Introduction
Our first Expedition Northern Thailand was launched for the first 8 nights of October 2024. Unlike our other expeditions, we would be staying at just one location for the full duration of the tour, a luxurious resort surrounded by rainforest. Despite these comforts, we were out early every morning and spent the majority of each day in the field searching for herpetofauna. Much of this trip was spent road cruising, but we also embarked on some massive hikes and climbed through rocky rivers in search of our targets. The result was one of the most remarkable expeditions we have ever hosted.
To book Expedition Northern Thailand 2025, click here!
Day 1
Our group met near the airport in Nan city on the first day, immediately embarking upon the roughly 2 hour drive through the hills to our resort. The weather was ideal, with mixed cloud and sunshine dappling down upon the high quality tarmac roads which wind through the uplands of Northern Thailand. Unsurprisingly, this drive produced our very first snake of the trip, a Heller's red-necked keelback (Rhabdophis helleri). While common in many other parts of its range, Rhabdophis helleri can be very difficult to find in Northern Thailand, so this was a fantastic find to kickstart the expedition.
The good weather did not hold up, sadly, and we were subjected to thick fog and very cold conditions for our first night herping on the mountain. This is the worst conditions to find herpetofauna in the area, so we only saw a handful of common species that night, namely Lanna pit viper (Trimeresurus lanna), twin-spotted slug snake (Pareas geminatus), a Chapa wolf snake (Lycodon chapaensis) and a tiny Guo's pit viper (Trimeresurus guoi).
Rhabdophis helleri
View from our resort.
Low visibility road cruising.
Trimeresurus lanna
Cyrtodactylus phukhaensis
Trimeresurus guo with 10 baht coin
Pareas geminatus
Lycodon chapaensis
Day 2
The perks of staying with forest habitat all around was evident on our very first morning on location, when Platon caught a lovely Indo-Chinese ratsnake (Ptyas korros) crawling down from a tree directly outside out bungalows. We searched a lot more that day, but only found a green horned dragon (Acanthosaura lepidogaster) juvenile and some skinks which escaped being photographed.
At night, we were still subjected to extremely thick fog and occasional rains, which led to mostly the same few common species being observed as the previous night. However, we added Gumprecht's pit viper (Trimeresurus gumprechti) (the final of the 3 'green beans' in the area) to the tally, as well as a lovely blue-eyed bamboo ratsnake (Gonyosoma coeruleum). Adding to a more successful night 2 was a rare Yunnan mountain toad (Orphryophryne pachyproctus) and much larger Heller's red-necked keelback (Rhabdophis helleri), which we left undisturbed as it was digesting a huge meal.
Ptyas korros in our resort garden
Acanthosaura lepidogaster
Rhabdophis helleri
Trimeresurus guoi
Trimeresurus guoi
Orphryophryne pachyproctus
Trimeresurus gumprechti
Gonyosoma coeruleum
Day 3
Despite waking up early and cruising with multiple vehicles on the road, we were only about to catch one radiated ratsnake (Coelognathus radiatus), which gave us the 'aggressive' defensive display, followed shortly by playing dead, although we did catch a checkered keelback in the resort garden while checking out a small stream. The weather was still mostly cloudy with on and off rains, not ideal conditions.
Yet again, we tried to search at the highest elevations of the mountain at night, but the fog was so thick that we only saw some frogs and lizards. Instead, we decided to focus on exploring the mid-montane elevations of the mountain. While snakes were elusive here as well, we saw a very impressive white-lipped flying frog (Zhangixalus pachyproctus). The first time we had ever seen this species here. Better yet, another group of Thai herpers searching the same area as us found a very rare Spencer's stream snake (Opisthotropis spenceri), which they kindly shared with our group.
Coelognathus radiatus
Megophrys cf. major
Pseudocalotes microlepis
Leptobrachium chapaensis
Amolops sengae
Trimeresurus lanna
Opisthotropis spenceri
Zhangixalus pachyproctus
Day 4
While the first 3 days of the trip had included a lot of interesting encounters and impressive species, the weather had made finding our main targets very difficult. Worst still, every time we saw one of our targets, they were dead on the road or freshly hit by another car. This had included some really heartbreaking encounters which had put a dampener on our mood and had us working extra hard to turn up our target species.
With a monumental effort, things finally started to pick up on the fourth day. During our extensive daytime searching, we caught yet another (much larger) Indo-Chinese ratsnake (Ptyas korros) in the garden of our resort. While road cruising in the afternoon, we caught our one and only Vogel's bronzeback (Dendrelaphis vogeli) of the trip. This bronzeback inhabits mid-montane and sub-montane forests in the area, but can be quite difficult to find on many trips. We also road cruised a little oriental vine snake (Ahaetulla prasina).
Lucky for us, a heavy rainstorm hit the mountain in the early evening, which meant there was less fog and much better productivity at the high elevations. We caught a very nice selection of snakes, including our first mountain slug snakes (Pareas macularius) of the trip and an absolutely giant Yunnan green cat snake (Boiga cf. cyanea). While not a new species for the trip, we saw a huge Gumpecht's pit viper (Trimeresurus gumprechti) eating an equally large-sized rat high up a tree. The best was saved for last though, when Patrick kicked over some fallen banana leaves and revealed an adult Mountain pit viper (Ovophis cf. monticola) underneath. Our first real 'showstopper' find of the expedition.
Ptyas korros
Ahaetulla prasina
Dendrelaphis vogeli
A beautiful waterfall in the mid-montane elevations.
Pareas macularius
Road cruising fun
Trimeresurus gumprechti predating a rat
Dendrelaphis vogeli
Yunnan green cat snake (Boiga cf. cyanea)
Mountain pit viper (Ovophis cf. monticola)
Day 5
Just when we hoped that our luck had turned, and despite relatively good herping conditions, day 5 was undoubtedly our worst day of the trip. We saw some of our biggest targets DOR, namely a huge false cobra (Pseudoxenodon macrops), a Laotian bearded snake (Parafimbrios lao) and two juvenile Yunnan beauty ratsnakes (Elaphe taeniura yunnanensis) all dead on the road. Meanwhile, the only snakes we saw alive were a couple of checkered keelbacks (Fowlea piscator) in the daytime, and all 4 local species of slug snake at night (plus green vipers). Not that there's anything inherently wrong with slug snakes, it was quite impressive to see all the species in one night for the first time, but it hurt when every time we saw a target snake it was recently hit by a car (or ambulance, in this case). We did find one single new snake species for the trip, a banded wolf snake (Lycodon fasciatus).
Fowlea piscator & victim
Pareas cf. berdmorei
4 species of slug snake
Pareas macularius
Pareas margaritophorus
Lycodon fasciatus
Day 6
At this stage, the trip had fallen well below our expectations for what we hoped to have found by this point. It had been rainy and foggy almost every night since the trip began, and our luck with seeing the best snakes dead had been absolutely awful. Desperate to turn things around, we embarked on a huge hike to remote caves deep in the steep valleys, hoping to find a Yunnan beauty ratsnake (Elaphe taeniura yunnanensis) in one of them. Sadly, we only found one Lanna pit viper (Trimeresurus lanna) during the entire hike. To compound our misery, this day just happened to be the first cloudless and sunny day of the trip, meaning that we were absolutely cooking in the sun for hours, and the hike back to the hilltop at the end was undoubtedly a massive struggle for all involved. The beautiful views were great, but didn't quite make up for this.
Inspired even further by this failure, we didn't rest at all and immediately went out road cruising in the late afternoon. We saw nothing for a while, but right when we were about to call it and go to dinner, a huge dark snake appeared in the middle of the road at the high elevations. Running up to it, it spread a wide hood and turned to face us, showing itself to be an magnificent brown-banded mountain cobra (Naja fuxi), quite a rare cobra and one of our group's biggest targets for the expedition.
After dinner, we quickly got out road cruising again in the warm, dry conditions, and within minutes encountered an even larger mountain cobra, this time found directly between our two cars as we were crossing paths on the road. Having 10 people see the cobra on the road at the same time is a really rare occurrence enjoyed by all. Better yet, David found an alive Laotian bearded snake (Parafimbrios laos) later that night, another huge target for our group due to its rarity, similarities to the dragon snake (Xenodermus javanicus) and the bizarre scales on the face from which it gets its name.
Crossing streams
Steep hiking to caves
Northern Thailand scenery
Trimeresurus lanna
Naja fuxi seconds after encounter
Jace with Naja fuxi
Naja fuxi
The larger Naja fuxi
Parafimbrios lao
Parafimbrios lao
Day 7
The previous night was simply incredible and set the tone for the final 2 nights, whereby the weather had completely changed and all of a sudden it was hot and dry every day. We had officially reached the end of the rainy season, when dry weather brings everything out and the occasional rainstorms only boost activity even further.
Despite not getting up early, we cruised another two radiated ratsnakes (Coelognathus radiata) during the daytime, as well as a juvenile blue-eyed bamboo ratsnake (Gonyosoma coeruleum) in the late afternoon. After dinner, we immediately started finding even more snakes. While road cruising, we found another Gonyosoma coeruleum, multiple Chapa wolf snakes (Lycodon chapaensis) & banded wolf snakes (Lycodon fasciatus), another Yunnan green cat snake (Boiga cf. cyanea), and slug snakes galore. This streak culminated in ecstasy when a large, bright orange snake appeared in the middle of the road. Finally, we had found our first (alive) Yunnan red bamboo ratsnake (Oreocryptophis porphyracea pulchra).
Once road activity slowed down, we went out for a ridiculously productive stream hike, where we found two Lanna pit vipers (Trimeresurus lanna), by far our biggest blue-eyed bamboo ratsnake (Gonyosoma coeruleum) of the trip and a sleeping many-banded green ratsnake (Ptyas multicinctus). The latter is very rare in Thailand and was a huge target for those in our group who had come to Northern Thailand to see its beautiful colubrids. An absolutely incredible evening consisting of well over 10 species of snake and almost 30 total snake encounters.
Coelognathus flavolineatus
Gonyosoma coeruleum
Resort garden
Peak conditions
Injured Plagiopholis nuchalis
Slug snakes!
2 different Lycodon fasciatus
Boiga cf. cyanea
Chapa wolf snake (Lycodon chapaensis)
Gonyosoma coeruleum
Oreocryptophis!
In-situ Ptyas multicinctus
Oreocryptophis porphyracea pulchra
Ptyas multicinctus
Day 8
After such an incredible turnaround in fortunes, where we went from seeing everything good dead, to seeing everything good alive and in higher abundance than usual, it felt like our trip could not get much better. We were so wrong.
For the first time this trip, we took most of the day off. The mid afternoon was taken up by an incredibly heavy thunderstorm, and during the late afternoon we were consumed with our final day barbecue. By that point, the sun was out and drying everything up, making way for another night of absolutely prime herping conditions. Come sunset, we were out cruising and this time we were actively expecting some special encounters.
We began by doing road cruising passes on the highest elevations of the mountain, and merely a few minutes after it got dark, our guide Bank slammed on the breaks and started shouting "SLOWINSKII!!!". While leaning out the window shining the edges of the road, he had spotted our absolute number one biggest target for the expedition cruising along the edge of the tarmac. Moments later, our entire group was out of the two cars and marvelling at what is undoubtedly the best 'final night find' we have ever had across our many expeditions. The red river krait (Bungarus slowinskii) is one of the rarest elapid snakes in South-East Asia, with this only being the 6th confirmed record in Thailand. It is a very large snake, and despite being extremely venomous, certainly one of the most docile snakes you can encounter in its cold, submontane forest habitat.
With the best final night find under the belt, we continued herping with the mentality that anything else is a bonus at this point. Not even 10 minutes later, we spotted a bright red snake rapidly moving across the road. Unsure of what it was, we jumped out of the car to find a huge red coral snake (Sinomicrurus cf. annularis) on the road. This was another of our biggest targets which we had only seen DORs of so far, and this was possibly the best individual ever. Strangely, it had a orange band on its head as opposed to the usual white band. It was also double the size of any individual we had seen before, dead or alive. Simply ridiculous.
Over the next hour, we saw several more snakes, including the bulkiest Lanna pit viper (Trimeresurus lanna) we have ever laid our eyes on, more wolf snakes, and of course many slug snakes. We wrapped up extra early so we could all appreciate, photograph and release the amazing snakes we had encountered that night, since some people had to leave early the next day. A simply incredible end to the expedition. A flurry of fantastic finds, checking off most of our biggest targets - both for guides and guests.
Group pic
JB on barbecue duty, legend
Prime conditions, again.
Something special...
This!
Trimeresurus lanna
Lycodon chapaensis
Must be something good...
Yep!
Bungarus slowinskii
Annulated coral snake (Sinomicrurus cf. annularis)
Day 9 (extension)
While Expedition Northern Thailand had officially ended, some of the guests extended for an extra day (with the guides) as the herping had been astronomically successful, the good conditions seemed like they would continue, and there was still one very special snake which had eluded us in the first 8 days. Sure enough, Jordi, Platon and Niklas went for hike to the high elevations of the mountain and during a cloudy spell at midday, Platon spotted a juvenile black-striped green ratsnake (Ptyas nigromarginata) - the very snake we were hoping for the most - basking on top of an exposed shrub.
As we were split up at the time, we could not believe that this had happened and were convinced they were joking when they told us they have found "nigromarginata". This snake is truly one of the most beautiful animals to exist on this planet, both in juvenile and adult form. They only occur at the very highest elevations of the mountain in Northern Thailand, and are very rarely seen, even if you spend weeks searching. Everything had come together with perfection - the perfect script.
Later that afternoon, we visited a local snake keeper who had recently caught a Harold Young's supple skink (Lygosoma haroldyoungi), one of the most incredible lizards in the world. While it was a shame we were not able to find one of these ourselves during this expedition, it was still great to see and interact with this crazy skink in person. We all enjoyed it greatly.
Despite rain in the late afternoon, we went out for a quick final night of herping together and focused on highlands. We turned up several of the species featured many times this report, along with another (much smaller) coral snake (Sinomicrurus cf. annularis) with the typical colour morph. This made it 4 back to back days of sensational sightings.
Ptyas nigromarginata
Ptyas nigromarginata
Lygosoma haroldyoungi & Platon
Small rain showers
Coral snake
Sinomicrurus cf. annularis
And that concludes our first ever Expedition Northern Thailand. A rollercoaster experience which saved the very best until last. Looking back at our species list, we missed very few of the 'showstopper' species occurring in the area, finding the two biggest snake targets (B. slowinskii and P. nigromarginata) which we had highlighted on the expedition page prior to the start of the expedition. One could say it cannot get better than this, but we have said that before and were proved wrong...
To join our next Expedition Northern Thailand (10th - 19th October 2025), click here!
