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Difficulty: MediumCommand of Evidence: Textual

Biologist Dr. Sarah Jenkins and her team investigated the impact of artificial light at night (ALAN) on the foraging behavior of the Eastern pipistrelle (*Perimyotis subflavus*), a species of insectivorous bat. Jenkins hypothesized that while ALAN increases the local concentration of insects around streetlights, it actually reduces the overall foraging efficiency of the bats by making them more visible to predators like owls, forcing them to spend more time in sheltered, darker areas of the forest canopy instead of hunting in the open.

Which finding from Jenkins's study, if true, would most directly support her hypothesis?

  1. A
    The density of nocturnal insects was found to be three times higher within a five-meter radius of artificial streetlights than in unlit forest gaps.
  2. B
    In forest areas with high populations of predatory owls, the overall population of Eastern pipistrelle bats was lower regardless of the level of artificial light at night.
  3. Eastern pipistrelle bats in habitats with high levels of artificial light at night spent the majority of their foraging time in dense, dark canopy cover, where insect density was low, resulting in fewer insect captures per hour than bats in unlit habitats.Answer
  4. D
    Eastern pipistrelle bats foraging directly under streetlights captured significantly more insects per hour than did bats foraging in completely dark control sites.

Answer

The correct answer is the finding that Eastern pipistrelle bats in habitats with high levels of artificial light at night spent the majority of their foraging time in dense, dark canopy cover, where insect density was low, resulting in fewer insect captures per hour than bats in unlit habitats.
The correct answer shows that bats in habitats with high levels of artificial light at night spent most of their time in the dense, dark canopy cover (where insect density was low), resulting in fewer insect captures per hour. This directly supports both components of the hypothesis: that the bats are forced into sheltered, darker areas of the canopy and that this behavioral change reduces their overall foraging efficiency.

Step-by-Step Solution

1
Identify the core claim or hypothesis in the passage.
The hypothesis is that artificial light at night (ALAN) reduces bats' overall foraging efficiency by making them more visible to predators, forcing them to hunt in darker, sheltered canopy areas rather than in the open.
Understanding the specific hypothesis is necessary to determine what kind of evidence would support it.
2
Evaluate the choices to find one that demonstrates both the behavioral shift (seeking shelter in the canopy) and the resulting impact (reduced foraging efficiency).
The correct finding shows that bats in ALAN areas forage primarily in dark canopy cover where insect capture rate is lower, confirming both the behavioral shift and the loss of efficiency.
Connecting the cause (ALAN leading to shelter-seeking) and the effect (reduced insect capture rates) is required to validate the hypothesis.

Key Concept

Identifying textual evidence that directly supports a specific scientific hypothesis or claim.
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Topics

Command of Evidence: Textual

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