Bird Migration Theory
Hibernation theory
● It was believed that birds hibernated underwater or buried themselves in
● This theory was later disproved by experiments on caged birds.
Transmutation theory
● Aristotle believed birds changed from one species into another in summer and winter.
- In autumn he observed that redstarts experience the loss of
and thought they then turned into robins.
- Aristotle’s assumptions were logical because the two species of birds had a similar
17th century
● Charles Morton popularised the idea that birds fly to the
in winter.
Scientific developments
● In 1822, a stork was killed in Germany which had an African spear in its
- previously there had been no
that storks migrate to Africa.
● Little was known about the
and journeys of migrating birds until the practice of ringing was established.
- It was thought large birds carried small birds on some journeys because they were considered incapable of travelling across huge
- Ringing depended on what is called the ‘
’ of dead birds.
● In 1931, the first
to show the migration of European birds was printed.