It is with a heavy heart that I must report the loss of Баян (BAYAN), one of the Mongolian Cuckoos.
The last signals received from his tag were at 1035 local time on 12 May 2020 and showed him almost exactly 100km north of Kunming in China’s Yunnan Province. Since then, there has been radio silence. The following analysis of the data from BAYAN’s tag was provided by Dr Chris Hewson of the British Trust for Ornithology (BTO) who fitted the tag to BAYAN in Mongolia in June 2019:
In the small hope that the tag’s temperature sensor was malfunctioning or there was an alternative explanation, we waited a few days for further signals. None were forthcoming, strongly suggesting that BAYAN had indeed died on 8 or 9 May 2020.
It is always sad when we lose a tracked bird but we should celebrate his life and the impact he has had on people around the world.

After crossing the Arabian Sea to India, hot on the heels of ONON, he captivated a country with an incredible surge of interest among people in India, most of whom were previously unaware of the distances travelled by some of the most familiar migratory birds. Below are just a few of the reactions to BAYAN’s crossing of the Arabian Sea:
BAYAN is almost going in same path as ONON, we are waiting to welcome BAYAN in India🇮🇳
— Mahesh (@maheshsoratur) May 5, 2020
Enjoying Onon and Bayan journey..found something new in life.and admist this lockdown.mthis is such a beautiful stuff..ful of positivity..
This is called " real leap of faith".— RJ (@ravijha1417) May 5, 2020
Amazing..!!
— Sandip Bhatt (@BhattSm) May 6, 2020
One of the main purposes of the project was to reach and inspire more people about the wonders of bird migration. Judging from the reaction on social media, BAYAN certainly did that.
Being able to follow the incredible journeys of these cuckoos opens our eyes to the phenomenal endurance of these birds and the mind-boggling distances they travel. It also reminds us that migratory birds live life on the edge with little margin for error.
If there is one message BAYAN, whose name translates as “prosper”, could carry with him, I am sure it would be something like this:
“Migratory birds like me don’t recognise human borders. We travel around the Earth, crossing oceans and deserts, powered sustainably by caterpillars, just to survive and breed. As humans, you are changing the planet in profound ways. Please ensure there are places for us to rest and refuel along the way so that we all may prosper.”
The fact that we last heard from BAYAN close to Kunming, Yunnan Province in China is fitting. Next year, this city is due to host the 15th Conference of the Parties (COP15) to the United Nations Convention on Biological Diversity, at which governments are due to agree a “new deal for nature” including targets to slow and reverse the loss of biodiversity. In many ways it is the most important meeting ever on nature.
Wouldn’t it be good to think that BAYAN’s legacy is to send his message to delegates to the UN meeting in Kunming?
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Thank you to everyone who has supported, followed and engaged with Баян (BAYAN) and the other Mongolian Cuckoos during this project. You have all helped to raise awareness about migratory birds and the places they need.
BAYAN’s journey at a glance:
7 June 2019: fitted with a tag (number 170437) at Khurkh in northern Mongolia.
11 June 2019: named by schoolchildren at Khurkh Village School
7 June 2019 to 9 May 2020: Mongolia – China – Myanmar – India – Bangladesh – India – Oman – Saudi Arabia – Yemen – Saudi Arabia – Eritrea – Ethiopia – South Sudan – Kenya – Uganda – Kenya – Tanzania – Mozambique – Malawi – Mozambique – Malawi – Mozambique – Zambia – Malawi – Tanzania – Kenya – Somalia – India – Bangladesh – India – Myanmar – China (31 border crossings involving 18 countries)
Total distance: c24,000km
Rest In Peace Баян (BAYAN) 🙏