USFWS Bald Eagle Population Update — An Estimated 316,708 Eagles in the Lower 48 States

by Duane Nichols on March 24, 2021

Eagles need clean streams for their fish diet

Bald eagle count quadruples, thanks in part to eBird data boost

From an Article by Gustave Axelson, Cornell Chronicle, March 24, 2021

For the past 50 years, the U.S. Fish and Wildlife Service (USFWS) has been assembling counts of bald eagle nests to track the triumphant recovery of America’s national symbol. But in its new bald eagle population report – tabulated with the help of results using eBird data from the Cornell Lab of Ornithology – the USFWS found many more eagles than previously thought to exist in the Lower 48 states. A lot more.

The latest USFWS Bald Eagle Population Update report estimates more than quadruple the eagle population noted in the 2009 report, or 316,708 eagles across the contiguous United States. The rising number of bald eagles undoubtedly reflects the continuing conservation success story that stretches back to the banning of DDT in 1972. But it also represents a major advance in using citizen-science powered supercomputing to generate better estimates for the eagle population.

“Working with Cornell to integrate data from our aerial surveys with eBird relative abundance data on bald eagles is one of the most impressive ways the we have engaged with citizen science programs to date,” said Jerome Ford, USFWS migratory birds program assistant director. “This critical information was imperative to accurately estimate the bald eagle population in the contiguous United States, and we look forward to working with Cornell in the future.”

In addition, the new USFWS report estimates 71,467 nesting pairs of bald eagles in the Lower 48 states, which is double the number of eagle nests noted in the 2009 report – and many multitudes higher than the all-time recorded low of 417 known eagle nests in 1963. Back then, the popular use of DDT pesticides after World War II had decimated the eagle population. In 1967, the bald eagle received protection under the predecessor to the federal Endangered Species Act (ESA). Then in 1972, the United States banned DDT.

Thanks to legal protections, captive-breeding programs and habitat protection around nests, the bald eagle population rebounded. The USFWS tracked the recovery through counts from states and by aerial surveys every few years, as pilots from the agency’s Migratory Bird Program flew eagle-counting missions over high-density eagle-nesting areas to count numbers of occupied nests.

But for this latest USFWS report, the federal government collaborated for the first time with the Cornell Lab to augment their aerial surveys with a big-data population model generated by eBird.

The computer science that built the eBird model was powered by citizen science. More than 180,000 birders shared data with the Cornell Lab by uploading eBird checklists – tallies of which bird species they saw, and how many, in a single outing. Cornell Lab scientists then developed a model that uses eBird estimates of relative abundance for bald eagles to generate numbers of occupied nesting territories in the areas that USFWS were not able to cover in their aerial surveys.

“One of our main objectives was to see if population modeling based on eBird data would enhance the survey work the Fish and Wildlife Service was already doing,” said Viviana Ruiz-Gutierrez, assistant director of Cornell Lab’s Center for Avian Population Studies, who supervised the lab’s role in this partnership. “We’re hoping that this will allow the Fish and Wildlife Service to track bald eagle populations over a much wider area in the most cost-effective manner in the future.”

And, Ruiz-Gutierrez says, she also hopes those eagle models continue to show positive momentum. Since the USFWS delisted the bald eagle from the ESA in 2007 – a historic moment for species recovery under the act – the number of known occupied nests in the Lower 48 states has more than doubled, according to the latest report.

It’s a great American conservation success story,” Cornell Lab Center for Avian Population Studies Senior Director Amanda Rodewald said March 24 at a virtual press conference hosted by the USFWS. She thanked the agency for hosting the event to celebrate eagle recovery, and to celebrate the role of citizen science – the thousands of birders who shared their observations to help build the population models.


See also: Bald eagle that suffered from lead poisoning, treated, released back to the wilderness, Jeff Morris, WCHS News 8, February 11, 2021

RANDOLPH COUNTY, WV — A bald eagle that was treated after suffering from lead poisoning was released back to the wilderness in Pocahontas County. West Virginia Natural Resources Police report that land owners found the eagle on their property and the bird was unable to fly.

The adult eagle was treated and banded at the Avian Conservation Center of Appalachia in Morgantown and returned to the Upper Shavers Fork area of Randolph County for release.

Police said lead poisoning occurs when eagles ingest lead most likely while scavenging carcasses of other wildlife. When ingested, lead has detrimental effects on the nervous and reproductive systems of eagles. Eagles with lead poisoning may have loss of balance, gasping, tremors and an impaired ability to fly. The birds can die within two to three weeks after ingesting lead.

{ 1 comment… read it below or add one }

L. A. Times March 24, 2021 at 5:48 pm

We need faster action on removing the DDT graveyard off the L.A. coast

Editorial by The L.A. Times Editorial Board, March 22, 2021

On a clear day, looking south from Rancho Palos Verdes’ Point Vicente Lighthouse across the San Pedro Channel to Catalina Island offers a stunning postcard-worthy vista of coastline, sparkling blue water and the busy comings-and-goings from the ports of Los Angeles and Long Beach.

What you can’t see is what lies below the water: As many as 500,000 corroding barrels of DDT, an extremely effective insecticide the U.S. government banned in 1972 because it caused long-term damage to the environment and wildlife — and because it was a probable human carcinogen.

How those barrels wound up on the bottom of the San Pedro Channel was detailed last October by The Times’ Rosanna Xia. Recounting a practice that began in the years after World War II, she reported how contractors working for Montrose Chemical Corp. of Torrance loaded reinforced barrels of the dangerous chemical onto boats, chugged a few miles out into the channel and pushed them overboard. Often they pounded holes in the sides of the barrels to ensure they’d sink 3,000 feet to the bottom of the San Pedro Basin.

Xia based her reporting on work going back decades by several researchers, most recently a project by David Valentine, a professor at UC Santa Barbara’s Marine Science Institute, who used a borrowed deep-sea robot to capture images of the rusting and leaking barrels.

The presence of the barrels has long been known to state and federal regulators, who sidelined the matter in favor what seemed to be a more pressing problem — Montrose’s discharge of DDT and PCBs, another banned substance, through offshore sewer pipes. That discharge zone, 17 square miles in size and about 200 feet down just off Palos Verdes, is a Superfund cleanup site.

Officials initially decided to bury the most contaminated part of the seafloor with a layer of sand, hoping to seal it in place. That pilot project initially seemed to work, but later tests revealed more DDT. The EPA is now considering other options.

If you look out from Point Vicente for the next few weeks, you may see the research vessel Sally Ride mixed among the ships and boats plying the channel. Those aboard include 31 scientists and crew members who are mapping 50,000 acres of seafloor to try to catalog the scope of the DDT barrel graveyard, a critical early step in trying to figure out the best way to deal with the barrels and chemical seepage.

It’s frustrating that the federal government has moved so slowly to address such a significant environmental hazard. Recent studies have linked the incidence of cancer among sea lions to DDT, most likely ingested and concentrated as the poison moved its way up the food chain.

Although the seabird populations that had declined because of DDT exposure have rebounded in recent years, the lingering presence in wildlife of the slow-to-decompose chemical remains a risk to top predators, including dolphins, which accumulate the chemical in their fat after eating infected prey.

Granted, there are no easy resolutions here. Simply removing the contaminated seafloor soil would be astronomically expensive, and then the government would have to do something with it. Ocean currents and naturally shifting sands compound the challenge, as does the depth at which the pollutants have rested.

But knowing that it will be difficult to remedy the contamination doesn’t justify lack of focused, deliberate action.


Leave a Comment

Previous post:

Next post: