BIRDS OF THE PANAMA CANAL ZONE 



we cannot consider them as distinct species 

 because of intergrading individuals not de- 

 finitely assignable to either form. Such in- 

 termediates occur especially in the areas 

 lying between the territories occupied by the 

 extremes of variation. These geographical 

 races or varieties are designated subspecies, 

 and when they are found to exist, we require 

 for their designation a third word, the sub- 

 species name, added to the bird's scientific 

 name. 



Thus in the name of the Panama House 

 Wren (Troglodytes musculus inquietus) Trog- 

 lodytes is the genus which includes all the 

 house wrens of North and South America, 

 musculus is one of the distinct kinds of house 

 wrens which constitute that genus, and 

 inquietus designates the geographical race 

 or subspecies of the species musculus that 

 inhabits the Canal Zone. I 



In the case of birds of stationary habits, 

 only one subspecies of any species is usually 

 to be found in a given area ; that is, each sub- 

 species has its own territory, but in the case 

 of birds that migrate though this rule 

 generally still applies during the breeding 



1 The reader has very likely observed that the name of 

 some person is often added to the last word (species or sub- 

 species name) of scientific names. This is the authority or 

 author who originally described the species or subspecies 

 as the case may be. If his name is not inclosed in paren- 

 theses he is authority for the whole name as it stands; if 

 it is inclosed in parentheses he is authority for the last 

 word of the name only, the bird being now placed in some 

 genus other than that in which its original describer in- 

 cluded it. This matter of authorities for scientific names 

 is, however, not one that any except ornithologists need be 

 concerned with. 



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