阅读下面短文, 根据其内容写一篇60词左右的内容概要。
Scientists say a huge percentage of bird species are in danger because their habitats, or homelands, are disappearing. Traditional migration paths take birds through countries that are not protecting locations to stop, rest and feed. The scientists studied the migration, or flight paths of almost 1, 500 species. They decided that 91 percent of them passed through dangerous areas.
The major danger for migratory birds is development. Building and paving have covered over nature where birds stop and feed as they move from one part of the world to another. For example, a bird called bar-tailed godwit migrates from it’s breeding grounds in the Arctic. It flies all the way to the southern hemisphere in Australia and New Zealand. Along the way, the small birds stop at Yellow Sea mudflats in China, Democratic People’s Republic of Korea and Republic of Korea. One of the scientists working on the study says “many of these critical sites have been lost to land reclamation(开垦) owing to urban, industrial and agricultural expansion”.
The problem, according to investigators, is that many of these small birds die along their migration because they don’t have a safe place to eat and rest. There is no place to restore their energy for the next leg of their journey. “They simply perish(死亡) along the way”, says one of the scientists. Countries in North Africa, Central Asia and those along the coasts of East Asia are having the most difficult time conserving land. The scientists say these countries do not have enough areas that are safe for birds.
The researchers say countries need to work together and provide safe stop over areas for birds that pass through their boundaries. For example, one country might have preserved safe zones for migrating birds. But a neighbor country might not. A bird might perish. One scientist tells the Los Angeles Times that while some habitats are changing, more work can be done to make urban areas safe for birds. He says small changes—like planting more native plants or keeping cats out of the areas birds would be likely to use—could make a big difference.
