DIRECTION OF THE MIGRATION FLIGHT 27 



approximate computation, have regularly maintained this direc- 

 tion from the first commencement of their migration. Indeed, a 

 migration stream of such force as that which is constituted by these 

 Hooded Crows throughout the whole of October and a great part 

 of November, could only have been generated by a breeding area 

 extending from the western boundary of Russia eastward to 

 Kamtschatka. 



These birds again, which, by reason of their low migration flight, 

 are brought more easily than other species within the sphere of 

 observation, atibrd a most striking proof of the patience, or rather 

 obstinacy, with which migrants continue in the direction of their 

 migration flight. During the autumn migration it frequently 

 happens that when out at sea they are carried into air currents 

 stronger than is suitable to their line of flight, a violent south-east 

 wind being especially unfavourable to their normal progress. To 

 escape the disagreeable experience of having this wind blowing 

 through their plumage obliquely from behind, they turn their body 

 southwai-ds, and appear to be flying in this direction. This, however, 

 is not the case. They do not make the least forward progress to 

 the south, but their flight is continued in as exact a westerly course, 

 and with the same speed, as though the birds were moving under 

 favourable conditions straight forwards, i.e. in the direction of the 

 long axis of their bodies. This is shown in the most convincing 

 manner by such bands as happen to pass immediately over the 

 head of the observer. 



Besides Hooded Crows, many other, indeed perhaps all species 

 are capable of executing a laterally directed movement of flight of 

 this nature, not only under such compulsory conditions as they 

 may encounter during the flight of migration, but also during the 

 ordinary activities of their daily life, and are able to accelerate this 

 movement at pleasure, both for temporary purposes as well as for 

 prolonged periods. Originally, I used to think that Hooded Crows, 

 not being particularly good flyers with a violent side-wind, drifted 

 just as much to leewards as they progxessed straight forwards, 

 after the manner of a badly sailing ship, and that in this way their 

 course came to assume a direction almost exactly west. Continued 

 observations have, however, convinced me that this view cannot be 

 maintained. Moreover, in innumerable instances, I have seen not 

 only Crows, but also Buzzards, notably Honey Buzzards, maintain 

 a similarly-directed migration cour.se. Gulls, again — especially 

 Great Black-backed, Herring, and Common — may be seen daily and 

 hourly flying at a greater or less speed, now to the right, now to the 

 left, in directions at right angles to the long axis of their bodies. A 

 further proof of a migration in a dii'ection from the far east to the 



