BOOK X. XXXIV, 71-XXXV111. 74 



many days later help would arrive and a sortie must 

 be made. 



XXXV. Blackbirds, thrushes and starlings also ^^!'^ 

 migrate in a similar way to neighbouring districts ; 

 but these do not moult their plumage, and do not 



go into hiding, being often seen in the places where 

 they forage for winter food. Consequently in Ger- 

 many thrushes are most often seen in winter. The 

 turtle-dove goes into hiding in a truer sense, and 

 moults its feathers. Wood-pigeons also go into re- 

 treat, though in their case also it is not certain exactly 

 where. It is a pecuHarity of the starhng kind that 

 they fly in flocks and wheel round in a sort of circular 

 ball, all making towards the centre of the flock. 

 The swallow is the only bird that has an extremely 

 swift and swerving flight, owing to which it is also 

 not liable to capture by the other kinds of birds. 

 Also the swallow is the only bird that only feeds 

 when on the wing. 



XXXVI. There is a great difference in the seasons ^^^.'^ 

 of birds ; some stay all the year round, e.g. pigeons, 

 some for six months, e.g. swallows, some for three 

 months, e.g. thrushes and turtle-doves and those 

 that migrate when they have reared their brood, 

 such as woodpeckers and hoopoes. 



XXXVII. Some authorities state that every year ^^ African 

 birds fly from Ethiopia to Troy and have a fight 



at Memnon's tomb, and consequently they call them 

 ' Memnon's daughters.' Cremutius records having 

 discovered that every four years they do the same 

 things in Ethiopia round the royal palace of Memnon. 



XXXVIII. The meleagridesa in Boeotia fight in a ^noti^r. 

 similar manner ; this is a kind of hen belonging to 

 Africa, hiunp-backed and with speckled plumage. 



339 



