Gbe Marbler 29 



draw up their feet beneath their warm covering of down, and thus every 

 part of the body is protected against the influences of the cold. There is 

 another circumstance with regard to the capacity of birds to endure cold, 

 which is not generally taken into consideration — it is the high decree of 

 temperature in birds. The temperature of the human body is generally 

 placed at 97 or 98 degrees of Fahrenheit. That of animals two or three 

 degrees higher, and that of birds as high as 106 making a difference of eio-ht 

 or nine degrees between bird and man. A large mass of air penetrates the 

 lungs, and all the aerial sacs and canals of the bird, increasing the actions 

 of the heart and propelling the tide of circulation with great rapidity. The 

 pulsations in birds follow each other in such quick succession that they can 

 scarcely be counted. The heat of their bodies being much greater than that 

 of animals they are thus enabled to bear with ease the rigors of cold in the 

 distant North, and in the elevated regions of the air. 



Some birds migrate only from one extreme of our Union to the other. 

 Thus many species that go under the name of Sparrows that breed at the 

 North, with the exception of three: the Snow Bunting {Emberiza nivalis), the 

 Tree Sparrow {Fringilla arbor ed), and the White-crowned Bunting (Fringilla 

 leucophryd) spend their winters in tens of thousands in Carolina. The Mea- 

 dow Lark {Sturnus ludovicianus) and the Brown Lark {Authus spurolettd) which 

 find the snows of the North covering the earth and hiding their fav- 

 orite food, retreat before it and seek sustenance in our Southern States. 

 Other families of birds, such as feed on ripe berries that abound in the win- 

 ter, also remain with us. These are the Robins (Turdus migrator ia), the Wax 

 Bird {Bombicilla americana) and the Bluebird {Saxicola sialis), which feed on the 

 berries of the Tupelo {Nyssa aquaticd), the Holly {Hex opaca), the Capena {Ilex 

 capetia) and the small black or red berries of several species of Smilax and 

 Prinos. Yellow-crowned Warbler {Sylvia corona/a) is the only Sylvia out 

 of fifty species inhabiting the United States that remains with us in the 

 winter, and even this bird could not find a subsistence among us were it 

 not that it almost changes its nature in winter, and lives on the berries of 

 the wild Myrtle {Myrica sibifera). This is always the case with the only Fly- 

 catcher that winters in Carolina. The Pewee fattens on the seed of our im- 

 ported tallow-tree, {Stillingia sebifera). 



It is doubtful whether there are any birds that never migrate in the 

 changes of the seasons. Hawks and Crows are infinitely more abundant in 

 the North in summer than in winter, the greatest number of them retreat 

 southerly. Those of the South may at the same time proceed still farther 

 toward the equinox. Our Cardinal Grosbeaks (Fringilla cardiualis) are 

 found in New Jersey during summer, and abundant in Virginia; hence the 

 name of Virginia Nightingale, and yet during winter very few remain in 

 those states. In the meantime, our own number of birds of this species 



