aditya8062 wrote:Kate: The recent decline in numbers of the Tennessee warbler, a North American songbird that migrates each fall to coffee plantations in South America, is due to the elimination of dense tree cover that formerly was a feature of most South American coffee plantations.

Scott: The population of the spruce budworm, the warbler's favourite prey in North America, has been dropping. This is a more likely explanation of the warbler's decline.

Question: Which of the following, if true, most seriously calls Scott's hypothesis into question?

1). The numbers of the Baltimore oriole, a songbird that does not eat budworms but is as dependent on South America coffee plantations as is the Tennessee warbler, are declining.

2). The spruce budworm population has dropped because of a disease that can infect budworms but not Tennessee warblers

3). The drop in the population of the spruce budworm is expected to only be temporary

4). Many Tennessee warblers have begun migrating in the fall to places other than traditional coffee plantations

5). Although many North American songbirds have declined in numbers, no other species has experienced as great a decline as has the Tennessee warbler.

aditya8062 wrote: modified A : The numbers of the Baltimore oriole, a songbird that does eat budworms and is as dependent on South America coffee plantations as is the Tennessee warbler, are declining.

aditya8062 wrote:thanks GURU
sorry i wrote it wrongly
i meant it as below:

modified A 1: The numbers of the Baltimore oriole, a songbird that does eat budworms and is as dependent on South America coffee plantations as is the Tennessee warbler, are not declining.

also please tell me about the following modified A 2

modified A 2 : The numbers of the Baltimore oriole, a songbird that does eat budworms and is just as much dependent on them as Tennessee warbler are not declining.

thanks and regards

GMATGuruNY wrote:

aditya8062 wrote:Kate: The recent decline in numbers of the Tennessee warbler, a North American songbird that migrates each fall to coffee plantations in South America, is due to the elimination of dense tree cover that formerly was a feature of most South American coffee plantations.

Scott: The population of the spruce budworm, the warbler's favourite prey in North America, has been dropping. This is a more likely explanation of the warbler's decline.

Question: Which of the following, if true, most seriously calls Scott's hypothesis into question?

1). The numbers of the Baltimore oriole, a songbird that does not eat budworms but is as dependent on South America coffee plantations as is the Tennessee warbler, are declining.

2). The spruce budworm population has dropped because of a disease that can infect budworms but not Tennessee warblers

3). The drop in the population of the spruce budworm is expected to only be temporary

4). Many Tennessee warblers have begun migrating in the fall to places other than traditional coffee plantations

5). Although many North American songbirds have declined in numbers, no other species has experienced as great a decline as has the Tennessee warbler.

When a CR passage includes two speakers, the conclusion of the second speaker is that the first speaker is WRONG.
Kate's conclusion:
The decline in the warbler population is due to the elimination of dense tree cover that was formerly a feature of South American coffee plantations.
Scott's conclusion:
The decline in the warbler population is NOT due to the elimination of dense tree cover that was formerly a feature of South American coffee plantations.
Rather, the reason for the decline is a lack of the warbler's favorite prey, the spruce budworm.

Answer choice A:
The numbers of the Baltimore oriole, a songbird that does not eat budworms but is as dependent on South America coffee plantations as is the Tennessee warbler, are declining.
Here, the decline in the oriole population cannot be attributed to a lack of budworms.
Implication:
Another bird species dependent on South American coffee plantations is suffering, weakening Scott's conclusion that there is no link between the decline in the warbler population and South American coffee plantations.

The correct answer is A.

aditya8062 wrote: modified A : The numbers of the Baltimore oriole, a songbird that does eat budworms and is as dependent on South America coffee plantations as is the Tennessee warbler, are declining.

HI Mitch,

In this modified version, another species dependent on budworms is suffering, possibly STRENGTHENING Scott's conclusion that a lack of budworms is to blame for the decline in the warbler population -- the OPPOSITE of what we need.

NandishSS wrote:

Kate: The recent decline in numbers of the Tennessee warbler, a North American songbird that migrates each fall to coffee plantations in South America, is due to the elimination of dense tree cover that formerly was a feature of most South American coffee plantations.

Scott: The population of the spruce budworm, the warbler's favourite prey in North America, has been dropping. This is a more likely explanation of the warbler's decline.

Question: Which of the following, if true, most seriously calls Scott's hypothesis into question?

1). The numbers of the Baltimore oriole, a songbird that does not eat budworms but is as dependent on South America coffee plantations as is the Tennessee warbler, are declining.

What is the correlation between Baltimore oriole & Tennessee warbler?

It says Baltimore oriole, a songbird that does not eat budworms are declining too. Does it mean Tennessee warbler has nothing to do with spruce budworm?

Thanks
Nandish