. Beginners' Zoology . Fig. 316.—European Swallows {Hirzwdo u7-bica),azsemh\\Tig{ to South. not a bhnd, infallible instinct, but the route is learned andtaught by the old birds to the young ones; they go inflocks to keep from losing the way (Fig. 316); the oldestand strongest birds guide the flocks (Fig. 317). The birdswhich lose their way are young ones of the last brood, ormothers that turn aside to look for their strayed adult males seldom lose their way unless scatteredby a storm. Birds are sometimes caught in storms orjoin flocks of another species and arrive in
. Beginners' Zoology . Fig. 316.—European Swallows {Hirzwdo u7-bica),azsemh\\Tig{ to South. not a bhnd, infallible instinct, but the route is learned andtaught by the old birds to the young ones; they go inflocks to keep from losing the way (Fig. 316); the oldestand strongest birds guide the flocks (Fig. 317). The birdswhich lose their way are young ones of the last brood, ormothers that turn aside to look for their strayed adult males seldom lose their way unless scatteredby a storm. Birds are sometimes caught in storms orjoin flocks of another species and arrive in countriesunsuited for them, and perish. For example, a sea or. BIRDS 173 marsh bird would die of hunger on arriving in a very dry country. The landmarks of the route are mountains, rivers, valleys,and coast lines. This knowledge is handed down from onegeneration to another. It includes the location of certainplaces on the route where food is plentiful and the birdscan rest in security. Siebohm and others have studiedthe routes of migration in the OldWorld. The route fromthe nesting places in^ northern Eu- Africa fol- 4f ^^^^^^^^^ ... rope to lows the Rhine, S^!^^ ~<^ ^^ the Lake of Geneva,the Rhone, whence some spe-cies follow the Itahan and others the Span- fig. 317.—cranesish coast-line to Africa. Birds choose the migrating, withlowest mountain passes. The Old World travels every year from the NorthCape to the Cape of Good Hope and back again ! An-other route has been traced from Egypt along the coastof Asia Minor, the Black Sea and Ural Mts. to Siberia. Field Study of Migration. —Three columns may be filledon the blac
Size: 2408px × 1037px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1920, bookidbeginnerszoo, bookyear1922
