°So4 J Field, Birds of Port Henderson, Jamaica, W.I. 11^ 



immediate cause), and to unusual protracted warmth enlarging 

 the food area and encouraging birds northward. 



(c) To failure of food independent of sudden severe cold. 



(6) That extended protraction of migration southward and the 

 partial passage further south of regular winter and resident 

 species, that are uninfluenced by sudden ice and snow, are due to 

 adjustment in distribution that prevents over-crowding, and not 

 to climatic reasons. 



(7) That fixity in destination in the majority of birds is as 

 essential as migration itself, for without it there could be no uni- 

 formity of dispersion. 



(S) That time, experience, and a high order of intelligence 

 have brought about the adjustment necessitated by the physical 

 conditions. 



I have thus presented the facts observed during a long field 

 experience and the conclusions and inferences that have suggested 

 themselves in my endeavor to interpret them. 



NOTES ON THE BIRDS OF PORT HENDERSON, 

 JAMAICA, WEST INDIES. 



BY GEORGE W. FIELD. 1 



The beautiful island of Jamaica, though but a little larger in 

 area than the State of Massachusetts, presents many diverse con- 

 ditions affecting the local distribution of its bird-life. On 

 account of the regularity with which these conditions are main- 

 tained, there is a remarkable uniformity in the species and 

 numbers of birds found at any given locality. Chiefly on 



1 [An annotated list of the Birds of Jamaica, by Mr. W. E. D. Scott, was recently 

 published in 'The Auk,' in instalments beginning with the number for October, 1891, 

 and closing with the number for October, 1893. It is but just to Mr. Clark to state 

 that the article here printed was received for publication in March, 1892, and has been 

 unavoidably delayed. As Mr. Scott's observations were made in December, January, 

 February, and March, and Mr. Clark's in May, June, July, and August, the two lists 

 admirably supplement each other. — Edd.] 



