Bird Song Study: Which Summary Is Defensible?
Text: 'A 2023 study in Tenerife compared bird song in two pine forests: one beside a busy road, one 3 km away. Birds near the road sang at a higher minimum frequency. The researchers stress this is a behavioural adjustment, not proof of long-term adaptation, and that recordings were made only in spring. A local newspaper reported: "Road noise is forcing birds to change their songs forever."' Two candidates summarise the text. Student A: 'The study shows birds near roads sing higher songs, but the newspaper exaggerated the findings.' Student B: 'The study proves road noise permanently changes bird songs, so the newspaper is right.' You are advising them before they write their answers. The question asks for the best summary, not a personal opinion about road noise.
1. Which summary is more accurate? Justify by quoting two phrases from the text and explain what each phrase rules out.
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Summary A is more accurate. The text says the change is 'a behavioural adjustment, not proof of long-term adaptation' - that rules out B's 'permanently'. It also says recordings were made 'only in spring', which limits how far the result can be generalised. The newspaper's 'forever' is therefore unsupported. A correctly reports the finding (higher minimum frequency near the road) and correctly labels the newspaper as exaggerating. B repeats the newspaper's error and adds 'proves', which the researchers explicitly refuse. A good answer quotes both limiting phrases and explains that they are the author's hedges, not minor details.
2. Identify the newspaper's two logical errors. What extra evidence would make the headline's 'forever' defensible?
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The two errors are (1) overgeneralisation from one season - spring recordings cannot establish a permanent change; and (2) confusing behaviour with evolutionary adaptation - a behavioural adjustment may be temporary or reversible. To defend 'forever', the study would need longitudinal recordings across several years and seasons, evidence that the change persists after noise stops, and ideally evidence of a genetic or developmental mechanism. A single spring comparison cannot carry that claim. The newspaper has turned a cautious correlation into a dramatic certainty.
3. If a candidate wrote 'The study proves that noise pollution damages birds' health', would it be a valid inference? Explain.
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No. 'Damages birds' health' is not in the text. The study measures song frequency, not health, stress or survival. A valid inference would stay close to the evidence: 'Noise may affect how birds communicate.' The candidate has imported a causal health claim from general knowledge. In PAU reading tasks, an option that is true in the world but not supported by the text is still wrong; the question tests textual inference, not environmental awareness. The safest answer quotes the measured variable and avoids adding outcomes the researchers did not report.