The Cormorant

Who is that silhouetted in the blue spring sky, circling the Sycamore Wetlands above the honking geese and burring blackbirds? A little bit bigger than your average duck, smaller than a Canada goose, with a long tail that seems a little out of place on a waterbird?

It's a double-crested cormorant (Phalacrocorax auritus; the melodious genus name Phalacrocorax translates to "bald raven")! Not a rare bird, but a treat to see nonetheless. There are several species of cormorant (streamlined, diving seabirds that eat fish and other aquatic creatures), but the double-crested variety is the only one that makes its way far enough inland to visit Iowa during their breeding season.

The common name "double-crested" refers to a pair of small black tufts on the heads of breeding adults (also the source of the species name auritus, "eared"), which can be difficult to see from a distance, or when they lay flat against the bird's head.

You can often see cormorants standing on a rock or branch with its wings outstretched, sunning itself. Cormorants' feathers are not as waterproof as those of ducks or other waterfowl, and this posture is thought to help dry them after a swim or dive. 

Like the bald eagle and other large predatory birds, the double-crested cormorant suffered population decline in the miod-20th century to to DDT poisoning weakening eggs and reducing the survival of viable offsprint. Since the banning of DDT, their populations have greatly increased to the point where large congregations of cormorants cause problems for fish populations. Though there is no hunting season for cormorants, the US Fish and Wildlife Service has regulations in place that allow strategic culling of double-crested cormorants to help control their numbers.