Question 100·Easy·Inferences
Ecologists compared the daily foraging times of gray squirrels living in a brightly lit city park with those of gray squirrels in a nearby unlit forest. They observed that the park squirrels routinely began searching for food more than an hour before sunrise, whereas the forest squirrels did not emerge until after daylight. The ecologists propose that artificial lighting in the park influences the squirrels’ schedule. Given this information, the ecologists would most likely infer that earlier foraging by park squirrels ______
Which choice most logically completes the text?
For SAT inference questions that ask which option “most logically completes” a passage, first restate what the passage clearly says (who, what, when, why) and identify the key cause-and-effect relationships. Then, eliminate choices that introduce new topics (like predators or senses not mentioned), use extreme language (“permanent,” “primarily”) that the passage does not justify, or contradict the author’s main point. Finally, pick the answer that directly extends the passage’s logic—here, tying artificial light to a reasonable benefit of earlier foraging—without adding unsupported details.
Hints
Focus on what is actually mentioned
Underline what the passage does talk about: differences in foraging time and the role of artificial lighting. Be cautious of choices that introduce completely new ideas.
Think about likely benefits of starting earlier
If squirrels can begin searching for food earlier than others because of artificial light, what advantage might that give them compared with animals that wait until daylight?
Watch out for extreme or specific claims
Look for words like “permanent,” “primarily,” or specific claims about predators. Ask yourself: Did the passage say that, or is this going too far beyond the information given?
Connect back to artificial lighting
Among the options, which one clearly ties earlier foraging to the effect of increased illumination rather than bringing in unrelated factors?
Step-by-step Explanation
Restate what the ecologists observed
First, summarize the key facts:
- Park squirrels: start searching for food more than an hour before sunrise.
- Forest squirrels: do not emerge until after daylight.
- Ecologists' proposal: artificial lighting in the park influences the squirrels’ schedule.
So, the main difference is that park squirrels have artificial light and start earlier in the dark; forest squirrels only come out after it’s naturally light.
Identify what kind of inference is needed
The question asks what the ecologists would most likely infer about earlier foraging by park squirrels.
That means we want a logical consequence of the earlier start time that fits with the idea that artificial light affects their schedule.
Ask: If squirrels start earlier because of artificial light, what advantage or effect would that likely have?
Check each option against the passage
Now test each choice against the information given, asking, Is this clearly supported?
- Choice A: Talks about a permanent disruption of biological clocks. The passage never mentions anything permanent or harmful.
- Choice B: Claims predators in the park are more active at night. The passage never mentions predators or their activity.
- Choice C: Says squirrels rely on sound rather than sight. But the whole setup is about lighting, which is related to sight, not sound.
- Choice D: Connects extra illumination (artificial lighting) with the benefit of finding food before other animals are active, which lines up with earlier foraging and the mention of artificial light.
Only one option directly uses the idea of artificial lighting to explain a reasonable benefit of earlier foraging and stays within what the passage supports.
Select the supported, logical inference
The only answer that logically follows from the ecologists’ observations and their proposal about artificial lighting is that earlier foraging by park squirrels allows them to exploit the extra illumination to locate food before other animals are active.