Survey: Eagle Nesting Strong, Coast Rebounds From Bird Flu

Social Circle, Ga.

Bald eagle surveys in Georgia revealed the iconic raptors nesting and fledging young at healthy rates this year, including in coastal areas where avian influenza hammered eagles last spring.

Survey leader Dr. Bob Sargent of the state Department of Natural Resources said nesting success was average to above-average in areas surveyed. Sargent, a program manager with DNR’s Wildlife Conservation Section, called the findings “excellent,” especially considering the toll that highly pathogenic avian influenza took nationwide on bald eagles, black vultures and many other bird species last year.

"Last year’s exceptionally poor nesting results on the coast, as well as the lower than usual success rate in southwest Georgia, was worrisome because those areas combine for  about 85 percent of our known eagle nests,” he said.
“The comeback of the bald eagle in Georgia is a great conservation success story, but the species is listed as threatened in the state and if high nest failures continued they could chip away at population gains. I’m pleased to see the nest success rates rebound this year.”

Although survey flights this year covered less territory than the once-every-five-years statewide survey in 2022, they still recorded 198 nest territories. Of those, 150 were successful, fledging 232 eagles. Accounting for nests not monitored, the totals suggest Georgia has maintained over 200 nest territories a year since 2015 and the number of eagles nesting has continued to increase, according to Sargent.

DNR monitors eagle nesting by helicopter twice a year, splitting the state into five sections for surveys. The coast is surveyed annually. The other areas are checked at least every other year. Flights in January and February mark nests in use. Follow-ups in March and April help gauge how the nests fared.

The 2023 survey included southwest Georgia, the coastal counties and barrier islands, the Oconee and Ocmulgee river corridors in north-central Georgia, and a few reservoirs southeast of Atlanta.

Sargent said he sighed in relief when it became clear that nest success rates, especially on the coast, would register within normal ranges. In April 2022, DNR announced that highly pathogenic avian influenza – the viral disease dubbed bird flu – had ravaged bald eagles on the coast, home to about a third of Georgia’s eagle nests. Nest success there dropped about 30 percent last year. Fewer than half of the nests fledged even one eagle.

However, no influenza-positive cases have been reported in bald eagles in Georgia for more than a year, and there have been no cases in other species for about four months, according to Sargent. The virus also caused substantial die offs at black vulture roosts in 2022.

“I did see dead eaglets in two coastal nests in March this year, which is unusual and suggests the virus might still linger in some hotspots, but that’s certainly not a definitive conclusion,” he said. Eaglets die from many causes, including illness, starvation and predation by great horned owls, but predators and scavengers usually remove those carcasses or the eaglets fall out of the nest.

Nest success rates charted in this year’s survey rated from average in southwest Georgia (75 percent) and on the coast (73 percent) to above average (83 percent) in the area bounded by Athens to the northeast, Atlanta to the northwest and Macon to the south.

The 232 eagles fledged, almost 1.6 young per nest, is slightly more than the state’s long-term average. In comparison, last year’s record 229 nest territories fledged 227 eagles from 146 successful nests.

On the coast, the 81 nest territories recorded measured notably higher than average. The total in 2022 was 73 territories. Nesting success this year rated average at 1.5 young per nest. But the 89 eaglets fledged from 59 coastal nests far exceeds the 50 eaglets fledged from only 34 successful nests last year.

The survey also documented 92 nest territories in southwest Georgia, which is comparable to the 96 in 2022. Sixty-nine of this year’s nests fledged young. The better-than-average 1.6 eaglets per nest (113 eaglets fledged) topped the 1.5 eaglets per nest from 62 successful nests in the region in 2022.

“The nest success on the coast and in southwest Georgia are a reminder of the importance of not overreacting to a poor nest success year,” Sargent said. “Severe weather in early to mid-winter, viral outbreaks and other problems that seem like calamities at the time can result in poor reproductive years. But eagles are resilient, and have bounced back from far worse population-level challenges.”

Indeed, the bald eagle has rebounded in Georgia and across the species’ range. Factors feeding that recovery include a U.S. ban on DDT use in 1972, habitat improvements after enactment of the federal Clean Water and Clean Air acts, protection through the Endangered Species Act, increased public awareness, restoration of local populations through release programs, and forest regrowth.

Following a steep decline in the eagle population in Georgia, the state went from no known successful nests during most of the 1970s to one in 1981, 48 by the turn of the century and more than 200 today.
The public is encouraged to report eagle nests via www.georgiawildlife.com/conservation/eaglenest, (478) 994-1438) or bob.sargent@dnr.ga.gov. Such reports typically lead to the discovery of 10-15 new nests a year. (Tip: Osprey nests are sometimes confused with eagles. Learn more at https://georgiawildlife.com/bald-eagle.)

DNR works with landowners to help protect bald eagle nests on private property. Although delisted from the Endangered Species Act in 2007, eagles are protected by the Bald and Golden Eagle Protection Act, the Migratory Bird Treaty Act, and state law. In Georgia, the species is classified as threatened.

The surveys of these birds are part of DNR Wildlife Conservation Section’s mission to conserve nongame wildlife – native animals not legally hunted or fished for – and native plants and natural habitats.

The conservation of bald eagles is supported in part by people who buy an eagle or monarch license plate or renew these or the older hummingbird designs. The tags cost only $25 more than a standard license plate and $19 of each purchase and $20 of each annual renewal goes to help conserve eagles and hundreds of other Georgia plant and animal species listed as species of conservation concern.

EAGLE NESTING IN GEORGIA/AT A GLANCE

  • Occupied bald eagle nest territories: 198*
  • Successful nests: 150
  • Young fledged: 232 (1.55/nest)
  • New nests (first time surveyed): 22
  • Overall nest success rate: 76%
  • By region (occupied nests/successful nests/young fledged/new nests):
    • Coast: 81 occupied; 59 successful; 89 fledged; 8 new nests

    • Southwest: 92 occupied; 69 successful; 113 fledged; 8 new

    • North-central: 18 occupied; 15 successful; 22 fledged; 4 new

    • Nests monitored separate from flights: 7 occupied; 7 successful; 8 fledged; 2 new

    • *Not a statewide survey
      SOURCE: Georgia DNR

HOW THIS WORKS

DNR began monitoring bald eagle nesting in Georgia in the 1980s. The Wildlife Conservation Section now checks nests by helicopter in January-February and again in March-April. Following 2017, the statewide survey was scaled back. From 2018-2020, about 50-70 percent of Georgia was surveyed annually. Because of COVID, only the coastal counties were flown in 2021. In 2022, the entire state was surveyed again.

Since 2017, the survey has been split into five regions: the six coastal counties, southwest Georgia, east/northeast (most of the area between Interstates 16 and 85 east of Atlanta and Macon), north/northwest and southeast (bounded by interstates 75 and 16 and west of the coastal counties). Coastal counties, where about a third of nest territories are found, are surveyed annually. Other sections are checked in an every-other-year rotation. The southeast area has the fewest nests and is mostly monitored by volunteers on foot. In 2023, DNR added a survey route covering an upside-down triangular area from Atlanta (northwest corner) to Athens (northeast corner) to Macon (inverted apex).

Flights involve two rounds. The first, started between January’s second and fourth week, focuses on finding active nests. An active nest is one with eggs, eaglets (rare in Georgia in January), an adult eagle in an incubating posture or evidence eagles have been prepping it for use. The second round of flights, from mid-March to early April, gauges the reproductive outcome of those nests and checks reports of new ones. By late winter, most nests have eaglets 4-14 weeks old or they are empty because the nest failed or, in a few cases, the eaglets fledged.

Nest cycles: DNR survey leader Dr. Bob Sargent said there is a marked latitudinal gradient for the timing of the nest cycle. Eagles on the coast nest and fledge young earlier than those in middle Georgia and much earlier than those nesting around mountain reservoirs. As with all birds, the causes of nests failing vary. They include severe weather, the death of one or both parents, insufficient food available to rear the young and predation of eggs or the young by raccoons, great horned owls and other wildlife.

Aviation aid: By the end of the 2023 surveys, Sargent and DNR pilots Capt. Jaye Bridwell, Lt. Ryan Buller and Lt. Jamie Allen had peeked into nearly 240 nests from Atlanta to Bainbridge and St. Marys to Savannah. Sargent calls the pilots “ornithologists in training” and said their role in the surveys goes beyond flying. “They often find the nests before I do, they are as fascinated by the big birds as I am and they are especially conscientious about keeping a safe distance from the nests – for the eagles’ sake – while giving me the best possible look at the contents. The success of these survey efforts is in large part due to the talent and dedication of our pilots.”