Tuesday, March 17, 2009

Hybrid Duck: A Wood Shoveler?

My sisters (Sarah and Belinda) visited the Brandywine Zoo in Wilmington over the weekend and found a very strange duck in one of the enclosures. This does not resemble any known species of duck, or at least not any depicted in my field guides. Instead, it is most likely a hybrid between two species. So the question is, which species are involved?

Here are two photos of the bird:

When I first saw those two pictures I thought it was a hybrid Mallard, possibly crossed with a Green-winged Teal. The green head and chestnut breast suggested Mallard, while the fine barring on the flanks and blue-green speculum suggested the Teal. However, the following picture suggests another answer.

Sarah told me that the Northern Shoveler in that photo, left alone with no female shovelers to woo, instead was seeking the company of the female Wood Ducks in the same pond. His amorous advances were agressively resisted by the male Wood Ducks, who clearly saw the shoveler as a competitor. If the male shoveler's courtship had been successful in a previous breeding season, this hybrid duck could be a Northern Shoveler X Wood Duck.

That answer does not satisfy me entirely, since it fails to explain the presence of fine gray barring along the bird's flanks, a feature present in neither Wood Ducks nor Northern Shovelers. However, it seems the most likely solution given the observed behaviors. Any thoughts?

All photos by Sarah Beetham.