GMAT Changed on April 16th - Read about the latest changes here

 It is currently 21 May 2018, 02:09

### GMAT Club Daily Prep

#### Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

# Events & Promotions

###### Events & Promotions in June
Open Detailed Calendar

# Most of the year, the hermit thrush, a North American songbird, eats a

Author Message
TAGS:

### Hide Tags

Verbal Forum Moderator
Joined: 15 Apr 2013
Posts: 191
Location: India
Concentration: General Management, Marketing
GMAT Date: 11-23-2015
GPA: 3.6
WE: Science (Other)
Most of the year, the hermit thrush, a North American songbird, eats a [#permalink]

### Show Tags

15 Jul 2015, 03:45
10
KUDOS
22
This post was
BOOKMARKED
00:00

Difficulty:

25% (medium)

Question Stats:

74% (02:08) correct 26% (01:53) wrong based on 2060 sessions

### HideShow timer Statistics

Most of the year, the hermit thrush, a North American songbird, eats a diet consisting mainly of insects, but in autumn, as the thrushes migrate to their Central and South American wintering grounds, they feed almost exclusively on wild berries. Wild berries, however, are not as rich in calories as insects, yet thrushes need to consume plenty of calories in order to complete their migration. One possible explanation is that berries contain other nutrients that thrushes need for migration and that insects lack.

Which of the following, if true, most seriously calls into question the explanation given for the thrush’s diet during migration‘?

A. Hermit thrushes, if undernourished, are unable to complete their autumn migration before the onset of winter.

B. Insect species contain certain nutrients that are not found in Wild berries.

C. For songbirds, catching insects requires the expenditure of significantly more calories than eating wild berries does.

D. Along the hermit thrushes’ migration routes, insects are abundant throughout the migration season.

E. There are some species of wild berries that hermit thrushes generally do not eat, even though these berry species are exceptionally rich in calories.

"Please hit kudos, if you like this post"
[Reveal] Spoiler: OA
Intern
Joined: 25 May 2015
Posts: 22
Re: Most of the year, the hermit thrush, a North American songbird, eats a [#permalink]

### Show Tags

15 Jul 2015, 22:25
NA song bird diet mainly consist of insects

In autumn they migrate to Central and South America where their
diet is exclusively wild berries

wild berries are low in calories

the possible reason could be it has some other nutrients that they need for migartion that insect lacks.Conclusion

we have to find a reason other than nutrients to explain the birds eating habit.

Option C : this gives a counter opinion for the conclusion ,since the calories expelled was more for insect catching , the birds feed on wild berries
Senior Manager
Joined: 28 Jun 2015
Posts: 297
Concentration: Finance
GPA: 3.5
Re: Most of the year, the hermit thrush, a North American songbird, eats a [#permalink]

### Show Tags

16 Jul 2015, 01:56
I found both C and D to be valid responses.
_________________

I used to think the brain was the most important organ. Then I thought, look what’s telling me that.

Manager
Joined: 11 Aug 2011
Posts: 184
Location: United States
Concentration: Economics, Finance
GMAT Date: 10-16-2013
GPA: 3
WE: Analyst (Computer Software)
Re: Most of the year, the hermit thrush, a North American songbird, eats a [#permalink]

### Show Tags

16 Jul 2015, 11:04
8
KUDOS
1
This post was
BOOKMARKED

Premise - Hermits feed on insects most of the times but during migration they feed on wild berries though wild berries are not as rich in calories as insects are and Hermits require plenty of calories during migration.
Conclusion - Berries contain other nutrients that Hermits need for migration and that insects lack.

If we want to weaken the conclusion we should look for a choice which provides an alternate reason as to why the Hermits prefer eating berries during Migration.

There could be various reasons one can think of
- It is possible that no insects are available that the Hermits can eat during migration.
- Or some other reason.

A. Hermit thrushes, if undernourished, are unable to complete their autumn migration before the onset of winter.
- There is not mention of undernourishment in either the premise or the conclusion. This statement does not affect the conclusion in any way.

B. Insect species contain certain nutrients that are not found in Wild berries.
- This statement too does not affect the conclusion. Even if Insect species contain certain nutrients that are not found in berries , this choice does not provide any reason as to why the hermits prefer berries to insects during migration.

C. For songbirds, catching insects requires the expenditure of significantly more calories than eating wild berries does.
- This choice provides an alternate reason to the fact that hermits prefer berries. If catching insects requires significantly more calories than catching wild berries does then the hermits by choice have berries because they would want to conserve energy during their migration.

D. Along the hermit thrushes’ migration routes, insects are abundant throughout the migration season.
- Does not provide any reason as to why hermits prefer berries.

E. There are some species of wild berries that hermit thrushes generally do not eat, even though these berry species are exceptionally rich in calories.
- Does not affect the conclusion. Even if there are some species that are rich and hermits do not eat them this choice does not provide any alternate cause.
_________________

Kudos me if you like my post !!!!

Manager
Joined: 26 Jan 2015
Posts: 91
Re: Most of the year, the hermit thrush, a North American songbird, eats a [#permalink]

### Show Tags

14 Jun 2016, 09:01
akhil911 wrote:

Premise - Hermits feed on insects most of the times but during migration they feed on wild berries though wild berries are not as rich in calories as insects are and Hermits require plenty of calories during migration.
Conclusion - Berries contain other nutrients that Hermits need for migration and that insects lack.

If we want to weaken the conclusion we should look for a choice which provides an alternate reason as to why the Hermits prefer eating berries during Migration.

There could be various reasons one can think of
- It is possible that no insects are available that the Hermits can eat during migration.
- Or some other reason.

A. Hermit thrushes, if undernourished, are unable to complete their autumn migration before the onset of winter.
- There is not mention of undernourishment in either the premise or the conclusion. This statement does not affect the conclusion in any way.

B. Insect species contain certain nutrients that are not found in Wild berries.
- This statement too does not affect the conclusion. Even if Insect species contain certain nutrients that are not found in berries , this choice does not provide any reason as to why the hermits prefer berries to insects during migration.

C. For songbirds, catching insects requires the expenditure of significantly more calories than eating wild berries does.
- This choice provides an alternate reason to the fact that hermits prefer berries. If catching insects requires significantly more calories than catching wild berries does then the hermits by choice have berries because they would want to conserve energy during their migration.

D. Along the hermit thrushes’ migration routes, insects are abundant throughout the migration season.
- Does not provide any reason as to why hermits prefer berries.

E. There are some species of wild berries that hermit thrushes generally do not eat, even though these berry species are exceptionally rich in calories.
- Does not affect the conclusion. Even if there are some species that are rich and hermits do not eat them this choice does not provide any alternate cause.

Hi,

Option D might also say that since insects are present through out the migration routes, birds will eat insects along the route since they started with less energy by eating berries initially. Can you please help me understand what I am missing.
_________________

Kudos is the best way to say Thank you! Please give me a kudos if you like my post

Board of Directors
Status: QA & VA Forum Moderator
Joined: 11 Jun 2011
Posts: 3436
Location: India
GPA: 3.5
Re: Most of the year, the hermit thrush, a North American songbird, eats a [#permalink]

### Show Tags

14 Jun 2016, 11:03
2
KUDOS
WillGetIt wrote:
Most of the year, the hermit thrush, a North American songbird, eats a diet consisting mainly of insects, but in autumn, as the thrushes migrate to their Central and South American wintering grounds, they feed almost exclusively on wild berries. Wild berries, however, are not as rich in calories as insects, yet thrushes need to consume plenty of calories in order to complete their migration. One possible explanation is that berries contain other nutrients that thrushes need for migration and that insects lack.

Which of the following, if true, most seriously calls into question the explanation given for the thrush’s diet during migration‘?

 Thrush : Most of the year---> InsectsThrush : Autumn ------------> Wild BerriesCalories : Wild Berries < InsectsSo , Thrushes need plenty of Wild Berries to complete their migration.Possible reason : Berries contain other nutrients not found in Wild Berries

Prethink : What's the reason that Thrushs consume only Wild Berries not Insects during migration ? Check the answers -

A. Hermit thrushes, [color=#ff0000]if undernourished, are unable to complete their autumn migration before the onset of winter.

Out of scope , this options talks about undernourishment.

B. Insect species contain certain nutrients that are not found in Wild berries.

Out of scope , this options talks about other nutrients which is not under discussion in the present context.

C. For songbirds, catching insects requires the expenditure of significantly more calories than eating wild berries does.

Calorie Used : Catching Insects > Eating wild berries ; for same calorific intake...

Say 10 KCAL of Energy is consumed ...

Catching Insects = 4KCAL
Eating wild berries = 3 KCAL
Energy Requirement for flight = 5KCAL

Keeping in mind that the bird requires energy for flight it is definitely beneficial for the bird to use it economically and consume high calorie food/nutrients...

D. Along the hermit thrushes’ migration routes, insects are abundant throughout the migration season.

So, why do the birds not catch insects ? Can not weaken the conclusion.

E. There are some species of wild berries that hermit thrushes generally do not eat, even though these berry species are exceptionally rich in calories.

Completely out of scope and irrelevant under present context..

Hence IMHO definitely with (C)

_________________

Thanks and Regards

Abhishek....

PLEASE FOLLOW THE RULES FOR POSTING IN QA AND VA FORUM AND USE SEARCH FUNCTION BEFORE POSTING NEW QUESTIONS

How to use Search Function in GMAT Club | Rules for Posting in QA forum | Writing Mathematical Formulas |Rules for Posting in VA forum | Request Expert's Reply ( VA Forum Only )

Director
Joined: 04 Jun 2016
Posts: 612
GMAT 1: 750 Q49 V43
Re: Most of the year, the hermit thrush, a North American songbird, eats a [#permalink]

### Show Tags

15 Jul 2016, 05:28
1
KUDOS
C is the unopposed winner

Insect gives 100 calorie; Catching insect requires bird to lose 40 calorie. (Finding insect, Flying, then chasing insect, then breaking its shell).
Birds net calorie gain from insect 100-40=60 calorie

Berries gives only 80 calories, But finding berry requires 10 calorie. Find a tree and hop and hop and eat as much as you like without any problem.
Birds Calorie gain from berries 80-10=70 calorie.

Therefore the songbird eats only berries to gain as much calorie as they can. Chasing and catching insect is not viable for songbirds.
What option reconfirms our conclusion

C. For songbirds, catching insects requires the expenditure of significantly more calories than eating wild berries does.

WillGetIt wrote:
Most of the year, the hermit thrush, a North American songbird, eats a diet consisting mainly of insects, but in autumn, as the thrushes migrate to their Central and South American wintering grounds, they feed almost exclusively on wild berries. Wild berries, however, are not as rich in calories as insects, yet thrushes need to consume plenty of calories in order to complete their migration. One possible explanation is that berries contain other nutrients that thrushes need for migration and that insects lack.

Which of the following, if true, most seriously calls into question the explanation given for the thrush’s diet during migration‘?

A. Hermit thrushes, if undernourished, are unable to complete their autumn migration before the onset of winter.

B. Insect species contain certain nutrients that are not found in Wild berries.

C. For songbirds, catching insects requires the expenditure of significantly more calories than eating wild berries does.

D. Along the hermit thrushes’ migration routes, insects are abundant throughout the migration season.

E. There are some species of wild berries that hermit thrushes generally do not eat, even though these berry species are exceptionally rich in calories.

"Please hit kudos, if you like this post"

_________________

Posting an answer without an explanation is "GOD COMPLEX". The world doesn't need any more gods. Please explain you answers properly.
FINAL GOODBYE :- 17th SEPTEMBER 2016. .. 16 March 2017 - I am back but for all purposes please consider me semi-retired.

Manager
Joined: 24 Apr 2014
Posts: 117
Location: India
Concentration: Strategy, Operations
GMAT 1: 730 Q50 V38
GMAT 2: 750 Q48 V45
GPA: 4
WE: Information Technology (Computer Software)
Re: Most of the year, the hermit thrush, a North American songbird, eats a [#permalink]

### Show Tags

15 Jul 2016, 06:21
Most of the year, the hermit thrush, a North American songbird, eats a diet consisting mainly of insects, but in autumn, as the thrushes migrate to their Central and South American wintering grounds, they feed almost exclusively on wild berries. Wild berries, however, are not as rich in calories as insects, yet thrushes need to consume plenty of calories in order to complete their migration. One possible explanation is that berries contain other nutrients that thrushes need for migration and that insects lack.

Which of the following, if true, most seriously calls into question the explanation given for the thrush’s diet during migration‘?

A. Hermit thrushes, if undernourished, are unable to complete their autumn migration before the onset of winter.

General statement, no impact on the explaination given in argument.

B. Insect species contain certain nutrients that are not found in Wild berries.

This tells there are certain nutrients in insects, but doesn't say the ammount of nutrients is more than berry.
No impact

C. For songbirds, catching insects requires the expenditure of significantly more calories than eating wild berries does.

This tells, if birds catch insects they the energy expenditure is more than if they eat berry

This gives a reason to think that to conserve energy expenditure, birds eat berry

Z causes Y

Weakens

D. Along the hermit thrushes’ migration routes, insects are abundant throughout the migration season.
This tells that insects are in abundance during migration period but doesn't tells about the feeding behaviour. Irreverent because explanation given above says because of high nutrients in berry ,birds eat them.
E. There are some species of wild berries that hermit thrushes generally do not eat, even though these berry species are exceptionally rich in calories. Out of scope
[color=#0000ff]

Sent from my Le X507 using GMAT Club Forum mobile app
_________________

way to victory .....

Intern
Joined: 10 Aug 2016
Posts: 38
Location: India
GMAT 1: 560 Q47 V21
GMAT 2: 710 Q50 V35
WE: Supply Chain Management (Manufacturing)
Re: Most of the year, the hermit thrush, a North American songbird, eats a [#permalink]

### Show Tags

19 Dec 2016, 22:27
WillGetIt wrote:
Most of the year, the hermit thrush, a North American songbird, eats a diet consisting mainly of insects, but in autumn, as the thrushes migrate to their Central and South American wintering grounds, they feed almost exclusively on wild berries. Wild berries, however, are not as rich in calories as insects, yet thrushes need to consume plenty of calories in order to complete their migration. One possible explanation is that berries contain other nutrients that thrushes need for migration and that insects lack.

Which of the following, if true, most seriously calls into question the explanation given for the thrush’s diet during migration‘?

A. Hermit thrushes, if undernourished, are unable to complete their autumn migration before the onset of winter.

B. Insect species contain certain nutrients that are not found in Wild berries.

C. For songbirds, catching insects requires the expenditure of significantly more calories than eating wild berries does.

D. Along the hermit thrushes’ migration routes, insects are abundant throughout the migration season.

E. There are some species of wild berries that hermit thrushes generally do not eat, even though these berry species are exceptionally rich in calories.

"Please hit kudos, if you like this post"

ChiranjeevSingh , Why is option D wrong here ? If birds find insects on route , then probabaly the calories gained to complete migration are not from berries but from Insects.

Although C is a promising answer , question specifically asks for diet's during migration ? While option C indicated the situation before Migration. Also when birds about to start their journey, they need to accumulate certain value of calories say 100J , no matter how much they spend calories during accumulation process.

_________________

Consider giving Kudos, if you find worth it !!

Manager
Status: Private GMAT Tutor
Joined: 22 Oct 2012
Posts: 85
Location: India
Concentration: Economics, Finance
Schools: IIMA (A)
GMAT 1: 780 Q51 V47
Re: Most of the year, the hermit thrush, a North American songbird, eats a [#permalink]

### Show Tags

20 Dec 2016, 01:18
AbhiGarg2007 wrote:
Why is option D wrong here ? If birds find insects on route , then probabaly the calories gained to complete migration are not from berries but from Insects.

Option D is wrong because OG says so!

The point we are trying to explain here is why don't they eat insects in autumn. Right? We are not saying that they don't eat insects in North America; we are saying that they don't eat insects at all in autumn! And now option D tries to explain so by saying that they have insects during their routes! Wow! Then, why don't they eat them? We're stuck on the same question!

AbhiGarg2007 wrote:
Although C is a promising answer , question specifically asks for diet's during migration ?

While option C indicated the situation before Migration.

Nowhere does option C indicate that it is about "before migration". or am I missing something?

AbhiGarg2007 wrote:
Also when birds about to start their journey, they need to accumulate certain value of calories say 100J , no matter how much they spend calories during accumulation process. Please help !

Is it? Energy expended doesn't matter? If you eat 100J and spend 100J, then how much do you have left?

- CJ
_________________
Intern
Joined: 10 Aug 2016
Posts: 38
Location: India
GMAT 1: 560 Q47 V21
GMAT 2: 710 Q50 V35
WE: Supply Chain Management (Manufacturing)
Re: Most of the year, the hermit thrush, a North American songbird, eats a [#permalink]

### Show Tags

24 Dec 2016, 04:38
ChiranjeevSingh wrote:
AbhiGarg2007 wrote:
Why is option D wrong here ? If birds find insects on route , then probabaly the calories gained to complete migration are not from berries but from Insects.

Option D is wrong because OG says so!

The point we are trying to explain here is why don't they eat insects in autumn. Right? We are not saying that they don't eat insects in North America; we are saying that they don't eat insects at all in autumn! And now option D tries to explain so by saying that they have insects during their routes! Wow! Then, why don't they eat them? We're stuck on the same question!

AbhiGarg2007 wrote:
Although C is a promising answer , question specifically asks for diet's during migration ?

While option C indicated the situation before Migration.

Nowhere does option C indicate that it is about "before migration". or am I missing something?

AbhiGarg2007 wrote:
Also when birds about to start their journey, they need to accumulate certain value of calories say 100J , no matter how much they spend calories during accumulation process. Please help !

Is it? Energy expended doesn't matter? If you eat 100J and spend 100J, then how much do you have left?

- CJ

Got it CJ !!!

So my explanation now as follows:-

C. For songbirds, catching insects requires the expenditure of significantly more calories than eating wild berries does. (Correct)

As before migration to C&S America, birds need to accumulate enough calories, so as their time for migration approaches, they start eating exclusively berries to accumulate calories.

It means Berries have something special other than calories which help them to complete their migration.

Now to weaken argument, we need to establish that it is the calories which they gain and require for completion of migration.

This choice correctly establishes that feeding on berries provides them more calories as they need not to spend the same on picking berries than
hunting insects

So it is none other than calories they gain from Berries in order to complete migration.

D. Along the hermit thrushes’ migration routes, insects are abundant throughout the migration season.

But they have already stopped eating insects so what would they do with the insects?
_________________

Consider giving Kudos, if you find worth it !!

Manager
Status: Private GMAT Tutor
Joined: 22 Oct 2012
Posts: 85
Location: India
Concentration: Economics, Finance
Schools: IIMA (A)
GMAT 1: 780 Q51 V47
Re: Most of the year, the hermit thrush, a North American songbird, eats a [#permalink]

### Show Tags

24 Dec 2016, 08:52
AbhiGarg2007 wrote:

Got it CJ !!!

So my explanation now as follows:-

C. For songbirds, catching insects requires the expenditure of significantly more calories than eating wild berries does. (Correct)

As before migration to C&S America, birds need to accumulate enough calories, so as their time for migration approaches, they start eating exclusively berries to accumulate calories.

It means Berries have something special other than calories which help them to complete their migration.

Now to weaken argument, we need to establish that it is the calories which they gain and require for completion of migration.

This choice correctly establishes that feeding on berries provides them more calories as they need not to spend the same on picking berries than
hunting insects

So it is none other than calories they gain from Berries in order to complete migration.

D. Along the hermit thrushes’ migration routes, insects are abundant throughout the migration season.

But they have already stopped eating insects so what would they do with the insects?

Bang on, now!
_________________
Intern
Joined: 10 Jul 2016
Posts: 10
Re: Most of the year, the hermit thrush, a North American songbird, eats a [#permalink]

### Show Tags

14 Jan 2017, 02:57
akhil911 wrote:

Premise - Hermits feed on insects most of the times but during migration they feed on wild berries though wild berries are not as rich in calories as insects are and Hermits require plenty of calories during migration.
Conclusion - Berries contain other nutrients that Hermits need for migration and that insects lack.

If we want to weaken the conclusion we should look for a choice which provides an alternate reason as to why the Hermits prefer eating berries during Migration.

There could be various reasons one can think of
- It is possible that no insects are available that the Hermits can eat during migration.
- Or some other reason.

A. Hermit thrushes, if undernourished, are unable to complete their autumn migration before the onset of winter.
- There is not mention of undernourishment in either the premise or the conclusion. This statement does not affect the conclusion in any way.

B. Insect species contain certain nutrients that are not found in Wild berries.
- This statement too does not affect the conclusion. Even if Insect species contain certain nutrients that are not found in berries , this choice does not provide any reason as to why the hermits prefer berries to insects during migration.

C. For songbirds, catching insects requires the expenditure of significantly more calories than eating wild berries does.
- This choice provides an alternate reason to the fact that hermits prefer berries. If catching insects requires significantly more calories than catching wild berries does then the hermits by choice have berries because they would want to conserve energy during their migration.

D. Along the hermit thrushes’ migration routes, insects are abundant throughout the migration season.
- Does not provide any reason as to why hermits prefer berries.

E. There are some species of wild berries that hermit thrushes generally do not eat, even though these berry species are exceptionally rich in calories.
- Does not affect the conclusion. Even if there are some species that are rich and hermits do not eat them this choice does not provide any alternate cause.

"eating" wild berries..and not "catching"...threw me off a bit originally
Intern
Joined: 09 May 2016
Posts: 43
Re: Most of the year, the hermit thrush, a North American songbird, eats a [#permalink]

### Show Tags

Updated on: 22 Mar 2017, 14:17
Most of the year, the hermit thrush, a North American songbird, eats a diet consisting mainly of insects, but in autumn, as the thrushes migrate to their Central and South American wintering grounds, they feed almost exclusively on wild berries. Wild berries, however, are not as rich in calories as insects, yet thrushes need to consume plenty of calories in order to complete their migration. One possible explanation is that berries contain other nutrients that thrushes need for migration and that insects lack.

Which of the following, if true, most seriously calls into question the explanation given for the thrush’s diet during migration?

(A) Hermit thrushes, if undernourished, are unable to complete their autumn migration before the onset of winter.
(B) Insect species contain certain nutrients that are not found in wild berries.
(C) For songbirds, catching insects requires the expenditure of significantly more calories than eating wild berries does.
(D) Along the hermit thrushes’ migration routes, insects are abundant throughout the migration season.
(E) There are some species of wild berries that hermit thrushes generally do not eat, even though these berry species are exceptionally rich in calories.

I know this question is already discussed in the forum but My doubt is I took C as strengthening the argument instead of weakening it as it also goes in the same line as the conclusion in argument goes that there is some other reason why birds prefer going for berries during migration.

Originally posted by KARISHMA315 on 22 Mar 2017, 13:22.
Last edited by carcass on 22 Mar 2017, 14:17, edited 1 time in total.
Edited by Carcass
Verbal Forum Moderator
Joined: 13 Feb 2015
Posts: 755
Re: Most of the year, the hermit thrush, a North American songbird, eats a [#permalink]

### Show Tags

22 Mar 2017, 17:23
Merging topics. Please, search questions posting!
_________________

Manager
Joined: 10 Apr 2015
Posts: 198
GPA: 3.31
Most of the year, the hermit thrush, a North American songbird, eats a [#permalink]

### Show Tags

24 Mar 2017, 13:08
Most of the year, the hermit thrush, a North American songbird, eats a diet consisting mainly of insects, but in autumn, as the thrushes migrate to their Central and South American wintering grounds, they feed almost exclusively on wild berries. Wild berries, however, are not as rich in calories as insects, yet thrushes need to consume plenty of calories in order to complete their migration. One possible explanation is that berries contain other nutrients that thrushes need for migration and that insects lack.

they feed almost exclusively on wild berries , berries are not as rich in calories as insects, yet thrushes need to consume plenty of calories in order to complete their migration.

"possible explanation is that berries contain other nutrients that thrushes need for migration and that insects lack."
Ask is- what suggests the requirement is not nutrients / calories , i.e., it is something different.

Which of the following, if true, most seriously calls into question the explanation given for the thrush’s diet during migration‘?

A. Hermit thrushes, if undernourished, are unable to complete their autumn migration before the onset of winter.
irrelevant.
B. Insect species contain certain nutrients that are not found in Wild berries.
not a concern.

C. For songbirds, catching insects requires the expenditure of significantly more calories than eating wild berries does.
that is one reason which suggests - requirement is not nutrients / calories. it is something different.
Correct.
D. Along the hermit thrushes’ migration routes, insects are abundant throughout the migration season.
Irrelevant.

E. There are some species of wild berries that hermit thrushes generally do not eat, even though these berry species are exceptionally rich in calories.

some species of wild berries ? does not matter. no mention.
overall it does not suggest anything apart from nutrients/ calories.
_________________

In case you find my posts helpful, give me Kudos. Thank you.

Intern
Joined: 14 Jun 2017
Posts: 2
Re: Most of the year, the hermit thrush, a North American songbird, eats a [#permalink]

### Show Tags

02 Aug 2017, 08:54
LogicGuru1 wrote:
C is the unopposed winner

Insect gives 100 calorie; Catching insect requires bird to lose 40 calorie. (Finding insect, Flying, then chasing insect, then breaking its shell).
Birds net calorie gain from insect 100-40=60 calorie

Berries gives only 80 calories, But finding berry requires 10 calorie. Find a tree and hop and hop and eat as much as you like without any problem.
Birds Calorie gain from berries 80-10=70 calorie.

Therefore the songbird eats only berries to gain as much calorie as they can. Chasing and catching insect is not viable for songbirds.
What option reconfirms our conclusion

C. For songbirds, catching insects requires the expenditure of significantly more calories than eating wild berries does.

WillGetIt wrote:
Most of the year, the hermit thrush, a North American songbird, eats a diet consisting mainly of insects, but in autumn, as the thrushes migrate to their Central and South American wintering grounds, they feed almost exclusively on wild berries. Wild berries, however, are not as rich in calories as insects, yet thrushes need to consume plenty of calories in order to complete their migration. One possible explanation is that berries contain other nutrients that thrushes need for migration and that insects lack.

Which of the following, if true, most seriously calls into question the explanation given for the thrush’s diet during migration‘?

A. Hermit thrushes, if undernourished, are unable to complete their autumn migration before the onset of winter.

B. Insect species contain certain nutrients that are not found in Wild berries.

C. For songbirds, catching insects requires the expenditure of significantly more calories than eating wild berries does.

D. Along the hermit thrushes’ migration routes, insects are abundant throughout the migration season.

E. There are some species of wild berries that hermit thrushes generally do not eat, even though these berry species are exceptionally rich in calories.

"Please hit kudos, if you like this post"

But it could be the following case?
Birds net calorie gain from insect 100-40=60 calorie
Birds Calorie gain from berries 80-25=55 calorie.

How should we understand "significantly more"? in the above the calculation, i change the consumption of eating wild berries to a bit more, then the whole calculation is different.
VP
Status: Learning
Joined: 20 Dec 2015
Posts: 1141
Location: India
Concentration: Operations, Marketing
GMAT 1: 670 Q48 V36
GRE 1: 314 Q157 V157
GPA: 3.4
WE: Manufacturing and Production (Manufacturing)
Re: Most of the year, the hermit thrush, a North American songbird, eats a [#permalink]

### Show Tags

03 Aug 2017, 08:18
1
KUDOS
WillGetIt wrote:
Most of the year, the hermit thrush, a North American songbird, eats a diet consisting mainly of insects, but in autumn, as the thrushes migrate to their Central and South American wintering grounds, they feed almost exclusively on wild berries. Wild berries, however, are not as rich in calories as insects, yet thrushes need to consume plenty of calories in order to complete their migration. One possible explanation is that berries contain other nutrients that thrushes need for migration and that insects lack.

Which of the following, if true, most seriously calls into question the explanation given for the thrush’s diet during migration‘?

A. Hermit thrushes, if undernourished, are unable to complete their autumn migration before the onset of winter.

B. Insect species contain certain nutrients that are not found in Wild berries.

C. For songbirds, catching insects requires the expenditure of significantly more calories than eating wild berries does.

D. Along the hermit thrushes’ migration routes, insects are abundant throughout the migration season.

E. There are some species of wild berries that hermit thrushes generally do not eat, even though these berry species are exceptionally rich in calories.

"Please hit kudos, if you like this post"

The logic of the question is why the birds prefer to eat wild berries when they need very large amounts of energy while migrating .
We have show that this particular behavior is the most efficient one

C gives us the reason why birds prefer to eat wild berries when they migrate they reduce their energy by not catching insects .

_________________

Intern
Joined: 29 Aug 2015
Posts: 17
GMAT 1: 550 Q44 V22
Re: Most of the year, the hermit thrush, a North American songbird, eats a [#permalink]

### Show Tags

12 Aug 2017, 22:48
Selected D but later realized C is the undisputed choice. Good question

Posted from my mobile device
Director
Joined: 29 Jun 2017
Posts: 505
GPA: 4
WE: Engineering (Transportation)
Re: Most of the year, the hermit thrush, a North American songbird, eats a [#permalink]

### Show Tags

29 Aug 2017, 11:15
My ques
A causes B can be weaken by C causes B
C causes B ok

see the option C
what if
calorie reqd to catch insect = 200
calorie gained from eating = 400
net gain = 200.

calorie reqd to eat berry = 100
calorie gained = 200
net benifit= 100

since 200>100 we can not use it to prove that berries eating will be more calorific as compared to eating insects.

kindly clear this doubt.. thanks in advance.
_________________

Give Kudos for correct answer and/or if you like the solution.

Re: Most of the year, the hermit thrush, a North American songbird, eats a   [#permalink] 29 Aug 2017, 11:15
Display posts from previous: Sort by