求救:GWD 这个月的JJ songbirds那篇

theone2007

这篇文章看了几变,搞不明白这个songbirds的生物圈到底是怎么样的? 牛牛帮忙提醒下形容下, 本来就要考试了!

Grassland songbirds often nest in

the same grassland-wetland complexes

as waterfowl, particularly in a certain

Line part of those complexes, namely,

 (5) upland habitats surrounding wetlands.

Although some wildlife management

procedures directed at waterfowl, such

as habitat enhancement or restoration,

may also benefit songbirds , the impact

(10) of others, especially the control of

waterfowl predators, remains difficult to

predict. For example, most predators

of waterfowl nests prey opportunitistic-

ally on songbird nests, and removing

(15) these predators could directly increase

songbird nesting success. Alterna-

tively, small mammals such as mice

and ground squirrels are important

in the diet of many waterfowl-nest

(20) predators and can themselves be

important predators of songbird

nets. Thus. Removing waterfowl-nest

predators could affect songbird nesting

success through subsequent increases

(25) in small-mammal populations.

In 1995 and 1996, researchers

trapped and removed certain waterfowl-

nest predators. primarily raccoons and

striped skunks, then observed subse-

(30) quent survival rates for songbird nests.

Surprisingly. They observed no sig-

nificant effect on songbird nesting

Success. This may be due to several

Factors. Neither raccoons nor striped

(35) skunks consume ground squirrels,

which are important predators of song-

bird nests. Thus, their removal may

not have led to significant increases

in populations of smaller predators.

(40) Additionally. Both raccoons and striped

skunks prefer wetlands and spend little

time in upland habitats; removing these

species may not have increased the

nesting success of songbirds in the

uplands enough to allow detection.

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Q32

 The passage suggests that removing

Waterfowl-nest predators could possibly

Have a negative effect on songbird popu-

lations because

A.  songbird populations could then

grow to unsustainable numbers

B.  small-mammal population could

then move out of the uplands

into wetland areas

C.  competition among remaining

waterfowl-nest predators could

decrease significantly

D.  a resulting increase in waterfowl

populations could crowd out

songbird populations

E .  a resulting increase in small-mammal

populations could increase small-

mammal predation on songbirds

answer:

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Q33

it can be inferred that the habitat preferences

of raccoons and striped skunks affected the

results of the experiment described in the

passage for which of the following reasons?

A  . Songbird nests in the wetlands are

usually located in places that most

waterfowl-nest predators cannot reach.

B.  Raccoons and striped skunks are not

usually found in areas where songbird

nests tend to be located.

C.  Mice and ground squirrels tend to avoid

predation by raccoons and striped

skunks by remaining exclusively in

the uplands.

D.  The populations of small mammals in

the wetlands are usually controlled by

larger waterfowl-nest predators such

as raccoons and striped skunks.

E.  The waterfowl on which raccoons and

striped skunks prey in the wetlands

compete with songbirds for food.

Answer:

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Q34

the primary purpose of the passage is to

1. describe some procedures used for

     wildlife management and consider

     some problems associated with the

     execution of those procedures

2. outline a problem related to a wildlife

management procedure and offer

potential explanations for the results of

an experiment bearing on that problem

3. present experimental results that

illustrate the need for certain wildlife

management procedures and point out

some inconsistencies in those results

4. argue that a certain procedure used

for wildlife management should be

modified because of its unintended

consequences.

5. propose that further experiments be

performed to assess the long-term

effects of certain wildlife management

procedures.

Answer:

theone2007

helps!