Common Swift – Wild Beijing 北京自然

“Woohoo!” was the shout when the first geolocator-carrying Swift was caught early this morning at The Summer Palace.

After a wait of 12 months, we were finally going to find out, for the first time, where Beijing’s swifts spent the winter. In the end we re-captured 13 of the 31 birds fitted with geolocators last spring and, after downloading and processing the data (all worked perfectly – big kudos to Migrate Technology in England), we discovered that these magnificent birds travel an incredible 26,000km per year on migration to spend the winter in southern Africa. It’s astonishing to think that, over the lifetime of the average Beijing Swift, the distance travelled on migration is equivalent to half way from Earth to the Moon!

The map below shows a typical track of a Beijing Swift, based on preliminary analysis of the data from the 13 birds re-trapped today. A fuller analysis will be made in due course with a scientific paper planned for later this year.

A typical track of a Beijing Swift based on preliminary analysis of the data captured today.

These iconic birds – synonymous with Beijing since 1417 when they made their nests in the original city gatehouses – arrive in Beijing in April and, after breeding, begin their long journey to Africa in late July, taking a route that first leads them west-northwest into Mongolia, from where they pass north of the Tianshan mountains, then south through Iran and central Arabia into tropical Africa, before spending 3 months of the winter in Namibia and the Western Cape. They begin the return journey in February, retracing a similar route, arriving in Beijing in mid-April, a journey that sees them cross about 20 borders. Wow!

Again, I was hugely impressed with the professionalism of the China Birdwatching Society and its army of volunteers. Not only did they get up incredibly early to set up the nets at 0230 but, together with visiting swift ringer Lyndon Kearsley and Dick Newell, they captured, processed and released more than 80 birds in 2 hours, including downloading data from 13 birds with geolocators and fitting a further 25 geolocators to ‘new’ birds. Impressive stuff. And it was great to see Liu Yang, one of China’s top ornithological professors, making the trip from Guangdong to participate in the catch.

This was the scene at around 0600 on the day of the catch. A wonderful sight and sound.

I had the privilege of releasing a geolocator-tagged bird and Zhang Weimin took this photo. A special moment for me. I wish it well on its journey to southwest Africa..

Terry releasing a Swift fitted with a geolocator at The Summer Palace this morning.

Swift expert, Lyndon Kearsley, releasing a Swift this morning at The Summer Palace.

You can read the full story in the press release.

Big thanks to Professor Zhou, Ms Fu Jianping and Wu Lan from the China Birdwatching Society for their incredible hard work in making this project possible. And big kudos to Dick Newell and Lyndon Kearsley for their vision and expertise. I’d also like to thank Lyndon’s wife, Hilde and Rob Jolliffe (“JJ”) for their help and good company during these past few days..

Chinese/中文

走出非洲！北京雨燕那难以置信的迁徙路线图终于被绘制出来啦

“哇哦！！！” 今天早晨，当第一只佩戴了定位器的雨燕在颐和园被捉住时，人群中爆发出一阵欢呼。经历了整整一年的漫长等待，我们终于第一次将要知道，夏季盘旋在北京的雨燕会去那里度过冬天了。去年我们在这里给31只雨燕佩戴了定位器，而截止到上午工作结束，我们一共回收了其中的十三只。在对定位数据进行下载和处理（都进展得十分顺利，感谢英国Migrate Technology公司）后我们发现，这些小鸟每年要进行2万6千公里的难以置信的长途旅行，并在非洲南部越冬。这一切想想都让人吃惊，按北京雨燕的平均寿命来算，在它们的一生中，每年迁徙的距离至少相当于从地球到月球的一半那么远！下图所示的是针对我们今天重捕的13只北京雨燕迁徙数据进行初步分析后得到的典型的迁徙路线。更为详细的分析数据将在今年晚些时候发表在学术期刊上。

基于今天初步数据分析的北京雨燕迁徙路线图

这些象征着北京形象的鸟——因为它们从1471年开始就在这座城市的旧城门上筑巢了——每年四月来到北京，在这里生儿育女之后，七月底又开始了飞向非洲的漫长旅程。它们先是朝西北方向飞到蒙古，又从北部飞跃天山山脉，然后向南穿过伊朗和阿拉伯半岛中部直到非洲热带地区，最后到达它们将要度过3个月冬天的纳米比亚和西开普省。次年2月，它们又沿着近乎一致的路线开始了回程，最终在4月中旬到达北京。哇！这一路可是穿越了20个左右的国家呢！我再一次为中国观鸟会志愿者们的专业而深感钦佩。不仅仅是他们令人难以置信地在凌晨两点半就赶来布网，而且和远道而来的雨燕环志专家Lyndon Kearsley、Dick Newell一起，在短短两个小时内就捕获、处理、放飞了超过80只雨燕，这其中还包括从13只已戴定位器的雨燕身上下载数据、给25只“新鸟”带上定位器。他们真是令人佩服。

同时，很高兴在这里遇到了中国顶尖的鸟类学教授刘阳，他特意从广州赶来参加。

Terry在颐和园放飞一只带有跟踪器的雨燕

雨燕专家Lyndon Kearsley今天早上在颐和园放飞雨燕

我被允许放飞了一只佩戴了定位器的雨燕，并从拍摄雨燕放飞照片的张为民先生那里得到了授权。照片定格了我那特别的瞬间。希望它飞向非洲西南部的旅途一切都好。你可以点击这里看到关于这个故事的完整报道。

深深的感谢来自中国观鸟会的赵欣如教授、付建平老师和吴岚的辛勤付出，让这个项目变成可能。同样深深感谢 Dick Newell 和Lyndon Kearsley专长和视野。同样，我还想感谢Lyndon的妻子Hilde和他们的好朋友“JJ”这些天来的美好陪伴。

With mid-summer a little slow on the birding front in Beijing (the heat, as much as anything, makes birding uncomfortable), I decided to use the opportunity of a free sunday afternoon/evening to check out the local Common Swift (Apus apus) colonies in Tiananmen Square. The subspecies in Beijing is pekinensis and it is a common breeder in the old-style buildings and hutongs, exploiting gaps under tiles as nesting areas. They supposedly winter in Africa with the nominate Common Swifts from Europe (I don’t know if this has been proved through ringing recoveries – comments welcome).

In Beijing the only other swifts frequently seen are the Pacific Swift (Apus pacificus) and, on passage, the very different White-throated Needletail (Hirundapus caudacutus). Neither should cause any identification problems.

The pekinensis subspecies of Common Swift is a potential vagrant to Western Europe but, for me at least, picking out one would be challenging. There has been some discussion of this possibility before and, I think, a few papers in the various birding journals, some of which warn of possible confusion with the similar Pallid Swift (Apus pallidus).

So it was with this in mind that I went to check out the pekinensis swifts at Tiananmen. The first thing I learned was that they are variable and that the same individuals can look quite different in changing light conditions. Although structurally the pekinensis birds look like the nominate Common Swift, some exhibit plumage characteristics (e.g. a dark eye mask, ‘cold’ tones, a dark ‘saddle’) that, in a European context, might suggest the closely related Pallid Swift if only brief or distant views are gained.

Anyway, here are a few images from Sunday evening with some personal comments.

2012-07-22 Common Swift pekinensis — Common Swift ssp pekinensis, Beijing. Typical Common Swift structure with ‘scythe’-like wings and a relatively deep fork to the tail. Note also the contrastingly dark underwing coverts.

2012-07-22 Common Swift pekinensis 2 — Common Swift ssp pekinensis, Beijing. Again, note the contrasting dark underwing coverts. The white throat patch contrasts with the side of the head.

2012-07-22 Common Swift pekinensis 3 — Common Swift ssp pekinensis. This individual shows quite a distinctive dark eye patch, reminiscent of Pallid Swift, and a strong pale throat patch.

2012-07-22 Common Swift pekinensis 4 — Common Swift ssp pekinensis. Again, showing a dark eye mask but with dark underwing coverts and light ‘scaling’ on the underparts. Note that many birds flew with trailing feet.. I wondered if that was a reaction to the heat?

2012-07-22 Common Swift pekinensis 6 — Common Swift spp pekinensis. This individual appeared darker overall and with a less obvious throat patch. One thing I learned – these birds can look quite different in changing light conditions.

Another observation from Sunday was the variability of the white throat patch, linked to the crop. Compare these two images of two different birds in similar flight positions – one with a full crop, the other with an empty crop. Striking!

2012-07-22 Common Swift pekinensis full crop — Common Swift ssp pekinensis with full crop. Note the striking pale throat.

2012-07-22 Common Swift pekinensis empty crop — Common Swift ssp pekinensis with empty crop.

In conclusion, if seen well, these pekinensis birds should not cause major confusion with Pallid Swift. The combination of structure and plumage (relatively narrow scythe-shaped wings, slim body, relatively deep forked tail combined with dark underwing coverts, ‘warm’ plumage tones and a lack of an obviously dark eye mask) should be enough to make identification relatively straightforward. But beware that, in some light conditions, some pekinensis Common Swifts can display one or more Pallid-like plumage features!

However, picking out a pekinensis among Common Swifts, or identifying a single individual in Western Europe in late autumn is another challenge and one I would not be so sure about meeting!

Finally, at one point on Sunday all of the swifts suddenly stopped wheeling around the Qianmen Gate at Tiananmen and gained height fast. The reason was this Eurasian Hobby that suddenly appeared and started to hunt the swifts over Mao’s mausoleum! It made a couple of half-hearted attempts to chase a swift but, after a couple of minutes, it drifted off west and the swifts returned to lower altitudes.

Tag: Common Swift

Out of Africa! The Beijing Swift’s Incredible Journey Charted At Last

‘Pekinensis’ Common Swifts