THE MIGRATION OF INLAND BIRDS. 101 



with some is surprisingly regular, though not absolutely 

 so, as is so often asserted. 



Let us now glance at the peculiarities of this family 

 of birds, and compare them with the thrushes and war- 

 blers. One marked difference is seen in their wonderful 

 flight-power, the thrushes and warblers being weak in 

 their powers of flight, positively as well as compara- 

 tively ; and my observations bear me out in asserting, as 

 a law of migration, that its regularity is in proportion to 

 and solely dependent on the flight-powers of the species. 

 With the entire list of inland birds of New Jersey we 

 believe this to hold good. 



I have already expressed my belief that many birds 

 have the ability to foretell a coming storm. As this is not 

 directly connected with the subject of migration, as I am 

 now considering it, I will pass to another feature of this 

 prophetic power, as it apparently is, in birds, and that is, 

 their ability to judge of the general character of the com- 

 ing season by a visit of a few days' duration early in spring. 

 I have so frequently noticed that certain birds, common 

 to a locality during the summer, occasionally fail to visit 

 it, except in the case of one or two individuals, that come 

 for a few days in April, that it has appeared as if these 

 pioneer birds had satisfactory reasons for believing that 

 there would be a scarcity of food, and so returned to meet 

 their fellows, and, informing them of the fact, they all de- 

 parted to " fresh fields and pastures new," just as a single 

 crow, discovering danger, will turn a whole colony from 

 their course as they are going to their roosting-place. This, 

 be it understood, is a supposition, and may be wholly un- 

 true ; but how are we to interpret the meaning of any 

 habit or particular movement of a bird, except by the 

 human standard ? An act on the part of a bird is intel- 

 ligible to us only as we would interpret a corresponding 



