West Palm Beach, FL - The 23rd annual South Florida Wading Bird Report released by the South Florida Water Management District (SFWMD) showed that several key "indicator species" of birds that are critical to gauging the health of the Everglades had an above average breeding season in 2017.
The wood stork, an indicator species, in particular had a banner year, nearly doubling the annual average number of nests over the past decade. The population of wood storks has been climbing for the past several years as SFWMD's work to restore the hydrology and water quality of the Everglades has progressed. Thanks partly to this effort, the wood stork, once listed as a federally endangered species, was upgraded to a federally threatened species by the U.S. Fish and Wildlife Service in 2014.
"One of the primary goals of the Comprehensive Everglades Restoration Plan (CERP) and other ongoing restoration projects is to return the populations of wading birds in the Everglades to healthy numbers by improving the quality, quantity, timing and distribution of water in the system," said SFWMD Lead Environmental Scientist Mark Cook, who helped produce the annual wading bird report. "This report's findings show that with improved habitat and favorable weather conditions, wading birds can feed, breed and flourish."
SFWMD staff, in collaboration with staff from several partner agencies, counted 46,248 new wading bird nests between December 2016 and July 2017. That is more than a 73 percent increase in nesting
||Populations of several key species of wading birds like those seen here in Stormwater Treatment Area 3/4 in Palm Beach County, had above average breeding seasons in 2017. Click on the image to see a larger version.
activity from the 2016 breeding season when a drier than average summer of 2015 followed by unprecedented heavy rainfall during the typically dry season in early 2016 severely hampered nesting and led to one of the worst breeding seasons in the past decade. The 2017 nest count was the second highest yearly count since 2009 and well above the five-year and 10-year averages for new wading bird nests found.
Wood storks were at the top of the list for population growth of the key wading bird species being studied last year. Staff counted more than 3,800 nests, roughly 1.8 times the average annual number of wood stork nests found over the past 10 years.
The increased breeding activity of key indicator species of birds such as the great egret and white ibis can be attributed to that same heavy rainfall in early 2016 that resulted in poor nesting activity that year. However, those wet conditions in 2016 also increased the populations of prey such as fish that the wading birds feed upon, and the drier conditions in early 2017 concentrated the prey in smaller areas so the birds could feed upon them more easily.
Not all species studied had above average breeding years. The number of nests started by small herons continued a decline that has been observed for several years. The exact reasons for the decline of nesting activity by these particular species is unknown but being studied further.
SFWMD also made regular observations of conditions and, subsequently, made critical water management decisions during this period, such as putting more water through the stormwater treatment areas into Water Conservation Area 2A to help promote habitat conducive for breeding.
"This is the essence of how water management based on sound science can help the environment thrive," said SFWMD Water Resources Division Director Terrie Bates. "Rainfall is out of our control and can fluctuate from year to year, leading to better or worse breeding activity. However, our efforts to restore habitat and water quality, as well as conduct careful operations of the water management system, allow us to optimize conditions for wading birds as much as possible."
About the Annual Wading Bird Report
SFWMD has produced the annual wading bird report since 1995 in collaboration with agencies and organizations involved with monitoring wading bird colonies such as the Florida Fish and Wildlife Conservation Commission and the Florida Department of Environmental Protection.
Wading birds are a key indicator species for CERP and other restoration programs. Multiple aspects of breeding cycles such as numbers of nesting pairs and timing of nesting are used as performance measures to evaluate restoration progress. Agencies and organizations collect nesting data across South Florida and submit that information to the District for incorporation into the annual wading bird report.