Natural Wetlands are First Choice for Egrets

While human-influenced wetlands such as flooded rice fields and ponds are available to great egrets (Ardea alba) in Louisiana and South Carolina, they still prefer to forage in natural wetlands, according to a recent study.

“Rice fields have been fairly well studied as bird habitat in many parts of the world, but much less so in Louisiana,” said Jason Fidorra in a press release. Fidorra is a wildlife biologist with the Washington Department of Fish and Wildlife and lead author of the study published in The Condor: Ornithological Applications. “We found that while great egrets did use rice fields, they were never selected more strongly than natural wetlands. This suggests that they are less-than-adequate replacements to natural wetlands.”

As part of the study, researchers used satellite transmitters and conducted aerial surveys to determine habitat use of great egrets in Louisiana and South Carolina. They found that tagged birds didn’t use flooded agricultural fields at all; however the aerial survey showed they did visit some human-influenced wetlands including ponds and crayfish production impoundments.

Even as more fish hatcheries, flooded agricultural fields, artificial ponds and reservoirs pop up, researchers concluded that, for the most part, birds in the southeastern United States still prefer their natural habitat.

The health and abundance of long-legged wading birds is related to the wellness of their habitat including freshwater, estuarine wetlands, ponds lakes and rivers, said John Brzorad, an expert on egret movements and energy requirements and director of the Reese Institute for Conservation of Natural Resources at Lenoir-Rhyne University in a press release. “This study is an excellent reaffirmation of the conservation value of natural wetlands and will further stimulate research on the value of golf courses, suburban and retention ponds using advancing telemetry methods.”