Ecologist: Before finding a mate

Answer choices

1. A

   No Impact3% picked this

   Adult starlings are able to defend themselves against

   This answer is trying to trick us into thinking it attacks the Opposing Idea, but really it has no impact. The fact that adults can defend themselves against parasites doesn't make it any less plausible that the decorations are to defend the babies against parasites.

   3%
2. B

   Opposite1% picked this

   Male starlings do not decorate their nests in areas with unusually small populations

   This is a "no cause, no effect" style strengthener for the Opposing Conclusion that the parasites are the cause of the decorating. If, in the absence of the cause (parasites), there is no effect (decorating), that strengthens the idea that the decorations are to ward off parasites.

   1%
3. C

   Opposite (if anything)1% picked this

   Nestlings grow faster in nests that incorporate aromatic plants than in nests

   We're trying to support the idea that the reason we decorate is to attract the females. If the babies grow faster in decorated nests, this makes it less plausible that the decoration is about attracting the ladies and more plausible that it's about helping the babies in some way. It doesn't go so far as to explicitly support the Opposing Idea because the decorations could help the babies in a way that isn't about parasites, but nonetheless, if anything, this weakens our argument instead of strengthening it.

   1%
4. D

   Correct93% picked this

   Male starlings tend to decorate their nests with a greater number of aromatic plants when a caged female is

   Why this is right

   This makes the "attract a female" explanation more plausible with a classic "more cause, more effect" strengthener. While that might not seem to be that helpful at first glance, consider that the only evidence we had for this explanation to begin with was that males stopped decorating after the eggs were laid. Knowing there's at least a correlation between the presence of a female and this decorating behavior makes that explanation more plausible.

   Skill tested: Strengthen · how this choice captures the argument's function is the move to repeat next time.

   93%
5. E

   No Impact2% picked this

   The compounds in the aromatic plants used by the male starlings to decorate their nests

   This only tells us that, whatever reason the male starlings have for using these plants, they aren't harming the nestlings in the process. This doesn't support or undermine either of the possible explanations for the behavior.

   2%