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The prairie vole, a small North American grassland rodent, [#permalink]
18 Mar 2007, 18:23
90% (01:47) correct
9% (02:32) wrong based on 11 sessions
The prairie vole, a small North American grassland rodent, breeds year around, and a group of voles living togather consists primarily of an extended family, often including two or more litters. Voles commonly live in large groups from late autumn to winter; from spring thru early autumn, however, most voles live in far smaller groips. The seasonal variation in groups size can probably be explained by a seasonal variation in mortality among young voles.
Which of the following, if true, provides the strongest support for the explanation above?
A) It is the spring and in the early summer that prairie vole communities generally contain the highest proportion of young voles.
B) Prairie vole populations vary dramatically in size from year to year.
C) The prairie vole subsists primarily on broad-leaved plants that are abundant only in spring.
D) Winters in prairie vole's habitat are often harsh, with temperatures that drop well below freezing.
E) Snakes, a major predator of young prairie voles, or active only from spring thru early autumn.
Re: The prairie vole, a small North American grassland rodent, [#permalink]
28 Nov 2013, 09:02
Actually E is the only answer which explains a difference in mortality. However, I do not understand one thing here.
If snakes are active from spring through early autumn, probably killing a lot of young voles, how can the group be bigger in winter (after the snakes killed the voles)? I think that's a flaw in the answer... The other answers are not better, but this made me stuck...
Re: The prairie vole, a small North American grassland rodent,
28 Nov 2013, 09:02