Throughout May, crabs arrive on Delaware’s beaches to lay eggs. Migrating shorebirds that rely on these eggs for food stop there before continuing to their northern breeding grounds. The earlier in the season they reach those breeding grounds, the greater their likelihood of breeding successfully. Because the crab population was much smaller this year than last, the shorebirds lengthened their Delaware stay considerably in order to consume enough crab eggs to permit completion of their migration.
For which of the following hypotheses does the information given above provide the strongest support?The key to getting a Conclusion question correct is identifying the one answer choice such that there is something we can point to in the passage that supports that choice.
A. The shorebirds will leave their northern breeding grounds earlier this year than they have in years past.The passage indicates nothing about when the birds will "leave" their breeding grounds.
Eliminate.
B. The decline in the crab population was largely due to the shorebirds’ consumption of crab eggs in years past.The passage doesn't say anything about why the decline in the crab population occurred.
Eliminate.
C. The average number of eggs laid per egg-laying crab will be significantly lower next year than this year.
The passage indicates that the number of crabs will be lower but not that eggs "per" crab will be lower.
Eliminate.
D. The proportion of the migratory shorebirds that breed successfully will be lower this year than it was last year.The passage says the following:
The earlier in the season they reach those breeding grounds, the greater their likelihood of breeding successfully. and
the shorebirds lengthened their Delaware stay considerably in order to consume enough crab eggs to permit completion of their migration Those statements in combination indicate that the birds likely arrived at their breeding ground later this year than last.
In that case, they have a lower likelihood of breeding successfully.
This choice is supported by something we can point to in the passage.
Keep.
E. Many fewer of the shorebirds will reach their northern breeding grounds this year than did last year.The passage doesn't indicate anything about the likelihood that birds will "reach" their breeding grounds.
Eliminate.
Correct answer: D