110 RAMBLES ABOUT HOME. 



I know not how, of a strong upper current of air, that 

 bears them along in the direction they desire to go. 



It has been suggested that the vigor of the male birds 

 and the distended ovaries of the females, at this time of 

 the year, are doubtless coupled with a general vigor of 

 the whole body ; but it is questionable if this additional 

 strength of itself is sufficient to enable these birds to fly 

 for hundreds of miles without rest ; and furthermore, if 

 such is the case in spring, they have not this added strength 

 in autumn, when also these long journeys are made. 



Let us next study our birds during the autumn. A 

 careful examination of the many notes, jotted down at 

 frequent intervals, during the months of August, Sep- 

 tember, October, and November, with respect to the de- 

 parture south of such of our birds as are summer resi- 

 dents, and of some that, having passed the summer in 

 regions far to the north, are now likewise seeking their 

 accustomed winter-quarters, indicates an apparent regu- 

 larity in the southward movements of our birds, similar 

 to what is seen in the spring, when they are on their way 

 northward, and at the same time it shows an actual de- 

 gree of irregularity in the dates of departure exceeding 

 that of the dates of arrival. 



An instance of this was brought to my notice one 

 August morning in 1881. As a point of observation for 

 noting the movements of certain birds frequenting the 

 tops of our tallest trees, I sought a seat as near the top 

 of a fine old chestnut-oak as I dared to go. While on my 

 elevated perch, I was surprised to find that, now and then, 

 a stray specimen of some unlooked-for bird would tarry 

 a moment in the tree-tops, and then, resuming its high, 

 southern flight, would pass quickly out of sight. Such 

 birds were orioles, both the Baltimore and orchard ; sin- 

 gle rusty grakles; a Maryland yellow-throat, a ground 



