Page:Bird-lore Vol 01.djvu/335

The Orientation of Birds 107 no interest attached him. With one powerful sweep of his wings he has crossed four or five hundred kilometers, perhaps more, in the wrong direction. Perceiving his error, he knows how, thanks to a mysterious instinct, to take up again his reverse scent and find the point of departure, of which he has hardly caught a glimpse in the morning. The combined action of the five senses cannot explain such a return. The lost dog acts absolutely in the same manner. When taken away in the railwa}' train to a hunting ground entirely unknown to him, if he happens to go astray, he comes back to the point where he saw his master for the last time, and stations him- self there until someone comes to find him, or else, resuming his reverse scent, he reconstitutes in an inverse sense his itinerary through which he has been brought, and finds again his home. The migrations of birds have been the object of observation too well known for us to dilate upon, and we will limit ourselves to explaining, with the aid of our theory, some evident truths. The migratory bird is subject, like his species, which invariably inhabits the same region, to the law of cantonment. Only, he has two domains, one summer residence, the other for winter. We know that the same Swallows come every year to occupy the same nest and to live in the same canton. The same fact is true regarding Storks and many other birds. When the time for departure has sounded, birds of the same kind living in the same region assemble together for the journey. Those w^hich have already made the passage take the head of the flock and follow in an inverse sense the itinerary which brought them to their present quarters. The younger birds, born since the preced- ing trip, limit themselves to following their elders. And when, a few months later, it will be a question of returning, they will be in their turn capable of finding their way unaided. The migratory bird born in our climate not having yet made any journey, that for any reason whatever fails to leave with the other birds, renounces emigrating. It is this way wounded Woodcock, not in a condition to undertake a long journey, resign themselves to living in our country until the following spring. The same thing has been remarked concerning Peewits, Curlews, Storks, or Swallows held in captivity at the time of the departure of their comrades. Some of these birds endure the rigors of the climate ; others, notably the Swallows, succumb to it. Thus, then, it is a sort of tradition that migratory birds transmit to each other from generation to generation the indication of their aerial passage. These passages once traced are immutable. The itinerary of the Quail, which arrive from Africa in Provence,