INTRODUCTION. 21 
ing Dove are only summer visitors in most of the state, but permanent resi- 
dents in the southernmost counties. For present purposes we may almost 
disregard the so-called permanent residents, merely remarking that although 
several species, including Woodpeckers, Chickadees, Creepers, Grouse, and 
Owls, may be well represented throughout the year in any given locality, 
we have little proof that the individuals representing these species are the 
same, and there is every reason to believe that, with a few exceptions, every 
species of Michigan bird is more or less migratory in some part of its range. 
Apparently the Ruffed Grouse and the Prairie Chicken are stationary in 
Michigan wherever found, yet we know positively that in Minnesota, Iowa, 
and other trans-Mississippi states this last named species makes a well marked 
though not very extensive southward migration in autumn, returning north- 
ward, however, so gradually and quietly that it attracts little attention. 
In attempting to study migration as it occurs in this country the solitary 
observer works at a great disadvantage. Even in the most favorable location 
and with the best equipment in the way of education and time, such an 
observer can do little more than record the observed facts and trust that the 
opportunity may come sooner or later when he or some one else may combine 
his observations with thousands of others and in this way accomplish some- 
thing definite toward the solution of what must be considered one of the 
greatest mysteries of nature. In 1896 the great British naturalist, Alfred 
Newton, said of bird migration, “‘We are here brought face to face with the 
greatest mystery which the whole animal kingdom presents, a mystery 
which attracted the attention of the earliest writers and can in its chief point 
be no more explained by the modern man of science than by the simple minded 
savage, or the poet or prophet of antiquity. The flow and ebb of the mighty 
feathered wave has been sung by poets and reasoned of by philosophers, 
has given rise to proverbs and entered into popular superstitions, and yet 
we may say of it still that our ignorance is immense.” 
Fifteen years have added much to the total of our knowledge of birds, 
yet the gain in that time has come also through subtraction, for we have 
been compelled to unlearn much that was once considered fixed and sure. 
The attempt today to sift the known from the unknown in this matter is a 
task of such gigantic proportions that any scientist may well hesitate before 
the undertaking. It is scarcely possible to exaggerate the mystery, super- 
stition and absurd speculation which has been thrown about this subject. 
Educated writers within the last hundred years have seriously advanced 
the theory that birds leave the earth entirely during winter and migrate to 
the moon, also that swallows and some other species plunge into lakes and 
streams and pass the winter buried like frogs beneath the mud. Hardly 
less absurd are the claims that migrating birds are guided by an instinct or 
by some unknown sense which enables them to travel safely and securely 
both day and night over thousands of miles of land and sea and to arrive 
at last with unerring certainty at the end of a journey, every step of which 
was foreseen from the first. 
No doubt many species make long journeys safely and rapidly, but we 
now know that a heavy percentage of loss of life goes with every movement. 
Undoubtedly certain individual birds find their way back to their birth place 
after a trip of hundreds of miles and an absence of many months; but it is 
more than likely that where one individual succeeds in doing this many 
more fail. Thanks to patient investigation and careful exploration we now 
know pretty accurately where most of our migrants spend their winters, 
and we have much reliable information as to the general routes by which 
