#24 - Many Seychelles warblers of breeding age forgo

[Administrator]

Complete Question Explanation

Resolve the Paradox-CE. The correct answer choice is (C)

According to the stimulus, many Seychelles warblers forego breeding because of the scarcity of nesting territory on their island, and instead help raise their own siblings. Paradoxically, this pattern of cooperative breeding does not change when healthy warblers are transplanted to a larger island. To resolve this paradox, the correct answer must identify a reason why the warblers’ behavior persists despite the apparent abundance of space on the new island.

Answer choice (A): According to the information in the stimulus, most of the transplanted warblers maintained a pattern of cooperative breeding, and only warblers of breeding age engaged in such breeding. The fact that some warblers were not of breeding age and therefore did not engage in cooperative breeding does not explain why the majority of warblers continued to do so.

Answer choice (B): The stimulus contains no evidence suggesting that climate has anything to do with cooperative breeding. The fact that the two islands had the same climate is therefore irrelevant to the paradox in question.

Answer choice (C): This is the correct answer choice. If most of the terrain on the new island was not suitable for nesting, the scarcity of nesting territory could have been comparable to that on their native island, even if the new island was much larger in size. The real cause for the warblers’ cooperative breeding was not the size of the island per se, but the limited size of their nesting territory.

Answer choice (D): If the size of the new island is much larger than the old one, its environment should be able to sustain a rise in the warblers’ population. It is therefore even more puzzling that the warblers’ behavior does not conform to the expected norm.

Answer choice (E): If the warblers had fewer competitors for nesting territory on the new island, why did they continue to engage in cooperative breeding? This answer choice further clouds the issue and is therefore incorrect.

[netherlands]

Hi there PS,

Im having trouble understanding why you ruled out A. The stimulus says that "many" warblers of breeding age forgo breeding and instead do cooperative breeding, not that "only" warblers of breeding age do so.

Isn't it possible that non-breeding age warblers are also participating in cooperative breeding - which doesn't necessarily mean that they're breeding but only that they're assisting their parent?

To me both A and C explain why they're not going off and breeding elsewhere on the island.

[Dave Killoran]

Hi Netherlands,

Great question, because (A) is a very tricky answer. I think you see how answer choice (C) works to reduce the size of the neighboring island back down to a smaller size. So, I'll leave (C) alone for now, and focus on (A).

With (A), the fact is that warblers not of breeding age don't really count. If they aren't of breeding age, they wouldn't engage in breeding behavior of any kind, and thus that wouldn't tell us why "most of those [transplanted] warblers maintained a pattern of cooperative breeding." Because, to engage in cooperative breeding, a warbler would have to be of breeding age. So, in this sense, (A) doesn't help resolve what's occurring because it isn't shedding any light on why the breeding warblers continue to behave in the same manner.

However, let's say that the above interpretation isn't the case, and the warblers mentioned in (A) are part of the whole pool under consideration. Would (A) then be right? While (A) would be closer to correct, the answer is still no. At best, if we knew that many transplanted warblers were not of breeding age (and thus might not strike out on their own), that would explain why some warblers maintained a pattern of cooperative breeding, but the stimulus is specific about most warblers maintaining a pattern of cooperative breeding (and we don't have enough evidence to prove most). Under this interpretation, (A) is brutally tricky, and it feels like it partially explains what's happening. But, if this was the correct interpretation (and I don't think it is), LSAC would still have the "most helps to explain" in the question stem to fall back on, and they would argue (C) is still better than (A).

Good question--please let me know if this helps explain it. Thanks!

[netherlands]

Aah. Ok, I think I understand what you're saying.

With (A), the fact is that warblers not of breeding age don't really count.

For some reason - my brain still isn't allowing me to understand how we can assume that "being of breeding age" is a prerequisite for participating in cooperative breeding. As defined in the stimulus - cooperative breeding doesn't really required the "ability" to breed, does it?. (Sorry If I'm digging too deep into it - but since part of my focus has been trying to teach myself/drill myself not to mistakenly make assumptions while reading stimuli i really want to understand when connections are valid or just "real-world truths" I should know.)

Am I missing a point that both "the act of foregoing their own breeding AND remaining to help with siblings was the definition of "cooperative breeding". Not simply helping to raise siblings - which both non-breeding and capable breeders would have been able to do?

If I understood that, I would see why "A" would be completely irrelevant because we'd be talking about the wrong group as you said.

Another way that I think I probably could have eliminated A should have been via the same method I tried to justify it. It says that "many warblers hadn't reached breeding age - not that all hadn't. Which still doesn't justify why "some" who possibly had reached breeding age were still doing cooperative breeding.

I feel like this should have been an easy question for me and am not sure why I made it so complicated for myself!

Regardless, please let me know any of your further advice and thank you!

[Dave Killoran]

Hey Netherlands,

Thanks for the response. I understand where you are coming from with this, which is kind of why I explained it from both perspectives.

As far as the "breeding ages" point, let's return to the stimulus (and for those of you reading, this is from the December 2005 LSAT, Logical Reasoning section 2, #24). The opening line sets the tone: "Many Seychelles warblers of breeding age forgo breeding..." (italics added). Then, later "This behavior, called cooperative breeding, results from the scarcity of nesting territory for the birds on the tiny island" (italics added)--which naturally suggests that the need for nesting (and thus the requirement of being of breeding age) is in play here. Those two elements strongly suggests that we are talking about breeding age warblers here.

I have a feeling that this question was one that got scrutinized closely at LSAC headquarters. They may very well have played with the language a bit because while they knew the above point was valid, they still wanted a defense in case someone argued that the first point was invalid, and that they'd then need the second point we've been talking about. Thus, we have the "many" issue, which I think we agree provides some explanation but not a full explanation. I also think that all of this explains why this is question #24 (typically a harder question), and not a question like #4 or something similar.

Please let me know if that helps--I definitely don't think (A) is easy to dismiss right off the bat. Thanks!