Oceanic Bird Navigation

 

 

Migratory birds are well known to navigate over long distances between feeding grounds and breeding sites, often over thousands of miles. Ornithologist G. V. T. Matthews demonstrated this in early studies of the Manx shearwater seabird. From a colony of shearwaters nesting on the island of Skokholm off the southwest coast of Wales. individual birds were transported away in various compass directions, including westward across the Atlantic Ocean and released. The birds were observed as they were released and many quickly showed significant orientation toward home, apparently based on the environmental features around them, even in an unfamiliar location. Most reached their nest sites on Skokholm far more rapidly than they could have done by random searching. Recently, highly sophisticated experiments have been undertaken using satellite tracking to monitor the activity of returning home, or homing behavior, of oceanic birds to which miniature radio transponders have been attached.

These forms of homing behavior are natural phenomena that resemble human navigation on land, by sea, or in the air, but without the use of human gadgetry. Shearwaters, and homing pigeons too, when taken to a locality with which they are unfamiliar seem able to determine their correct homing direction quite quickly, with reference only to cues available to them in the novel locality. One possible explanation for this is that they are able to make a comparison between astronomical information, such as the position of the sun, moon. or stars at the new locality compared with home at a particular time of day. To make such a comparison they would require a biological clock that signaled to them where, say, the sun should be at a particular time of day at home, compared with its observed position and apparent orbit in the new locality. Then, having established their position in relation to home they would also require some form of compass mechanism to permit them to establish the correct bearing (direction) to return.

An alternative hypothesis is that birds carry with them and are able to read some form of map. In that event they would still require a compass to navigate home, but they might not need a clock. One line of research along these lines postulates that oceanic birds have an awareness of the pattern of the Earth’s magnetic field, a map that they carry and use to determine their homing directions. To test the hypothesis, experiments have been carried out on a number of oceanic bird species by attaching magnets to their bodies on the assumption that the birds would then be confused if they normally navigate in response to the Earth’s geomagnetic field. Albatrosses, shearwaters. and petrels have all been tested in this way and all navigated over very long distances to their nesting sites as normal as if their navigation system was unaffected by the presence of an artificial magnetic field around them. However, notwithstanding the consistency of evidence so far against the hypothesis, it remains unresolved whether or not magnetic cues are involved in global navigation by oceanic birds.

A search is also under way to determine whether some birds might also navigate by a form of olfactory map-a mental map of odors. Particular success in this approach has been achieved in studies of Leach’s petrel which for some years has been known to navigate locally back to its nesting burrow using its sense of smell. More recently, too, the same species of bird has been shown to be able to detect the smell of the volatile compound dimethyl sulfide, which is produced by many phytoplankton species that form the basis of marine plankton food chains. Productive areas of the ocean surface that are rich in phytoplankton and the planktonic animals that feed on it are favorite feeding grounds for Leach’s petrels, attracted by the smell of dimethyl sulfide emitted copiously there. Evidence that this form of navigation by the petrels has been perfected during evolution comes from experiments in which the sense of smell of a few birds was artificially and temporarily impaired and the affected birds were unable to show homing behavior when released over a feeding area. So, the apparently featureless surface of the ocean may present a varied olfactory landscape to marine birds with a keen sense of smell.

 

 

1

Migratory birds are well known to navigate over long distances between feeding grounds and breeding sites, often over thousands of miles. Ornithologist G. V. T. Matthews demonstrated this in early studies of the Manx shearwater seabird. From a colony of shearwaters nesting on the island of Skokholm off the southwest coast of Wales. individual birds were transported away in various compass directions, including westward across the Atlantic Ocean and released. The birds were observed as they were released and many quickly showed significant orientation toward home, apparently based on the environmental features around them, even in an unfamiliar location. Most reached their nest sites on Skokholm far more rapidly than they could have done by random searching. Recently, highly sophisticated experiments have been undertaken using satellite tracking to monitor the activity of returning home, or homing behavior, of oceanic birds to which miniature radio transponders have been attached.

According to paragraph 1, all of the following statements about the birds in Matthews’ studies are true EXCEPT:

AThey all came from the same colony of Manx shearwaters.

BThey were all transported westward across the Atlantic Ocean before being released.

CMany of them quickly headed in the direction of their nesting site after being released

DThey were not all released in the same place.

 

2

Migratory birds are well known to navigate over long distances between feeding grounds and breeding sites, often over thousands of miles. Ornithologist G. V. T. Matthews demonstrated this in early studies of the Manx shearwater seabird. From a colony of shearwaters nesting on the island of Skokholm off the southwest coast of Wales. individual birds were transported away in various compass directions, including westward across the Atlantic Ocean and released. The birds were observed as they were released and many quickly showed significant orientation toward home, apparently based on the environmental features around them, even in an unfamiliar location. Most reached their nest sites on Skokholm far more rapidly than they could have done by random searching. Recently, highly sophisticated experiments have been undertaken using satellite tracking to monitor the activity of returning home, or homing behavior, of oceanic birds to which miniature radio transponders have been attached.

According to paragraph 1, how did Matthews’ studies demonstrate that migratory birds have the ability to navigate?

ABy establishing that the birds regularly traveled long distances between feeding grounds and breeding sites

BBy attaching miniature radio transponders to the birds and using satellite tracking to monitor the birds’ return home

CBy identifying the environmental features birds used to determine their unfamiliar location

DBy showing how rapidly many of the birds were able to reach their nest sites after being released in unfamiliar locations

 

3

These forms of homing behavior are natural phenomena that resemble human navigation on land, by sea, or in the air, but without the use of human gadgetry. Shearwaters, and homing pigeons too, when taken to a locality with which they are unfamiliar seem able to determine their correct homing direction quite quickly, with reference only to cues available to them in the novel locality. One possible explanation for this is that they are able to make a comparison between astronomical information, such as the position of the sun, moon. or stars at the new locality compared with home at a particular time of day. To make such a comparison they would require a biological clock that signaled to them where, say, the sun should be at a particular time of day at home, compared with its observed position and apparent orbit in the new locality. Then, having established their position in relation to home they would also require some form of compass mechanism to permit them to establish the correct bearing (direction) to return.

The word “cues” in the passage is closest in meaning to

Asigns

Bobjects

Cplaces

Dsights

 

4

These forms of homing behavior are natural phenomena that resemble human navigation on land, by sea, or in the air, but without the use of human gadgetry. Shearwaters, and homing pigeons too, when taken to a locality with which they are unfamiliar seem able to determine their correct homing direction quite quickly, with reference only to cues available to them in the novel locality. One possible explanation for this is that they are able to make a comparison between astronomical information, such as the position of the sun, moon. or stars at the new locality compared with home at a particular time of day. To make such a comparison they would require a biological clock that signaled to them where, say, the sun should be at a particular time of day at home, compared with its observed position and apparent orbit in the new locality. Then, having established their position in relation to home they would also require some form of compass mechanism to permit them to establish the correct bearing (direction) to return.

According to paragraph 2, why would a bird require a biological clock in order to use astronomical information to determine its correct homing direction?

AIt needs to know at what time the sun, moon. or stars will first appear.

BIt needs to be able to calculate what time of day it would arrive at its home position.

CIt needs to be able to determine how long it will take to get from its present position to its home destination

DIt needs to be able to compare the position of astronomical objects at its current location with their position at home at the same time

 

5

An alternative hypothesis is that birds carry with them and are able to read some form of map. In that event they would still require a compass to navigate home, but they might not need a clock. One line of research along these lines postulates that oceanic birds have an awareness of the pattern of the Earth’s magnetic field, a map that they carry and use to determine their homing directions. To test the hypothesis, experiments have been carried out on a number of oceanic bird species by attaching magnets to their bodies on the assumption that the birds would then be confused if they normally navigate in response to the Earth’s geomagnetic field. Albatrosses, shearwaters. and petrels have all been tested in this way and all navigated over very long distances to their nesting sites as normal as if their navigation system was unaffected by the presence of an artificial magnetic field around them. However, notwithstanding the consistency of evidence so far against the hypothesis, it remains unresolved whether or not magnetic cues are involved in global navigation by oceanic birds.

According to paragraph 3, the experiment to test the hypothesis that oceanic birds have a map of the Earth’s magnetic field assumed that these birds

Aalso have a biological clock

Bcould travel long distances even with magnets on their bodies

Cwould have difficulty navigating when magnets were placed on their bodies

Dare able to establish new nesting sites even when they are unable to determine the Earth’s magnetic field

 

6

An alternative hypothesis is that birds carry with them and are able to read some form of map. In that event they would still require a compass to navigate home, but they might not need a clock. One line of research along these lines postulates that oceanic birds have an awareness of the pattern of the Earth’s magnetic field, a map that they carry and use to determine their homing directions. To test the hypothesis, experiments have been carried out on a number of oceanic bird species by attaching magnets to their bodies on the assumption that the birds would then be confused if they normally navigate in response to the Earth’s geomagnetic field. Albatrosses, shearwaters. and petrels have all been tested in this way and all navigated over very long distances to their nesting sites as normal as if their navigation system was unaffected by the presence of an artificial magnetic field around them. However, notwithstanding the consistency of evidence so far against the hypothesis, it remains unresolved whether or not magnetic cues are involved in global navigation by oceanic birds.

What can be inferred from paragraph 3 about scientists’ beliefs about oceanic birds and the Earth’s geomagnetic field?

AScientists have not completely rejected the idea that the Earth’s geomagnetic field may play a role in bird navigation but lack evidence of it.

Bcientists recognize the important role of the Earth’s geomagnetic field in bird navigation and have identified its role in studies of bird homing behaviors.

CScientists have concluded that oceanic birds lack the ability to map and therefore could not use the geomagnetic field to navigate.

DScientists view studies of the use of compasses and clocks in oceanic birds as evidence that birds do not need to depend on the Earth’s geomagnetic field for navigation.

 

7

A search is also under way to determine whether some birds might also navigate by a form of olfactory map-a mental map of odors. Particular success in this approach has been achieved in studies of Leach’s petrel which for some years has been known to navigate locally back to its nesting burrow using its sense of smell. More recently, too, the same species of bird has been shown to be able to detect the smell of the volatile compound dimethyl sulfide, which is produced by many phytoplankton species that form the basis of marine plankton food chains. Productive areas of the ocean surface that are rich in phytoplankton and the planktonic animals that feed on it are favorite feeding grounds for Leach’s petrels, attracted by the smell of dimethyl sulfide emitted copiously there. Evidence that this form of navigation by the petrels has been perfected during evolution comes from experiments in which the sense of smell of a few birds was artificially and temporarily impaired and the affected birds were unable to show homing behavior when released over a feeding area. So, the apparently featureless surface of the ocean may present a varied olfactory landscape to marine birds with a keen sense of smell.

Which of the sentences below best expresses the essential information in the highlighted sentence in the passage? Incorrect choices change the meaning in important ways or leave out essential information.

AExperiments show that petrels in which the sense of smell was temporarily impaired lost their ability to find feeding areas

BThere is experimental evidence to support the idea that petrels evolved the ability to navigate by using their sense of smell

CIn experiments concerning navigation by petrels, the birds were unable to show homing behavior when released over feeding areas but were able to show homing behavior when released in other areas.

DEvidence from experiments on petrels shows that the sense of smell of birds can be artificially and temporarily impaired.

 

8

A search is also under way to determine whether some birds might also navigate by a form of olfactory map-a mental map of odors. Particular success in this approach has been achieved in studies of Leach’s petrel which for some years has been known to navigate locally back to its nesting burrow using its sense of smell. More recently, too, the same species of bird has been shown to be able to detect the smell of the volatile compound dimethyl sulfide, which is produced by many phytoplankton species that form the basis of marine plankton food chains. Productive areas of the ocean surface that are rich in phytoplankton and the planktonic animals that feed on it are favorite feeding grounds for Leach’s petrels, attracted by the smell of dimethyl sulfide emitted copiously there. Evidence that this form of navigation by the petrels has been perfected during evolution comes from experiments in which the sense of smell of a few birds was artificially and temporarily impaired and the affected birds were unable to show homing behavior when released over a feeding area. So, the apparently featureless surface of the ocean may present a varied olfactory landscape to marine birds with a keen sense of smell.

Paragraph 4 supports all of the following statements about the compound dimethyl sulfide EXCEPT

AIt is produced by areas rich in phytoplankton and the animals that feed on it

BIt is present in the ocean feeding grounds of Leach’s petrels.

CIt is a volatile compound that may be harmful to certain species of planktonic animals

DIts smell is detected by and attracts Leach’s petrels.

 

9

Migratory birds are well known to navigate over long distances between feeding grounds and breeding sites, often over thousands of miles. [■] Ornithologist G. V. T. Matthews demonstrated this in early studies of the Manx shearwater seabird. [■] From a colony of shearwaters nesting on the island of Skokholm off the southwest coast of Wales. individual birds were transported away in various compass directions, including westward across the Atlantic Ocean and released. [■] The birds were observed as they were released and many quickly showed significant orientation toward home, apparently based on the environmental features around them, even in an unfamiliar location.[■]  Most reached their nest sites on Skokholm far more rapidly than they could have done by random searching. Recently, highly sophisticated experiments have been undertaken using satellite tracking to monitor the activity of returning home, or homing behavior, of oceanic birds to which miniature radio transponders have been attached.

Look at the four squaresthat indicate where the following sentence could be added to the passage

In fact, over half of the birds are recorded as having returned back by the second night after their release.

Where would the sentence best fit？Click on a square  sentence to the passage.

10

Scientists know that migratory birds can navigate over very long distances but are interested in how they do it

AThe Manx shearwater was an ideal species for Matthews’ homing experiments because it was easily able to overcome unfavorable environmental conditions in order to return to its nesting site.

BBirds may determine their homing direction by comparing the position of an astronomical object with its position at home at that time, but this would require a biological clock and a compass

CBirds might have an awareness of the pattern of the Earth’s magnetic field and use it as a map to determine their homing direction, but no positive evidence in support of this hypothesis exists.

DThere is evidence that some birds navigate at least short distances y their sense of smell and that they are able to locate ocean feeding grounds by the smell given off by some phytoplankton.

EIn several experiments, researchers attached magnets to the bodies birds and successfully demonstrated the importance of the Earth’s geomagnetic field in bird orientation.

FRecent studies have shown that Leach’s petrels have a stronger homing instinct than the Manx shearwater because the petrels have evolved a navigational system using both environmental features and

 

 

 

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答案：

 

1B

2D

3A

4D

5C

6A

7B

8C

9D

10BCD

翻译：

候鸟以其在觅食地和繁殖地之间长距离迁徙而闻名，常常跨越数千英里。鸟类学家G. V. T. Matthews 在对曼克斯鹱这种海鸟的早期研究中展示了这一点。从威尔士西南海岸斯科霍姆岛上一个鹱类鸟巢的群体中，单独的鸟被运送到不同的指南针方向，包括横跨大西洋向西方释放。这些鸟被释放时进行了观察，许多鸟很快就显现出明显的回家方向定位，显然是基于它们周围的环境特征，即使是在不熟悉的地方。大多数鸟比随机寻找更快地回到斯科霍姆岛的巢穴。最近，使用卫星跟踪来监控海鸟回家行为的高度复杂实验已经进行，这些鸟身上附着了微型无线电应答器。

 

这些回家行为的形式是一种自然现象，类似于人类在陆地、海上或空中的导航，但不使用人类的仪器设备。鹱和信鸽在被带到一个不熟悉的地方时，似乎能很快确定正确的回家方向，仅参考他们在新地点可得到的线索。这一现象的一个可能解释是，它们能够根据天文信息进行比较，比如太阳、月亮或星星在新地点与家中特定时间的位置。为了进行这样的比较，它们需要一个生物钟，来提示它们在家中的特定时间太阳应该在哪个位置，与新地点观察到的位置和表面轨迹相比。然后，确定了自己相对于家的位置后，它们还需要某种形式的指南针机制，以确定返回的正确方向。

 

另一个假设是，鸟类身上携带并能够阅读某种形式的地图。在那种情况下，它们仍然需要一个指南针来导航回家，但可能不需要时钟。沿这条线的一个研究假设认为，海洋鸟类意识到地球磁场的模式，这是一张它们携带并用来确定回家方向的地图。为了测试这一假设，已经在多种海洋鸟类身上进行了实验，通过在它们身上附加磁铁，假设这些鸟会在通常响应地球地磁场导航时感到困惑。信天翁、鹱和海燕都以这种方式接受了测试，并且都像往常一样在很长距离内导航到它们的筑巢地点，仿佛它们的导航系统未受人为磁场的影响。然而，尽管到目前为止的证据一致反对这一假设，但海洋鸟类的全球导航是否涉及磁性线索仍未解决。

 

目前也在探索是否有些鸟可能还通过一种嗅觉地图导航——一种气味的心理地图。在这方面取得了特别成功的是关于利奇海燕的研究，多年来已知这种鸟使用嗅觉在局部回到它的筑巢洞穴。最近，这种鸟类还被发现能够检测到由许多浮游植物种类产生的挥发性化合物二甲基硫化物的气味，这些浮游植物是海洋浮游生物食物链的基础。海洋表面富含浮游植物及以此为食的浮游动物的富饶区域是利奇海燕的最爱觅食地，它们被那里大量散发的二甲基硫化物的气味吸引。这种导航形式已在进化过程中被完善的证据来自于对一些鸟的嗅觉被人为临时削弱的实验，这些受影响的鸟在被释放到一个觅食区时无法表现出回家行为。因此，看似无特征的海洋表面可能对嗅觉敏锐的海鸟来说呈现出一个多样的嗅觉景观。9