On the Migration of North American Birds. 83 



feathers are so light, that they float in the atmosphere, for many 

 hours, with very httle artificial support. The tubes of these feath- 

 ers are hollow ; the bones are specifically lighter than those of quad- 

 rupeds ; the bones, also, are hollow, and instead of marrow, are filled 

 with air. They are furnished with lungs of an unusually large size, 

 adhering to the ribs, and provided with aerial cells, insinuating them- 

 selves into the abdomen. These, added to the great length and 

 strength of wing, enable them, with ease and rapidity, to navigate 

 the air — to elevate themselves above the clouds, and pass from one 

 country and climate to another. 



We perceive, then, from the very structure of birds, that they 

 are admirably formed for rapid flight and migration. From a varie- 

 ty of accurate experiments, which have been made, at different pe- 

 riods, it appears, that the Hawk, the Wild Pigeon, (Columba migra- 

 toria^) and several species of wild ducks, fly at the rate of a mile 

 in a minute and a half; this is at the rate of forty miles an hour, 

 four hundred and eighty between the rising and setting of the sun, 

 and nine hundred and sixty miles in twenty four hours. This would 

 enable birds to pass from Charleston to our distant northern settle- 

 ments in a single day, and this easily accounts for the circumstance, 

 that geese, ducks, and pigeons, have been taken in the northern and 

 eastern states, with undigested rice in their crops, which must have 

 been picked up in the rice fields of Carolina or Georgia but the day 

 before.* There is a well attested account of a falcon from the Ca- 

 nary Islands, sent to the Duke of Lerma, which returned from An- 

 dalusia to the Island of TenerifFe in sixteen hours, which is a pas-, 

 sage of seven hundred and fifty miles. The story of the falcon of 

 Henry the second is well known, which, pursuing with eagerness, 

 one of the small species of bustards at Fontainbleau, was taken, the 

 following day, at Malta, and recognized by the ring which she bore. 

 Swallows fly at the rate of a mile in a minute, which would be one 

 thousand four hundred and forty miles in twenty four hours. That 

 many birds continue their migrations by night, as well as by day, 

 and are thus enabled to make an additional progress, may be easily 

 ascertained from their notes, which, in autumn and spring, the sea- 

 sons of their migration, we often hear by night. The cries of geese, 



* I had an opporlunity, several years ago, in ihe state of New York, of examin- 

 ing the contents of the craws of several pigeons, taken from the same flock, which 

 were pronounced by the country people to be rice. It proved, however, to be a 

 different grain, the wild rice of the western lakes, {Zizania aquatica.) 



