AVES. 293 



ears. The sense of taste is very Imperfect in all birds, and touch little better, 

 though the latter is amply developed in the ducks and other aquatic birds 

 which seek for sustenance with the bill. In all other birds this sense is very 

 dull, and almost exclusively confined to the feet. 



Birds are eminently migratory. The majority of the species found in the 

 temperate zones during the summer, rearing their young, pass the winter 

 many degrees south of the place of their nativity, and even penetrate into the 

 torrid zone. In the course of these migrations many of the small birds per- 

 form journeys which would appear almost incredible. Many of the American 

 warblers, for instance, pass the winter on the shores of the Gulf of Mexico, 

 and proceed in the spring as far north as Labrador. 



The red winded starling and other birds of North America, known as 

 blackbirds, also proceed during winter to the extreme southern limits of the 

 United States ; while a few species, such as the rose-breasted grosbeak and 

 yellow-breasted chat, push into South America. The migrations of European 

 birds are very remarkable, many of the common species passing the winter in 

 Africa, some species crossing the Straits of Gibraltar, and others venturing 

 boldly across the Mediterranean. 



PI. 105 h presents a view of the migrations of numerous species. These 

 extensive flights are performed during both day and night ; the latter time 

 appears, however, to be that most universally adopted. Some small birds 

 during their migrations fly at very considerable heights, much greater than is 

 attempted by them at any other period. 



Classification of Birds. 



Birds occupy a station in the great circle of the Vertebrata between Quad- 

 rupeds and Reptiles. No class of animals has engaged the attention of 

 naturalists to a greater extent, nor have their conclusions respecting subdi- 

 vision or classifying been more various upon any other subject. 



There are nearly as many systems as there are ornithologists. 



We are disposed to look upon the circular or quinary system of Vigors and 

 Swainson as the first approximation to the natural system, and in all respects 

 the most philosophical. It will be impossible, however, to bring Avithin our 

 limits more than a mere outline of this remarkable system. 



Birds are naturally divided into five orders, each of which, of course, is 

 characterized by general characters. The following is according to the vieAvs 

 of Mr. Swainson. 



1. Insessores, or tj'^pical Birds, comprising all the well known Sparrows, 

 Warblers, Thrushes, Woodpeckers, and other small birds. In this order 

 is found the highest development of the general characters of Birds, the 

 greatest variety and beauty of plumage, and an organization especially 

 enabling them to live habitually amongst trees. 



2. R APTOREs, or rapacious Birds, composed of the Vultures, Falcons, and 

 Owls. These subsist entirely upon animal substances, and are the strong- 

 est and most powerful of all birds. They are strictly analogous to the 

 tigers, dogs, hyenas, and other carnivorous quadrupeds. 



ICONOGRAPHIC EXCYCLOP.EDIA. VOL. II. 32 497 



