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Technology Gives Scientists Better Ways to Follow Birds

A well-fed songbird jumps around in grass near Washington, D.C. On its back it carries a very small, lightweight electronic device called a tag. The bird, a robin¹, sees an insect nearby. The bird attacks fast --- and wins a meal.

Ecology scientist Emily Williams watches from behind a bush. On this clear spring day, she says, "Now I'm watching to see whether he's found a mate," The bird has moved to a nearby tree where there is another robin.

When the bird leaves, the device it carries will send data about its position to a special satellite, then back to Williams' computer.

The Georgetown University ecologist will be able to track the animal's movement.

The satellite involved is Argos. The goal of the project is to learn why some American robins² travel long distances on a usual basis, or migrate, but others do not. The new tracking system promises to give more exact information about the places robins mate and raise their young and where they spend the winter. That will help scientists understand the importance of "genetics versus³ the environment in shaping why birds migrate," Williams said.

Researchers have been attaching tracking tags on birds and animals for many years. But, the International Space Station and the Argos satellite now provide new ways to receive the information sent by the tags. The new system permits scientists to watch songbird movements from afar in much greater detail than before.

"We're in a sort of golden age for bird research," said Adriaan Dokter, an ecologist at Cornell University, adding that the technology is improving as the tags are made smaller and smaller.

"We can satellite-track a robin with smaller and smaller chips. Ten years ago, that was unthinkable," said the scientist, who is not involved in Williams' study.

The device that the robin wears can report its immediate⁴ place on Earth, within about 10 meters.

A second new device, for only the heaviest robins, provides more information about the bird's movements; future versions may also measure the humidity and barometric⁵ pressure of the space the bird occupies.

The devices are known as ICARUS tags.

Martin Wikelski is director of the Max Planck Institute of Animal Behavior. His scientific team is working to improve the ICARUS technology. He hopes that more and better devices could help develop what he called, "an 'Internet of animals' - a collection of sensors⁶ around the world giving us a better picture of the movement of life on the planet."

The first bird of spring

The American robin is a well-known songbird in North America. Its song announces the coming of spring. Yet its migratory⁷ life remains⁸ mysterious.

Ken⁹ Rosenberg is a conservation scientist at Cornell University. He says it is surprising "how little we know about some of the most common songbirds."

An earlier study Williams worked on showed some robins are long-distance migrants – from Alaska to Texas - while others, for unknown reasons, stay in a single place most of the year.

Williams hopes more detailed¹⁰ data from satellite tags will answer her questions. She is working with partners who are tagging robins in Alaska, Indiana and Florida for a three-year study.

Catching¹¹ a robin

Williams has placed nets between tall poles in her yard. When a robin flies into the net, she carefully removes the bird. She measures the bird's body and pulls out a single feather to check on its overall health.

Then she weighs the bird. This one is about 80 grams, just big enough to wear the satellite tag. The technology has only recently become small and light enough to use with small songbirds. Tracking devices have to weigh less than five percent of the animal's weight for it to fly normally.

30 percent drop in bird population

Cornell scientist Rosenberg co-wrote a study in 2019 that showed North America's population of wild birds has dropped by almost three billion, or 30 percent, since 1970.

Ben Freeman is a life scientist at the Biodiversity Research Centre at the University of British Columbia. He says the tracking will help show why the bird population numbers are going down. Better information about migration¹² paths "will help us look in the right places."

Words in This Story

versus – prep. used to indicate two different things, choices, etc., that are being compared or considered

migrate – v. to move from one area to another at different times of the year

track – v. to follow or watch the path of (something)

tag – n. a small piece of cloth, paper, metal, or an electronic device that is attached to something

humidity – n. moisture in the air

barometer¹³ – n. an instrument that is used to measure air pressure and predict changes in the weather

feather – n. one of the light growths that make up the outer covering of the body of a bird

1 robin   

n.知更鸟，红襟鸟

参考例句：

• The robin is the messenger of spring.知更鸟是报春的使者。
• We knew spring was coming as we had seen a robin.我们看见了一只知更鸟，知道春天要到了。

2 robins   

n.知更鸟，鸫( robin的名词复数 )；（签名者不分先后，以避免受责的）圆形签名抗议书（或请愿书）

参考例句：

• The robins occupied their former nest. 那些知更鸟占了它们的老窝。 来自《现代汉英综合大词典》
• Benjamin Robins then entered the fray with articles and a book. 而后，Benjamin Robins以他的几篇专论和一本书参加争论。 来自辞典例句

3 versus   

prep.以…为对手，对；与…相比之下

参考例句：

• The big match tonight is England versus Spain.今晚的大赛是英格兰对西班牙。
• The most exciting game was Harvard versus Yale.最富紧张刺激的球赛是哈佛队对耶鲁队。

4 immediate   

adj.立即的；直接的，最接近的；紧靠的

参考例句：

• His immediate neighbours felt it their duty to call.他的近邻认为他们有责任去拜访。
• We declared ourselves for the immediate convocation of the meeting.我们主张立即召开这个会议。

5 barometric   

大气压力

参考例句：

• Electricity compensates for barometric pressure as well as system pressure variations. 用电补偿大气压和系统压力的变化。
• A barometric altimeter indicates height above sea level or some other selected elevation. 气压高度表用以指示海平面或另外某个被选定高度以上的高度。

6 sensors   

n.传感器，灵敏元件( sensor的名词复数 )

参考例句：

• There were more than 2000 sensors here. 这里装有两千多个灵敏元件。 来自《简明英汉词典》
• Significant changes have been noted where sensors were exposed to trichloride. 当传感器暴露在三氯化物中时，有很大变化。 来自辞典例句

7 migratory   

n.候鸟，迁移

参考例句：

• Many migratory birds visit this lake annually.许多候鸟每年到这个湖上作短期逗留。
• This does not negate the idea of migratory aptitude.这并没有否定迁移能力这一概念。

8 remains   

n.剩余物，残留物；遗体，遗迹

参考例句：

• He ate the remains of food hungrily.他狼吞虎咽地吃剩余的食物。
• The remains of the meal were fed to the dog.残羹剩饭喂狗了。

9 ken   

n.视野，知识领域

参考例句：

• Such things are beyond my ken.我可不懂这些事。
• Abstract words are beyond the ken of children.抽象的言辞超出小孩所理解的范围.

10 detailed   

adj.详细的，详尽的，极注意细节的，完全的

参考例句：

• He had made a detailed study of the terrain.他对地形作了缜密的研究。
• A detailed list of our publications is available on request.我们的出版物有一份详细的目录备索。

11 catching   

adj.易传染的，有魅力的，迷人的，接住

参考例句：

• There are those who think eczema is catching.有人就是认为湿疹会传染。
• Enthusiasm is very catching.热情非常富有感染力。

12 migration   

n.迁移，移居，（鸟类等的）迁徙

参考例句：

• Swallows begin their migration south in autumn.燕子在秋季开始向南方迁移。
• He described the vernal migration of birds in detail.他详细地描述了鸟的春季移居。

13 barometer   

n.气压表，睛雨表，反应指标

参考例句：

• The barometer marked a continuing fall in atmospheric pressure.气压表表明气压在继续下降。
• The arrow on the barometer was pointing to"stormy".气压计上的箭头指向“有暴风雨”。