PERCHING BIRDS. 109 



their peculiarities not easily understood by any but 

 ornithologists, it will be better to consider the series 

 of fifty families of Passeres as one compact group, and 

 endeavour to point out what external peculiarities are 

 most distinctive of those which inhabit tropical countries. 



Owing to the prevalence of forests and the abundance 

 of flowers, fruits, and insects, tropical and especially 

 equatorial birds have become largely adapted to these 

 kinds of food ; while the seed-eaters, which abound in 

 temperate lands where grasses cover much of the sur- 

 face, are proportionately scarce. Many of the peculiarly 

 tropical families are therefore either true insect-eaters or 

 true fruit-eaters, whereas in the temperate zones a mixed 

 diet is more general. 



One of the features of tropical birds that will first 

 strike the observer, is the prevalence of crests and of 

 ornamental plumage in various parts of the body, and 

 especially of extremely long or curiously shaped feathers 

 in the tails, tail-coverts, or wings of a variety of species. 

 As examples we may refer to the red paradise-bird, 

 whose middle tail-feathers are like long ribands of 

 whalebone ; to the wire-like tail-feathers of the king 

 bird-of-paradise of New Guinea, and of the wire-tailed 

 manakin of the Amazons ; and to the long waving 

 tail-plumes of the whydah finch of West Africa and 

 paradise-flycatcher of India ; to the varied and elegant 

 crests of the cock-of-the-rock, the king-tyrant, the 

 umbrella-bird, and the six-plumed bird-of-paradise ; 

 and to the wonderful side-plumes of most of the true 

 paradise-birds. In other orders of birds we have such 

 remarkable examples as the racquet-tailed kingfishers 

 of the Moluccas, and the racquet-tailed parrots of 



