( vi ) 
mometrical and Barometrical observations, which occur under this head, are given on the authority of my ever- 
venerated maternal uncle, the late David Rittenhouse, Esq. These observations were made in Philadelphia. 
§.v. 
It must not be imagined, that I communicate these sketches to the public as exhibiting even the names of all th( 
migratory birds of Pennsylvania. I am persuaded, that many of these birds have escaped my notice. This is, per- 
haps, especially the case with the birds of the genera Anas, Tringa, and of the extensive order of Passeres, &c 
which I suspect are constant in their migrations from the north to the south, and from the south to the north. M 
good many of the birds which are mentioned by Mr. Pennant as natives of New- York have not hitherto, to mj 
knowledge, been observed in Pennsylvania : but it can hardly be supposed that those species which are common iij 
New- York (if we except such as delight in the vicinity of the sea-coast) are uncommon, or never seen, in Pennsyl- 
vania. Here, however, I must observe, that I cannot but suspect, that Mr. Pennant, Mr. Latham, and other able 
ornithologists, have sometimes described as distinct species, birds which merely differ in sex, or in age, and in theii 
coloming, for which these animals, at different seasons of the year, are so remarkable. 
§.vi. 
Besides the constant migratory birds, there are others, which may be denominated occasional migratory, or visit- 
ant, birds of Pennsylvania. Such, not to mention several others, are the Columba passerina, or Ground-Pigeon 
the Fringilla bicolor, or Bahama-Finch, and a species of Psittacus, or Parrot. i 
§.vii. 
The. two first of these birds were seen in the neighbourhood of Philadelphia, between thirty and forty years ago 
The Psittacus, most probably the Psittacus pertinax, Illinois Parrot, or the Psittacus carolinensis, Carolina Parrot 
has been occasionally observed in Shareman's Valley, on Shareman's Creek^ a branch of the river Susquehanna 
within twenty miles of the town of Carlisle.* This last fact seems to contradict the observation of Mr 
William Bartram, who says, " The parakeet (Psittacus carolinensis) never reach so far north as Pennsylvania, whicl 
to me is unaccountable, considering they are a bird of such singular rapid flight, they could easily perform the jour 
ney in ten or twelve hours from North-Carolina, where they are very numerous, and we abound with all the fruit; 
which they delight in."t It is well known, that the late M. de BufFon had limited the range of the whole of th( 
Parrot-kind to exactly twenty-five degrees on each side of the equator. J Mr. Pennant has shown that the eloquen 
French naturalist was, in this instance, mistaken. §' My observation is an additional objection to the hypothesis. J 
may add, that a very large flight of parakeets, which came from the westward, was seen, a few years ago, abou 
twenty-five miles to the north-west of Albany, in the state of New- York. The arrival of these birds in the deptl 
of winter || was, indeed, a very remarkable circumstance. The more ignorant Dutch settlers were exceedingly 
alarmed. They imagined, in dreadful consternation, that it portended nothing less calamitous than the destructioi 
of the world. H 
§.VIII. 
I suspect it will be found, that, in general, our southern birds migrate farther north in the tract of country wesi 
than in that east of the great ranges of our mountains. With respect to the birds, I hazard this merely as a con- 
* A friend of mine has informed me, that the Parakeet Been in this valley is the same species which is frequently met with in the neighbourhood o 
the river Ohio. This last is 8upi)08ed to be Pwittacus i)ertinax. 
t Travels through North and South Carolina, Georgia, East and West Florida, &c. P. joi. Philadelphia: 1791. 
I Histoire Naturelle des Oiseaux. Tom. XI. P. iij and 114. Duodecimo-edition. Paris: 1780. § Arctic Zoology. Vol. I. P. 285. 
II In January, 1780. % This fact was communicated to me by Egbert Benson, Esq. of the. State of New- York. 
