But numbers have plummeted this year, falling an estimated 87 percent for four key species in water conservation areas strung together in marshy pools from the Loxahatchee National Wildlife Refuge west of Boynton Beach to the Tamiami Trail.

The birds, an indicator of prosperity in Florida's unique river of grass, are suffering from an imperfect recipe of rainfall and desiccation that has made it difficult to get enough food to support hatchlings while also making nests easier targets for predators.

Scientists aren't overly concerned about the dearth of fertility this season.

"Thank goodness for last year," said Susan Gray, bureau chief for applied sciences at the South Florida Water Management District in a presentation last month.

But they are eyeing 2020 warily. Too many bad years can dent not just the wading bird population, but signal setbacks in restoration efforts and water management of the delicate Everglades ecosystem.

"Wading birds are almost instantaneous indicators of ecological conditions because they can move about and respond quickly to changes," said Mark Cook, who takes aerial surveys of nests as section leader for Everglades Systems Assessment at the water management district. "They can take care of themselves foraging in yards or other places, but when they have three to four chicks, they need to find really high densities of food or the chicks will starve."

Wading birds flourish when a prolonged or unusually wet rainy season encourages higher fish populations that spread with rising waters over the corrugated ridges and sloughs of the Everglades. As the waters dry up during winter months, fish are consolidated into smaller areas.

The high densities of fish are needed by wading birds who hunt by touch, groping with their bills in shallow water, then snapping them shut when they touch prey.

A wood stork's bill closes with a 25-milli second reflex action - the fastest known for vertebrates.

For nesting, healthy tree islands are also required so birds can stay off the predator-rich ground, but enough water is needed for patrolling alligators. Alligators eat the raccoons that want to eat the birds' eggs.

And we add:

As a result our colony here in BallenIsles may well be the largest breeding colony in South Florida.   Our own bird island is truly worthy of a National Geographic special!