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A Bird Ringer’s Journey to East Asia

In early August 2023, Matt Prior — a licensed bird ringer based in Wiltshire — was lucky enough to have visited Ugii Lake in Mongolia, joining local conservationists in their efforts to monitor birds migrating through the area. His main goal was to ring wading birds originating in Siberia and the Arctic as they made their way to their wintering grounds in south-east Asia, Oceania, and Australia.

Taking the Pulsar Axion 2 XG35 — a powerful thermal imaging monocular with a highly sensitive 640×480, 12 µm, <40mK NETD thermal sensor designed to detect even the most minute temperature difference in a variety of challenging conditions — with  him, Matt’s intention was to discover a whole new dimension to the work of a bird ringer, showcasing how thermal imaging can reveal so much more than traditional dazzling methods.

As thermal imaging monoculars are licensable devices, an export license was needed before he could take the Axion abroad. So, once Matt had applied for and received his export license, he was off on his journey. This is part one of the journals Matt kept during his time in Mongolia.

Matt’s Journey: 6th-8th August

The journey to Mongolia has proven difficult: the plane experiencing technical difficulties has caused my journey time to equate to two days rather than the 14 hours or so I expected, but once I eventually touched down and disembarked, I met up with Carlos, a fellow bird ringer from Seville, Spain. Keen to get on our way, we headed over to the Wildlife Science and Conservation Centre. Ulan Bataar is the capital of Mongolia, and its new airport is located an hour away from the city; It is also known to have the coldest average annual temperature and highest annual level of pollution of any capital city in the world.

At the headquarters, I met up with Sam, a young bird ringer in his early twenties and, before too long, what can loosely be termed as a “taxi” arrived to take us to our final destination: Ugii Lake. It turns out the taxis around here operate as a lift sharing service through Facebook, whereby people advertise where they are going and then people who are looking for a lift to nearby areas pay them their share of the cost of the journey. We thought we would be leaving at 11am, which we did, only we weren’t aware of the four hours we then had to wait for the next passenger to join us. Evidently time is not of much consequence in Mongolia!

Once we were properly on the way, our journey was largely uneventful — the surrounding countryside is open steppe and, in most places, it has been over-grazed by cattle, sheep, and goats; so, aside from Asian Short-Toed Larks and Upland Buzzards, bird sightings were sparse.


The journey to the camp.

Arriving & Meeting the Team

Arriving well after darkness had fallen in a small shanty town, we met our host, Batmunkh — a good friend of mine who runs the ringing station, and, after a quick transfer into a car that would most certainly have failed its MOT in the UK, we were soon driving down a series of dirt tracks and then a couple of fords (which, in retrospect, I think the car did incredibly well to get through). Our driver spoke not a word of English, but he did seem to take great delight from our reaction to his driving style, which can only be described as rally cross-esque. Whenever I am travelling to a new destination like this there is always that sense of anticipation of what it will be like. Being thrown about in the back of a bone-rattling car like this in the pitch black was one of the more interesting journeys of my life.

At last, after a sprawling, day-long journey, I have finally arrived at the ringing station. The station consists of two large circular tents known as Gers, one of which doubles as a catering tent and sleeping quarters, with beds for two people, and the other has a bird ringing table and three more beds.  We have met up with a huge young German chap called Emil who has already been here for several weeks. After a good long chat with him, it has become apparent that catches are low in the area due to extremely high water levels caused by the wet spring they have just endured.

At Ugii, nets are checked hourly throughout the night, and they operate on a two-shift system — one from 10pm until 3am and one from 4am until 8am. Birds are kept in keeping cages and then processed at 8am. Sam and I are both now feeling the effects of our long journey, so, being spared any work, it is with a mixture of both excitement about what we will see tomorrow and concern over the lack of birds, that we finally get some rest.

Day One: 9th August

The first morning waking up anywhere new is filled with excitement and anticipation of what the new place will bring, so it’s with these emotions that I’ve woken up after a good nights’ sleep on a camp bed in the ger. It has been a cold night, so I’ve woken up with a cold nose; my head, however, is nice and warm, as I had the foresight to sleep with my woolly hat on. Sam remains fast asleep tucked very deep inside his sleeping bag.

Yesterday I was told that, if any birds are caught, they are put into keeping cages in our ger overnight and then ringed first thing in the morning. Peering across the ger I can see a couple of cages have been erected, which means at least we’ve caught something.


Morning at the camp (left), large tower hide (right)


At 8 am I walked outside the ger and was greeted by a huge expanse of long grass, a short distance away I could see a huge lake with lines of very noisy Swan Geese, but no other signs of life. The air was cool with a gentle breeze and the first thing that struck me was the lack of noise; no sound of humans, including traffic, and that really was incredibly refreshing. Looking to my left I spotted the large tower hide that overlooks the lake, heaving with Tree Sparrows chipping away. I have dedicated much of my adult life to conserving Tree Sparrows in Wiltshire and the prospect of spending more time amongst these wonderful birds was very exciting.

Away in the distance I could see a figure walking towards me. As the figure got closer, I could make out Emil approaching, walking barefoot and wearing shorts — not at all what I was expecting, as I’ve brought along waders to walk in the water. He has no birds, and the nets are still open.

There was no noise from the catering ger, so we stepped inside quietly to make a cup of coffee — essential before we could start the morning. The catering tent is full of boxes of basic foods; mostly rice, pasta, bread, jam, and vegetables.

We returned outside, taking the ringing table out from our ger. The catch is very small with 1 Wood Sandpiper, 1 Common Sandpiper, but — brilliantly for me — there were also 4 Sharp-tailed Sandpipers.


Eastern Yellow Wagtail (left), Sharp-tailed Sandpiper (right).

‘Sharpies’, as they are affectionately known, are exceedingly rare in the UK, with fewer than 40 records, and it is a bird I have never seen. I was instantly struck by how solid the bird is. They are phenomenal migrants that winter in Australia, and for the most part they have built up large pectoral muscles and have ample fat stores for their migration. The ageing of Sharpies is easy: these were all adults, because the juveniles all head to Alaska, apparently!

We put leg flags on the birds. These flags have alpha-numeric codes, so that individuals can be seen in the field without having the need to recapture them. I am normally quite dextrous, but I am finding these a bit fiddly. I am sure I will get the hang of it!

There is a lone net near the tower which a local student was monitoring, taking out the occasional Tree Sparrow. We have to check the birds after she has ringed them, and it is a silent process as she speaks no English. She also brought an Eastern Yellow Wagtail back, so Sam ringed that and we all had a good look at it for reference, in case we ever see one in the UK.

Batmunkh called out from his ger and we sat down to a decent breakfast of fried eggs and bread and jam; it is basic, but it was all we needed.


Batmunkh has taken us round the nets this afternoon. I decided to go local, taking a page out of Emil’s book — wearing shorts and walking around barefoot. As we walked through the grass there, billions of insects swarmed up in front of us, small toads were everywhere, and there were so many grasshoppers that they are beyond counting. This pristine habitat is so rich in biodiversity it is frightening to realise how bereft our own country is.

There were small shallow pools dotted around the grassland with Wood Sandpipers and Common Sandpipers all around, but there was nowhere to concentrate birds to be able to catch them for ringing.

We reached the first net set — an E-shape along the shoreline of a river that feeds into the lake. There was a lovely little marsh, but Batmunkh explained that, during last year’s pioneering camp, the water in the river was a few centimetres deep and the whole area was heaving with waders. There were no waders near the nets at all, and the nets are in a poor state due to semi-wild horses running through them. I had brought more nets with me and was keen to get some more up, so we took a walk around the wider site. Batmunkh strolled confidently out into the knee-deep, heavily weeded water. Sam and I followed, slipping and tripping as we go — Batmunkh makes it look so easy! We were sure that one of us was going to come a cropper.

The two most obvious birds were White-winged Black Terns, cruising along the shoreline in small noisy flocks — I have a big soft spot for these most beautiful of Terns and I was thinking about how I was going to catch them. The other was a huge line of 2000 Swan Geese that gathered on the lake to moult — Ugii Lake is the premier site in Mongolia for this globally threatened bird.


Swan Geese seen through the Pulsar Axion 2 XG35 thermal imaging monocular.


A Chinese group was here two weeks ago and hired a boat at great expense, managing to ring a small number of them Swan Geese. They have erected a cage for the geese, and they are to be released in a months’ time. It seems weird to me, but this is a scientific study to see if captured birds are able to find their way to the wintering grounds without following the rest of the flock. The Tree Sparrows find the feature very attractive and flocks of 50 were flying to and fro incessantly. There was an unfamiliar call amongst them, and a quick scan with binoculars revealed it to be a pretty stunning Père David’s Snowfinch — a bird that I would love to ring.


It is now dinnertime, and we’re sitting down to that Mongolian staple of clear soup with pasta and small lumps of fatty lamb. It is not my favourite meal in the world! We’re discussing who is doing the net rounds. Batmunkh and Emil are doing them tonight, which is a bit of a relief to be honest, as I am still lagging from yesterday’s long and drawn-out journey.

Day Two: 10th August


It’s morning and, after one full day in the field, I’ve been weighing the situation up and have realised that we need to set more nets if I’m going to make my trip around the world worthwhile — we have a group of Korean students coming tomorrow and we need to catch some birds to show them. Sam and Emil saw some Pallas’s Reed Buntings and a Yellow-breasted Bunting yesterday afternoon, and I had flushed a snipe species from the marsh. We had also seen a few birds moving along the northern shoreline towards the Observatory Tower (it’s an obvious feature for birds to head towards), so I set a line of low nets through the marsh right to the shoreline and then furled them ready for today.


Left: Emil with Common Tern , Right: Matt with Black Tern (left hand) and White Winged Black Tern (right hand).


The White-winged Black Terns are blowing my mind, they are one of the most prominent birds of the site — and considering how rare they are in the UK, I have to try for these. Sam and I have put up a net in what seems to be the most obvious spot: in open water but between two offshore spits. I spent hours back home before I started on my travels creating recordings of birds that I thought I might possibly see, and the White-winged Black Tern was one of them, so I put the player in a bird bag and tied it to the mist net pole. It’s all good fun working like this in the dark whilst waist deep in the lake, and luckily none of us have not fallen in yet!


Dusk has beaten us and it’s now dark. We’ve gone beyond Batmunkh’s set and put up a line of two-shelf wader nets across a shallow lagoon that has a reasonable number of small waders on.

Day Three: 11th August


It’s now dawn, and what a dawn! There is not a breath of wind, and the sun is a dazzling ball of orange fire amongst a scattering of clouds with a perfect reflection on the mirror-like lake. Wading out to the tern net has been lovely, the water was warm and the weed incredibly soft as I dragged my feet through it. Straining my eyes towards the net I thought I could see something in the net, which was very exciting, as I can hear terns in the distance! Sure enough, I found two Terns in the net, and one was the White-winged Black Tern I was so looking forward to seeing!

I continued on the net round and, once I reached the lagoon, I saw a great big lump in the net. I tried to wade quickly towards it, but the mud is slippery with bioslime and it is all I could do to stay upright, and, after a high-class impression of ‘Bambi on Ice’, I got to the big bird. It was a juvenile herring-type gull. I have handled lots of large gulls and this one is pretty simple to handle; adults can be a different matter. Rather than delight, my first thought was, how sad that it isn’t a Pallas’s (my favourite large gull). I extracted a few waders and there were not many birds, but at least we have something impressive to show our Korean guests.

Returning to camp, we set the ringing table up outside, and waited with a coffee for our guests. They were running late, so I finished my drink and took a stroll to the two-shelf nets where I found a smattering of Pallas’s Reed Buntings, but sadly no Yellow-breasted. As I neared the nets a couple of Snipe flushed out of the long grass and one plopped straight into the net in front of me. As soon as I held it, I could see the characteristic tail pattern of a Pin-tailed; I love all snipe species so this has been a real highlight for me.


Juvenile Mongolian Gull (left), Long-Toed Stint (right).

A vehicle appeared in the distance, and it was quite funny watching it zig-zagging across the landscape. It was obvious that they did not know where they were going, or how to navigate the shallow waters that are dotted all over the terrain, but, eventually, they made it to camp. The Korean students disembarked from the minibus and we stood back as Batmunkh introduced them to Ugii Lake and explained the station’s mission. We were introduced as the foreign ringers and then we started the ringing demo.

The Koreans are exceptionally polite, but they are showing a level of nervousness near the birds and I want to bridge that gap. Their local guide is Nari, who it turns out has ringed birds before, and she speaks good English, so we have had a really good chat. The low number of birds really helped as we have been able to show the birds to our audience, and we worked through familiar species including Redshanks, Common Sandpiper, Wood Sandpiper, and Little Ringed Plover. For me, the highlight so far has been Long-toed Stint, a species that I have not seen before; they are cracking little birds, quite wriggly and surprisingly strong.

The Koreans are really keen on videos of the release and like to get photos of them behind the bird. Doing a ringing demo for people who speak very little English, and with me speaking no Korean, is proving to be good fun. Next up, the Pin-tailed Snipe, and wow, those tail feathers! They then got a real treat seeing the White-winged Black Tern. Lastly, unbeknownst to our guests, it was time for the gull. I had to be very careful with this, holding it by the neck so that it cannot bite me, and then securing it safely to remove it from the keeping cage. The sight of the gull evoked a satisfying prolonged ‘ooooh’ from the audience, and close examination of the gull revealed it to be a juvenile Mongolian Gull. Some authorities classify Mongolian as a separate species, but at the moment it is lumped in as Vega Gull, even though they breed in a very discrete area.


Matt demonstrates bird ringing best practices.

Our guests brought out their breakfast and very generously share it with us. This was a real bonus — when staying in a remote place like Ugii, you accept that living will be tough and food will be basic, so fruit juice, fruit, and biscuits was a real treat. Our guests left us, but not before exchanging our contacts on Instagram.


It is now early evening and Emil has spent hours banging and clanging in the kitchen. He has made the most delicious chicken schnitzels; this is way above the standard of expedition food and the team are deeply appreciative of his phenomenal effort and the outstanding food.

Batmunkh has asked me to take him out with the thermal imager. He wants to target Common Cranes and Black Storks. I don’t fancy our chances, but he is the boss, so off we go.

We have just got back from a massive, largely fruitless walk. We walked inland away from the lake and reached the river that feeds the lake. We did not see any storks, but, using the Pulsar Axion 2 XG35 thermal imaging monocular, we did spot hundreds of cranes mixed with Grey Herons far in the distance. Despite being a long way off, they all flew off noisily from a long way away. On the return journey, we tried for larks, but really struggled to see any. We caught two Short-toed Larks, so at least we did not draw a blank. We also spotted a huge Mongolian Lark but, unfortunately, it evaded us. Batmunkh advises that Mongolian Larks are rapidly declining due to over-grazing, so sadly this may be the only one we see during my trip. Some good news to end the day with, however, is that the Asian Shrot-toed Larks are easy to approach and catch.


The next installment of Matt’s diaries will be available soon. Keep reading to find out how he uses thermal imaging to observe the behaviour of Swan Geese prior to catching them.

For more information about export licences and travelling abroad with thermal imaging and night vision devices, please click here to visit the Gov website.

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