Animals in the Arctic,including reindeer and golden eagles,are migrating earlier due to climate change,say researchers who have gathered a huge amount of data to study the behavior of 86 Arctic species over the past three decades.
"We have the ability to keep our eyes on animal movements on a very large scale," says Eliezer Gurarie at the University of Maryland."It seems that animals are unknowingly reacting and adapting to climatic changes,and have been doing for years."
Gurarie and his team used GPS and satellites to track the spring migration of more than 900 female reindeer over the past 15 years.They discovered that the females are migrating to give birth about a day earlier year on year,probably as a result of warming temperatures.Earlier birthing times can be risky in northern parts of the Arctic,says team member Gil Bohrer at Ohio State University."There are higher chances of their children facing strong and unexpected storms," he says.If they do,many will die because they cannot deal with extreme conditions.
Similarly,golden eagles - which usually nest in the Arctic area - have been starting their spring migration half a day earlier each year over the past 25 years.
"The day-to-day change of climate is very small," says Bohrer."To understand how animals react to climate change,you need a very long period of observation - something that has only recently been possible."
The researchers' archive of Arctic animal movement currently covers more than 15 million data points related to 8，000 animals."Our archive can help to advise management methods to preserve endangered species,as climate change only becomes more extreme," says Bohrer.



What can we conclude from Gurarie's words？ ______

A. Researchers can guide animal movements.
B. Animals can adapt to climate change easily.
C. Animals don't know how to react to the changes.
D. Earlier migration is animals' reaction to warmer climate.

What is a possible bad effect of animals' giving birth earlier？ ______

A. Children have less opportunity to survive.
B. There will be more unexpected storms.
C. Fewer children will be delivered.
D. They may migrate earlier in spring.

What does Bohrer want to stress in Paragraph 5？ ______

A. The small change of climate.
B. The challenge of the research.
C. The possibility of observing animals.
D. The purpose of the research.

What does the passage mainly talk about？ ______

A. The observation of animals.
B. Newly-found animals in danger.
C. The discovery of animals' migrating earlier.
D. Animals' extinction caused by global warming.