Questions 31-40
Most birds are believed to migrate seasonally.
Hibernation theory
It was believed that birds hibernated underwater or buried themselves in 31.
This theory was later disproved by experiments on caged birds.
Transmutation theory
Aristotle believed birds changed from one species into another in summer
In autumn he observed that re
Aristotle’s assumptions were logical because the two species of birds had a
17th century
Charles Morton popularised the idea that birds fly to the 34 in winter.
Scientific developments
In 1822, a stork was killed in Germany which had an African spear in its 35.
previously there had been no 36 that storks migrate to Africa.
Little was known about the 37 and journeys of migrating birds until
It was thought large birds carried small birds on some journeys because they were considered incapable of travelling across huge 38.
Ringing depended on what is called the ‘39’ of dead birds.
In 1931, the first 40 to show the migration of European birds was printed.
