Q26 - Bird watcher: The decrease in the mourning-dove

[asafezrati]

Hey,

Is C wrong because we don't really need to understand why the MD don't nest in the orchard, so the whole "sprinklers" explanation is obsolete (and the important thing is that for some reason the doves stopped nesting there)?

[maryadkins]

Yeah, I think that works. The argument core is:

MDs used to nest in the orchards but stopped once the sprinklers came --> decrease in population is probably b/c they lost nesting habitat

But what if there's nesting in the area other than in the orchards? Then they haven't lost nesting habitat.

(B) takes care of this possibility and in doing so strengthens the argument.

(C) brings in Blue Jays...what do they have to do with nesting habitat availability?

(A) weakens the argument if anything.

(D) doesn't explain anything, nor does (E).

Hope this helps!

[cacrv]

I'm still failing to see how E doesn't help the stimulus. If mourning doves often nest in fruit trees, that would mean that the overhead sprinklers in the nearby orchards could have led to the loss of nesting habitat for the doves, no? Or is it the word "often"? because orchards don't necessarily mean fruit trees? would appreciate any help to pin down what I'm missing here - thanks!

[tommywallach]

Hey Cac,

We already know they used to nest in the orchard, so we already knew this. It doesn't affect the argument one way or the other.

[andrewgong01]

I am still curious as to why "C" is wrong? To me this argument is like a Corr/Cause argument that states sprinklers caused doves to leave (bcausse, I assume, sprinklers take away habitat).

My pre-phase going in was find something about how sprinklers are related to losing habitat, which was not successful. Then I was attracted to "C" because it is giving another example that bluebirds also stopped coming back, which gives more credence to this alleged correlation/causation issue because it is another example. This in turn allows us to better rule out an alternative reason why doves stopped coming back (e.g. it could be that the dove population itself declined but now that we know other birds were also affected there is a lower chance that the cause of less doves was an internal dove issue).


My "dislike" for the credited response, B, is that it brings up nothing about sprinklers. In fact, how is sprinklers even related to removing orchard trees because all the stimulus says is that we installed overhead sprinklers; that does mean we got rid of trees. In fact, if anything, we are helping orchards survive better by providing them with a water source.

[christine.defenbaugh]

I think the source of your confusion here is that you're not fully separating what you *know* (from the premises) from what you're trying to support (the unproven conclusion).

An additional example, like the blue jays, that connected sprinklers to the birds abandoning habitat (or 'loss of habitat'), would be awesome....IF we were trying to establish that the sprinklers were actually causing the birds to leave. But that's not what the argument seeks to prove.

We know the birds left the orchard trees. That's a fact. It seems pretty likely that it was because of the sprinklers, but honestly, I don't really care why they left. It could have been that a new predatory snake moved into the orchard, it would have the same essential result: the birds no longer have the orchards as part of their habitat.

What the author hasn't proven, and needs to, is that this particular loss of habitat is the cause of the ultimate effect -- population decline.

We could bolster this causation claim in a few ways - we could make it less likely there's an alternate cause *for the population decline*, or we could make it more likely that the loss of habitat itself more likely to cause that decline.

The correct answer does the latter here, making the loss of habitat that we already know occurred significant enough to be more likely to be a cause of population decline.

(As a side note - 'loss of habitat' doesn't necessarily mean the trees are gone, it just means the birds can't or won't live in them anymore. If I lose my home, it might be because it burned down, or it might be become it was foreclosed on, and the bank took it away from me. The house still exists, but I can't live there anymore.)