REPTILES: proceedings of the 1986 U.K, Herpetological Sadeties symposium on captive: breeding. © BrItisb Herpetological Society 1987.

THE PYTHONS OF NEW GUINEA

MARK T. O'SHEA

46 Buckingham Road, Penn, Wolverhampton WV4 5TJ, England

PART ONE: INTRODUCTION AND TAXONOMY

The Second Largest Island in the World New Guinea is composed of a large tropical island, the second largest in the World, and

several attendant archipelagos which stretch themselves across the seas north of Australia. The western half of the island, formerly part of the Dutch East Indies and now known as Irian Jaya, comprises the largest single land mass in the Indonesian Republic. The eastern half of the island was originally divided into a northern section, formerly German New Guinea, and a southern section, British New Guinea or Papua, which were later placed under the Australian Administration as Papua New Guinea and finally received Independance in 1975. The most important archipelagos to the east of Papua New Guinea are the Admiralty Islands, New Britain, New Ireland, the D'Entrecasteaux Islands, the Trobriand Islands, th,e Louisiade Archipelago and Bougainville Island which borders the archipelagoes of the Solomons Islands.

Much of the mainland is comprised of steep ridgeback mountains covered by montane rainforest or, at higher altitudes, by alpine vegetation, and broken only by raging torrents thundering down narrow gorges. In many areas the rainforest gives way to secondary forest or grassland and in the south, where the relief is much lower, there are extensive areas of lowland rainforest, monsoon forest, savanna, swamp woodland and mangroves swamps. There are several large river systems the largest being the Fly-Strickland System in the south and the Sepik System in the north.

New Guinea would seem the ideal environment for tropical reptiles and amphibians but, in common with Australia, several taxa are conspicuous by their absence such as the Viperidae and others are relatively :poorly represented, i.e. the subfamily Colubrinae. In their place other taxa have diversified greatly, notably the elapids. In addition the Pythoninae are well represented in the Australasian region and eight species of pythons are known to occur in Papua New Guinea and Irian Jaya. In 1986 the author spent 3 Y2 months in Southern Papua New Guinea conducting a herpetological survey as part of Operation Raleigh. During that time thirteen live pythons of five species were captured and numerous dead specimens were encountered on roads or in cooking fires.

However, before entering into a discussion of the ecology and distribution of the pythons of Papua New Guinea it is necessary to review the taxonomic problems which currently exist concerning their nomenclature.

The Taxonomy of New Guinea Pythons Outside the Australo-Papuan region the pythoninae is relatively easily defined

constituting only the West African Calabaria and the Afro~Asian Python group. However,

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Plate I: Carpet Python (male) Morelia spilolO.

Plate 2: Amethystine Python (juvenile) Morelia arne/hislina .

02

THE PYTHONS OF NEW GUINEA

within the Australasian region the generic positions and relationships of the numerous diversified species ofpython have been the source ofcontinual controversy from which only the monotypic Chondropython seems exempt.

McDowell, (1975), differentiated between Python and Liasis by defining members of the Python group as those pythons possessing a prehensile tail and lacking apical pits from all of, or most of, their dorsal scales whereas members of the Liasis group were those species in which apical pits were present on most scales and which lacked a prehensile tail. Accordingly McDowell's Liasis group would contain the New Guinea species albertisi, boa, makloti and papuanus whilst the Python group would include amethistinus, boeleni, spilotes and Chondropython viridis. McDowell removed amethistinus from Liasis and placed it in Python largely because of its apparent relationships with Python timorensis, from the Lesser Sunda Islands, and Python reticulatus. He also placed boeleni, (formerly Liasis boelem), andspilotes, (formerly Morelia spilotes), in Python in the 'reticulatus'group as distinct from the 'molurus' group containing the Afro-Asian species of Python. Schwaner and Dessauer, (1981), examined the immunodiffusional reactions which occurred between transferrins from two of McDowell's 'reticulatus' group, P. amethistinus and P. spilotes, together with Python regius, from the 'molurns' group, and Liasisalbertisi andL. papuanus. Their results indicated that the immunological differences between the two Papuan Python spp. and Python regius were greater than those which existed between the Papuan Python spp. and the Liasis spp. The argument therefore exists whether to place amethistinus, boeleni and spilotes in Python as proposed by McDowell or to follow other authors in placing one, two or all three species in Liasis, Morelia or another species other than Python.

€ogger et. al., (1983), proposed that to recognise Python for the prehensile tailed Australo-Papuan pythons when they appeared to be closely related to Liasis would be 'inconsistent with the continued recognition of the genus Liasis' as defined by McDowell. Therefore they resurrected Morelia from its synonymy with Python for those species of pythons placed in Python by McDowell and their Australian allies, oenpelliensis, bredli and carinata. They make no mention of whether they include all species from the 'reticulatus' group in this revision but to separate amethistinus from timorensis and reticulatus would seem to be a counter productive measure in view of their apparent similarities. Further immunodiffusional work, such as the Papuan study carried out by Schawaner and Dessauer, (1981), to ascertain relationships between reticulatus and the 'molurus' group of Python would be a useful aid in determining the validity of McDowell's 'reticulatus' group within Python.

Another problem relating to the New Guinea pythons concerns the validity of the genus Liasis in which McDowell placed the species boa, albertisi, mackloli andpapuanus, pythons which lack a prehensile tail but possess apical scale pits. McDowell cited the Australian Liasis childreni as the type species for Liasis but he acknowledged that it is less typical of mainstream Liasis than was the monotypic Bothrochilus boa. He argued that there were more grounds for placing Liasis childreni in a monotypic genus, or removing all other Liasis spp. from Liasis, than there were for recognising the monotypic Bothrochilus boa. Therefore McDowell reduced Bothrochilus boa to a synonymy of Liasis as Liasis boa in preference to the further splitting of Liasis. McDowell's reasons for citing childreni as the type for Liasis were based upon the following sequence of events.

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MARK O'SHEA

Plate 3: Papuan Python (preys on Amethystine Python) I.illSis Jl(lfl 11011 liS.

Plate 4: Papuan Python Liosis papuanus.

THE PYTHONS OF NEW GUINEA

In 1842 Gray erected the genus Liasis but he did not cite a type species even though he included the species childreni, amethyslinus and d/ivacea. In 1849 Gray split Liasis into three subgenera as follows:

Simalfa containing amethystinus and mack/olii; Liasis containing chi/dreni; Lisalia containing olivaceus.

McDowell, therefore, took childreni as the intended type for Liasis but he overlooked the fact that in 1846 Desmarest had defined Boa ameth istin us as the type for Gray's genus LiasLs. Thus Liasis could be relegated as a synonym of either Python as defined by McDowell or Morelia of Cogger et. al., (1983), based on the current taxonomic position of amethistinus. Afore/ia, according to Cogger et. al., would therefore contain the species; amethistina, spilota, oenpelliensis, carinata, and bred/i. They further proposed the resurrection of Bothrochilus for those species of Australian pythons remaining in Liasis, namelyalbertisii, fUscus, olivaceus, childreni, perthensis and presumably also the New Ireland species boa since that was the original species in BOlhrochilus. No mention is made of the fate of the New Guinea species mackloti or papuanus.

However, it would appear that the amethystinus of Gray's original description of Liasis, (1842), and therefore, the amelhistinus designated as the type species by Desmarest, was. based on Dumeril and Bibrons's mackloti rather than Schneider's amethistina. Therefore Liasis mackloli, and not Boa amethistinus or Liasis childreni, should be declared the type species of Liasis and the synonymy of Liasis with either Python or Morelia can be avoided.

For the purpose of this paper I have decided to follow McDowell, (1975), in his retention of the genera Chondropython and Liasis and his suppression of Bothrochilus but I support Cogger et. al., in their resurrection o fMoreliaspilota from its synonymy with Python. It also seems likely that Cogger et. al. 's expansion of Morelia to include amethistinus and boeleni, the three Australian species, (and possibly also reticulatus and timorensis) will find increasing favour amongst most workers even thoughspilotes does differ from amethistinus and boeteni through the possession of maxillary teeth and small granular scales on the top of the head rather than the more familiar scutes, (Banks 1979). However, in the absence of a more suitable name and in anticipation of a possible move, but also in appreciation of the considerable taxonomic problems involved, I have decided to adopt Morelia for McDowell's prehensile tailed Python spp.

PART TWO: PREHENSILE-TAILED PYTHONS

Morella Amethistina (Schneider) Scrub or Amethystine python The amethystine python, Morelia amethistina, is one of the largest pythons known to

occur in the Australo-Papuan region and occasional specimens from Australia have measured up to 8.5m. (28ft Worrell 1963). although 5.5m. (l7l1z ft). is a more common maximum length. Parker. (1982). records the largest Western Province Papuan specimen at around 6m. (19Y21't). The Amethystine Python occurs from the Moluccan islands of Halmahera, Ceram and the Tanimbar Islands, where it exists sympatrically with the S.E. Asian Python reticula/us. east through the islands to north and south of Irian Jaya.

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MARK O'SHEA

throughout the entire New Guinea mainland to altitudes of IDOOm, {McDowell 1975), except the Papuan province of Southern Highlands which has only three recorded snake species, to the eastern Papuan archipelagoes of New Britain and New Ireland, (Whitaker and Whitaker 1982). In Australia the species is confined to northeastern Cape York Peninsula, Queensland, (Worrell 1963, Cogger 1975, Gow 1976).

The python gets its name from the iridescent bluish-purple sheen which colours the scales when the light catches them. Parker, (1982), reports that there are two distinct colour morphs, a pale brown savanna form and a dark grey-brown rainforest form but the author has not experienced these differences having only seen southern Western Province specimens. It was noticed, however, that juveniles are more vividly patterned with bright reddish markings which are most conspicuous on the tail. This species was also noted for its irritability and irascibility and its willingness to bite when handled. The dietary range of this python, due to its considerable size range, will also be extremely wide and include birds, lizards to the size of goannas and mammals from rodents to wallabies and pigs.

Boos, (1979), records mating in a pair ofwild caught Queensland Amethystine pythons at Taronga Zoo, (male 4.3m, female 2.1m). The sexes were separated from January for 13 months and then reintroduced. Six months later mating took place but was not observed and a clutch of 12 eggs were laid in mid-August, seven hatching, (three dead and two infertile), after 77 79 days between October 30th and November 1 s1. The average length of the hatchlings was given as 64.5mm and they first fed on mice and sloughed in mid-November. Parker, (1982), records an instance of a wild Daru femaleM. arne/his/ina incubating her 11 eggs in her coils.

Within Western Province Parker, (1982), records the Amethystine python as very common, especially in savanna areas, with large numbers collected in the Trans-Fly region and from Daru and Bobo Islands. During the expedition three specimens were seen by the author in the vicinity of Kunini and further specimens of the snake the locals refer to as the 'Great Python' were frequently reported by returning hunters or village women washing clothes in the creek near Kunini. Several stories of enormous carpet pythons, Morelia spilo/a, must be attributed to this species rather than the smaller species. A very large python reported to the author by a hunter in secondary forest near Oriomo was also probably this species but by the time the author and two members ofthe herpetological team had returned to the area with the hunter the snake had gone. The largest specimen seen by the author was a 2745mm, (9ft), python killed by village boys near Kunini but by the time the body was received decomposition was too advanced for preservation to be possible. In addition a 1950mm, (6ft 4in), specimen was retrieved from the stomach of a slightly shorter drowned Papuan python, Liasis papuanus, removed from a fishermans gill net on the Binaturi River, (O'Shea 1987). A 1 090mm, (3ft 7in), juvenile was discovered in a hollow in a tree besides the Binaturi River between Kunini and Boze and while held in captivity this python was observed to feed avidly on small rodents.

MoreNa boeleni (Hrongersma) Hoelen's python The rarest python in Papua New Guinea, and also the country's most protected reptile, is

the endemic Boelen's python, Morelia boeleni. It is an extremely attractive species with a dark glossy black dorsum and a yellow to cream venter with fingers of yellow pigment extending upwards and forwards onto the dark flanks.

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THE PYTHONS OF NEW GUINEA

McDowell, (1975), suggested that whereas Python timorensis might provide a link between Python reticulatus and Morelia (Python) amethistina, so Morelia (Python) boeleni might represent a connection between M. (Python) amethistina and M. (Python) spilota through similarities in head scutation with amethistinus and scale, ventral, subcaudal, tooth and labial counts, and also possibly patterning, with spilota.

Parker, (1982), reports that although no specimens of this species have been positively recorded forthe Western Province. Villagers in the Star Mountains have seen itand state that it is present, though rare. As a mid-montane species McDowell, (1975), records M. boelenl from the Wissel Lakes in Irian Jaya in the far west, Kainantu in Papua's Eastern Highlands Province and the mountains behind Lae in Morobe Province. Parker reports specimens from Mt. Brown and Woitape in Central Province and Zweifel reports a specimen from Wau in Morobe, (McDowell, 1975). Whitaker and Whitaker, (1982), also include Western Highlands Province in the distribution of M. boeleni but without citing their source. Although the author searched for this species whilst in the Tapini-Woitape region of the Owen Stanley Mountains and many villagers were interviewed concerning its whereabouts no specimens were forthcoming. The University of Papua New Guinea did obtain a large specimen from this area of the Central Province some months earlier but this is by no means a common species even in areas where it has been reported on several occasions. The University's specimen died soon after arrival, possibly due to its removal from the relatively humid montane environment to the hot, continental Australian climate of lowland Port Moresby. If these pythons are to be maintained and studied successfully in captivity in New Guineaa more favourable highland locality would seem necessary for their well-being. Little is known about this curious python's natural history, breeding habits or preferred diet. Worrell, (1958), recorded that the note accompanying the type-specimen ofPython taronga, (= M. boelem), listed the diet as 'water-birds, eggs and paw-paws'.

Morelia spilota (Lacepede) Carpet Python The Carpet Python or Carpet Snake, Morella .5pilota, is essentially an Australian species

and Hoser, (1982), is of the opinion that six regional forms exist which mayor may not deserve sub-species or even species status within Australia. However, this species only enters Papua New Guinea in two areas. It occurs from Merauke in Irian J aya to the mouth of the Fly River in Western Province but no further east than Balimo on the edge of the rainforest. M. spilota is also apparently absent from Daru Island to the south. The second population occurs in the Yule island/Port Moresby region and Central and NCD, (National Capital District), Provinces where it seems to be the commonest nocturnal snake, large numbers perishing nightly on the roads around the capital. This distribution pattern in two distinct areas of Papua New Guinea mirrors the distributional ranges of several other Australian species, namely the elapids Oxyuranus scutellatus and Glyphodon tristts, (McDowell 1975), which may have invaded Papua New Guinea from Australia during a glacial period when the sea level was lower. It is also possible that the New Guinea green tree python, Chondropython viridis, may have made a reverse invasion of Australia from southern New Guinea during the same or a similar period.

Carpet pythons have probably been bred on numerous occasions. At Taronga Zoo, Sydney a2.1m female and a 1.9m male mated in September, (Boos 1979). Thefemale laid 14 eggs in early December and after a 37 39 day incubation period, during which time the

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MARK O'SHEA

female was never seen to leave her coiled position around the eggs, 11 hatched. The Carpet python, which grows to over 1.6m, (5ft). has quite a variable pattern even in

New Guinea and almost every specimen encountered was different in some way. However, the basic pattern consists of a patchwork ofdeep brown and light yellow-brown patches with a dark chestnut brown arrow marking on the top of the broad head. The Carpet python appears to be largely a rodent feeder so it is of positive benefit to the Port Moresby area where, unfortunately, it is actively persecuted by the human population. This persecution was illustrated by the discovery of a dead sub-adult Carpet python on Waigani Drive I km from the University of Papua New Guineaearly one morning with a rope tied to its tail. It had obviously been swung under the passing traffic during the night.

In three nights on the tarmac surfaced Hiritano and Hubert Murray Highways the author saw nine Carpet pythons. Of these five were DOR, (dead on road), measuring approximately 6lOmm, (2ft), (one); 1220mm, (4ft), (two); 1525mm, (5ft), (two), anda further juvenile male specimen measuring 578mm, (1ft I lin). which was found stunned and subsequently died soon after regaining consciousness. Three live specimens, a juvenile female of 633mm, (2ft I in), and two males measuring 1350mm. (4ft Sin), were also captured and removed from the road and later released in countryside to the west of Port Moresby which was crossed only by dirt and dust roads. (It is well known that nocturnal snakes linger on warm tarmac roads at night and many are killed by passing motor vehicles.) These snakes were extremely aggressive when handled but the juvenile fed easily on several ground skinks, Carliafusca.

In the Western Province lv/orelia spilota seems to be far less common and only one specimen was found during the expedition's two months in that province. However, this specimen was a large male measuring 1815mm, (almost 5ft), which is very large for Papua New Guinea. This python was found crawling over the ground on the bare earth below a house in the village ofMabaduwane at 20:00 in the evening. According to the villagers it was seeking chickens.

With the survival of the POft Moresby population of Carpet pythons in mind the author believes that some sort ofeducational programme to deter the deliberate slaughter of snakes, and Carpet pythons in particular, should be considered, pointing out the benefits to the local population of having large, non-venomous, rat eating snakes around human habitations. Many of the serpentine road casualties may be accidental but an equal number are obviously deliberate attempts to run snakes over judging by the skid marks which accompany many of the DOR examples.

Chondropython viridis (Schlegel) Green Tree Python

The Green Tree Python is probably the most strikingly attractive snake species in New Guinea where it has been recorded from every mainland province of Papua New Guinea, again with the exception the Southern Highlands Province, and throughout Indonesian New Guinea or Irian Jaya to an altitude of 1500 - 2oo0m in forested habitats. Although the species has also been reported from the islands of Geelvink Bay and Normanby Island to the northwest of Irian Jaya it appears to be absent from the large archipelagoes to the east of Papua. Extralimitally Chondropython also occurs on the Indonesian islands of Misool, Salawati and the Aru Islands and also in the eastern rainforests of Cape York Peninsula. Queensland, (Worrell 1963, Cogger 1975).

TJ II-: PYTHONS OF NEW GUINEA

Pla tt? 5: (irc' LIl' l rc'c I'\'lll!lll ( pl \'cllik) ( '!/( l/u /r(lI' ,,',!w!I "iridi,'

The h igh ly arboreal bright green adult ~ , \\hi ch reach I , 6m, (51'1), 11 ~l \'e \'Cllow venters and a

~erie<; of \I hilt \cak\ along the mid-do rsa l ,ca lc rO Il which produces the effect of a

:oll li n llOu ,> , i f\ l ig htly punC luateu, \tTlebra l siriflc', Occa <; ionalJy a seriC'> of irregular lateral

hlue blotch e<; may al so be prc'>e l1l , Th e i ri , of the el e is b ron ze and Ihe vertically elliplical

pupi l is bi sected by a uark broil n ,q ri pe through it scen t rc , The j ul'en i Ie is el'en more <;{ ri king

heing coloureu viv id lemon yello \\ 'l ith a se ries of Sill ell I w hite centred, black edged

cJor~o lateral triangles anu latcral bJack Ikd ing ~j l () ng il s len gt h , The head is i/lladed by

s~ \ e ral or th ese black ed ged, whi t l' mark ings and one , uch st ripe passe', f rom the tip olthe

snout, through t he light yellow eye, b isect ing I he I ert icalJy c llipt ica l pupi I, to I he angle of t he

j a\\', The ven ter is pal c yellow bu t I he t :lilt ip is a co nt ra st i ng da rk black, It has been suggested

I ha t I he I a i1t i p may be used as a II r igg l i ng lure to ci I her all ract I izards and smalllllammai s to

within slriking distance or 10 momenta ri ly distral' l th ei r allenlion ('ru i ll Ihe head of the

pYlhon, The author did observe 'tail II riggling' whenlhe JUl enlle PYlhonll'as presenled wilh

a new ly-furred mouse and similar 'Iail -Illilching' behaviour has been reponed in th e

Australo-Papuan dealh adder, Acal1/hophis anlOrCliclIs, the African puff adder, Bilis

arie/a/ls , and the Central American barba amar illa, BOlhrops alrox asper, Wheth er th e

purpose of this behaviour is Ihe sam e i~ open to discussion. As Ihe juvenile reaches early

maturit y it changes from ye llo w to th e green livery of the adull, Parker, (1982), maintains

thaI this change only takes 2 - 3 days and Iha t the cen tre of each scale becomes green and

gradually thi s pigment spreads OUI to en ve lope th e en lire scale, It is also interesting to note

that occasionally red or orange ju veniles ha ve been found In West Sepik Province, Th e di et

of these python s appears to in c lud e bird ~ , ~ mall mammal s and lizard s, a captured juvenile

disgorging a ground skin k, Car/ia fusca, and bOlh juvenile and adult specimens eagerly

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MARK O'SHEA

taking mice captured in the herpetological survey drift fences. Certain prey animals are captured whilst aloft but Chondropython viridis does descend to the ground to forage after dark and this is probably when most specimens are captured by villagers for food. McDowell also suggests that Chondropython feeds on the ground rather than aloft because most adult stomach contents he examined were comprised of mammalian remains rather than feathers as would be expected in an arboreal predator. Parker, (1982), reports a large female, (l245mm SVL), from Kunini which laid 13 eggs measuring 41 - 49mm x 26 - 30mm. All the eggs failed to hatch.

Four specimens of C. viridis were found in the Southern Trans-Fly region of Western Province during the expedition. Two adult males measuring 1574mm and 1578mm were found on the ground after dark in garden areas between the village ofKunini and the Binaturi River, A sickly 1264mm female was also collected in the same area just after dark indicating that the species is very common. A 442mm yellow juvenile was obtained in the early afternoon on a path near the village of Giringarande 5km north of Kunini on the Gomoni River. Several of the adult specimens had fairly heavy infestations of cestodes, (tapeworms), which manifested themselves as raised soft subcutaneous blisters. Specimens of the tapeworms, which were also discovered in a wide variety of other snake species including colubrids and elapids, were removed by excision ofa blister with a scalpel and then eased out with a pair of narrow forceps to be preserved in 10070 formalin for museum examination. People in villages which specialised in eating pythons were interviewed to see if any particular precautions were taken in the preparation of python meat infested with these tapeworms but they seemed unconcerned. Within the Western Province Parker, (1982), also reports specimens from monsoon forest areas at Wipim, Peawaand Woroi on theOriomo River, on Daru Island off the southern coast, from Balimo and Kiunga north of the Fly River and Morehead to the west.

It is interesting to note that Chondropython viridis bears a very striking resemblance to the South American emerald tree boa, Coral/us caninus, which exhibits the same habitat and dietary preferences and which also undergoes an ontogenic colour change from orange juvenile to green adult. So similar are the two species that it is often necessary to examine the labial heat sensitive pits to tell them apart in captivity. In Chondropylhon viridis the pits are intralabial, (within the labial scales), whereas the pits of Corallus caninus are interlabial, (between the labial scales).

PART THREE: NON-PREHENSILE-TAILED PYTHONS

Liasis albertisi (Peters & Doria) White-lipped or 0'Albertis python D'Albertis python is a fairly large endemic species. Parker, (1982), reports a2410mm, (7ft

llin), specimen from Wipim, Western Province. It has been recorded from Irian Jaya as far west as Salawati Island and in all of the mainland provinces of Papua New Guinea except for Milne Bay, Southern Highlands and, perhaps strangely, Gulf Province. One curiously isolated popUlation exists on Mussau Island in the St. Matthias Group far to the north of New Ireland although no specimens are known from either New Britain or New Ireland in the Bismarck Archipelago to the east of Papua New Guinea. It is possible that the Massau population is a relict from a time when Liasisalbertisi occupied both the New Guinea and the

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THE PYTHONS OF NEW GUINEA

Bismarck Archipelago prior to the evolution of the Bismarck's own endemic fauna, including Liasis boa which does not occur on Massau. The presence ofL. albertisi on Mussau Island, whilst it is absent from neighbouring island groups, is interesting because the wart snake, Acrochordus granulatus, has also been recorded from the 81. Matthias Group and on the New Guinea mainland but not from the other islands of the Bismarck Archipelago. L. albertisi appears to be a lowland rainforest and monsoon forest species, not usually occurring above approximately 1000m. It is believed to prey on small mammals and Loveridge, (1948), found spines from a Bandicoot from the faeces ofa specimen from Toem.

Parker, (1982), lists two clutches of eggs from L. albertisiwhich were collected in the wild but which failed to hatch; nine eggs from Karimui, Chimbu Province, measuring 69 -77mm x 39 - 41mm, and five eggs from 80geri, Central Province, measuring 70 - 87mm x 35 - 42mm. Ten eggs from Lae, Morobe Province, measuring 56 - 64mm x 33 - 35mm were successfully incubated for 58 days and the hatchlings measured 350 - 363mm 8VL. Parker notes that as the snakes in the northern populations are smaller than their southern counterparts the eggs and hatchlings of southern clutches can be expected to be larger than those in the Lae clutch.

The python is easily identified since it has an iridescent blue-black dorsum and a pale cream or off-white underbelly. The head is glossy black in stark contrast to the distinct black­barred, white labials. The specimens on the northern coast are smaller with brown dorsums and yellow venters but the glossy head and the distinctive white labials are still apparent, (McDowell 1975, Boos 1983).

Apart from the Wipim specimen Parker records L. albertisiin the Western Province from Abam on the Oriomo, Ture Ture on the coast near Kunini, Emeti in the east and from a number of localities in the north of the province. Two specimens were collected during the herpetological survey. A 2440mm, (8ft), male with a damaged left eye was rescued alive from a local fisherman's gill net on the Binaturi River a few kilometres upstream of Kunini. Pythons frequently become accidentally entangled in this way. A second specimen, measuring 2300mm, (7ft 6in), also a male, was collected from a ditch near the centre of the village of Boze 5km northeast of Kunini on the Binaturi River. These pythons appear to be associated with riverine habitats. Parker, (1982), states that L. albertisi is a widespread species of rainforest and monsoon forest habitats but that it is nowhere common contrary to McDowell's comment that this species is probably the most common species ofLiasis in New Guinea.

Liasis boa (Schlegel) New Ireland Ringed Python The New Ireland Python is confined to forested areas of the Bismarck Archipelago in the

New Ireland and East and West New Britain Provinces of Papua New Guinea but it is absent from the 81. Matthias Group to the north. Two colour morphs exist; a unicolour brown phase with a yellow venter and a black and orange-brown banded phase. In both phases the head is dark brown to black with a paler throat and chin. In some unicolour specimens a faint series of darker brown blotches are evident on the flanks which fuse to form the suggestions of dorsal crossbands. The banded pattern is particularly well illustrated in juveniles. Very little is known of the natural history of this species although London Zoo are attempting a breeding programme with a male on a breeding loan from an American collection.

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Liasis mackloti (Dumeril & Bibron) Macklot's Water Python McDowell, (1975), recognises the name Liasis mack/oli over LiasisJuscus for this species

in New Guinea and Australia stating that they are probably distinct from the Lesser Sunda Island specimens. Other authors, (Cogger 1975, Hoser 1981, Cogger et. al. 1983), retain Juscus either for the species as a whole or for the Australian populations.

Liasis mack/ati, Macklot's water python, is recorded as occurring in Northern Territory and Queensland, Australia, on the Torres Strait Islands and the Lesser Sunda Island of Timor and its neighbours but its range in Papua New Guinea is confined to the southern coastal strip of Western Province where it inhabits lagoons and grassland swamps preying on mammals, birds, lizards and apparently young crocodiles, (Hoser 1981, Parker 1982). A Sigabaduru specimen caught in a fisherman's net regurgitated a heron. Parker records this 2m, (3m in Australia - Hoser (981), python from Abam, Mabaduwanand Sigabaduruin the expedition area and from Balamuk in the west, Balimo in the east and Lake Murray near the Fly-Strickland River confluence to the north. It has been suggested that L. mack/oli may also be found in the Central Province/NCO coastal strip from Port Moresby towards the d'Entrecasteaux Islands in the east. This dual Western Province/Central Province distribution is quite common for Australian colonising species occurring in New Guinea i.e. M. spilata, Oxyuranusscutellatus, Glyphodon tristis. However, in Western Province Parker does not believe L. mack/ati occurs any further east than Balimo on the edge of the rainforest. No specimens of Liasis macklali were found during the expedition.

It is a slender, though still powerful, species and it can be distinguished from Liasis a/bertisi and L. papuanus by the absence, or only feeble representation, of rostral pits. In the Western Province Parker reports the species as dorsally black or blackish brown with a glossy iridescent sheen and.ventrally bright yellow with a white chin, grey subcaudal:> and a black tail tip.

Ross and Larman, (1977), brcd the water python in captivity in the United States. The hatchlings from a clutch of eight eggs measured between 270 and 290mm. Boos, (1983), reports a female in captivity at Taronga Zoo which coiled around a clutch of II eggs to incubate them until they hatched after 57 61 days. She left the eggs periodically to feed or slough her skin.

Liasis papuanus (Peters & Doria) Papuan python Liasis papuanus is extremely widespread throughout New Guinea from Misool Island to

the east of Irian Jaya, through the lowlands of the mainland and as far east as Fergusson Island in the d'Entrecasteaux Islands, Milne Bay Province. In the Western Province it is common in both lowland monsoon forest and savanna having been recorded from Wipim, Oriomo, Lake Murray and the Kiunga region by Parker, (1982). Whitaker and Whitaker, (1982), record that specimens from the roads around Port Moresby are frequently delivered to the Moitaka wildlife station. This is a large python, (specimens measuring over 4m, 13 14ft, have been collected), and McDowell states that the species could exceed Morelia amethistina as the largest species of New Guinea python. It is possible that the giant skin of Liasis maximus, (Werner 1936), which was thought to have originated from New Guinea, (possibly Astrolabe Bay), and which measured 4300mm, (14ft), may have been a large example ofL. papuanus. Unfortunately, the skin, which was in the collection of the National Museum of Budapest, has been destroyed. However, a specimen in the American Museum of

72

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Natural History from Buniguni village was reportedly measured at 4390mm, (l4Ihft), before skinning. Liasis papuanus also exceeds More/ia amethistina in build as the latter is a more slender species.

In colouration L. papuanus is dorsally olive-brown with black interstitial skin and ventrally light grey. The labials are light buff or grey and speckled with darker pigment. The dark colour of the interstitial skin contrasts with the light colour of those tissues in both Liasis mack/oti and the Australian Liasis o/ivaceus. Stull, (1935), placed L. papuanus as a subspecies of L. olivaeus, possibly because they both exhibit high ventral counts unlike any other Australasian pythons, (McDowell 1975). McDowell argues for the recognition of L. papua nus as a distinct species based on the closer apparent relationship between L. o/ivaceus and L. mack/oti which exist sympatrically in Australia.

Three specimens ofLiasis papuanuswere found whilst 'road-cruising' on the Hiritanoand Hubert Murray Highways to the north and east of Port Moresby. Two of these were DOR, (dead on road), specimens which measured over 1830mm, (6ft). The third specimen was a female measuring 915m, (3ft), found alive on the Hiritano Highway between the Laloki River and Brown River road-bridges. This specimen had the heaviest infestation ofcestodes ofany snake examined by the author during the expedition but whilst it was kept captive and observed it was also found to possess a voracious appetite taking any mice offered. Two large specimens of 2 3m were also reported by expedition patrols visiting villages where the pythons were being prepared as food.

L. papuanus, due to its size, has been recorded as taking a wide variety of different prey animals from small mammals to a 22.7kg agile wallaby, (Parker, 1982), swallowed by a 3830mm SVL, (12ft), specimen from Wipim. The type specimen was found to have eaten a Dorcopsis wallaby, (McDowell 1975). However, a drowned 1932mm, (6ft 3in), Papuan python retrieved from a fisherman's gill net on the Binaturi River near Kunini was found to contain a 1950mm, (6ft 4in) Amethystine python, Morelia amethistina, and large numbers of nematode worms, (O'Shea 1987). Ophiophagy, (snake cannibalism), is rarely seen in pythons in the wild and only one species, the desert dwelling Australian black -headed python Aspidites melanocepha/us, is recorded as a habitual snake-eater. As no other prey was present in the gut of the Papuan python it must be assumed that one python deliberately preyed upon the other. Although Boos, (1983), reports that this species is reputed to be ophiophagous the author has been unable to locate any other reports of such behaviour.

ACKNOWLEDGEMENTS

For invaluable assistance in the field during the 31h months duration of the project, thanks to the Venturers of Operation Raleigh; also the University of Papua New Guinea, (John Pernetta, Peter Lambley, John Hillary); National Museum of Papua New Guinea, (Jim Menzies); Fred Parker and Division of Environment and Conservation, (Karol Kisokau).

74

THE PYTHONS OF NEW GUINEA

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Boo<" H.E.A .. 1983. Australo-A<,ian Python, with Some Breeding Records in Captivity, ASRA Journal 2(1): 22 32.

Cogger, H.G., 1975, Reptiles and Amphibians of Australia. Reed.

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O'Shea, M" 1987, Snake Sneaks Snake Snack, BBC Wildlife Magazine, March p.112,

O'Shea, M., 1987, Predation by a Papuan Python, Liasls papuanus on an Amethyqine Python, /\1arelia arnelhis/ina, in Papua New Guinea. Herp. Review at press,

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Ross, R., & Larman, R" 1977, Captive breeding in two species of Python, International Zoo Yearbook, 17: \33 136.

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Stull, O,G., 1935. A Checklist of the Family Boidae. Proc, Boston Soc. Nat. Hi,t. 40(8); 387 - 408.

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Werner, F., 1936. Nova species boidarum. Ann. His!. Nal. Mu" Natl. Hungarici 30: 105.

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Worrell, E., 1963. Reptiles of Australia. Angus & Robertson.

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