Songbirds learn to respond to and imitate their species’ songs from an early age. With each generation, small differences are introduced that result in distinct variations—called dialects—among geographically isolated populations of the same species. A research study examined whether twelve-day-old Ficedula hypoleuca (pied flycatcher) nestlings prefer local dialects over the unfamiliar dialects of nonlocal F. hypoleuca populations: the more begging calls the nestlings made in response to a song, the stronger their preference. The researchers found that nestlings produced more begging calls in response to their own dialect than to nonlocal dialects. Since song preference plays a role in songbird mate selection, the finding suggests that ______
Which choice most logically completes the text?
Explanation
Context: Pied flycatcher nestlings were tested for dialect preference: more begging calls = stronger preference. They produced more begging calls in response to their local dialect. The blank states what this early dialect preference likely leads to when the birds mature.
Answer: C) F. hypoleuca nestlings' preference for their own dialect likely drives them when they mature to reproduce with other F. hypoleuca from local rather than nonlocal populations.
Why? Dialect preference begins in the nest. As adults, if birds prefer the sounds of their local population, they'll seek mates from that population — driving local reproduction and potentially dialect-based isolation. C states this reproductive consequence.
Traps:
- A) nestlings' dialect preference disappears as they mature → contradicts the implication; early preference is likely to persist and influence adult behavior
- B) nestlings who show early preference will show it more strongly later → about preference intensity over time, not the reproductive implication
- D) nestlings show preference for both local and nonlocal dialects → contradicts the finding that nestlings preferred their local dialect