Bound for New Britain
Snakebusters PNG 2008: Part 4

by
Mark O’Shea
Consultant Curator of Reptiles, West Midland Safari Park
Honorary Research Fellow, Australian Venom Research Unit

Although I’d been to Papua New Guinea (PNG) eight times since 1986, I’d spent all my time on the island of New Guinea, or on its small satellite islands ie. Karkar and Daru. I had never ventured out to investigate the huge archipelagos to the east of the mainland. These archipelagos comprise five entire provinces and the insular part of a sixth, Milne Bay Province that also includes the extreme southeastern portion of the mainland Papuan Peninsula. Why not? You might ask. The answer is simple, most of my PNG fieldwork since 1990 had revolved around the medically important venomous snakes, with other herps providing interest and distractions along the way, and since there were no medically important venomous snakes out on those great eastern archipelagos I had never been able to justify a visit. Until now that is!

Dave was due to fly to Jakarta to present our paper on Snakebite in the Asia-Pacific Region, at a WHO conference, and I had been invited to visit the Dami oil-palm estates in West New Britain Province. I was very keen to go, there might not be any dangerous venomous snakes over there but there was a python I was particularly keen to see in the wild. This would be my first ever opportunity to search for the Bismarck ringed python, Bothrochilus boa, probably the least python-like of all New Guinea pythons, and although my visit was short, only a few days, I was thoroughly looking forward to it.

 

Northern West New Britain showing the Willaumez Peninsula and Lake Dakataua. The road running down the eastern side of the peninsula passes through Kimbe, then several plantations, including Mosa, before turning northeast to Dami and on to Hoskins.
(click on map to enlarge southern portion of map)


Let’s get our bearings. The largest islands to the east of the New Guinea mainland are New Britain, New Ireland and Bougainville, the former two often being combined and known as the Bismarck Archipelago, named after Count Otto von Bismarck – northwestern New Guinea was a German colony from 1884 until 1914.

New Britain is the largest of the three, a vaguely curving island with a strange northern tentacle-like protrusion, the Willaumez Pensinsula. This peninsula is swollen at thetip, further enhancing is somewhat organic appearance on the map, and virtually entirely taken up by Lake Dakataua, which is said to contain an interesting population of crocodiles. I had long wanted to visit this lake to see the crocs but I only had a few days so it was out of the question for this visit. New Britain is divided into two provinces, East New Britain (ENB) and West New Britain (WNB). The main town in ENB was Rabaul but it had been devastated by volcanic activity in 1994 so the town of Kokopo had taken over as the new provincial headquarters. The provincial capital of WNB is Kimbe but the main airport is further east along the coast at Hoskins.

 

Bismarck ringed python, Bothrochilus boa,
from New Ireland.


It was into Hoskins that I flew on the morning on 23 May, a short 1hour 20minute flight from Port Moresby, to be met by fellow Brit, Charles Dewhurst, the senior entomologist at the PNG Oil Palm Research Association, Dami Research Station. Charles is also a keen amateur herpetologist and we had exchanged emails since 2006. One of his pet projects was to promote respect for snakes on New Britain, to stop people from killing them out of hand in the hopes that the large pythons at least could help as a natural biological control against introduced rats that were causing havoc in the oil-palm plantations. I should be easier to teach people to be ‘kind to snakes’ in the Bismarck Archipelago, than on the mainland, since the only venomous snake is the Müller’s crowned snake, Aspidomorphus muelleri, which we met in the previous blog in this series in the Southern Highlands. It should be easier, but it isn’t! Locals still insist in running over or bashing every python or other snake they meet. Quite often Charles would keep any pythons he came across in cages beneath his house and use them for demonstrations before releasing them again. He had been hoping to obtain a Bismarck python for me to photograph but had been unsuccessful. However, he did have a sizeable amethystine or scrub python, Morelia amethistina, the largest snake in the archipelago, in residence and awaiting my visit.

Looking across the bay from Dami towards the Willaumez Peninsula,
West New Britain Province.

I was not just in WNB to search for live snakes however. The Dami Research Station had a collection of preserved and frozen reptiles for me to identify, victims of the local over-eagerness to reach for a blunt or even a sharpened instrument when ever a snake, or sometimes a lizard, popped its head up. I spent most of my first day and the start of the second, working my way through the specimens, eventually identifying them all. The snakes included two blindsnakes. There were several specimens of the ubiquitous and parthenogenetic* Brahminy blindsnake, Ramphotyphlops braminus, also known as the flowerpot snake because of its ability to colonise foreign shores hidden inside the roots of pot-plants. A tiny creature less than 1mm in diameter and only a few cm long, I had recently obtained a live specimen to photograph from Kaibar in Central Province.

* Parthenogenetic means exists only as females that reproduce without copulation. laying eggs which hatch to produce clones of the mother. You only need a single female to start an entire new colony, hence the success of this tiny snake species, the only known parthenogenetic snake species in the world, although there are numerous parthenogenetic lizard species.


Brahminy blindsnake, Ramphotyphlops braminus,
this specimen from from Kaibar, Central Province.


Head detail of same blindsnake,
EOS400; MP-E65mm; MT-24EX macro twinlite
;
hand-held with moving snake.

The other blindsnake was more the thickness of a pencil and a species confined to these eastern archipelagos, the yellow-bellied blindsnake, R.flaviventer. There were also several Bismarck pythons, and a large amethystine python in the freezer, which I thawed out and scale-counted. The colubrid snakes were well represented by the rear-fanged brown treesnake, Boiga irregularis, probably the most commonly encountered New Guinea snake, a couple of common treesnakes, Dendrelaphis punctulatus, a ground snake, Stegonotus cf. parvus,** similar but subtly different from the mainland S.parvus, and one of the two endemic Bismarck keelbacks, Tropidonophis dahlii, a harmless frog and fish-eater. There were oddly no tree or ground boas and no Müller’s snakes in the collection. The lizards included the large oceanic gecko, Gehyra oceanica, the emerald tree skink, Lamprolepis smaragdina, an anglehead, that I identified as Hypsilurus cf. godeffroyi, and a small mangrove monitor lizard, Varanus indicus, in other words one species from each of the lizard families present on the island.

** The abbreviation cf. indicates "compare with" and is used for an undescribed species which resembles a described species.

Yellow-bellied blindsnake, Ramphotyphlops flaviventer,
Dami, West New Britain Province.


Inquisitive Green tree ant, Oecophylla smaragdina,
EOS400; MP-E65mm; MT-24EX macro twinlite
;
hand-held.

Having worked through the assembled dead specimens I was rather keen to go and find some live specimens to photograph and document. Also working in the lab was a Kenyan research scientist called Catherine. Charles had previously also worked in Kenya and it was somewhat strange to hear them conversing in Swahili rather than Tok Pisin (Pidgin English), the usual lingua franca in PNG. Cathy was also excited by the prospect of going snake hunting so after lunch Charles provided two of his best workers, Seset and Paul, and the four of us, not Charles as other duties and visitors called, went snake hunting in the oil-palm plantation. We searched hard but failed to find so much as a skink on the ground or a gecko on flaking, epiphyte-strewn trunks or crowns of the oil-palms. It was disappointing as I was used to finding snakes and lizards aplenty in these habitats on the mainland.

Epiphyte-shrouded oil-palms, Dami Research Station
West New Britain Province.


 

Mys' four-fingered skink, Carlia mysi.

Solomons wedge skink, Sphenomorphus solomonis.

 

Bent-toed gecko, Nactus cf. pelagicus.

The next day we tried again in a plantation nearer to the research station and we did find a few four-fingered skinks, Carlia mysi, and wedge-skinks, Sphenomorphus solomonis, as well as the usual bent-toed or pelagic geckos, Nactus cf. pelagicus, I generally find everywhere in PNG including the last two blogs, but again, no snakes.

Back at Dami I borrowed a vehicle and set off with Seset and Paul to search for coconut husk piles, usually a good place for reptiles (see earlier blog Island of the White Snake).

“Turn right here” said Seset, so I turned off the plantation track into what appeared to be a wall of vegetation, higher than the vehicle, “yes, it is a road” being his response to my questioning glance, so I pointed the 4x4 into the green wall and drove at it, only to see it yield before the great bull-bar and disappear beneath our wheels. We drove on into high grasses, climbers and scrubs that fell like an infantry battalion hit by a heavy cavalry charge, Seset occasionally giving direction and me wondering how he knew his bearings in here. I looked at my GPS, nothing, we were driving in space with no indication of what or where we were going, but at least we could find our way out, either by retracing the GPS trackline or simply the visible swathe we had cut through the dense undergrowth. We passed a compound, it high wire-fence obscured and made irrelevant by the even higher vegetation, wound past occasional trees standing like Gulliver in a crowd of pygmies, the trunks of which were invisible until the surrounding greenery was tugged away by our passing. There was the occasional ‘thunk’ beneath us as a branch snapped and leapt up to chastise us for running it over, or a wheel flicked up a half-buried tree trunk, but I was more concerned about the numerous deep but often invisible creeks that criss-cross all plantations, drive into one of those and we were in trouble. I need not have worried, Seset and Paul knew the area well and we passed through ‘jungle’ without incident and broke onto another track and into a clearing with a stand of coconut palms.

The main crop here was, of course, oil-palm but many of the settlements in and around the large plantations maintained a few coconuts and where there are harvested coconuts there are usually coconut husk piles. The clearing and a small hill beyond appeared to have about twelve decent sized husk piles, easily enough for three men with a few hours to play with. We set to work, surrounding the husk pile, as well as three can do, and started to disassemble them in search of their occupants, which again turned out to be bent-toed geckos and wedge skinks, plus a surprisingly large population of giant Scolopendra centipedes. These centipedes are venomous and can deliver an extremely painful bite which lasts for days, but there have been few fatalities around the world, you will not die….. you may just wish you could!

Seset and Paul half-way through a coconut husk pile.

We also found a few giant stick insects, a couple of direct-breeding frogs, Platymantis cf. papuensis, and a huge introduced, puffed-up and proud ‘Toad of Toad Hall’ cane toad, Rhinella marina.

Direct-breeding frog, Platymantis cf. papuensis.

On about the fourth or fifth husk pile one of the boys spotted a snake and backed off, even though I am certain he knew it was harmless. It was a ground boa, sometimes called ‘viper boa’ due to its body shape, Candoia aspera, a pretty common species in the husk piles of Karkar Island (Island of the White Snake) but it was one of the species I had hoped to see here and which had not been represented in Charles’ pickled/frozen collection. Basically Olive Stull (1932) and Arthur Loveridge (1948) recognized two subspecies (when the boa Candoia aspera was known as Engyrus asper), the New Guinea form I was familiar with, subspecies schmidti, and a Bismarck form, subspecies asper (now aspera of course) which I had not yet seen other than live specimens at the University of PNG which had been brought back from New Ireland. The two subspecies are largely separated by scale counts but when I compared my Dami specimen with the counts for the two subspecies it was clear that the boa I had found belonged to the New Guinea, not the Bismarck population. I began to wonder if the division was further east, whether New Britain ground boas were the same subspecies as New Guinea ground boas and whether Candoia aspera aspera should be known as the New Ireland ground boa. With only the one specimen to hand it was impossible to make a decision but it raised the question in my mind.

New Guinea ground boa, Candoia aspera schmidti.


 
DMB
V
SC
SL
IL
CO
Candoia aspera aspera
37-41
149-150
18-19
10
12-13
13-15
Candoia aspera schmidti
34-37
127-138
15-21
10-12
12-16
11-16
Dami specimen
34
146
17
11
15
13

DMB = dorsal scale rows at midbody; V = ventral scales; SC = subcaudal scales; SL = supralabials (upper lip scales);
IL = infralabials (lower lip scales); CO = circum-orbital scales (scales around the eye).

It was easy to sex the boa, however, she was a female, she completely lacked the cloacal spurs used by the male to stroke the female during courtship and mating.

Several husk piles, several skinks and geckos, and not a few centipedes further on we encountered our second, and as it turned out, final snake. I got a glimpse of a white belly as it slid off into the protective darkness of the pile. It did not look like the belly of the only venomous snake found here, the Müller’s crowned snake mentioned earlier, and that species has not been recorded as inhabiting husk piles. Some early authors claimed the New Guinea small-eyed snake, Micropechis ikaheka, so common on Karkar Island and the quest species of the previous blog, might occur here and some claim death adders, Acanthophis laevis, from New Britain. I personally believe these were misidentifications of the Bismarck ringed python and the ground boa respectively, but you can never take anything for granted in PNG – I had caught a python in 2000, whilst filming for O’Shea’s Big Adventure, which turned out to belong to the genus Antaresia, previously thought endemic to Australia. But PNG did not advertise itself as The Land of the Unexpected without good reason, it was necessary to proceed with caution.

For a while I thought the snake had given us the slip, disappeared in the remnants of husk piles beneath our feet or down a bandicoot burrow, but perseverance was eventually rewarded and I was able to effect a capture. As suspected, the snake turned out to be a ground snake Stegonotus cf. parvus, similar to but slightly distinguishable from the mainland species. All the husk piles now disassembled we returned to base tired and dirty.

Bismarck ground snake, Stegonotus cf. parvus.


So I did not find a Bismarck ringed python but did find the following species during my short stay which allowed only two days in the field:
Cane toad, Rhinella marina
Direct-breeding frog, Platymantis cf. papuensis
Bent-toed gecko, Nactus cf. pelagicus
Mys’ four-fingered skink, Carlia mysi
Solomons wedge skink, Sphenomorphus solomonis
New Guinea ground boa, Candoia aspera schmidti
New Britain ground snake, Stegonotus cf. parvus

Plus the following species which I recorded either as preserved, frozen or live specimens at Dami Research Station:
Oceanic gecko, Gehyra oceanica
Emerald tree skink, Lamprolepis smaragdina
Godeffroy’s anglehead dragon, Hypsilurus cf. godeffroyi
Mangrove monitor lizard, Varanus indicus
Brahminy blindsnake, Ramphotyphlops braminus
Yellow-bellied blindsnake, Ramphotyphlops flaviventer
Bismarck ringed python, Bothrochilus boa
Amethystine python, Morelia amethistina
New Britain keelback, Tropidonophis dahlii
Common treesnake, Dendrelaphis punctulatus
Brown treesnake, Boiga irregularis
New Britain ground snake, Stegonotus cf. parvus

 

Amethystine python, Morelia amethistina.

I had one full day left in West New Britain but it would not be used for grubbing around searching for snakes, so it proved that on my first visit to the Bismarck Archipelago the Bismarck ringed python had eluded me. I spent the morning documenting, photographing and releasing my captures, and then at 13:00 Charles collected me and delivered me to the local school to give a snake awareness talk, accompanied by the little ground boa, but not the ground snake – they are harmless but a bit ‘bitey’ and there is nothing less likely to get the message “be kind to snakes” across than the speaker being chewed by a snake, harmless or otherwise. I then had one hour back at the house before leaving again to present one of my OBA films (Magic Man, about small-eyed snakes in Karkar coconut husk piles) and a Keynote presentation on PNG snake identification, awareness and conservation as the New Guinea Oil-Palm Association’s Mosa Club. Both talks went down extremely well, and the second was followed by a lamb curry, which also went down well!

The next morning I flew back to Port Moresby and two days later I flew back to the United Kingdom.