Wrapping Up the Statewide Reddish Egret Survey

By Andrew Cox

The reddish egret (Egretta rufescens) is North America’s rarest heron and is state-listed as Threatened in Florida. In 2016 we visited 305 coastal islands during the first statewide survey of the species to document its distribution, estimate Florida’s population size, and learn more about its nest-site selection patterns. In 2017 we attended to the less glamorous side of our work – sitting at our desks, crunching numbers and writing.

Reddish egrets were primarily concentrated in four areas of Florida: in and near Merritt Island National Wildlife Refuge, Florida Bay, the Lower Keys, and the Tampa Bay area south to Marco Island. The species has continued to slowly expand northward on the Gulf coast, with nesting occurring in Cedar Keys National Wildlife Refuge. There were an estimated 480 (95% CI: 375–606) nesting pairs at the 58 sites where birds we found birds. The largest colony we found had 23 nesting pairs, which is fewer than the three largest colonies documented in Florida Bay during 1978. Half of all colonies had 3 or fewer pairs.

Reddish egret foraging behavior can be something of a spectacle as birds move throughout tidal flats and other shallow estuarine waters in a graceful, high-energy pursuit of prey. Foraging habitat is probably the largest limiting factor for reddish egret populations, and our nest-site selection analysis confirmed that it was the most substantial predictor of occupancy and abundance of nesting reddish egrets. These results confirm the importance of incorporating foraging habitat into our restoration planning and highlight the need to understand how the shallow flats upon which reddish egrets rely will be affected by sea-level rise.

The photo accompanying this article was taken by Anne Macias. Anne was a retiree in Bonita Springs and a strong advocate for Florida’s birds. She took great pride in the colony of nesting wading birds in her neighborhood and raised awareness of their importance within her community. Our jobs are made that much easier by people like Anne. Anne unfortunately passed away earlier this year and will be deeply missed.