日批在线视频_内射毛片内射国产夫妻_亚洲三级小视频_在线观看亚洲大片短视频_女性向h片资源在线观看_亚洲最大网

Vital clues shed light on avian migration routes

By XIN WEN | CHINA DAILY | Updated: 2022-08-03 07:15
Share
Share - WeChat
A young swift lies in a nest at an ancient building in Beihai Park, Beijing. CAO XIAORONG/FOR CHINA DAILY

Stopover sites

It was widely believed that Beijing Swifts migrated directly to destinations without stopping, but the research results showed otherwise.

Swifts typically travel more than 250 km on average each day. They are considered to have reached a stopover site if they do not travel any farther than 500 km for at least three days, the study found.

Liu said: "The Beijing Swifts visited two to six stopover sites during their autumn migration, while remaining at one or two such sites in the spring migration, according to the observed data. We presume the birds spend more time accumulating fat reserves or flying locally during their time at stopovers so that they can manage a long migration."

The three main stopovers for the Beijing Swift are the Congo Basin and its surrounding areas, the southwestern coast of the Red Sea, and the Caspian Sea's southern coast.

Ancient buildings

In spring, flocks of Beijing Swifts hover in the sky over the capital. They nest in the city's ancient buildings, including the Beihai Park pavilion, the Palace Museum and the city's ancient gates.

The birds have four short, forward-facing claws. To become airborne, they extend their wings to the full, retracting their claws in flight.

Zhao, the ornithologist, said: "This species flies nearly all its life, except during the breeding season. The swifts' forward-facing claws are suitable for clinging to cracks in cliffs and gaps in ancient buildings and walls.

"In Beijing, the roofs of ancient architecture provide ideal wooden perches for the birds, which they prefer due to the layer of thermal insulation that exists in wooden structures."

In 1870, the Beijing Swift was first observed in the capital by British naturalist Robert Swinhoe, before becoming a symbol of the city's avian diversity.

In recent years, surveys on the birds' numbers carried out by the Beijing Wildlife Rescue and Rehabilitation Center indicated that their nesting locations were increasing, with the swifts showing a preference for nesting in tall buildings.

Shi Yang, director of the center's wildlife rescue department, said the birds now nest widely across the capital, while in 2008, they were only found at 40 nesting locations.

Zhao said artificial nesting boxes should be provided for the birds at suitable locations throughout Beijing, and sounds of them chirping should be broadcast near artificial caves to encourage the birds to build nests.

|<< Previous 1 2 3 4 Next   >>|
Top
BACK TO THE TOP
English
Copyright 1994 - . All rights reserved. The content (including but not limited to text, photo, multimedia information, etc) published in this site belongs to China Daily Information Co (CDIC). Without written authorization from CDIC, such content shall not be republished or used in any form. Note: Browsers with 1024*768 or higher resolution are suggested for this site.
License for publishing multimedia online 0108263

Registration Number: 130349
FOLLOW US
主站蜘蛛池模板: 狠狠操你 | 超碰在线国产97 | 香蕉福利视频 | 精品一区久久 | 欧美精品久久久久久久久老牛影院 | 亚洲裸体视频 | 色资源网| 国产精品久久在线观看 | 久久密av| 亚洲区国产区 | 精品久久久久久中文字幕 | 好·色·先·生t∨ | 成人在线视频网址 | av中文在线| 91久久精品日日躁夜夜躁欧美 | 97超碰在线播放 | 91精品久久香蕉国产线看观看 | 午夜看毛片 | 国产婷婷一区二区 | 精品自拍视频 | 欧美性xxxx在线播放 | 性爱在线免费视频 | 午夜三级影院 | 91精品国产91久久久久青草 | 久久精品第一页 | 国产成年人 | 欧日韩一区二区三区 | 亚洲美女激情视频 | 一级免费av| 91精品国自产 | 亚洲精品一级片 | 午夜久久久久 | 精品一区二区三区中文字幕 | 午夜精品福利在线观看 | 一级欧美日韩 | 国产精品麻豆入口 | 欧美视频亚洲 | 免费视频99 | 日韩欧美亚洲综合 | 精品久久久av | 全部免费毛片在线播放一个 |