The song of the yellow warbler signals to other yellow warblers that a particular area has been appropriated by the s...

Timur on February 1, 2015

Clarification

In negating answer choice D, you would negate "Warblers often share" as opposed to "which often do not". Correct?

4 Replies

Melody on February 3, 2015

Exactly! Great work.

Amanda on November 17, 2017

Why is C correct - how do we know there are no birds other than yellow warblers that compete with yellow warblers for food?

Amanda on November 17, 2017

Is it because the conclusion says yellow warblers have no competition for the food supply?

Mehran on November 28, 2017

Hey @sharpen7, thanks for your post. You may have misread this Strengthen With Necessary Premise question as a Must Be True question. We do not know there are no birds other than yellow warblers competing with yellow warblers for food - but that is the unstated assumption on which the argument in the stimulus relies. Without this unstated assumption, the stimulus's conclusion - that yellow warblers "have no competition for the food supply within the range of their restricted flying" - would not hold. Thus, (C) is the necessary premise needed to strengthen the argument. And this is why it is the correct answer.

Hope this helps.