The northern cardinal, a nonmigratory songbird, was rare in Nova S

Hi Chasingthesun,

The argument is: The songbirds (northern cardinals) proliferated (meaning prospered) from 1980 to 2000. So, their number increased in that period due to warmer winters. We need to weaken this argument. The argument has proposed a "cause-and-effect" relationship between the increase in the number of songbirds and the warmer winter. We need something to hit on this causality established by the author. If we look at (E), even if the number of predators increased, how does that weaken the claim that the songbirds' numbers have not increase due to warmer winters? Let's assume that the predators did in fact increase in numbers, but that could be due to a "huge" increase in the number of songbirds, attracting predators into the region. Even this occurrence won't weaken the claim of the author that the songbirds increased due to warm winters.

Thankyou for your explanation, I took a second shot only to realize I misinterpreted the argument in the first place
Its quite clear now

The northern cardinal, a nonmigratory songbird, was rare in Nova Scotia in 1980; the province was considered to be beyond that bird's usual northern range. By 2000, however, field observations indicated that northern cardinals were quite common there. The average winter temperature rose slightly over that period, so warmer winters are probably responsible for the northern cardinal's proliferation in Nova Scotia.

Which one of the following, if true, most weakens the argument?


(A) Bird feeders, an important source of nutrition to wintering birds, became far more common in Nova Scotia after 1980. - CORRECT. Had a doubt whether NC were wintering birds. However, relatively its better and gives another reason for common spotting NC in 2000s.

(B) Because of their red plumage, northern cardinals are easier to spot than most other songbird species are. - WRONG. How does it impact the warm weather/climate reasoning. A comparison of 2000 population to 1980's would have made some sense.

(C) Some songbird species other than the northern cardinal also became more common between 1980 and 2000. - WRONG. Irrelevant.

(D) According to field observations, the populations of migratory birds fluctuated less during the period from 1980 to 2000 than the populations of nonmigratory birds. - WRONG. Again irrelevant. Not concerned of Migratory birds plus comparison is awkward for it to be considered.

(E) Birds that prey on songbirds became more common in Nova Scotia between 1980 and 2000. - WRONG. Irrelevant. Does those birds prey on NC?

Answer A.