Wednesday, August 17, 2011

From rarity to dirt-common


This bird - a Eurasian Collared-Dove, of course - has steadily conquered North America ever since its first release in the mid-1970s in the Bahamas. It is still spreading rapidly, including into areas that already have a rich columbiform avifauna, like Mexico.

In central Veracruz, where I arrived yesterday for another fall season of hawk watching, this bird was still rare as recent as 2008. That fall was my first season here, and around the village of Chichicaxtle, where the Pronatura counters are housed and one of the two count sites is located, I saw it a few times in 2008. Then, in 2009, I found it to be regular in a few isolated spots.

Now, in 2011, this has become the most common dove in the area! Its three-syllable coo and its mewing display flight call is heard constantly throughout the community. That's no small feat in an area where pigeons and doves are both diverse and common.

In 1995, when Howell & Webb's Guide to the Birds of Mexico and Northern Central America came out, this bird was still unknown from the region.

eBird of course documents the spread of this species wonderfully. Watch an animated distribution map that starts with the period 1900-2000, followed by 1900-2002, 1900-2004, 1900-2006, 1900-2008, and finally 1900-2011.

how do you make a gif

Image provided by eBird (www.ebird.org) and created 17 August 2011.

Evidently, there were records from Central Veracruz as early as 2002, but the species didn't 'catch on' in the area until the late 2000's. eBird's filter still thought that the 12 Eurasian Collared-Doves I reported today was an "excellent count". I expect the regional editor will soon grow used to (perhaps tired of) approving high counts of this species in central Veracruz, and will adapt the filter.

I'm here for three months and expect to be entering quite a number of Eurasian Collared-Doves this season.

No comments: