Wading bird report shows increase in nesting birds

OKEECHOBEE — There is good news and bad news for bird lovers.

The “23rd annual South Florida Wading Bird Report” released March 28 by the South Florida Water Management District (SFWMD) found the 2017 wading bird nesting season produced some of the highest nest counts in a decade, with a total of 46,248 nests which represents an improvement from the 10-year annual average of 39,065 nests.

After El Niño-related climatic conditions made 2016 breeding season one of the worst in the last decade, the drier months of early 2017 promoted habitat conditions that allowed key Everglades health “indicator species” to bounce back.

Record rainfall and water management actions taken by the district to address prior year rainfall conditions helped promote an above average breeding season for wading birds in 2017, especially wood storks like the one seen nesting here. Courtesy of SFWMD.

Hydrological conditions in 2017 were almost ideal throughout most of the Everglades ecosystem, according to Florida Audubon’s “2017 Wading Bird Nesting in the Everglades.”

The 2017 nesting season (Dec. 2016 to July 2017) was preceded by a very wet summer, followed by a brief drought at the onset of the dry season (winter-to-spring), Florida Audubon explained. These back-to-back weather extremes recreated similar pre-drainage conditions in the Everglades, where propagation of prey fish during the wet season followed by a natural drawdown in marshes during the dry season resulted in a reliable source of food for populations of wading birds to feed their young throughout the entire nesting season. In the areas where water levels receded on a timeframe that mirrored historic recession rates, the birds responded favorably by nesting in large numbers.

While the news overall is good, researchers warn that two important bird habitat areas saw a decline in birds. In 2017, Lake Okeechobee water levels dropped too rapidly to support the Everglades Snail Kite breeding season. According to Florida Audubon, the kite’s breeding success is closely tied to the water levels at Lake Okeechobee. These highly specialized hunters rely on apple snails to feed their young, and the snails rely on the lake’s plants for food. Too much water, and the plants drown. Too little, and the habitat dries up.

Researchers counted only 130 Everglades Snail Kite nests in 2017, compared to more than 800 the previous year. Then in September, Hurricane Irma destroyed the active nests, along with eggs and flightless chicks.

Another area of concern is Audubon’s Corkscrew Swamp Sanctuary, where the water levels dropped too soon to ensure the wood stork nesting success.

Overall, according to the SFWMD report, the wood stork, an indicator species, 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.

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.

“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.”

Not all species studied had above average breeding years, the SFWMD report shows, The number of nests started by small herons continued a decline that has been observed for several years.

During 2017, 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.”

Compared to the 10-year average in the Greater Everglades Ecosystem:

• Wood Stork nesting increased 83 percent, but very few storks nested in Audubon’s Corkscrew Swamp Sanctuary;

• White ibis nesting increased 13 percent;

• Great egret nesting increased 2 percent;

• Little blue heron nesting increased 62 percent;

• Snowy egret nesting decreased 54 percent;

• Tricolored heron nesting decreased 18 percent;

• Roseate spoonbill nesting was slightly below average. However, low nesting in Florida Bay represents one of the lowest breeding season totals since the beginning of data collection.

“The 2017 numbers represent a ray of hope for the future of wading bird populations in America’s Everglades, but with some of the key indicator species still in decline, it is a reminder that our work is far from over,” said Celeste De Palma, Audubon Florida’s director of Everglades policy.

The high counts observed in 2017 are a result of hydrologic patterns that resembled near-historic water conditions in the Everglades, she explained. Where the water levels were right, the birds responded favorably. However, areas like Florida Bay that depend on improved freshwater flows to support large roseate spoonbill breeding colonies still show decline. The same applies to the overdrained wetlands of Audubon’s Corkscrew Swamp Sanctuary.

“Though the count was one of the highest in nearly a decade, the underperformance of special wading bird historic strongholds like Audubon’s Corkscrew Swamp Sanctuary and Florida Bay, should put the impetus on accelerating Everglades restoration efforts to get the water right for the entire watershed,” Ms. De Palma added. “In a fully restored River of Grass, wading birds in these areas should be nesting by the thousands. Speeding up Everglades restoration and protecting quality foraging habitat is key to giving the birds their best chance to face increasing challenges like sea level rise and fluctuations in rainfall patterns.”
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.

 

Editor Katrina Elsken can be reached at kelsken@newszap.com

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