Siamese Russell's Viper, Daboia siamensis

About a week ago, finally my dream to see a Siamese Russell's Viper, Daboia siamensis in the wild came true!
Also known as the Eastern Russell's Viper, it is Thailand's largest viper and the only species in the country that is not a pit viper. It lacks the typical heat sensing pits found in e.g. the green pit vipers. Though, it is believed that it does have a different kind of heat sensing organ to find its prey.

In reply to Paul's post early 2014 to ask what our hopes were for the coming year ( www.wildlifethailand.com/forums/1-genera...your-hopes-for-2014/ ), I mentioned that I hoped to see this particular species.
That year I only got to do one short, poorly planned trip to look for it, but to no avail.
End of last year I learned about a location where the species was known to occur. I did get to do 2 night walks there, and found a roadkill, but obviously that was not exactly satisfying.

Then I received some new tips from another herping enthusiast living in Thailand, after he had found various roadkills in another location in Eastern Thailand.
And coincidently, shortly after I got contacted by some English & Australian herping friends that were planning to come to Thailand again, and one of the main target species was this Daboia siamensis.
With a group of 8 experienced and ambitious herpers, we headed to Eastern Thailand to explore the rice fields and other open habitats where this species should feel at home.
The first night, we returned to the resort at about 2:00AM after a long night in which we found a total of 30 snakes, 7 different species. Successful for sure, but we did not find the target species...

The next day we decided to go scouting in daytime to find some promising locations for the second night. We talked with the locals, most seemed to know the species which was a good sign, but the first thing all of them told us was to come back in the cold winter time... And some mentioned that they were not seeing them as much as in the past. Not very promising as we happened to be there in pretty much the hottest time of year, not to mention one of the driest years in decades.

But they can't have just migrated hundreds of kilometres South like birds might do, so we remained positive.
It helped that we had found a trail of a rather heavy snake on a dust road with rather short movements which looked like it could have been our target species.

After dinner we headed back to that location and all 8 of us spread out to cover as much area as possible.
I was loosing hope when walking through various burned rice fields. No idea how this species would cope with the burning practices and would it stay in the area, or move to different places?
But then at 20:30 I am walking along the edge of a burned rice paddy and as I move my torch light around to check every hole and interesting spots in front of me, suddenly the amazing unmistakable pattern of the Russell's viper appeared in the light and immediately the adrenaline rushed through my body.
I haven't felt this much excitement for a snake encounter for quite some time. "RUSSELL's" I yelled out to the other party members, and they ran as fast as they could in my direction. All of them totally over the moon.



The 1m long viper perfectly coiled itself up and hissed loudly while in- and exhaling. Some say it is the loudest snake in the world. Not sure if that is true, but it was loud enough to be audible from quite some distance, and seemed louder than a Monocled Cobra, Naja kaouthia.

The Siamese Russell's Viper, Daboia siamensis, was elevated as full species after previously being considered a subspecies of the Daboia russelli that occurs in e.g. India and Sri Lanka.
It is one of Thailand's most dangerous snakes. In daytime they might lay in ambush on the floor and their camouflage makes them blend in perfectly. That combined with a highly toxic venom and a defensive attitude, it's a danger especially for farmers in its range. It mostly occurs in Central Thailand, North up to Nakhon Sawan, found even around Bangkok, and further east towards the Cambodian border.
It does not like forested areas, so the chance to encounter it in a national park is virtually non-existent.



All in all the encounter was even better than I expected it would be, I guess it helped that I could share it with this group of snake enthusiasts.
I hope I can do some more searches later this year to learn more about its status, range, and habits/ habitat preferences.

Fantastic photo and pics. I don't know anything about snakes but I love to see a subject master at work!

Thanks for your comment, Templehound.
Well, they don't occur in Krabi, and I haven't heard of any sightings in Kamphaeng Phet but it might be possible. So far the most Northern range what I have heard off, should be around Nakhon Sawan. Seems like this species is quite localized. There are some unverified records from Prachuap Khiri Khan which would be the most Southern range, but I have my doubts about that. Very likely false id's of other species.
It occurs mostly in Central and Eastern Thailand, around Bangkok

From what I have heard from other herpers, Malayan Pit Vipers should be quite common in areas near Krabi. Some say it is one of the more commonly encountered species down there. But honestly I have no experience in Southern Thailand so can not help with locations.
There's lots of viper species in Krabi area. I hope I have some time this year to explore Southern Thailand a bit more, there are a lot of species that I haven't seen yet.

Thanks Adrian for sharing the information. In the meantime I have also learned about more locations, and have been lucky to see the species again on another trip. But it certainly remains easier to find them as roadkill than to see them alive. November - December especially the males tend to be on the move a lot.
If time allows I might check the area coming winter.