White-winged tern visits Pennsylvania for the first time
Anglers often visit Tioga County’s Lake Nessmuk to try their luck for panfish or largemouth bass, but it was another species that attracted crowds to the lake in August.
Thursday was Rich Hanlon’s day off — he set out to see what birds might be around a few local lakes. His first stop was Lake Nessmuk, just a short distance from his home in Wellsboro. He stopped about 40 yards short of the water’s edge when he noticed an unusual dark-colored bird perched on a post. He checked it out with his binoculars — it had some gray on its face — and he thought it might be a molting black tern.
“Believing I was in the presence of a rare migrating black tern, I called my birding friends, Kathy Riley and John Corcoran, both active in the Tiadaghton Audubon Society,” Hanlon said.
Riley and Corcoran arrived 10 minutes later — about 11:45 — and the trio used their binoculars, camera, spotting scope and a field guide to rule out the rare black tern. Instead, they suspected that they could be looking at a super-rare white-winged tern.
The white-winged tern is a Eurasian species that visits the United States very infrequently. According to The Sibley Field Guide to Birds of Eastern North America, it is unusual to have even one reported sighting in the U.S. each year. Unlike the common or Forster’s terns that one might see on the Atlantic Coast, the white-winged tern never plunge-dives. It feeds on the wing by catching large insects in the air or skimming small fish from the surface of the water.
“We got the word out quickly, and within a few hours, crowds were beginning to form at the lakeshore,” Hanlon related. “It was mostly locals at first, but then people from all over Pennsylvania and New York were there by evening on that first day – Aug. 10.”
At 5 p.m., a team arrived from the Cornell Lab of Ornithology in Ithaca, N.Y. They verified the identification made by the three local birders. It was a rare white-winged tern – it was the first sighting in the United States this year and the first-ever reported in Pennsylvania.
At 60 acres, Nessmuk is a rather small lake. So why did the white-winged tern visit there?
“I was told by the Cornell crew that one of the reasons the tern decided to settle at Nessmuk was because the habitat is very good for it,” Hanlon said.
In Europe, white-winged terns prefer unpolluted, shallow marsh habitats that have good perches close to the water’s surface. Lake Nessmuk is a small, shallow, Fish and Boat Commission-owned impoundment, with post clusters sticking out of the water and downed treetops to provide perches for the tern.
There was rain the following evening, Aug. 11, but about a dozen birders, including this blogger, braved the weather and were clustered around cameras and spotting scopes set up on tripods. Once the rain stopped, the crowd size quickly doubled – including a photographer from Pittsburgh and birders from New Hampshire and Massachusetts.
Cameras would really start clicking when the tern left its perch to feed. However, resident barn swallows that seemed to resent the competition for food harassed it each time. According to Hanlon, the swallows would roost just before dark, allowing the tern to feed in peace.
“My favorite experiences with the white-winged tern were in the evenings, just before dark, when it would go into a feeding frenzy, making pass after pass over the shallow marsh at the south end of the lake,” Hanlon said. “The chimney swifts especially seemed to welcome the white-winged tern and there were moments when the tern would assimilate with their flock, moving in unison with the swifts through areas of densest insect activity.”
It was a good find for Hanlon, the pastor of United Methodist Church in Wellsboro. According to the Tiadaghton Audubon Chapter, approximately 300 people came to Wellsboro to see the rare bird over those four days — some from as far away as Florida, Texas and Colorado. The highest numbers of onlookers were at Nessmuk during the weekend of Aug. 12-13. Many frequented local restaurants and hotels, making a welcomed economic impact on a small community.
“Another observation I’ve made through this experience is that it pays to nurture healthy ecosystems,” Hanlon said. “This is something that we can all participate in together – for the sake of the birds and our local economy.”
The white-winged tern was last seen on Aug. 13.