#6 - Besides laying eggs in her own nest, any female wood

[Administrator]

Complete Question Explanation

Must Be True. The correct answer choice is (D)

The argument is that nesting boxes are actually harmful to the reproduction of wood ducks, since the easy visibility of the boxes makes them vulnerable to the natural habit wood ducks have of laying eggs in the nests of other wood ducks. The behavior is normally harmless because real nests are hard to find. However, since the boxes are easy to spot, the nests become overly full of eggs which somehow inhibits hatching.

Answer choice (A): The stimulus does not state the preference of wood ducks, and you should not assume that creatures such as wood ducks have the ability to realize that their actions will be ineffective in the long-term. Furthermore, it seems that wood ducks definitely are choosing the boxes, and you should not assume that is because of a lack of natural sites, so this choice is unsupported and incorrect.

Answer choice (B): Since overloading a nest with eggs actually will actually limit the viability of the eggs, it seems that this answer choice might be false. The most successful ducks would probably be the ones that protect their own nests, and this choice is incorrect.

Answer choice (C): You should not infer that because the nests overfill, they are smaller than natural sites. The nests overfill because they are highly visible, and this choice is incorrect.

Answer choice (D): This is the correct answer choice. Since the main problem with the nests is that they are too visible, it makes sense that limiting their visibility would make them a better tool.

Answer choice (E): Since the stimulus never discussed the destruction of any habitat, this response is unsupported and incorrect. Furthermore, even if the boxes were helpful, there would be no reason to assume they are necessary.

[lbayliyeva@unm.edu]

I am struggling to see why the answer to question 8 is D. In the passage, nowhere does the author address what would be a more effective strategy to help the ducks breed. He only describes a scenario that shows that after people intervened and tried helping ducks breed, "they actually undercut the ducks' reproductive efforts." By selecting answer D, it feels that we are adding new information by providing a solution to what would be "more effective in helping wood ducks breed." That we cannot do in must be true questions.

What am I missing?

Thank you so much for your help in advance.

[BethRibet]

Hi,

Thanks for the question.

The stimulus does tell us something about why the visible nesting boxes are not effective -- meaning that they undercut the ducks' reproductive efforts. So it follows that to make them potentially more effective, you would want to make them less visible. There's not actually new information added here.

If you said: "balloons make me happy", and I wanted to find be effective at making you happy, it follows logically that I would give you a balloon.

Ideally, you want to be able to notice when phrasing in the answer choice either paraphrases or is essentially compatible with the language in the stimulus. In this instance, "undercutting" would match up to "less effective", so that if you want to be "more effective" you would take out whatever was causing the negative effect.

Hope that helps!
Beth

[srcline@noctrl.edu]

Hello Administrator

I have a couple of questions regarding this question. Would A also be incorrect because the wording is to strong?, EX: in that female wood ducks will establish nests in nest boxes only when natural nesting sited are not available.
Also for MBT questions you"re essentially trying to find a link b/w the premise and conclusion and this answer choice doesnt get to the issue of the nesting boxes correct? So this is an unsupported assumption?

Thank you for your explanations.
Sarah

[Robert Carroll]

Sarah,

Answer choice (A) is a strong statement about the preferences of wood ducks. Because this is a Must Be True question, we must have enough information in the stimulus to be sure that wood ducks will use nest boxes only when natural sites are not available. Note that "only" is the strong statement here - it says that wood ducks' using nest boxes requires unavailability of natural sites. We are not given any relevant information to make this determination in the stimulus, so this answer choice goes beyond the facts as given.

Moving on to your second point, the stimulus in a Must Be True question often does not contain an argument at all. Because the answer choice can refer to any information in the stimulus, there is no need for it to be of any particular degree of importance to the stimulus. The correct answer is simply something that is necessarily true based solely on some or all of the facts in the stimulus, no matter what facts those were.

Robert Carroll

[ginapark96]

I chose answer C because the last sentence in the stimulus states that the nesting boxes became crowded with eggs, so I inferred there must be less space in the nesting boxes than in natural sites, not that they are smaller in size (like the explanation states). Could you please explain the flaw in my reasoning, or a better way to think about it?

Thank you!

[Jonathan Evans]

Hi, Gina,

Thanks for the good question! As you describe it, you seem to be on the right track. We must find an answer choice that the statements in the stimulus "strongly support." You are correct to note that the last line states that the nesting boxes become so crowded that few, if any of the eggs hatch. However, we have no evidence that the nesting boxes themselves have less space for eggs than do the natural sites.

I suspect that we need to make explicit a distinction here:

Let's revisit Answer Choice (C) (abbreviated):

• 1. "The boxes [...] have less space for eggs than do [the] sites."

Contrast this statement with the following:

• 2. "The eggs have less space in the boxes than they do in the sites."

Observe the difference in meaning here. Statement 1 refers to the amount of space contained in the box overall (the size of the box), how much space the boxes have. Statement 2 refers to the space available for the eggs.

For example, a refrigerator box has more space than a hat box has, but even a refrigerator box could become crowded with duck eggs, given a sufficient number of ducks of course!

Answer Choice (C) refers explicitly to the space in the boxes, not the space available to each egg.

So, you are absolutely correct that the eggs have less space! Why? Because there are so many of them! It's just that (C) as written refers only to the volume of the boxes.

Does this explanation help to answer your question?

[ginapark96]

Mr. Evans,
The example with the refrigerator really helped in understanding. Thank you so much!

[martinbeslu]

The part that I don't understand about this stimulus is that it never explicitly tells us why nesting boxes become so crowded with eggs. It could be because of the size of the boxes or because more ducks are laying eggs there. All the stimulus says is that when people put up nesting boxes ... they actually undercut the duck's reproductive efforts. We could assume the reason given in C is correct just as easily as the answer in D since the author doesn't tell us the reason. Are we just supposed to assume that it's because of the visibility of the nesting boxes because they mentioned something about that earlier in the passage?

[Jonathan Evans]

Hi, Martinbeslu,

Good question! Actually there is sufficient information in the stimulus to distinguish between (C) and (D).

Note in the stimulus that it states that the parasitic behavior is rare because the nests are hidden.

In other words, the stimulus establishes that whether or not the nests are hidden is the key issue with the parasitic behavior:

• Nests hidden (cause) Parasitic behavior rare (effect)

Thus, we have strong support for the inference that in the presence of the cause identified above ("nests hidden"), the effect would also likely occur ("parasitic behavior rare").

In contrast, answer choice (C) brings in a new idea ("size of the nesting boxes"). There is not support for any causal connection between this concept and the parasitic behavior; therefore, (as you noted) one must bring in an additional assumption for the statement in this answer choice to be plausible. Thus, we cannot in fact assume that the reason given in (C) is just as plausible as that in (D), since there is no evidence for the statement in (C) but there is evidence for the statement in (D).

Excellent question. I hope this helps!