Borneo Dispatches #14: Dumeril's Monitor

Dedicated exclusively to field herping.

Moderator: Scott Waters

Post Reply
User avatar
Hans Breuer (twoton)
Posts: 3230
Joined: June 8th, 2010, 3:19 am
Location: Kuching, Sarawak (Borneo)
Contact:

Borneo Dispatches #14: Dumeril's Monitor

Post by Hans Breuer (twoton) »

Although we've been discovering more and more country roads with many promising cruising stretches (judging from the interesting DORs), we have yet to find our third live snake crossing a road in Sarawak. Why, just a few nights ago we clocked almost 150 miles up and down the coastal swamps between Kuching and Lundu, over one-lane bridges across rivers that look like backdrops for "Jurassic Park VII", and along oil palm plantations allegedly swarming with cobras and rat snakes, thanks to Rattus tiomanicus infesting the plantations where they eat the fruit that have dropped on the ground. But while Hans discovered a nice clump of Nepenthes x kuchingensis by the roadside during a pee break, not even a single reptilian road pizza was to be seen that night.

But in all fairness, occasionally we do find some spectacular stuff when we're not looking for it at all. At 0900 last Thursday, we had just spotted and removed from the road a well-flattened Amphiesma sarawacensis and were about to turn in to the entrance to Kubah National Park, where we had planned a morning constitutional along a very promising ditch, I saw something sitting in the middle of the road that looked like a lizard. Driving past it (we don't stop for no stinkin' lizards), I thought to myself, "damn, if that's a skink, it's the biggest damn skink I've ever seen". So we decided to U-turn and check the animal out, and what a smart decision that would prove to be. At close range, the lizard's truly dinosaurian features immediately gave it away as a monitor, but this one wasn't one of the ubiquitous water monitors (Varanus salvator). The lizard didn't seem to be hit very hard, only stunned, and had no visible injuries besides a little blood leaking from one nostril and one closed eye. But it wasn't moving, so we gently picked it up and placed it on the car, where it immediately began to mess up the paint with its impressive claws in an attempt to get off the vehicle. But that spurt of activity didn't last long, and the lizard quickly slumped back into its stupor. Our trusty field guide revealed it to be a Dumeril's Monitor (Varanus dumerilii, the rarest of the three Bornean species. It's also one of the most interesting, as Internet sources reveal:

Varanus dumerilii shares its range with three other large lizards, all of which belong to the genus Varanus; the Asiatic water monitor (V.salvator), the Bengal monitor (V.bengalensis) and the enigmatic rough-necked monitor lizard (V.rudicollis). Whilst water monitors and Bengal monitors are found in a wide range of habitats including human settlements, and are of great economic importance for their skins and flesh, both Dumeril's and the rough-necked monitors shun sites of human habitation and seem to frequent only undisturbed mangroves and forests. There is no trade in their leather and the flesh of both species has an undeserved reputation for being poisonous. Outside the pet trade (an albino specimen was recently offered for sale in the U.S.A. for $9000) they have no economic value. The fact that there have been so few sightings of such large animals suggests that they are very rare, and it seems certain that they have already been exterminated from a large part of their previous range and survive only in dwindling patches of undisturbed habitat. Very few attempts have been made to study these lizard in the wild and many of them have been completely unsuccessful. Forest monitors are of great ecological importance because they are large carnivores with very few natural predators. Despite their size and their ability to swallow large prey items whole, most of their food consists of invertebrates, which they consume in enormous numbers. An understanding of their way of life is vital if they, and the forests they live in, are to be properly conserved. (Source)

In this case, "invertebrates" means "crabs". The road where we found the lizard runs along the border between a rainforest and a mangrove swamp, so I guess the monitor had been on its way from its tree dwellings in the forest to its favorite breakfast buffet in the mudflats, where millions of fiddler crabs do their giddy little dance.

To enhance the reptile's survival chances, we didn't mess around with it too much, just took a few voucher shots and then brought it to the nearby head office at the National Park, where we were told just to put it somewhere in the forest, close to a stream. Nature would take care of the situation. And indeed, when we came back from our walk three hours later, little Dumie was gone. I sure hope he didn't just crawl under something dark to die, but is now out and about, growing up into a big adult, and maybe one day we can see him again crossing the road - for spotting these guys in the forest is almost impossible...

EDIT 11/22: THIS WAS A BABY. THEY CAN REACH FIVE FEET IN ADULTHOOD

Image

Image

Image

Image

Image

Image

Image

Image
User avatar
monklet
Posts: 2648
Joined: June 7th, 2010, 4:44 pm
Location: Ventura, CA
Contact:

Re: Borneo Dispatches #14: Dumeril's Monitor

Post by monklet »

Very nice Hans! ...how big do those get?
User avatar
Warren
Posts: 351
Joined: June 9th, 2010, 7:17 am

Re: Borneo Dispatches #14: Dumeril's Monitor

Post by Warren »

:thumb:
User avatar
John Martin
Posts: 515
Joined: June 9th, 2010, 10:57 pm
Location: North end of Lake Okeechobee, Florida

Re: Borneo Dispatches #14: Dumeril's Monitor

Post by John Martin »

Hans Breuer (twoton) wrote:Driving past it (we don't stop for no stinkin' lizards),

*and the flesh of both species has an undeserved reputation for being poisonous*.
:lol: @ the first statement... And as for the other statement - may be undeserved, but pretty danged fortunate for the species eh? :thumb:

Love your posts Hans. I learn something from each of them, not to mention the "fun factor"!
Retes
Posts: 78
Joined: August 18th, 2011, 8:47 am

Re: Borneo Dispatches #14: Dumeril's Monitor

Post by Retes »

Hi Hans, Nice find, Dums are rare to Varanid researchers, but then most varanids are hard for them to find. Go me?

I think monitors get assigned to very unique nitches, but are very much generalists. Which is so very true with diet. Varanids eat anything they can catch.(including some plants)

Also Dums use water, mud, etc etc and climb like crazy.

Please photo more for us, thank you.

They are very commonly collected for the pet trade.
User avatar
Hans Breuer (twoton)
Posts: 3230
Joined: June 8th, 2010, 3:19 am
Location: Kuching, Sarawak (Borneo)
Contact:

Re: Borneo Dispatches #14: Dumeril's Monitor

Post by Hans Breuer (twoton) »

Thanks, guys! Dang, I failed to mention that this was a baby. They grow up to five feet :-)

Retes, I assure and promise you we'll photograph the very scales off all the monitors we find here. But we have to find them first :-)
User avatar
Viridovipera
Posts: 339
Joined: June 7th, 2010, 7:40 pm

Re: Borneo Dispatches #14: Dumeril's Monitor

Post by Viridovipera »

HA! When I saw the first photo I assumed he was much bigger than that. ...But you just have a very small car hood. Oh well. Still a very cool find. Maybe now you'll think twice about just passing by these snake cousins... ;)

-Alex
User avatar
Hans Breuer (twoton)
Posts: 3230
Joined: June 8th, 2010, 3:19 am
Location: Kuching, Sarawak (Borneo)
Contact:

Re: Borneo Dispatches #14: Dumeril's Monitor

Post by Hans Breuer (twoton) »

Wow. That's a big'un. What do you feed him, and how big is his enclosure?
User avatar
Hans Breuer (twoton)
Posts: 3230
Joined: June 8th, 2010, 3:19 am
Location: Kuching, Sarawak (Borneo)
Contact:

Re: Borneo Dispatches #14: Dumeril's Monitor

Post by Hans Breuer (twoton) »

Thank you, John! "Hamsters and shrimp".... add strawberries and cream, and you pretty much have the hormone-addled diet of many a pregnant woman :-)
User avatar
TNWJackson
Posts: 277
Joined: June 22nd, 2010, 10:48 pm

Re: Borneo Dispatches #14: Dumeril's Monitor

Post by TNWJackson »

Great find Hans!
User avatar
withalligators
Posts: 329
Joined: June 29th, 2010, 6:50 am
Location: northern Westchester co., NY

Re: Borneo Dispatches #14: Dumeril's Monitor

Post by withalligators »

Awesome find Hans! It's too bad it didn't have the super vibrant juvie colors, I would love to see one o dem in da wild.
Cheers,
Alex
User avatar
moloch
Posts: 561
Joined: June 16th, 2010, 1:26 pm

Re: Borneo Dispatches #14: Dumeril's Monitor

Post by moloch »

An interesting find, Hans. I always enjoy your posts.
Post Reply