Bird migration theory: listening answers and explanations
A lecture on how ideas about bird migration developed. The speaker covers early theories of hibernation and transmutation, a seventeenth-century claim that birds flew to the moon, the 'arrow stork' of 1822 and the bird-ringing studies that finally showed where birds go.
One ten-gap note block in order. The lecture follows the headings: hibernation (31), Aristotle's transmutation (32-33), Charles Morton (34), then the scientific developments in date order: the stork (35-36), ringing (37-39) and the 1931 atlas (40).
Answer key and self-check
Type what you wrote and hit mark. Hide the key first if you haven't done the part yet. Every question number jumps to its explanation.
How to attack this block: All ten gaps are nouns, and the notes give you names and dates (Aristotle, Charles Morton, 1822, 1931) to hold on to. Several answers are short words said once (mud, moon, neck), so keep your eye one line ahead. Watch plurals: feathers, destinations, oceans.
Question 31
Answer: mudHibernation theory, right after the underwater idea
What did people think birds buried themselves in?
Another theory for the regular appearance and disappearance of birds was that they spent winter hidden in mud till the weather changed
Question says → You hear
buried themselves inspent winter hidden in mud
Why: 'Hidden in mud' is paraphrased as 'buried themselves in'. One word: mud.
The trap: Seas and oceans come just before, but they belong to the underwater part, which is already in the note.
Question 32
Answer: feathersWhen the lecturer describes Aristotle watching redstarts and robins
What did redstarts lose in autumn?
He observed that in the autumn small birds called 'redstarts' began to lose their feathers
Question says → You hear
experience the loss ofbegan to lose their feathers
Why: 'Began to lose their feathers' becomes 'the loss of feathers'. Plural.
The trap: 'Disappearance' comes up a lot in this section, but what the redstarts lost was their feathers.
Question 33
Answer: shapeEnd of the Aristotle section
What did redstarts and robins have in common?
These assumptions are understandable given that this pair of species are similar in shape
Question says → You hear
assumptions were logicalThese assumptions are understandable
had a similarare similar in shape
Why: 'Similar in shape' becomes 'a similar shape'. One word: shape.
The trap: Species is in the same sentence ('this pair of species'), but the species are the two birds. The gap is what they share: shape.
Question 34
Answer: moonWhen the lecturer calls it 'the most bizarre theory'
Where did Charles Morton say birds go in winter?
He wrote a surprisingly well-regarded paper claiming that birds migrate to the moon and back every year.
Question says → You hear
birds fly to thebirds migrate to the moon and back
Why: His paper said birds migrate to the moon. 'The' is printed, so write moon.
Question 35
Answer: neckWhen the lecture reaches 1822
Where was the African spear stuck in the stork?
This particular stork made history because of the long spear in its neck which incredibly had not killed it
Question says → You hear
an African spear in itsthe long spear in its neck
Why: The spear was in its neck. The note already has 'in its', so the gap is neck.
The trap: Germany and Central Africa are said around it, but they are places, not the part of the bird.
Question 36
Answer: evidenceWhen the lecturer calls it 'a truly defining moment'
What had there been none of before the stork?
it was the first evidence that storks spend their winters in sub-Saharan Africa
Question says → You hear
previously there had been noit was the first evidence
Why: If this was the first evidence, there had been no evidence before. The note turns the sentence round, but the word is the same.
The trap: History and ornithology are in the same sentence, but neither fits 'no ... that storks migrate to Africa'.
Question 37
Answer: destinationsWhen the lecturer says people didn't know much until ringing became established
What, besides journeys, was little known about?
very little information was available about the actual destinations of particular species and how they travelled there
Question says → You hear
Little was known about thevery little information was available about the actual destinations
journeyshow they travelled there
Why: 'Very little information' matches 'little was known', and the two unknowns are destinations and how they travelled. Plural: destinations.
The trap: Species comes right after 'destinations of particular', but the note is about where the birds go, not which birds.
Question 38
Answer: oceansWhen the lecturer explains the 'taxi service' idea
What were small birds thought unable to cross?
it seemed impossible that small birds weighing only a few grams could fly over vast oceans
Question says → You hear
incapable of travelling across hugeimpossible that small birds … could fly over vast oceans
The note turns it round: 'previously there had been no ...'. The lecture says the stork was 'the first evidence', so before that there was no evidence.
The lecture says 'actual destinations of particular species and how they travelled there'. The note's 'and journeys' covers the second part, so the gap is destinations, plural.
The word is said in quotation marks, 'recovery', and then explained. Don't write 'found' or 'identified' from the explanation.
Words from this recording worth keeping
hibernate(Hibernation theory)
spend the winter in a state like deep sleep
abundant(Hibernation theory)
existing in large amounts
instinct(Hibernation theory)
a natural behaviour an animal is born with
transmutation(Transmutation theory)
changing from one form or species into another
bizarre(17th century)
very strange
well-regarded(17th century)
thought of highly by others
ornithology(Scientific developments)
the scientific study of birds
speculated(Scientific developments)
guessed without firm evidence
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The full Cambridge 17 Test 3 listening paper with the real audio: all four parts, played once, marked the moment you finish. Already done it? Take it again and listen for the traps this page showed you.
Cambridge IELTS 17, Test 3, Listening Part 4. The recording, transcript and questions belong to Cambridge University Press and are not reproduced here. We quote short extracts of the transcript only as evidence for our own commentary, and the answers are published for self-marking. Get the book for the full material, or sit the test on Langujet.
