2021年6月26日雅思考试机经完整版(3)

2021年6月26日雅思考试机经完整版(3)关于这个问题下面小编就来为各个考生解答下。

2021年6月26日雅思考试机经完整版(3)

2021.06.26

SPEAKING

Passage2

Topic

The Return of Monkeys

As an east wind blasts through a gap in the Cordile de Tilaran, a rugged mountain range the splits northern Costa Rica in half, a female mantled howler monkey moves through the

swaying trees of the forest canopy.

A Ken Glander，a primatologist from Duke University, gazes into the canopy, tracking the female's movements. Holding a dart gun, he waits with infinite patience forthe right

moment to shoot. With great care, Glander aims and fires. Hit in the rump, the monkey wobbles. This howler belongs to a population that has lived for decades at Hacienda La

Pacifica, a working catle ranch inGuanacaste province. Other native primates一 white-faced capuchin monkeys and spider monkeys - once were common in this area,

too, but vanished after the Pan-American Highway was built nearby in the 1950s. Most of the surrounding land was clear-cut for pasture.

3 Howlers persist at La Pacifica, Glander explains, because they are leaf-eaters. They eat fruit, when it's available but, unlike capuchin and spider monkeys, do not depend on

large areas of fuiling trees. Howlers can survive anyplace you have half a dozen trees, because their eating habits are so flexible'，he says. In forests, life is an arms race

between trees and the myriad creatures that feed on leaves. Plants have evolved a variety of chemical defenses, ranging from bad-tasting tannins, which bind with plant-produced

nutrients, rendering them indigestible, to deadly poisons, such as alkaloids and cyanide.

C All primates, including humans, have some ability to handle plant toxins. "We can detoxifty a dangerous poison known ascaffeine, which is deadly to a lot of animals:" Glander says. For leaf-eaters, long-term exposure to a specific plant toxin can increase their ability to defuse the poison and absorb the leaf nutrients. The leaves that grow in regenerating forests, like those at La Paifica, are actually more hower friendly than those produced by the undisturbed, centuries-old trees that surive farther south, in the Amazon Basin. In younger forests, trees put most of their limited energy into growing wood, leaves and fruit, so they produce much lower levels of toxin than do well established, old-growth trees.

The value of matuing forests to primates is a subject of study at Santa Rosa National Park, about 35 miles northwest of Hacienda La Pacifica. The park hosts populations not only of mantled howlers but also of white -faced capuchins and spider monkeys. Yet the forests there are young, most of them less than 50 years old. Capuchins were the frst to begin using the rebom forests, when the trees were as young as 14 years. Howlers, larger and heavier than capuchins, need somewhat older trees, with limbs that can support their greater body weight. A working ranch at Hacienda La Pacifica also explain their population boom in Santa Rosa. "Howlers are more resilient than capuchins and spider monkeys for several reasons," Fedigan explains. "They can live within a small home range, as long as the trees have the right food for them. Spider monkeys, on the other hand, occupy a huge home range, so they can't make it in fragmented habitat."

E Howlers also reproduce faster than do other monkey species in the area. Capuchins don't bear their first young until about 7 years old, and spider monkeys do so even later, but howlers give birth for the first time at about 3.5 years of age. Also, while afemale spider monkey will have a baby about once every four years, well-fed howlers can produce an infant every two years.

F The leaves howlers eat hold plenty of water, so the monkeys can survive away from open streams and water holes. This ability gives them a real advantage over capuchin and spider monkeys, which have suffered during the long, ongoing drought in Guanacaste.

G Growing human population pressures in Central and South America have led to persistent destruction of forests. During the 1990s, about 1.1 million acres of Central American forest were flld yearly. Alejandro Estrada, an ecologist at Estacion de Biologia Los Tuxtlas in Veracruz, Mexico, has been exploring how monkeys suvive in a landscape increasingly shaped by humans. He and his colleagues recenty studied the ecology of a group of mantled hower monkeys that thrive in a habitat completely atered by humans: a cacao plantation in Tabasco, Mexico. Like many varieties of coffee, cacao plants need shade to grow. so 40 years ago the landowners planted fg, monkey pod and other tall trees to form a protective canopy over their crop. The howlers moved in about 25 years ago after nearby forests were cut. This strange habitat, a hodgepodge of cultivated native and exotic plants, seems to support about as many monkeys as would a same-sized patch of wild forest. The howlers eat the leaves and fruit of the shade trees, leaving the valuable cacao pods alone, so the farmers tolerate them.

Estrada believes the monkeys bring underappreciated benefits to such farms,dispersing the seeds of fig and other shade trees and frilizing the soil with feces. He points out that howler monkeys live in shade coffee and cacao plantations in Nicaragua and Costa Rica as well as in Mexico. Spider monkeys also forage in such plantations, though they need nearby areas of forest to survive in the long term. He hopes that farmers will begin to see the advantages of assciating with wild monkeys, which includes potential .

ecotourism projects.

"Conservation is usually viewed as a conflict between agricultural practices and the need to preserve nature," Estrada says. "We 're moving away from that vision and beginning to

consider ways in which agricultural ativities may become a tool for the conservation of primaltes in human-modifled landscapes."

14-19段落配对题

14. A reference of rate of reduction in forest habitats G

15. An area where only one species of monkey survived while other two species vanished. A

16. A reason for hower monkeys to choose new leaves as food over old ones C

17. Mention of howler monkey's diet and eating habits。 B

18. A reference of asking farmers to change ttitude towards wildlife H

19 The advantage of hower monkey's fexibility in living in a segmented habitat D

20-22为单选题

20. C

21. A

22. B

23-26填空题

23.reproduction

24.plant toxin/ toxin

25.water

26.drought

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