Discovering nocturnal bird migration in Beijing

Have you ever wondered what birds are flying over your home at night?  If you are on any sort of flyway, during the migration season it is possible that many hundreds, even thousands, of birds fly over your home in a single night. Recording sound during the dark hours can help to shed light on the number of birds and the diversity of species that are flying overhead as we sleep.

The practice of recording nocturnal flight calls (NFC) is gaining in popularity in Europe and the US (and elsewhere?) but is still in its relative infancy. Even with little knowledge of individual species’ calls, it is possible to gain an insight into the volume of birds that call as they pass overhead.

Of course most birders are also interested in identifying the species, but identification of the calls can be a challenge.  Not only does successful ID require a strong knowledge of the vocalisations of many of the resident and migratory species in the area but it appears that some species use different calls at night to those with which we are familiar, thus adding to the difficulty.  Lots of work is underway, including at Cornell Lab, to use AI to help scan recordings to identify the species but, for now at least, in East Asia that is a long way off.

With Beijing situated on a major flyway for birds commuting between Siberian breeding grounds and non-breeding grounds in China, SE Asia, Australasia and even Africa, there simply *must* be lots of nocturnal migration over the capital so, back in autumn 2017, living on the 13th floor of an apartment building at the time, I made my first attempts at nocturnal recording from my window.  Using a simple digital recorder, I was able to record species such as Olive-backed Pipit (Anthus hodgsoni 树鹨 Shù liù), Eurasian Skylark (Alauda arvensis 云雀 Yúnquè), Great Bittern (Botaurus stellaris 大麻鳽 Dà má jiān) and Siberian Rubythroat (Luscinia calliope 红喉歌鸲 Hóng hóu gē qú).  That experiment gave me a tantalising glimpse into the nocturnal migration over my apartment but a subsequent move to an apartment much less suitable for recording meant that the potential remained unfulfilled.  

Fast forward to summer 2021 and, in a conversation with Sir Danny Alexander, Vice President of the Asian Infrastructure Investment Bank (AIIB), we hatched an idea to begin a recording project on the roof of AIIB’s headquarters.  The building, 15 storeys high, is in a great location for such a project.  It is immediately south of the Olympic Forest Park in the north of the city, not close to any major roads, suffers very little from aircraft noise and with almost no tall buildings close by.  

The headquarters of the Asian Infrastructure Investment Bank (AIIB) in Beijing.

We purchased a Wildlife Acoustics Song Meter Mini (weatherproof and programmable), and set it up on the roof, programming it to begin recording from 24 August until mid-November.  The recorder is perfect for this project as the only maintenance needed is a change of batteries every two weeks or so.  The recorder automatically adjusts the recording time to allow for the changing sunset and sunset times and a 512GB memory card is capable of storing all the files for the whole period.

The Wildlife Acoustics Song Meter Mini digital recorder.

The primary objective of this project is to gain an insight into the volume of birds flying over central Beijing at night.  With identification of most calls straightforward, we hope to be able to gain an improved understanding of the timings, including peaks, of individual species and potentially also the relationship between weather patterns and the extent of migration.  Given the impressive volume of calls, we are already building up a large file of “unidentified calls” and, with the help of birders in the region and experienced ‘nocmiggers’ elsewhere, we hope to identify as many of the unknowns as possible.

The files from the first few weeks of recording have been downloaded and we are beginning to analyse them.  It’s a time-consuming process to go through them all but using the excellent free sound analysis software, “Audacity“, to produce spectograms in order to ‘visualise’ the files means it’s relatively easy to find the bird calls and skip through periods of silence. 

A typical sonogram, in this case showing a visualisation of the calls of Eurasian Skylark (Alauda arvensis 云雀 Yúnquè).

More than 4,000 calls have been identified so far.  Perhaps not surprisingly, in late August and September, the most dominant species have been Common Rosefinch (Carpodacus erythrinus 普通朱雀 Pǔtōng zhūquè), Olive-backed Pipit (Anthus hodgsoni 树鹨 Shù liù) and Eurasian Skylark (Alauda arvensis 云雀 Yúnquè) but these have been supported by a good selection of other species including Black-crowned Night Heron (Nycticorax nycticorax 夜鹭 Yè lù), Striated Heron (Butorides striata 绿鹭 Lǜ lù), Great Bittern (Botaurus stellaris 大麻鳽 Dà má jiān), Green Sandpiper (Tringa ochropus 白腰草鹬 Bái yāo cǎo yù), Common Sandpiper (Actitis hypoleucos 矶鹬 Jī yù), Wood Sandpiper (Tringa glareola 林鹬 Lín yù), Common Redshank (Tringa totanus 红脚鹬 Hóng jiǎo yù), Eurasian Curlew (Numenius arquata 白腰杓鹬 Bái yāo biāo yù), Forest Wagtail (Dendronanthus indicus 山鹡鸰 Shān jí líng), white-eye sp. (Zosterops sp., 绣眼鸟 xiù yǎn niǎo), Yellow-bellied Tit (Periparus venustulus 黄腹山雀 Huáng fù shānquè), and lots of thrushes and Muscicapa flycatchers (still to be identified to species).

You can follow the progress of the project at this dedicated page, where we will upload good examples of calls, a batch of unidentified calls (on which we welcome suggestions!) and, in due course, some statistics about the volume of birds each night and a full species list.  Analysis of all the files probably won’t be completed until well into 2022 but we are already excited about what this project will reveal about nocturnal bird migration in Beijing.

Huge thanks to the AIIB team, in particular Sir Danny Alexander, Alberto Ninio and Li Zeyu, for their support for this project and for their ongoing help and assistance.  And thank you to David Darrell-Lambert for initial advice about NocMig and to Geoff Carey and Paul Holt for advice and assistance with identifications.  Thanks also to all the birders in the East Asian Bird Vocalisation WeChat group and the NocMig WhatsApp group for help and assistance.

For the latest news about this project, to hear some of the calls we are recording and for a list of unidentified sounds, please see this dedicated page.

 

Header image: The Wildlife Acoustics Song Meter Mini in place on the roof of the Asian Infrastructure Investment Bank (AIIB) in Beijing.

Biodiversity rising up the agenda..

With biodiversity rising up the agenda due to the forthcoming UN negotiations due to take place in Kunming, China, in 2021, there is a lot happening here in Beijing and China.. on many fronts.  Here’s a quick summary of an eventful last few weeks.

At the end of October, I was honoured to be invited by my good friend, Shen Chu (Becky), of the Zoological Society of London (ZSL) to Kunming in Yunnan to deliver a public lecture at an event to celebrate International Snow Leopard Day.  With the exception of a couple of day trips into Hebei Province, this was my first trip out of Beijing this year.  The event was hosted by the Elephant Bookstore in Kunming and, as well as a live public audience, the event was streamed online to more than a hundred thousand people.  The organisers did a fantastic job, bringing together local artists, schools and musicians, and there was even a special Snow Leopard IPA produced by the local craft brewery which included a QR code with lots of facts about the Snow Leopard. 

Speaking about the Valley of the Cats community-based conservation and wildlife-watching project in Kunming.
Snow Leopard IPA. At 8% it’s a fitting strength for a beer celebrating the “King of the Mountains”!

With the city scheduled to host the 15th Conference of the Parties (COP15) to the UN Convention on Biological Diversity next year, it was wonderful to see such energy – and innovative ideas – among local people to engage the public about nature and wildlife.

Just a few days later, I set off to the Valley of the Cats with a subset of these brilliant young people from Kunming.  Having promised Becky several years ago to help her to see a Snow Leopard in the wild, there was an air of expectation as we landed in Yushu and made our way to the Valley.  It was my first visit of the year to this magical place and, as always, it did not disappoint.  We enjoyed a spectacular few days and treasured encounters with four Asian Brown Bears (an adult male and a separate mother with two cubs), a single Snow Leopard on a fresh kill of yak and a wonderful hike through some of the most stunning scenery I have seen. 

On our last morning we stopped by Yunta’s house for a cup of tea. Yunta is one of the village leaders and has been a strong supporter of the Valley of the Cats project since its inception.  It was early morning, around -10 degs C and I was shivering in four layers, yet Yunta was in a vest!

It was particularly encouraging to meet with a group of young local people who are keen to take on some of the running of the tourism project and to contribute to wildlife monitoring.  Seeing their enthusiasm and pride in their local environment was heartwarming.

Just a few days after returning from Qinghai, I was delighted to hear that the Valley of the Cats community-based wildlife-watching tourism project had been named as a runner-up and received a “recognition of excellence” under the Nature Stewardship category of the Paulson Prize for Sustainability.  Competing with more than a hundred projects across China, this was fantastic recognition for the local community.  You can read about the winning projects – on battery recycling in Wuhan and wetland restoration in Haikou – here.

Having been part of the team to produce the report entitled “Financing Nature: Closing The Global Biodiversity Financing Gap”, the authors have been busy reaching out to as many influential governments, ministers, organisations and individuals as possible to try to influence the debate on how countries finance the USD 700 billion per year needed to protect our most important biodiversity and ecosystem services.  That figure may sound like a lot of money – and it is – but to put it in context, it is less than the world spends each year on soft drinks.  Governments have a fundamental role to create the right regulation that generates funding for nature.  That means no longer allowing those that do harm to the environment to do so for free and rewarding those who protect and preserve.  Perhaps not surprisingly, the figure of USD 700 billion could be reduced by around half by reforming harmful subsidies (specifically on agriculture, fisheries and forestry).  It does seem out of step that, in the midst of a global biodiversity crisis, governments around the world are still paying people billions of dollars to employ practices that cause harm to our environment.  This week I was invited to brief senior staff at the Asian Infrastructure Investment Bank (AIIB) in Beijing.  As an organisation that funds many large infrastructure projects in developing countries, it was encouraging to hear about their enthusiasm for ensuring biodiversity and climate change criteria feature prominently in their lending criteria. 

Handing over a copy of the “Financing Nature” report to Sir Danny Alexander, Vice President of AIIB.

A second meeting has now been planned to examine how AIIB can become a leader amongst multilateral development banks on this issue.  There is a very long way to go to ensure that infrastructure projects are mandated to minimise harm to the environment and offset any unavoidable damage by investing in habitat protection and restoration elsewhere.. but that change is coming.. the only question is how fast?

Continuing the theme, last Saturday I participated in a discussion panel on biodiversity and climate change at the Caixin Global Summit in Beijing, an annual event that brings together an impressive line-up of people – from China and overseas – to discuss major global issues.  

And the following day I participated in the launch of the Beijing government’s “Urban Forestry Network”, a group of c30 people who will develop proposals for improving the quality of the capital’s tree planting and biodiversity-related projects in Beijing.  This network has the potential to make a big difference to how land is managed in Beijing, improving and restoring habitat for wildlife, and I look forward to playing an active role as the group develops its workplan.

Launch of the Beijing Urban Forestry Network on Sunday 15 November 2020.

You may be wondering if I have been able to do any birding recently and, sadly, the answer is no!  However, I am looking forward to this Sunday when I will be accompanying the new UK Ambassador to China, Caroline Wilson, on a birding trip to Yeyahu, during which we will be discussing biodiversity, China and the importance of the UK and China working closely together, as hosts of the UN climate change and biodiversity negotiations respectively, to ensure these processes are reinforcing and lead to a successful outcome.  It’s hugely encouraging to see the UK Ambassador taking a strong and early interest in these issues and I look forward to doing my bit to work for the strongest outcomes possible at both Kunming and Glasgow in 2021.

With Christmas in the UK out of the question this year due to the pandemic, I’m hoping for a few days of relaxation and birding around the capital.  With waxwings arriving and the first snow today, the excitement of what might turn up is palpable.  Will it be a Pallas’s Sandgrouse winter or could there be an influx of Asian Rosy Finches, or maybe even another of the special redstarts from the Tibetan Plateau.  Can’t wait to get out there and explore!