In testing a hypothesis that "territorial defence in European robins is a fixed action pattern that is released by the sight of orange feathers," researchers found that robins defended their territory by attacking anything that was of similar size and had an orange patch. How would you show that it was indeed colour that initiated the defence responses?
A) Repeat the experiment removing the orange patch.
B) Repeat the experiment using other shapes.
C) Repeat the experiment with giant specimens.
D) Repeat the experiment using live specimens.

Question

Quizplus · Accepted Answer

By repeating the experiment without the orange patch, researchers can determine if it is indeed the presence of orange coloration that triggers the territorial defence response. If the defense response is absent in the absence of orange coloration, it further supports the hypothesis that territorial defence is triggered by the sight of orange feathers. The other options (B, C, and D) do not directly address the role of color in initiating the defense response.

In Testing a Hypothesis That "Territorial Defence in European Robins