Philadelphia Vireos top list of Lehigh Valley bird sightings

Philadelphia Vireo

A profusion of sightings of migrating Philadelphia Vireos were reported during the week that ended on September 18. The unusual thing about these sightings is that the bird is seen infrequently in the Lehigh Valley even during migration, according to Birds of the Lehigh Valley and Vicinity.

Despite their name, the species is rarely are seen in Philadelphia except during migration. John Cassin, the American ornithologist, gave the bird its name upon observing one in Philadelphia in September 1842.

The Philadelphia Vireo is one of the most northerly breeding species of vireo. It spends its summers in northern New England and southern Canada from the maritime provinces west as far as Saskatchewan. It winters in the Yucatan Peninsula and Central America.

The species breeds in the treetops of second-growth aspens, birches, alders and ashes in woodlands and parklands. The birds forage for insects in trees, sometimes hovering or flying as they pick off their prey. They've even been known to hang upside down to catch insects at the tips of twigs. Their favorite meals are caterpillars, moths, beetles, wasps, bees and ants. They also eat the berries of bayberry and dogwood when the fruit becomes abundant in late summer and early fall.

Philadelphia Vireo

The Philadelphia Vireo is fairly small, less than 5 inches long and about 8.5 inches from wingtip to wingtip. Their appearance is similar to that of other species. For instance, the Philadelphia Vireo and the Warbling Vireo both lack wing bars, but the former has a strong yellowish cast across its breast and a more distinct white eyebrow. The Philadelphia Vireo's bill is stouter than that of a Tennessee Warbler. The vireo's back is grayish green; the warbler's is a brighter green.

Within the past week, Philadelphia Vireos have been seen in Northampton, Lehigh, Carbon and Bucks counties, according to reports compiled by Dave DeReamus of the Eastern PA Birdline, which is sponsored by the Lehigh Valley Audubon Society. 

Upper Mount Bethel Township, Northampton County
(along National Park Drive)
Philadelphia Vireo, 1 on September 15; 4 on September 18.
Gray-cheeked Thrush, 1 on September 18.
(along Institute Road)
Philadelphia Vireo, 1 on September 13.

Martins Creek Environmental Preserve, Northampton County
(Tekening area)
Philadelphia Vireo, 1 on September 17.

Albert Road Ponds, Northampton County
Caspian Tern, 1 on September 12.

Jacobsburg State Park, Northampton County
Philadelphia Vireo, 1 on September 11; 2 on September 12; and 1 on September 16.

Williams Township, Northampton County
Blue Grosbeak, 1 on September 14.
Also seen: Cerulean Warbler.

Little Gap, Carbon County
Bald Eagle, 5 on September 17.
Broad-winged Hawk, 832 on September 17.

Little Gap village, Carbon County
Connecticut Warbler, 1 on September 17.

Beltzville State Park, Carbon County
Yellow-bellied Flycatcher, 1 on September 13.
Philadelphia Vireo, 1 on September 15.
Connecticut Warbler, 1 on September 12.

Leaser Lake, Lehigh County
Connecticut Warbler, 1 on September 13.

Bake Oven Knob, Lehigh County
Bald Eagle, 6 on September 11; 23 on September 13; and 7 on September 14 and September 18.
Northern Goshawk, 1 on September 12.
Broad-winged Hawk, 678 on September 16; 1,237 on September 17; and 1,026 on September 18.
Merlin, 4 on September 13 and 5 on September 14.
Peregrine Falcon, 1 on September 13 and September 16.
Philadelphia Vireo, 1 on September 13 and September 17; and 2 on September 16.
Other species reported in addition to Dave DeReamus's report:
Warbler species: Magnolia, Black-throated Blue, Black-throated Green, Black-and-white, Chestnut-sided, Blackpoll and Blackburnian.
Other species: Northern Parula, Common Raven, Red-eyed and Warbling Vireos, Common Nighthawk and Eastern Wood-pewee.

Trexler Park, Lehigh County
Olive-sided Flycatcher, 1 on September 11.

Green Lane Reservoir, Montgomery County.
(at the Church Road area)
Northern Pintail, 1 from August 27 to at least September 12.
Snowy Egret, 1 from September 12 to at least September 17.
Little Blue Heron, 1 on September 13.
Stilt Sandpiper, 1 on September 11 and 3 on September 12.
Sanderling, 1 on September 12.
Red-necked Phalarope, 1 on September 13.

Peace Valley Park, Bucks County
Glossy Ibis, 1 on September 12 (a fly-by).
Lesser Black-backed Gull, 13 during the past week.
Philadelphia Vireo, 1 on September 15.

Merrill Creek Reservoir in New Jersey
(at Scotts Mountain Hawkwatch)
Bald Eagle, 12 on September 14.
Broad-winged Hawk, 449 on September 13; 647 on September 16; 1,025 on September 17; and 406 on September 18.
Merlin, 3 on September 16.
Peregrine Falcon, 1 on September 16.
Red-headed Woodpecker, 1 on September 11 and September 17.

To report bird sightings to Dave DeReamus, send an e-mail to becard@rcn.com with the word "Birdline" in the subject heading.