Hi everyone! Can you please explain your reasoning for choosing your answer for the following question:
The Laysan Rail, an insectivore bird once present on several of the Hawaiian Islands, can no longer be found and is thought to be extinct. Scientists originally thought that a decrease in the amount of ground vegetation available for nesting was responsible for the decline of the bird. However, they now believe that increase competition for food was ultimately responsible for the Layson Rail's inability to survive.
Which of the following would best help to account for the change in the accepted explanation for the Laysan Rail's extinction?
(A) The vegetation on the Laysan Rail's home island was decimated when rabbits were introduced to the island in the 1910s.
(B) When attempts were made to relocate the Laysan Rail to other islands, the birds lost the geographical cues that they relied on for fijnding mating sites.
(C) The Laysan Rail builds nests under dense ground cover to protect the eggs.
(D) An increase in the use of pesticides resulted in a decrease in the numbers of flies and moths present in the Laysan Rail's territory.
(E) Many species nested in the same types of vegetation as the Laysan Rail.
Thanks!
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Kaplan Premier--Q35--The Laysan Rail
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albertrahul
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IMO E.
It supports both, final conclusion that "increase competition for food was ultimately responsible for the Layson Rail's inability to survive" along with original thought that "decrease in the amount of ground vegetation available for nesting was responsible for the decline of the bird".
If many species nest in the same type of vegetation as this bird then there will be fight for space for nesting and there will be shortage of food as well.
It supports both, final conclusion that "increase competition for food was ultimately responsible for the Layson Rail's inability to survive" along with original thought that "decrease in the amount of ground vegetation available for nesting was responsible for the decline of the bird".
If many species nest in the same type of vegetation as this bird then there will be fight for space for nesting and there will be shortage of food as well.
I go with D..
two things here:
a)Scientists originally thought that a decrease in the amount of ground vegetation available for nesting
b)However, they now believe that increase competition for food was ultimately responsible for the Layson Rail's inability to survive
A This addresses point A
B Ou of scope
C Out fo scope
DTalks about decrease in the food available - best help to account for the change in the accepted explanation - The competition could be between Layson Rail s for access to this reduced food
E any species nested in the same types of vegetation as the Laysan Rail
- This indicates that many species nested , but never an indication if they were competiting against Layson Rail s for the same food...
Confused between D & E i go with D...
two things here:
a)Scientists originally thought that a decrease in the amount of ground vegetation available for nesting
b)However, they now believe that increase competition for food was ultimately responsible for the Layson Rail's inability to survive
A This addresses point A
B Ou of scope
C Out fo scope
DTalks about decrease in the food available - best help to account for the change in the accepted explanation - The competition could be between Layson Rail s for access to this reduced food
E any species nested in the same types of vegetation as the Laysan Rail
- This indicates that many species nested , but never an indication if they were competiting against Layson Rail s for the same food...
Confused between D & E i go with D...
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khanshainur
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hussein360
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newera wrote:Hi everyone! Can you please explain your reasoning for choosing your answer for the following question:
The Laysan Rail, an insectivore bird once present on several of the Hawaiian Islands, can no longer be found and is thought to be extinct. Scientists originally thought that a decrease in the amount of ground vegetation available for nesting was responsible for the decline of the bird. However, they now believe that increase competition for food was ultimately responsible for the Layson Rail's inability to survive.
Which of the following would best help to account for the change in the accepted explanation for the Laysan Rail's extinction?
(A) The vegetation on the Laysan Rail's home island was decimated when rabbits were introduced to the island in the 1910s.
(B) When attempts were made to relocate the Laysan Rail to other islands, the birds lost the geographical cues that they relied on for fijnding mating sites.
(C) The Laysan Rail builds nests under dense ground cover to protect the eggs.
(D) An increase in the use of pesticides resulted in a decrease in the numbers of flies and moths present in the Laysan Rail's territory.
(E) Many species nested in the same types of vegetation as the Laysan Rail.
Thanks!
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EconomistGMATTutor
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The conclusion: Increased competition for food was ultimately responsible for the Layson Rail's inability to survive.
Evidence: None given.
Since no evidence is given for the new explanation, providing some will strengthen the conclusion. That's what we're asked to do here.
Choice D directly states that food is a problem. With fewer flies and moths, this known insectivore is in trouble.
A number of people asked about Choice E. First, this is a poorly-written statement. Species of what? In any case, whatever the species, we have no way of knowing that it competes with the Laysan Rail.
Note: One student wrote that Choice E supported the conclusion (it doesn't) as well as the older explanation. We have no interest in supporting the older explanation. Read the question carefully!
Evidence: None given.
Since no evidence is given for the new explanation, providing some will strengthen the conclusion. That's what we're asked to do here.
Choice D directly states that food is a problem. With fewer flies and moths, this known insectivore is in trouble.
A number of people asked about Choice E. First, this is a poorly-written statement. Species of what? In any case, whatever the species, we have no way of knowing that it competes with the Laysan Rail.
Note: One student wrote that Choice E supported the conclusion (it doesn't) as well as the older explanation. We have no interest in supporting the older explanation. Read the question carefully!
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