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Parasitic Cuckoo Chicks

APBIO-LVEWY9

Brood parasites are organisms that rely on others to raise their young. For example, the cuckoo will lay its egg in nests belonging to the Reed warbler seemingly with the intent for the warbler to hatch and feed the cuckoo hatchling. Scientists have wondered how the parasitic cuckoo chick gets fed because other studies have shown that it takes stimulation of multiple open beaks—either sight or sound—to compel a mother warbler to provide food.

Researchers observed that the parasitic chicks have bright yellow patches on the ends of their wings and they make those patches quiver when the host parent returns to the nest. Researchers hypothesized that the bright yellow patches on the ends of the cuckoo's wings were related to stimulating the feeding process.

Which of the following procedures is NOT consistent with their hypothesis?

A

The researchers tested the hypothesis by masking the yellow patches with additional paint. When they did that, the parasitic chicks got no food.

B

The researchers tested the idea by adding additional patches with yellow paint. When they did that, the parasitic chicks got even more food than before.

C

The researchers tested the hypothesis by covering the yellow patches with additional paint and adding in the same number of red paint. When they did that, the parasitic chicks got no food.

D

The researchers tested the hypothesis by masking the yellow patches with additional paint and adding additional patches of UV pigments. When they did that, the parasitic chicks got more food.