386 
BIKD-LIFE. 
advance of the main body. When travelling slowly they 
catch insects on the way; whereas other birds are 
obliged to alight to seek their food. 
Those birds which migrate by night generally rest 
during the day, and those which travel by day do so in 
the afternoon. The latter start again before daybreak, 
flying without a halt until mid-day or the afternoon, when 
they rest from their labours ; if anxious to get on, however, 
they continue their journey towards evening, so as to get 
over a few extra miles. Most strong birds and good 
flyers travel by day, as we have before remarked. Under 
certain circumstances, however, they sometimes fly by 
night, like Sky Larks when they fear bad weather, in 
which case, though, they fly singly, and not in flocks as 
they do in the daytime. Cranes also travel by night 
when they are in a hurry, or have been disturbed 
at their roosting-place. The only true nocturnal 
migrants are the Owls and Goatsuckers, as well as bad 
flyers, such as Kingfishers, Buntings, Quails, Moorhens, 
spotted Crakes, Bitterns, Night Herons, Snipes, Ducks, 
Dippers, Ring Ouzels, Missel Thrushes, Blackbirds, 
Blue-throated Warblers, Robins, common and Philomel 
Nightingales, Whitethroats, and others of the warbler 
family. All these creatures hardly sleep at all during the 
period of migration : this may be gathered from observa¬ 
tions made on caged birds at this season, when they are 
cheerful the whole day long, and restless all night. In 
general the passage of night migrants is much more 
rapid than that of birds travelling by day, owing to the 
interruptions the latter meet with from attacks of birds 
of prey, and by halting to seek for food. 
Unfavourable weather or adverse winds hinder alike 
migrants of both classes—nocturnal and diurnal. Clear 
