The bald eagle is engrained in the fabric of the United States. The bird’s status as a national symbol predates the Constitution, being adopted on the national seal in June 1782.
Along the Treasure Coast, bald eagles can be seen soaring above Indian River, Martin and St. Lucie counties, their wings outstretched, their eyes trained on the waterways looking for fish.
But as the human population of the Treasure Coast grows and becomes increasingly urbanized, bald eagles face numerous threats.
"Florida has one of the largest (eagle) populations outside of Alaska and we would like to keep it that way. The Treasure Coast's population of eagles is currently steady," said Shawnlei Breeding, Florida Audubon EagleWatch program manager. "But factors such as increased urbanization and human encroachment into eagle habitat are posing threats."
"Bald eagles are extremely adaptable," said Barbara Pierzakowski, EagleWatch volunteer coordinator for Martin and St. Lucie counties. "Some can thrive in urban environments. However, some struggle with new surroundings, especially where recent development is occurring."
Protecting eagles from their No. 1 threat
Hope is not lost, though, as the Florida Fish and Wildlife Conservation Commission, EagleWatch, the Audubon Society and the Treasure Coast Wildlife Center all are actively working to protect bald eagles.
As the Treasure Coast has become more developed and eagles' natural habitat has shrunk, the majestic birds have had to adapt to survive.
"As we are cutting down their habitat, their territories are getting smaller," said Breeding. "Then water issues, and poorer fish quality from pollutants all mean humans are the No. 1 threat."
Rapid urbanization has forced eagles to stray from their traditional large-hardwood nesting areas to manmade structures such as cellphone towers and utility poles.
"Although they are resourceful, the more properties that are being built equals less places eagles can nest," said Pierzakowski. "Their habitat is being destroyed."
Other factors come into play, too.
"Some pairs are very successful in urban environments," said U.S. Fish and Wildlife Service Eagle Biologist Ulgonda Kirkpatrick. "However, even though they have been able to adapt, the large trees disappearing is hard on nesting."
Moreover, said Kirkpatrick, electrocution and powerline entanglements are commonplace.
There are an estimated 101 active bald eagle nests on the Treasure Coast: 30 in Indian River County, 46 in Martin and 25 in St. Lucie, according to Breeding. Active nests are those where eagles have been as recently as last year.
Across Florida, an estimated 1,500 nesting pairs call the Sunshine State home.
The entire human population of the Treasure Coast increased by nearly 50% from 2000 to 2020, according to U.S. Census data. In St. Lucie County it spiked by 70%.
Nearly 650,000 people called the Treasure Coast home in 2020, according to the Census.
Golf courses are a common place to spot eagles.
"Just like people, they like to watch the golfers take their swings," joked Kirkpatrick. "A lot of their comfort has to do with the amount of exposure to humans."
Yet the increased human exposure has led to unintentional consequences.
Prevalence of vehicle accidents involving eagles is on the rise in the Treasure Coast. Four bald eagles already have been brought in to the Treasure Coast Wildlife Center clinic — a non-for-profit wildlife rehabilitation center in Stuart, according Clinic Director Cindy Dionne.
"Eagles will fly low and get hit by semis, box trucks and occasionally cars as they swoop in to catch their prey or are scavenging for food," said Dionne. "Accidents with vehicles has overtaken the top spot as the leading cause of death."
Harkening back to past mistakes, another foe emerged — rodenticides.
"Especially in urban environments, eagles are opportunists and scavengers," said Dionne. "We see a lot of eagles with secondary poisoning from eating a critter that was killed with poison."
The consequences are grisly.
"Rodenticide poisoning in eagles often presents as lethargy and stumbling around like they are drunk, severe bleeding from the mouth and internal bleeding," said Kirkpatrick. "It is pretty gruesome."
Still, the Treasure Coast Wildlife Center boasts a 70% recovery rate for bald eagles that are brought in or found with rodenticide poisoning.
DDT nearly eliminated bald eagles
The insecticide DDT saw widespread usage in agriculture and as a household pesticide beginning in 1945.
The chemical leached into waterways and soils and concentrated in food sources of eagles, which can begin as fish but branch out to deer, roadkill, rodents, reptiles and even amphibians.
Eagles sometimes even steal food from osprey, which often are seen up and down the Indian River Lagoon, especially among the mangroves.
DDT inhibited the formation of egg shells, causing the shells to be increasingly thin, crack during incubation and hinder the development of eaglets.
By 1963, only 417 nesting pairs were known nationally. By 1973, only 88 were known in Florida, according to United States Fish and Wildlife Service and Center for Biological Diversity.
"DDT really was the big killer," said Dionne. "It basically wiped bald eagles out across the country."
The widespread ban of DDT finally occurred in 1972.
Prior to DDT, the main threats to eagles were hunting and trapping.
The Migratory Bird Treaty Act of 1918 was the first piece of legislation to protect bald eagles in North America, bolstered by the 1940 Bald and Golden Eagle Protection Act, which prohibited any harm, such as disturbances of nests.
By 1967 the bald eagle was officially declared an endangered species.
A species on the rebound
Since 1972 , the numbers of eagles nationwide has rebounded significantly, with an estimated 300,000 birds now inhabiting the United States, according to a 2020 U.S. Fish and Wildlife Service survey, the most recent data available. The Fish and Wildlife Service conducted national bald eagle population surveys in 2009, 2016 and 2020 to track eagle population growth.
Bald eagles often mate for life, and as such are grouped as nesting pairs. Bald eagles migrate along the eastern seaboard, along the Atlantic Flyway, with one Treasure Coast bald eagle being spotted as far north as Michigan, according to Breeding.
EagleWatch has monitored bald eagles in all of Florida since 1992.
"We got a request from Florida Fish and Wildlife to help monitor some nests in Central Florida," said Breeding. "It kind of grew from there. We started with a handful of volunteers and now we have more than 700 volunteers who monitor around 1,200 nests throughout the state."
"Humans are the biggest threat," said Dionne. "Eagles have no true predators. Humans are the ones that cause problems."
The different colors on the map below correspond to the county where a nest is located.
The Treasure Coast has a number of important eagle habitats, including Archie Carr National Wildlife Refuge, Pelican Island National Wildlife Refuge, Johnathan Dickinson State Park, Blue Cypress Lake and Lake Okeechobee.
The highest concentration of bald eagle nests on the Treasure Coast, about 25, is in the small sliver of Lake Okeechobee in Martin County.
Not all documented nests are inhabited, as bald eagles may leave the nest for days at a time, or a pair may have multiple nests.
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"There are tons of ways to help bald eagles along the Treasure Coast," said Kirkpatrick. "Plant native hardwood trees and stop using rodenticide. Pay attention when driving, because they are fast.
"There is always something the average person can do to help eagles."
Nick Slater is TCPalm's Indian River County Watchdog reporter. You can reach him at Nick.Slater@tcpalm.com and 224-830-2875 .
This article originally appeared on Treasure Coast Newspapers: Bald eagles along the Treasure Coast, elsewhere, facing continuing threats, experts say
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