Question 129·Hard·Command of Evidence
Great Tit Breeding Metrics after One Nesting Season in Different Urban Noise Conditions
| Urban noise level | Average clutch size (eggs) | Average chick survival rate (percent of chicks fledged) | Average adult body mass (grams) | Average peak song pitch (kilohertz) |
|---|---|---|---|---|
| High | 3.1 | 48 | 25.2 | 5.7 |
| Medium | 3.3 | 59 | 25.4 | 4.9 |
| Low | 3.4 | 64 | 25.7 | 4.2 |
Behavioral ecologist Daria Ramirez studied great tits (Parus major) nesting in city parks that differed in traffic noise. She found that birds exposed to louder environments tended to adjust their songs and experienced poorer reproductive outcomes.
Which choice uses data from the table to most effectively support Ramirez’s conclusion?
For "Which choice uses data from the table to most effectively support the claim?" questions, first restate the claim in your own words and identify the key variables (for example, noise level, song pitch, survival). Then scan only the relevant rows and columns to see how those variables change together (up, down, or stay the same). Finally, eliminate answer choices that (1) focus on irrelevant measures, (2) contradict the direction or size of the changes in the table, or (3) fail to connect both parts of the claim; choose the one that correctly summarizes the key pattern in the data and clearly supports the stated conclusion.
Hints
Focus on the key parts of Ramirez’s conclusion
Underline the parts of the conclusion that mention what changes in the birds and what outcomes they experience; then match those ideas to specific columns in the table.
Identify which columns in the table matter most
Ask yourself: which columns show how songs might change, and which columns show how successful reproduction is? Concentrate on those rather than on all four columns equally.
Look for patterns from low to high noise
Read the relevant numbers across the low, medium, and high noise rows. Do they go up or down as noise increases? Keep this trend in mind while checking the answer choices.
Watch for choices that misread or ignore the key trend
Eliminate any option that either (1) focuses on less relevant measures like body mass, (2) gets the direction of change wrong, or (3) does not connect noise level to both song changes and reproductive success.
Step-by-step Explanation
Understand the scientist’s conclusion
Ramirez concluded two things:
- In louder environments, birds adjust their songs.
- In louder environments, birds have poorer reproductive outcomes.
So the right answer must mention both a change in song characteristics and a negative effect on reproduction that are linked to higher noise levels.
Locate the relevant data in the table
Look at which columns in the table match the conclusion:
- Urban noise level: high, medium, low.
- Average peak song pitch (kilohertz): shows song adjustment.
- Average chick survival rate (percent of chicks fledged): shows reproductive outcome.
These are the key columns to compare across noise levels.
Check how song pitch and chick survival change with noise
Now read those two columns from low to high noise:
- Song pitch (kHz): Low = 4.2, Medium = 4.9, High = 5.7 → pitch increases as noise increases.
- Chick survival rate (%): Low = 64, Medium = 59, High = 48 → survival decreases as noise increases.
This pattern matches "adjusted songs" (higher pitch) and "poorer reproductive outcomes" (lower survival) in louder environments.
Match the choice that correctly states this pattern
Now compare each option to the pattern you just saw:
- The correct choice must say that birds in higher noise have higher song pitch and lower chick survival than birds in lower noise.
- It must also state these relationships accurately using the table’s data.
The only option that clearly and correctly describes that birds in high-noise environments sing at the highest pitch and have the lowest chick survival rate compared with birds in medium- and low-noise environments is:
Birds in high-noise environments sang at the highest average pitch and had the lowest chick survival rate relative to birds in medium- and low-noise environments.