Question 125·200 Super-Hard SAT Reading Questions·Information and Ideas
Fates of Tagged Acorns in Experimental Oak-Woodland Plots
| Plot treatment | Tagged acorns removed | Removed acorns producing established seedlings |
|---|---|---|
| No exclusion | 462 | 5.8% |
| Rodents excluded | 291 | 9.2% |
| Jays excluded | 354 | 2.5% |
Jays and mice both remove and cache acorns, but an acorn’s removal does not necessarily contribute to oak recruitment because the animal may later consume it. To compare the animals’ contributions, researchers supplied matched woodland plots with 500 tagged acorns each. Barriers excluded either rodents or jays from some plots, and camera recordings confirmed that nearly all removals in the rodent-exclusion plots were by jays, whereas nearly all removals in the jay-exclusion plots were by mice. The researchers then recorded which removed acorns had produced established seedlings after one growing season.
Taken together, the text and table best support which statement about the experimental results?
For evidence questions involving counts and percentages, first identify what group the percentage describes. Then calculate the relevant absolute amounts rather than comparing either the counts or percentages alone. Finally, use details from the text to connect experimental treatments with the groups or causes named in the answer choices.
Hints
Check the percentage base
The percentages apply to removed acorns, not to all 500 acorns initially supplied.
Find the relevant totals
For each treatment, multiply the number of removed acorns by the percentage that produced established seedlings.
Connect treatments to animals
Use the camera evidence to determine which animal was responsible for nearly all removals in each exclusion treatment.
Step-by-step Explanation
Interpret the treatments
According to the camera recordings, removals in the rodent-exclusion plots were dominated by jays, while removals in the jay-exclusion plots were dominated by mice. The no-exclusion plots included both animals.
Calculate established seedlings
Apply each percentage to the number of removed acorns:
- No exclusion:
- Rodents excluded:
- Jays excluded:
Compare the evidence with the choices
The no-exclusion and rodent-exclusion plots produced nearly identical numbers of established seedlings, despite the lower number of acorns removed in the jay-dominated rodent-exclusion plots. Therefore, the answer is Although jays removed fewer tagged acorns when rodents were excluded than jays and mice removed together, the jay-dominated removals produced nearly as many established seedlings.