Foto Diarist

Do birds mate with species other than their own? It seems the answer is a resounding quack in the affirmative! Writing for Science in the NY Times, C. Claiborne Ray cited findings by Irby J. Lovette, director of the Fuller Evolutionary Biology Program at the Cornell Lab of Ornithology, that 10% of the ten thousand known bird species have mated with other species, and that dabbling waterfowl, the Anatidae Family in the Order Anseriformes–that is, ducks, geese and swans–are particularly prone to having affairs with different species. Who knew?!

In early December, our Finca Cántaros groundsman, Yeimiry Badilla, a passionate birder, spotted a rare bird on Laguna Zoncho, our lake here, and mentioned it to me. Within a day or two after that, local Costa Rican naturalist guide and superb bird photographer, Pepe Castiblanco, also noticed and got a good shot of an odd bird among the Blue-winged Teal on Laguna Zoncho. It appeared to be closer to a male Green-winged Teal, but not exactly.

Birding enthusiasts began to hear about this unusual sighting, and soon a group of birders with the Asociación Ornithológico de Costa Rica showed up and declared the bird a hybrid. But a hybrid of what? Early speculation was a cross between the Blue-wing and Green-wing Teal. Before long, many visitors with spotting scopes and long camera lenses appeared at our nature reserve to observe the rare male bird. Some were fortunate and had sightings; others saw only one or more of the aquatic regulars of December through March: Blue-winged Teal and Purple Gallinule, Green Heron, Little Blue Heron and Green Kingfisher. (For many years Laguna Zoncho hosted seasonal visits of Masked Ducks, but in 2018, alas, not.)

On January 15, I was finally able to get decent photographs of the individual in question, swimming and behaving in the same way–dabbling for surface aquatic plants–and fully accepted by, his mates, the Blue-winged Teal.

Hybrid male lower right: Green-winged Teal X ?

On January 16, 2019, Finca Cántaros received birders with the tour group WINGS, led by Jon L. Dunn, co-author of various editions of the National Geographic Field Guide to the Birds of North America, including the most recent 7th edition. Accompanying him were Bob Steele, Nat Geo photographer, and Mario Cordoba, the group’s Costa Rican guide and photographer extraordinaire in his own right. Though it was the middle of the afternoon, the group had good fortune and saw the hybrid fowl. Bob Steele got a fine shot, and we may be seeing it soon in Nat Geo!

The interesting bit to me, conversing with the group at the end of their visit, was that Jon Dunn speculated that the bird is not a cross between the Blue-winged and Green-winged Teal, but instead might be a hybrid of the Northern Pintail and the Green-winged Teal. He particularly noted what seemed to him an unusually long bill, similar to the Pintail’s, but said he won’t be sure until he studies the photos he and Bob Steele took. The Northern Pintail (Anas acuta) is a rare winter resident of Costa Rica, a non-breeding migrant now occasionally seen in the northwest of the country–Palo Verde National Park and Cano Negro–and south to the Central Valley. The Green-winged Teal (Anas crecca) is called a “casual winter resident” also mostly seen in the northern Pacific lowlands, and never before in our environs of San Vito, Coto Brus.

Now I understand why so many people are coming to see this interesting hybrid waterfowl. Its parentage is a lively subject of debate, but no one will really know, unless one day it is captured and its DNA analyzed. Sorry, but that that won’t happen here where Mr. Mystery is a welcomed winter resident on Laguna Zoncho.

Mystery hybrid at Finca Cantaros’ Laguna Zoncho.

Below is an actual hybrid of a Green-winged and Blue-winged Teal, according to photographer Tom H. Ellis. This bird was photographed by him at Brazos Bend State Park in Needville, TX.

Green-winged and Blue-winged Teal hybrid, from Texas. Photo: Tom H. Ellis.

References:

Avian Affairs by C. Claiborne Ray in Science, NY Times.

The Birds of Costa Rica: A Field Guide, by Richard Garrigues and Robert Dean, a Zona Tropical Publication from Comstock Publishing Associates, a division of Cornell University Press, Ithaca, New York, 2013.

The Sibley Guide to Bird Life and Behavior, National Audubon Society, illustrated by David Allen Sibley, Alfred A Knopf, New York, copyright 2001 by Chanticleer Press.

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