The bald eagle recovery story, lingering worries

By Kate Nolan
Green Right Now

The recovery of North American bald eagles is a triumph for the Endangered Species Act.

One of the first species proposed for listing under the Act in 1973, bald eagles in the lower 48 states grew from a failing population of just 400 breeding pairs to 8,000-9,000 before they left the ESA list in August 2007.

A ban on the insecticide DDT initially halted the deadly assault on the species, but it was the Act’s sustained defense of eagle breeding zones that allowed the birds to multiply exponentially over the 34 years of protection.

DDT (which reduces the bird’s ability to reproduce) is still banned, and breeding areas will remain protected during a monitoring period that may last 20 years.

Now, almost three years since delisting, information is emerging on the condition of the birds. Much looks promising, but concerns linger, such as the risk of lead poisoning, illegal shootings and a controversy over whether eagles in the Southwest still need ESA protection.

A comparative eagle count is expected this spring, in mid April,  when the U.S. Fish and Wildlife Service releases a national population estimate. Based on a survey conducted by the U.S. Army Corps of Engineers,  the report will provide detailed information on specific geographic areas that can be compared to earlier surveys to assess growth.

Some numbers have already appeared informally, showing continued expansion in Delaware, Arkansas and the Upper Mississippi River National Wildlife and Fish Refuge area, which borders four states (Minnesota, Wisconsin, Iowa, and Illinois) and is something of a magnet for eagles.

The Refuge was expected to draw more than 5,000 migrating eagles this winter. In Minnesota alone, authorities have counted 700 nests; the state has the largest bald eagle population outside Alaska.

But beyond the numbers, some troubling details have emerged.

Lead suspicions

In Iowa, host to 2,000 to 4,000 migratory eagles every year, bird rehabilitation centers are reporting high lead levels in the eagles they are treating.

“Our database shows that in 2009, 26 eagles died in Iowa from ingesting lead. We shoot deer here with lead slugs. If animals are wounded and not retrieved, the eagles later feed off of it and absorb the lead,” said Kay Neumann of SOAR, a raptor rehabilitation group in Dedham, Iowa.

Lead damages nerves, and lead bullets have been banned in California because it was killing condors there. Few studies have focused on the effects of lead bullets on eagles.

Neumann found that 60 percent of eagles treated in Iowa had lead poisoning. Of the 78 with lead in their systems, only six could be released. She and other rehabbers are pushing for use of non-lead bullets. Wildlife authorities in Iowa and numerous other states encourage hunters to use copper and other types of ammunition.

In response to delisting, Iowa is setting up a program for monitoring the state’s 250 nests.

“Eagles are doing well in Iowa; there are more than ever. But we are approaching it a little more rigorously now from a research point of view,” said Stephanie Shepherd, a state wildlife biologist. The greatest concern is agricultural run-off. Chemicals from crops get into waterways and fish, and eagles eat the toxic fish.

“Lead is on our radar screen, but there are no good studies on how prevalent the poison is in a population of eagles,” Shepherd said.

Lead has a more acute impact when it involves shooting eagles. The law on “taking” eagles has changed somewhat since delisting. Under ESA protection, eagles could be disturbed or killed under specific circumstances, with a permit. Two federal laws still prohibit hunting of eagles, but permits remain available for removing nuisance eagles. New rules decrease the radius of the area around a nest that is protected.

Wildlife officials around the country report illegal eagle takings are not rampant, but there have been incidents. In 2009, a Florida man was convicted and sent to prison for shooting an eagle. And in Iowa, an unidentified hunter illegally shot a juvenile eagle that was feeding on a deer carcass.

“Shooting eagles and hawks was a huge problem in the 1950s, but shooting these birds has decreased greatly since then,” said Greg Burcher, Director of Bird Conservation at National Audubon Society. Sometimes eagles compete with fishermen, but rarely clash violently.

According to Burcher, the biggest long-term threats to bald eagles are coastal development and water quality issues.

Arizona birds retain protection

Water is a key survival factor for eagles in Arizona, which remain the only bald eagles in the U.S. still listed. Concerns for their viability have fueled a lasting struggle between conservationists and federal officials, culminating in a lawsuit that has at least postponed delisting the birds.

The Arizona population provides a good illustration of what it takes to bring back a failing flock.

The eagles had dwindled to five pair in the 1970s, when a local Audubon group teamed with the U.S. Forest Service to start a nest-watcher program that remains a key to recovery. Twenty watchers sign up each year to camp out for months in the vicinity of the mostly remote breeding areas, record bird behavior and alert authorities about problems. From the nest-watching activities has grown a consortium of Audubon groups, state and federal authorities, Indian tribes and public utilities that work together to protect and monitor nests and coax the eagle numbers upward.

The ESA’s habitat protection ensured that the state’s burgeoning development and cattle and mining activities wouldn’t take down the trees and cliff sides needed for nests. By now, 61 nesting areas and as many as 50 breeding pairs have been identified, but state biologists say the population remains fragile because it is so small.

Resources budgeted for the bald eagle recovery have been based on their endangered species status. So, when the Fish and Wildlife Service began efforts to delist eagles nationally, conservationists feared resources would dry up.

Maricopa Audubon and the Center for Biological Diversity petitioned to have the Arizona eagles listed separately as a “distinct population segment.” A fish-eating bird in the Sonoran desert, these bald eagles have made some dramatic adaptations to the heat. They are smaller, mate earlier in the season, and their eggs have thicker shells than other eagles. Some evidence suggests that, unlike other eagles, they fare better during drought than rainy periods.

But the Fish and Wildlife Service rejected the petition in 2006, so the groups sued in federal court. Subsequently the court ordered federal authorities to reassess the eagles.  In March, government officials submitted a new assessment, with more outside input, that drew the same conclusion as the first: the Arizona eagles were significantly different, had threats to their survival – but were not important to the survival of eagles in general and therefore should be delisted.

The court has not yet ruled on whether the finding is legal, but alarm is spreading among nature-watchers.

“It’s a very serious problem. It means more water transfers away from eagle nesting areas to cities and new developments. Eagles are going to go down the tubes if they aren’t protected here,” said Dr. Bob Witzeman, conservation chair of Maricopa Audubon.

Witzeman founded the state nest watch program and hired the state’s first nest guardian. In Arizona, eagle survival requires clear abundant streams. Mining and cattle activities can cloud the water with algae and sediment so eagles can’t see the fish they need to eat. Witzeman worries that without the force of the ESA, no one will have the authority to keep waterways unspoiled for eagles.

Because the complicated eagle support committee remains in force, state wildlife biologists are optimistic for the current breeding season. Nest watchers have observed 44 babies, but some eagle pairs haven’t laid their eggs yet. In 2009, 48 babies survived.

Historic rains have stirred up waterways, but in the words of one biologist, “there’s a hell of a fish population this year.”

James Driscoll, an Arizona Game and Fish Department biologist who has worked with Arizona eagles since 1991 when the annual baby count was 18, sees no looming problems, except for the state bureaucracy.

The eagle program is supported by so-called Heritage funds derived from the state lottery. They are increasingly eyed as a solution to a worsening state budget crisis.

“If so, we’ll have to reprioritize. We can’t lose 25 percent of our funding and continue to do the same thing,” said Driscoll.

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