2020 Everglades breeding season mixed for wading birds

The 2020 breeding season for wading birds in South Florida was about average, producing an estimated 43,860 nests, according to the annual South Florida Wading Bird Report produced by the South Florida Water Management District.

The number is just shy of the 10-year average annual number of nests (46,841) and about three times smaller than the banner nesting effort of 2018 (138,834 nests), which was by far the largest nesting effort observed since comprehensive systemwide nesting surveys began in 1996. Nest counts and the success of nesting activity are used to gauge the overall health of the Everglades.

“Drier than average conditions for most of the nesting season followed by a large rain event in May created unfavorable conditions for nesting,” said Mark Cook, lead editor of the report. “In past years, these conditions could have led to a very poor nesting year, but this was average. Things have improved over the past decades because we are improving water management and building additional restoration projects.”

Here’s a summary of how individual species fared.

White Ibises produced 21,849 nests, down 20% compared to the 10-year annual average.

Great Egrets produced 6,893 nests, which is almost double the low count of 2019 (3,487 nests) but is a 20% decrease compared to the 10-year average (8,699 nests).

The federally threatened Wood Stork has exhibited an increase in nesting effort in recent years, but produced only 1,795 nests in 2020, which is lower than the 10-year average of 2,491 nests.

Roseate Spoonbills produced 1,262 nests, a considerable improvement over recent years and more than double the decadal average (514 nests).

The smaller Egretta heron species have exhibited consistent and steep declines in nest numbers in recent years. In 2020, 2,068 Tricolored Heron and 761 Little Blue Heron nests were counted, representing about double the nests compared to the 10-year annual averages. While this is a moderate improvement, the counts remain considerably lower than the 10,000 or so pairs of each species that historically nested in South Florida. The exception to the improved nesting by small herons was the Snowy Egret (2,271 nests), which declined by 27% compared to the 10-year average. “The cause of the sharp declines in Egretta nesting has yet to be determined,” the report states.

Cook said preliminary data shows the 2021 wading bird nesting season may be well above average.