Keystone WILD! Notes
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WINTER 2007-2008

oldest known waterthrush fails to return to pennsylvania

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thrush in the wild
Researchers checked the bird’s band, right, in 2005 to verify that it was the same waterthrush. Photo courtesy of Terry Master
(click on photo to view full-size)

 

For two decades, biologists have taken to the woods, fields and streams of Pennsylvania counties searching for the biological needles in the haystack—the rarest plants and animals.

The oldest known Louisiana waterthrush in the world appears to have made its final nest.
Biologists from East Stroudsburg University say a waterthrush they had observed nesting for more than a decade along a stream in the Delaware Water Gap National Recreation Area did not return last summer.

That suggests the bird did not survive either the trip to or from its winter ground between fall 2006 and spring 2007, respectively.

This individual was the first one captured and banded in May 1995 when Terry Master, a biology professor at the university, and his students were perfecting techniques to study waterthrush productivity in the recreation area.

That project was originally supported by the Wild Resource Conservation Fund because the bird was considered a likely indicator of headwater stream quality within hemlock ravines.

Over the years, Master and his students observed the same banded waterthrush returning to its original territory along Van Campens Brook in the recreation area.

“The annual search for him in April became somewhat of a tradition around here,” Master said. “As his age increased I thought every year would be his last only to find him again the next spring.”

It appears the bird’s last spring may have been 2006, when he and his mate produced five eggs that hatched. But the nest was destroyed before the nestlings had fledged.

Because the bird was an adult in the early spring of 1995, it had to have been hatched in 1994 or a previous year, Master said, meaning it survived at least 13 years.

Previously, the longest-lived Louisiana waterthrush on record was 8 years, 11 months, according to the U.S. Fish and Wildlife Service’s Bird Banding Laboratory.

It was possible to follow the bird year-to-year not only because it was banded, but because the Louisiana waterthrush, a large warbler, often returns to the same nesting site each year. The birds typically nest under root overhangs along stream banks beginning in mid-April.

“It was certainly a privilege to follow his local exploits here over the years and I will return to Van Campen Brook this coming spring, just in case,” Master said.
Males, which establish their territory in April and May, sing loudly to attract mates in order to be heard above the rushing brooks they frequently nest along. They use their long beaks to snatch snails, nymphs and other aquatic animals, including minnows and salamanders on occasion.

The incubation of the typical five-egg clutch lasts for 13 days followed by a 10–11 day nestling period.

After nesting, the waterthrushes are the first migrants to leave for the tropics, usually departing Pennsylvania in late July/early August. Their winter range includes Caribbean Islands, Mexico and Central America.



 

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