20 
BIRDS OF PENNSYLVANIA. 
Habitat. — North America generally, breeding from Manitoba southward to Vir- 
ginia, Illinois, Texas and California ; in winter southward to Brazil. 
This species is found in Pennsylvania as quite *a rare and irregular 
visitor during the spring and fall migrations. In the summer of 1879 
I visited Cobb’s Island, Virginia, where this Tern was breeding quite 
plentifully in the marshes. Forster’s Tern feeds principally on little 
fish. 
Sterna hirundo Linn. 
Common Tern ; Wilson’s Tern ; Sea Swallow 
Description. 
Adult. — Bill (dried skin) red from base to about half its length, then black, with 
pale-yellowish point; iris brown; legs reddish-yellow; upper part of head and 
hind neck black ; back and wings light bluish-gray ; sides of neck and head, line 
along base of upper mandible, chin, throat, upper and lower tail coverts and most 
of tail, also lining of wings, white ; the outside tail feather has black outer web ; 
sides of breast and of lower part of neck and rest of lower parts grayish-white. In 
the young the bill is blackish and yellow, the latter color especially on lower mandi- 
ble ; tarsi yellowish ; front of head and entire under plumage white ; crown gray- 
ish-white and black plumage about eyes, back of head and upper part of hind neck 
dull black ; back and wings indistinct bluish-gray with patches of light-brown ; 
most of feathers on back edged with white. Length about 14| inches -• extent about 
31 inches. 
Habitat. — Greater part of the Northern Hemisphere and Africa. In North 
America chiedy confined to the Eastern Province, breeding trom the Arctic coast, 
somewhat irregularly, to Florida and Texas, and wintering northward to Virginia. 
The Common Tern or “ Sea-Swallow,” as this bird is commonly called 
by fishermen on the coast of New Jersey, is one of few species of this 
group, which has been frequently found in different sections of our 
state during migrations. Mr. George B. Sennett has observed it as an 
irregular migrant in the spring and fall in the vicinity of Erie city, 
where, I have no doubt, it is oftener met with than in any other section 
of Pennsylvania. Dr. John W. Detwiller, of Bethlehem, in a letter ad- 
dressed to me, says : I have shot the Common, Arctic and Least Terns 
on the Lehigh river in the fall, and he further adds they were “ prob- 
ably driven inland by severe storms.” Mr. August Koch, notes the 
species as an irregular migrant — spring and fall — in Lycoming county, 
and Dr. Walter Van Fleet, of Renovo, has found it in Clinton county as 
a straggler. InBerks county Mr. D. Frank Keller, of Reading, reports 
that he has observed it as an accidental visitor ; according to Dr. A. C. 
Treichler, of Elizabethtown, this bird is a straggler of rare occurrence in 
Lancaster county. Prof. J. R. Robertson, of Franklin, Venango county, 
mentions the Common Tern as a very rare and uncertain visitor in that 
locality. Several specimens of this species have been captured when 
migrating, particularly in the autumn, in the counties of Chester, Dela- 
ware and Philadelphia. The Common Tern breeds in New Jersey and 
elsewhere along the Atlantic, and also about many of the large inland 
lakes and ponds. 
