All eyes on the eagles: Eagle Expo brings experts to area

The hit of the Cajun Coast Visitors & Convention Bureau’s annual Eagle Expo is always the boat tour of waterways near Morgan City. There, tourists can see and photograph bald eagles in the Atchafalaya Basin habitat that helped sustain the species against bounties, development and DDT.
One vital part of the tour wasn’t there when the boat cast off Friday and Saturday. Lester Giordano, better known as Cajun Jack, died Feb. 7 after years of piloting his tour boat for the Eagle Expo. His stepson, Scott Estay, was at the wheel.
The eagles were present, too, perched atop tall trees along the canals, sometimes standing still as the boat drifts closer as if waiting for their annual turn in the spotlight.
But while the eagles steal the show every year, dedicated birders also show up early Saturday morning for breakfast at the local Holiday Inn and presentations by experts on eagles specifically and birds generally.
One was Nick Smith, researcher and GIS-remote sensing analyst for Ducks Unlimited, who recently conducted a study of Louisiana eagles in conjunction with the LSU AgCenter, the U.S. Geological Survey, the U.S. Fish & Wildlife Service and other organizations.
Smith shared the good news about eagles: After only seven active nests were counted in Louisiana 1975, 387 nests were counted by 2008.
Smith and information from the Fish & Wildlife Service say the resurgence came about because of the 1972 federal ban of the insecticide DDT, which hampered breeding by making egg shells thinner and breakable, and laws such as the 1940 Bald and Golden Eagle Protection Act, which went beyond a hunting ban to prohibit disturbing eagle nests.
In Louisiana, the original goal was to help bring back 40 active nests. Louisiana had 40 nests by 1990, and the number has been increasing 10 to 15 percent per year.
“We’ve exceeded those goals, and the population is increasing exponentially with really no sign of slowing as of 2008,” Smith said.
The Basin, which accounts for 18 percent of Louisiana’s area, is home to 81 percent of the active bald eagle nests. And, despite the good habitat for eagles, the concentration was a puzzle because so much land is being lost — a piece of land as big as a football field disappears every hour.
Using mapping software and aerial photos, Smith went looking for the sort of land cover that is amenable to successful eagle nesting. Trees are obviously important for nesting, and so are the distance from houses and the availability of open water where eagles can catch fish.
But Smith’s most reliable model, accurate about 70 percent of the time, found another variable: distance from roads. Not only does the Basin have a lot of trees and a lot of fish, but it also tends to lack roads.
The eagles could benefit from even more protection if wildlife management officials could trace the routes eagles use to migrate north from south Louisiana in late summer.
So Smith trapped eagles. He used nutria carcasses to lure them within the range of rocket nets, which were fired remotely. Once in the nets, the eagles were fitted with hoods to cover their eyes, which made them docile. Then they were fitted with solar-powered location transmitters held on the eagles’ backs with harnesses made of Teflon.
Of the 16 eagles trapped, five are still transmitted useful information, Smith said. He identified three major flyways: one more or less straight north, one each bending off to the east and west.
Smith discovered some interesting behavior. One eagle got as far as Illinois and stayed there. Another flew all the way to British Columbia in western Canada, then turned around and came back to Louisiana after only five days.
Mapping software also played a role in the work in which presenter Matt Brady of Baton Rouge, who talked about the Louisiana Bird Atlas, which he called a “fine-scale database of distribution” for all bird species. The project involved 200 observers who put in 25,000 hours between 2007-14 to develop 500,000 records, or individual observations, for the database.
The database and the color-coded maps based on the data turned up a few mysteries. Why, for example, is the American robin, so common in much of the United States, relatively rare in Louisiana except along the northern border? And why are so many of its nesting sites elsewhere concentrated in cities?
“Maybe there’s something about human habitation that is allowing these robins to breed south of their main range …,” Brady said. “
“What it is about metropolitan areas that allow them to breed outside their main range – I really don’t know what it is,” Brady said.