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  3. COGNITIVE MAPS IN ANIMALS (1) A

COGNITIVE MAPS IN ANIMALS (1) A

游客2024-01-02  18
问题                                             COGNITIVE MAPS IN ANIMALS
    (1) A central hypothesis of animal cognition is that many animals make use of cognitive maps—internal representations or codes—of the spatial relationships among objects in their surroundings. In a broad sense, most animals that migrate probably have some internal map of the way external objects are arranged.
    (2) The most extensive studies of cognitive maps have been made for animals that exhibit seasonal migration, the regular back-and-forth movement of animals between two geographic areas at particular times of the year. [A] Seasonal migration enables many species to access rich food resources throughout the year and to breed or winter in areas that favor survival. [B] One long-distance traveler is the gray whale. [0] During summer, these giant aquatic mammals feast on small, bottom-dwelling invertebrates that abound in northern oceans. [D] In the fall, they leave their northern feeding grounds and begin a long trip south along the North American coastline. Arriving in warm, shallow lagoons off Baja California (Mexico) in the winter months, they breed, and pregnant females give birth to young before migrating back north. The yearly round-trip, some 20,000 kilometers, is the longest for any mammal.
    (3) Among insects, the monarch butterfly has one of the most remarkable seasonal migrations. During winter, these insects decorate certain trees at the western tip of Cuba, in a few mountain valleys of central Mexico, and at a few sites along the California coast. All monarchs alive at the end of summer fly south to reach their wintering sites. With the onset of spring, monarchs mate at the wintering sites and begin migrating northward. As they arrive at summer destinations, they lay eggs and then die. Two or more generations are produced during the summer, repopulating the United States and southern Canada. With the approach of fall, the summer’s last generation of monarchs flies south to the wintering grounds. They migrate as far as 4,000 kilometers and end up at a specific site, although they have not flown the route before.
    (4) Researchers have found that migrating animals stay on course by using a variety of environmental cues. Gray whales, for instance, seem to use coastal landmarks to pilot their way north and south. Migrating south in the fall, they orient themselves with the North American coastline on their left. Migrating north in the spring, they keep the coast on their right. Whale watchers sometimes see gray whales stick their heads straight up out of the water, perhaps to obtain a visual fix on land. Many birds migrate at night, navigating by the stars the way ancient human soldiers did. In contrast, monarch butterflies migrate during the day, resting in trees and bushes at night; genetic programming may enable them to use the Sun as a compass.
    (5) Navigating by the Sun or by stars requires an ability to keep track of compass direction. Many migrators also must have an internal timing mechanism that compensates for the continuous daily movement of Earth relative to celestial objects. The timing mechanism must also allow for the apparent change in position of celestial objects as the animal moves over its migration route. Almost nothing is known yet about the nature of these timing mechanisms. At least one night-migrating bird, the indigo bunting, seems to avoid the need for a timing mechanism by fixing on the North Star, the one bright star in northern skies that appears almost stationary. Researchers have found that buntings learn a star map and fix on a stationary star when navigating at night.
     (6) Another interesting, and more or less open, question about migration is how birds continue navigating when the Sun or stars are obscured by clouds. There is strong evidence that some birds can orient themselves to Earth’s magnetic field. Magnetite, the iron-containing mineral once used by sailors as a crude compass, is probably involved in sensing the field. The mineral has been found in the heads of pigeons, in the abdomens of bees, and in certain bacteria that orient themselves to a magnetic field. Future research may show that magnetic sensing is a widespread, important part of a complex navigation mechanism in many animals. [br] Paragraph 2 mentions all of the following as reasons that animals engage in seasonal migrations EXCEPT________.
选项 A、to have access to rich food resources throughout the year
B、to spend the winter months in more favorable locations
C、to escape from other animals that feast on them
D、to reproduce in areas that make the survival of their young possible
答案 C
解析 本题问哪一项不是动物进行季节性迁徙的理由，属于否定事实信息题。第2段第4句提到，在夏天，这些巨大的海洋哺乳动物以大量存在于北部海洋中的小型底栖无脊椎动物为食。由此可以推断出，C项“为了逃离那些以它们为食的其他动物”弄错了feast on的对象，故不是动物进行季节性迁徙的理由，符合题意，故选。A项“为了获得全年充足的食物资源”和B项“为了在条件更有利的地方过冬”是第2段第2句“季节性迁徙使得许多物种获得全年充足的食物资源，并在有利于其生存的地区繁殖或过冬”的同义表述，都是动物进行季节性迁徙的理由。D项“为了在更有利于动物幼崽生存的地方繁殖”与原文第2段第6句“它们于冬季来到下加利福尼亚州(墨西哥)附近温暖的浅泻湖进行交配，怀孕的雌灰鲸在迁徙同北方之前就产下幼崽”表达的意思一致，同样为动物进行季节性迁徙的理由。
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