Homing pigeons can be taken from their lofts and transported hundreds

Question

Homing pigeons can be taken from their lofts and
transported hundreds of kilometers in covered cages to
unfamiliar sites and yet, when released, be able to
choose fairly accurate homeward bearings within a
 (5)  minute and fly home. Aside from reading the minds of
the experimenters (a possibility that has not escaped
investigation), there are two basic explanations for the
remarkable ability of pigeons to “home”: the birds
might keep track of their outward displacement (the
 (10)  system of many short-range species such as
honeybees); or they might have some sense, known as
a “map sense,” that would permit them to construct an
internal image of their environment and then “place”
themselves with respect to home on some internalized
 (15)  coordinate system.

The first alternative seems unlikely. One possible
model for such an inertial system might involve an
internal magnetic compass to measure the directional
leg of each journey. Birds transported to the release site
 (20)  wearing magnets or otherwise subjected to an
artificial magnetic field, however, are only 
occasionally affected. Alternately, if pigeons measure 
their displacement by consciously keeping track of the
direction and degree of acceleration and deceleration of
 (25)  the various turns, and timing the individual legs of the
journey, simply transporting them in the dark, with
constant rotations, or under complete anesthesia ought
to impair or eliminate their ability to orient. These
treatments, however, have no effect. Unfortunately, no
 (30)  one has yet performed the crucial experiment of
transporting pigeons in total darkness, anesthetized,
rotating, and with the magnetic field reversed all at the
same time.

The other alternative, that pigeons have a “map
 (35)  sense,” seems more promising, yet the nature of this
sense remains mysterious. Papi has posited that the
map sense is olfactory: that birds come to associate
odors borne on the wind with the direction in which the
wind is blowing, and so slowly build up an olfactory
 (40)  map of their surroundings. When transported to the
release site, then, they only have to sniff the air en
route and/or at the site to know the direction of home.
Papi conducted a series of experiments showing that
pigeons whose nostrils have been plugged are poorly
 (45)  oriented at release and home slowly.

One problem with the hypothesis is that Schmidt-
Koenig and Phillips failed to detect any ability in
pigeons to distinguish natural air (presumably laden
with olfactory map information) from pure, filtered air.
 (50)  Papi’s experimental results, moreover, admit of
simpler, nonolfactory explanations. It seems likely that
the behavior of nostril-plugged birds results from the
distracting and traumatic nature of the experiment.
When nasal tubes are used to bypass the olfactory
 (55)  chamber but allow for comfortable breathing, no
disorientation is evident. Likewise, when the olfactory
epithelium is sprayed with anesthetic to block smell
detection but not breathing, orientation is normal.    1 
 1. Which one of the following best states the main idea of the passage?

(A) The ability of pigeons to locate and return to their homes from distant points is unlike that of any other species.
(B) It is likely that some map sense accounts for the homing ability of pigeons, but the nature of that sense has not been satisfactorily identified.
(C) The majority of experiments on the homing ability of pigeons have been marked by design flaws.
(D) The mechanisms underlying the homing ability of pigeons can best be identified through a combination of laboratory research and field experimentation.
(E) The homing ability of pigeons is most likely based on a system similar to that used by many short-range species.

2 
 2. According to the passage, which one of the following is ordinarily true regarding how homing pigeons “home”?

(A) Each time they are released at a specific site they fly home by the same route.
(B) When they are released they take only a short time to orient themselves before selecting their route home.
(C) Each time they are released at a specific site they take a shorter amount of time to orient themselves before flying home.
(D) They travel fairly long distances in seemingly random patterns before finally deciding on a route home.
(E) Upon release they travel briefly in the direction opposite to the one they eventually choose.

3 
 3. Which one of the following experiments would best test the “possibility” referred to in line 6?

(A) an experiment in which the handlers who transported, released, and otherwise came into contact with homing pigeons released at an unfamiliar site were unaware of the location of the pigeons’ home
(B) an experiment in which the handlers who transported, released, and otherwise came into contact with homing pigeons released at an unfamiliar site were asked not to display any affection toward the pigeons
(C) an experiment in which the handlers who transported, released, and otherwise came into contact with homing pigeons released at an unfamiliar site were asked not to speak to each other throughout the release process
(D) an experiment in which all the homing pigeons released at an unfamiliar site had been raised and fed by individual researchers rather than by teams of handlers
(E) an experiment in which all the homing pigeons released at an unfamiliar site were exposed to a wide variety of unfamiliar sights and sounds

4 
 4. Information in the passage supports which one of the following statements regarding the “first alternative” (line 16) for explaining the ability of pigeons to “home”?

(A) It has been conclusively ruled out by the results of numerous experiments.
(B) It seems unlikely because there are no theoretical models that could explain how pigeons track displacement.
(C) It has not, to date, been supported by experimental data, but neither has it been definitively ruled out.
(D) It seems unlikely in theory, but recent experimental results show that it may in fact be correct.
(E) It is not a useful theory because of the difficulty in designing experiments by which it might be tested.

5 
 5. The author refers to “the system of many short-range species such as honeybees” (lines 9–11) most probably in order to

(A) emphasize the universality of the ability to home
(B) suggest that a particular explanation of pigeons’ homing ability is worthy of consideration
(C) discredit one of the less convincing theories regarding the homing ability of pigeons
(D) criticize the techniques utilized by scientists investigating the nature of pigeons’ homing ability
(E) illustrate why a proposed explanation of pigeons’ homing ability is correct

6 
 6. Which one of the following, if true, would most weaken Papi’s theory regarding homing pigeons’ homing ability?

(A) Even pigeons that have been raised in several different lofts in a variety of territories can find their way to their current home when released in unfamiliar territory.
(B) Pigeons whose sense of smell has been partially blocked find their way home more slowly than do pigeons whose sense of smell has not been affected.
(C) Even pigeons that have been raised in the same loft frequently take different routes home when released in unfamiliar territory.
(D) Even pigeons that have been transported well beyond the range of the odors detectable in their home territories can find their way home.
(E) Pigeons’ sense of smell is no more acute than that of other birds who do not have the ability to “home.”

7 
 7. Given the information in the passage, it is most likely that Papi and the author of the passage would both agree with which one of the following statements regarding the homing ability of pigeons?

(A) The map sense of pigeons is most probably related to their olfactory sense.
(B) The mechanism regulating the homing ability of pigeons is most probably similar to that utilized by honeybees.
(C) The homing ability of pigeons is most probably based on a map sense.
(D) The experiments conducted by Papi himself have provided the most valuable evidence yet collected regarding the homing ability of pigeons.
(E) The experiments conducted by Schmidt-Koenig and Phillips have not substantially lessened the probability that Papi’s own theory is correct.

Pankaj0901 · Answer

Request you to please share the explanations, including:
Question 1: How is A wrong? I find it the most apt.
Question 2: I find options B and C convey the same thing. Please clarify why is C wrong?
Question 7: Why not option A? It is clearly stating the relationship between the map sense and olfactory.

Saasingh · Answer

I don't get Q7 answer C. Explanation please?

(C) The homing ability of pigeons is most probably based on a map sense.
Why would Papi agree to the map thing? He was all about olfactory explanation which author disagrees with in the last passage.

(E) The experiments conducted by Schmidt-Koenig and Phillips have not substantially lessened the probability that Papi’s own theory is correct.
i thought this was correct because SK and Philips even though their experiments showed no connection between smell and homing, it actaully doesn't "substantially" lessen the Papi theory. I am not sure.

But I can clearly not see how C is correct.

Help appreciated.

Thanks.

EDIT : Well I see how C is right. So stupid of me, I got lost in the jargons. Both last 2 paras are about "internal map" hypothesis. The other alternative of "displacement system like bees" is briefly discussed in first para.

So yeah, both the author and Papi are doing "internal map" experiments so they must be in agreement for that.

bM22 · Answer

Hi  Pankaj0901 ,

1. Which one of the following best states the main idea of the passage?

(A) The ability of pigeons to locate and return to their homes from distant points is unlike that of any other species.
 (B) It is likely that some map sense accounts for the homing ability of pigeons, but the nature of that sense has not been satisfactorily identified.
 (C) The majority of experiments on the homing ability of pigeons have been marked by design flaws.
(D) The mechanisms underlying the homing ability of pigeons can best be identified through a combination of laboratory research and field experimentation.
(E) The homing ability of pigeons is most likely based on a system similar to that used by many short-range species.

Explanation: The author discusses two alternatives about the homing ability of pigeons and how pigeons and some short range species have a "map sense" that accounts for their homing ability that seems promising yet has not been completely identified. 
Option A is incorrect as this ability of pigeons is not unique and its similar to that of some short-range species such as honeybees.

2. According to the passage, which one of the following is ordinarily true regarding how homing pigeons “home”?

(B) When they are released they take only a short time to orient themselves before selecting their route home.
Option B can be inferred from the lines: "Homing pigeons can be taken from their lofts and transported hundreds of kilometers in covered cages to unfamiliar sites and yet, when released, be able to choose fairly accurate homeward bearings within a minute and fly home."

(C) Each time they are  released at a specific site they  take a shorter amount of time to orient themselves before flying home.

The word: "specific site" makes all the difference in making C incorrect. We are asked what is ordinarily true regarding how homing pigeons “home”. Now even if the pigeons are not released at specific sites, yet they can figure their way back and this is what the whole passage talks about.

(A) The map sense of pigeons is most probably related to their olfactory sense.
A is just Papi's hypothesis. The author discusses the problems of the same in the next paragraph and the author challenges it through the lines: "Papi’s experimental results, moreover, admit of simpler, nonolfactory explanations.". Npw option C is one that both Papi and author agree with, that is how homing ability of pigeons is most probably based on a map sense.

Hope This Helps.
Thanks.

Sajjad1994 · Answer

Explanation

5. The author refers to “the system of many short-range species such as honeybees” (lines 9–11) most probably in order to

Explanation

There could only be two possible purposes for the author to mention, in a parenthesis, the homing system of very different species. Either he wants to provide an analogy that will make the idea of the theory clearer to the reader, or he hopes to lend the theory some credibility by showing that a phenomenon is already present in nature. The latter of the two is what  (B)  picks up on. Since some short-ranging species use the  “inertial system,”  it’s at least worth exploring whether the long-ranging pigeon does too.

(A)  No  “universality”  is implied, since the detail in question is tied to one very specific theory.

(C), (D)  Discrediting theories,  (C) , is the purview of  Paragraphs 2-4 , not  Paragraph 1  where the reference in question appears. And while criticizing scientists’ methods,  (D) , never really occurs at all, those methods are likewise not discussed until the latter half of the passage, and certainly they don’t link up to  lines 9-11.

(E)  Even if  Paragraph 1  were designed to propound a particular theory—which it is not; we noted in our Roadmap that  Paragraph 1  simply describes a mystery and two possible solutions—the one to which  lines 9-11  relate, the  “inertial system,”  is not the one the author ends up favoring.

Answer: B

This is not Official explanation rather belongs to Kaplan LSAT

Sajjad1994 · Answer

Explanation

3. Which one of the following experiments would best test the “possibility” referred to in line 6?

Explanation

This question picks up on one brief yet intriguing reference early on. The sense of  “Aside from...,” lines 5-7 , seems jocular (pigeons who are the subject of homing experiments may somehow be reading the scientists’ minds); and then we hear that this is  “a possibility that has not escaped investigation.”  Can it be? Is science seriously considering whether pigeons telepathically home in on the minds of their human handlers? That seems to be the case, and as nutty as it might sound, such a hypothesis could best be tested by taking the human element out of the equation.

In other words, one would want to test whether pigeons can find their way back home without the ability (however acquired) to read the minds of the experimenters. And that’s

(A) . The pigeons’ continued ability to home in the absence of human handlers knowledgeable about the home location would certainly refute the idea in  lines 5-6 , while impaired homing ability might support it.

(B) ’s suggestion that human affection should be taken out of the equation has no relationship to the gist of  lines 5-7.  It’s human minds that some scientists suspect pigeons of homing in on, not human hearts. Whether friendly or hostile, the human needs to be unaware of the home location in order to test the hypothesis, and that’s what’s specified in  (A).

(C)  A vow of silence among handlers would not affect the test results. Pigeons are suspected of reading handlers’ minds, not eavesdropping on their conversations or homing in on their voices.

(D)  brings up an unwarranted comparison between teams and individuals. Irrelevant. If a mind is being read, it doesn’t matter whether that mind is solo or accompanied.

(E)  Presumably an unfamiliar site already contains  “unfamiliar sights and sounds.”  And even if it didn’t, adding same wouldn’t affect the peculiar, but apparently somewhat serious, hypothesis that pigeons are mind-readers. It just might add more obstacles to whatever seeing and hearing that pigeons engage in.

Answer: A

Explanation Credit: Kaplan LSAT

Sajjad1994 · Answer

Welcome! to GMAT Club

Explanation

7. Given the information in the passage, it is most likely that Papi and the author of the passage would both agree with which one of the following statements regarding the homing ability of pigeons?

Explanation

We know from the entire  final paragraph  that the author takes issue with Papi’s theory about pigeons’ olfactory sense as the key to their homing ability. So when we’re asked, as we are here, to come up with an area of agreement between the author and Papi, we have to find a broader, more fundamental view. We can find it in the idea of  “map sense,”  the second of the two alternatives mentioned in  paragraph 1  and the one that  “seems more promising.”  And Papi likes it too  (lines 36-37) . Though Papi and the author differ on the nature of that map sense, they agree that it’s likely the answer to the homing question—making  (C)  correct.

(A)  is their area of disagreement: This is Papi’s theory, about which the author is most skeptical.

(B)  The honeybees in this passage serve much the same role as does voir dire in Passage 1: as a basis for creating wrong answers! The author explicitly rejects the  “inertial system”  theory, the one akin to honeybees’ homing system; and insofar as Papi likes the “map sense” theory he’s probably not fond of the honeybee parallel either.

(D)  We’re sure that Papi is proud of his research, but the author spends all of  Paragraph 4  taking issue with its conclusions, so the seal of approval  (D)  plants on Papi’s work seems unjustified by the text.

(E)  Opposite, the experiments of Schmidt-Koenig and Phillips are explicitly cited in  Paragarph 4  as weakening Papi’s reasoning.

Answer: C

Sajjad1994 · Answer

Explanation

2. According to the passage, which one of the following is ordinarily true regarding how homing pigeons “home”?

Explanation

The key phrase is  “ordinarily true.”  Any reference to the  “ordinary truth”  about homing must take you to  Paragrah 1 , and indeed to  lines 1-5  in particular since everything from  line 5  on has to do with that which is unknown, that which is only speculated about pigeons’ homing ability. As it happens, correct choice  (B)  comes right out of that first sentence; it’s a simple paraphrase of  lines 3-5.

(A)  would be admirably precise of the pigeons if it were true, but nothing in the passage suggests that they shuttle back and forth between home and a remote site as predictably as a streetcar. Moreover, the scope of the passage concerns pigeons’ ability to return from unfamiliar sites  (line 3) , not those they visit multiple times.

(C)  implies that practice makes perfect, that pigeons find self-orientation easier with each trip home from a particular site. A plausible notion, but  (1)  it’s never mentioned, and  (2)  it violates the passage’s concern with pigeons and unfamiliar sites, as discussed in  (A) , above. If  (C)  was tempting, maybe you were drawing an unsupported inference from Papi’s hypothesis in  lines 37-40.  But if you did, what were you doing poking around in  Paragraph 3  during this question?

(D), (E)  The former describes pigeons wandering extensively in a seemingly random fashion, while  (E)  specifies a brief preliminary detour. Au contraire:  Lines 3-5  suggest proper homeward orientation in under a minute.  (D)  and  (E)  may describe ways in which many people return from vacation, but not pigeons.

Answer: B

4. Information in the passage supports which one of the following statements regarding the “first alternative” (line 16) for explaining the ability of pigeons to “home”?

Explanation

This question is asking in its shy way for the gist of  paragraph 2 . We know this because that  “first alternative”  is wholly and only described there. Immediately at  line 16  we learn that this alternative, the  “inertial system”  under which birds would have their own internal compass,  “seems unlikely,”  and the rest of the paragrapg spells out why: Any time scientists have tried to test the theory by fouling up the birds’ internal senses, using the ploys described in  lines 19-29 , the homing has continued just fine. What’s lacking, we learn at paragraph’s end, is a  “crucial experiment”  that would foul up or remove all of the key senses of an inertial system. Inferably, if the birds’ homing ability were impaired after such an experiment, the inertial system hypothesis would be supported. So  (C)  is right: No data have supported it yet, but it can’t be dismissed because a key experiment hasn’t yet taken place. (And a good thing, too: How’d you like to be a rotated, doped-up pigeon released in total darkness under a crazy magnetic field?)

(A)  is too pessimistic given the  “crucial experiment,”  as yet unperformed.

(B)  Contrary,  Paragraph 2  hints at several  “theoretical models”  under which a displacement tracking system might work: light, magnetism, consciousness, etc. The theoretical foundation seems fine; it’s the lack of empirical data that’s the problem.

(D)  No such experiments, recent or otherwise, support the  “first alternative,”  as far as the passage reports.

(E)  There seems little difficulty in designing the right experiment; indeed, the very design is described for us in  lines 29-33.

Answer: C

Sajjad1994 · Answer

Explanation

6. Which one of the following, if true, would most weaken Papi’s theory regarding homing pigeons’ homing ability?

Explanation

We should first review Papi’s theory before thinking about how to weaken it, and that’s in  Para 3  of course. He believes that pigeons’  “map sense”  is their sense of smell, that they follow wind-borne odors to get home. Well, if we can in some way drive a wedge between the pigeons’ homing ability and the odors that they allegedly respond to, then we certainly will have cast doubt on Papi’s theory—and that’s why  (D)  is the winner. If even birds far from familiar odors can get home, then Papi is on shakier ground in ascribing their  “map sense”  to an olfactory origin.

(A), (C)  Each of these speaks to the pigeons’ extraordinary homing ability, but since each fails to mention odors, they cannot affect Papi’s theory one way or the other.

(B)  would, if anything, support Papi’s idea, because it implies that the homing ability is impaired when the sense of smell is likewise.

(E)  makes an irrelevant comparison between the sense of smell of different bird species. So what? The characteristics of non-homing birds cannot tell us anything about why pigeons succeed in their efforts to get home.

Answer: D

agrasan · Answer

Hi  KarishmaB   GMATNinja   MartyMurray

In question-6 , I am have two doubts: not clear why option C is wrong and D is correct?

6. Which one of the following, if true, would most weaken Papi’s theory regarding homing pigeons’ homing ability?  
(C) Even pigeons that have been raised in the same loft frequently take different routes home when released in unfamiliar territory.
(D) Even pigeons that have been transported well beyond the range of the odours detectable in their home territories can find their way home.

My reasoning:  
Option C is correct because pigeons are raised in the same loft (same home) which means when they are released at an unfamiliar place, they  should have a unique route to the home due to the same odour , hence, C weakens my conclusion because pigeons take different routes.

Option D is wrong because the passage didn't mention that there can't be any other way to navigate the route to home when odour are out of detectable range so D doesn't impact my confidence.

Please help me to understand where I went wrong in my reasoning.

GMATNinja · Answer

Question 6 
 
The specific route taken doesn't really matter. For example, it's possible that different birds take slightly different routes based on variances in wind conditions, weather, seasonality, predators, or other factors. As long as the birds find their way home using their sense of smell, Papi's theory works. Variations in route wouldn't necessarily weaken that theory, so (C) is out.

Papi's theory is that the pigeons "only have to sniff the air en route and/or at the site to know the direction of home." That's because the birds "come to associate odors borne on the wind with the direction in which the wind is blowing, and so slowly build up an olfactory map of their surroundings."

If you release the birds "well beyond the range of the odors detectable in their home territories," then the birds will not recognize any of the odors at the release site. Without any recognizable odors, the birds would have no idea which way to go. The fact that the birds are able to find their way home even when there are no recognizable odors weakens Papi's theory.

So (D) is the better answer.

Homing pigeons can be taken from their lofts and transported hundreds

Prep Toolkit

Top 5 GMAT Debrief Videos

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards

GMAT Reading Comprehension (RC) Questions

Homing pigeons can be taken from their lofts and transported hundreds

Prep Toolkit

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards