year to being a common and familiar species just a few years later. Compared to none at all in 1900, the population in Europe at the beginning of the 21st century could be as many as 14 million pairs.
It is no less remarkable that, despite the magnitude of the Collared Dove’s expansion, we still don’t know why it took place, or how it was triggered. It is simplistic to suggest that, by some sort of genetic mutation it managed to fill a previously unoccupied niche, but that is as good as explanation as we have. We do know that the spread was carried out by young birds dispersing after fledging and then not returning, but the degree of dispersal is now slowing down in some areas, for unknown reasons. It could well be that this amazing spread, an unparalleled incident that has taken place in front of our eyes, will never be entirely explained.
As to the Collared Dove itself, its needs are well served by rural and suburban landscapes. It will nest in a small tree, bush or hedge, and feed on grain from farms and bird tables. Chimney pots and aerials provide excellent perches for bouts of calling, and bird baths, ponds or gutters sort out its need for water. It seems to belong there.
The Collared Dove has a highly repetitive call suitably rendered “Un-i-ted”, as chanted by a football fan. Bouts of calling often cease without warning, as the bird launches into a display flight that takes it up to 20 m or so at a steep angle before it stalls and, with wings and tail spread, glides down on a spiralling path. After its show of territorial prowess the first often lands, lifts up its tail, and utters an excited trumpeting call. It could be the trumpet of a victorious invader.