Raptor sets longevity record

[Lee Borgersen]

 
 Raptors banded by Duluth's Evans set longevity record


  Apr 21, 2015



 


 
How long can a bald eagle live in the wild? Well, at least one has lived more than 33 years, and Duluth's David Evans banded the bird when it was a chick.

 


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Evans, a longtime raptor bander and former lead bander at Duluth's Hawk Ridge Bird Observatory, learned recently that an eagle he banded in 1981 near Minong was officially the longest-living banded eagle in the United States. It lived 33 years, 5 months, surpassing the former eagle longevity record of 32 years, 10 months, according to the Bird Banding Laboratory at the U.S. Geological Survey's Patuxent Wildlife Research Center in Laurel, Md.

The eagle that surpassed the longevity record was found dead on Nov. 26, 2014, along a road two miles west of Thorp, Wis., east of Eau Claire. It was near a power line, but there were no obvious injuries to suggest a cause of death, Evans said. Its band information was passed along to the research center.


Birding experts don't know the average longevity of eagles, said Duluth birder Laura Erickson. Many don't make it to their first birthday, she said, but for those that do, life expectancy increases significantly.

"We can expect to be breaking the (longevity) record surprisingly often until we get a better sense of what their longevity really is," Erickson said.

In the 1980s, it was common for Evans to climb high into pine trees to band eagle chicks still in the nest, a practice that didn't always please the adult eagles. Eagles were much less common at that time than they are today.


"At the time," Evans said, "we were banding at over 90 percent of the bald eagle nests in the state."

In October 2010, an eagle Evans had banded on June 18, 1978, was found dead on the Drummond Grade, seven miles northwest of Two Harbors. That bird's band information was sent to the USGS lab in Maryland, and it was determined that the eagle was the second-oldest banded eagle at 32 years and 4 months old.

The former oldest banded eagle, 32 years and 10 months old, was banded in Maine in 1977 and found dead in New Brunswick, Canada, in 2010.

None of this is to say that some eagles still flying might not be older than these birds. Only if a bird is banded and later recovered can researchers at the USGS be certain of its age.

A couple of times a year, Evans hears about the death of eagles he has banded, he told the News Tribune in 2010.


Starting in 1970, Evans joined two others who had been banding eagle chicks in Wisconsin since the mid-1960s. At that time, the eagle population was endangered because of the pesticide DDT in the environment. DDT weakened the eggshells of eagles and other birds, preventing successful nesting. When DDT was banned in 1972, eagles began to make a comeback and now are off the endangered species list.

Evans acquired another longevity record in February for a gyrfalcon he caught off Connors Point in Superior. He originally had banded the gyrfalcon on Jan. 18, 2003, as a third-year male. When he recaptured it on Feb. 1 this year, it was 14 years, 8 months old, eclipsing the former banded gyrfalcon longevity record of 13 years, 6 months.

 

Duluth raptor bander David Evans holds a gyrfalcon he captured near Connors Point in Superior in February. He orginally had banded the bird as a 3-year-old in 2003. At 14 years, 8 months, it's the oldest banded gyrfalcon known to researchers. A bald eagle Evans originally banded in 1981 has been recognized as the oldest banded bald eagle in the United States. Sigrid Sorensen photo


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