44 LAND-BIRDS. 



parture, the Catbirds become rather reserved and shy, and I 

 have sometimes been able to detect their presence only by 

 occasionally hearing their characteristic cry, or seeing them 

 fly into " scrub " or other shrubbery, with their broad tails 

 expanded to their fullest extent, as they crossed some road or 

 path and dove into a thicket beyond. Their habits in the 

 fall of the year illustrate the fact that in spring most birds 

 can easily be detected, if even carelessly sought for at the 

 proper season, because of their song, their comparatively little 

 shyness, and those bright tints which, in the case of many 

 birds, are exchanged for duller tints when the summer either 

 is over or draws near to its end ; whereas in autumn, on the 

 other hand, many birds quietly, and in silence seldom bro- 

 ken, continue to spend their days about us, and to migrate 

 through those places where they were conspicuous in spring 

 escaping our observation through their greater shyness and 

 retirement. There are two other partial explanations of the 

 actually and apparently greater abundance of certain birds 

 when passing to the north through eastern Massachusetts 

 than when returning, which are, that in the autumnal mi- 

 grations many species for the most part choose a more inland 

 route, and that in spring the Warblers, for instance, are 

 prompted to their long journeys by a sudden outburst or a 

 gradual approach of genuine warmth, such as gives life to 

 the insects on which they feed ; whereas in fall, unless star- 

 tled by a sudden visitation of cold, they gradually leave their 

 summer homes, and by degrees straggle (if I may use the ex- 

 pression^ to their winter haunts. 27 



d. The song of the Catbirds, which is very much like 

 that of the Brown Thrush, is in some respects a striking one, 

 for the tone and accent are very marked ; and, though some of 

 the notes are rather harsh or uncouth, others are very mellow. 

 This song is not a definite or limited one, but is repeated for 

 several minutes together, from the time of their arrival until 

 the summer is nearly over, especially at evening ; but it is not 

 unfrequently marred or interrupted by the mimicry of others' 



27 It is hoped that the author will be excused for these digressive remarks by 

 those persons who are well acquainted with the facts mentioned. 



