Papuan dragon
| Papuan dragon | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Papuan dragon ( Varanus salvadorii ), Cincinnati Zoo |
||||||||||||
| Systematics | ||||||||||||
|
||||||||||||
| Scientific name | ||||||||||||
| Varanus salvadorii | ||||||||||||
| ( Peters & Doria , 1878) |
The Varanus Salvadorii ( Varanus salvadorii ), sometimes referred to as tree crocodile referred to is a kind of Squamata (squamates) from the genus of lizards ( Varanus ). With a total length of up to approximately 2.5 m of this is endemic of Guinea one of the largest known recent lizards. As detailed field observations are lacking, the species has been little researched.
features
The Papuan dragon reaches a total length of over 2.5 m, the longest reliably measured specimen was a total of 2.65 m long. Ten other specimens measured were 1.16 to 2.55 m long and weighed 5-6.38 kg. The tail is very long, its length is 2.7 times the head-trunk length . The older speculations and stories by locals cited to this day that the Papuan dragon can grow to be up to 4.5 m long are obvious exaggerations.
The head is built quite lightly, the muzzle blunt, the nostrils closer to the muzzle and more round than slit-shaped. The teeth are laterally flattened, slightly curved and very sharp, but only slightly serrated. They stand almost upright on the jawbone and are very long compared to other monitor lizards. The Papuan dragon has several gular folds . The tail is round in cross section at the base and becomes triangular in cross section further away from the body.
The basic color ranges from brown to deep black, in addition the species shows irregularly distributed yellow spots and eye spots as well as transverse rings around the tail. It can be distinguished from other, sympatric monitor lizards either by its non-laterally flattened tail and its many gular folds or by features in its scaling.
distribution
The Papuan dragon lives exclusively in New Guinea, a detailed list of all known sites can be found in Horn et al. (2007). He inhabits the north coast from the extreme west to Vamingo and the entire southern half of the island from the extreme west on the islands of Sarawati and Warir over the Vogelkopf peninsula to the area around Port Moresby in the east. It occurs from the coast to around 600 m above sea level and lives mainly in rain and swamp forests.
Way of life
The Papuan dragon is diurnal and a tree dweller, which can occasionally be found on the ground. The strong legs and strong, curved claws are adaptations to climbing, it uses its long tail to keep its balance when climbing and jumping from branch to branch, but not as a prehensile tail. He is highly agile and is characterized by extremely rapid movement and a high like all monitor lizards, probably the Varanus Salvadorii in the lower power range of endothermic lying metabolism of. Animals kept in captivity spend most of the day sunbathing on thick branches. Occasionally they rest in the water part of the enclosure for a long time, probably a thermoregulatory behavior.
Confirmed information on nutrition in nature in the form of examined stomach contents is not available. It can be assumed that it feeds on insects, small mammals, birds and their eggs; eggs in particular seem to be an important part of his diet. According to Schultze-Westrum (1972), local residents reported that the Papuan dragon kills deer , pigs and dogs; such prey should then be carried into the trees and eaten. This again seems very unlikely. Captive Papuan dragons eat cuts of meat, eggs, mice, rats, guinea pigs, hamsters, cuts of fish and dog food. They did not kill living rats by shaking their heads violently, which is typical of the war, but apparently could rely solely on their strong biting force and strong teeth. There is no information on hunting behavior in nature.
Ticks are particularly important as parasites of free-living Papuan dragons . Flagellates , mites, and tapeworms were confirmed to be endoparasites .
No data are available on social behavior and reproduction in nature. Male Papuan dragons cannot be kept together in captivity, as the males usually engage in comment fights immediately after they have come together. Captive clutches contained 4–12 eggs and were laid between October and January. There is no explanation for the large size differences between the eggs, which weigh 43.3–60.8 g. Most of the clutches released in captivity were sterile and only four times were bred. The hatchlings were about 45 cm long, more brightly colored ( more brilliantly in color ) than old animals and accepted small insects and reptiles as food.
Systematics
The first description was in 1878 by Peters & Doria. If the hemipenis morphology is taken as a systematic feature (Ziegler & Böhme 1997), then due to its unique hemipenes , Varanus salvadorii belongs to the monotypical subgenus Papusaurus , which is considered a sister group of all other Indo-Australian lines of development. According to molecular biological analyzes (Ast 2001), however, Varanus salvadorii is the sister taxon of Varanus komodoensis ; Varanus varius is the sister taxon to this cladus . This seems plausible, since Varanus varius occupies a similar ecological niche as Varanus salvadorii , possibly reaching New Guinea from Australia and developing there allopatricly to Varanus salvadorii . However, the common features of Varanus salvadorii and Varanus varius could also be due to convergent evolution .
Papuan dragons and people
In New Guinea, the natives consider the Papuan dragon to be "an evil spirit that climbs trees, walks upright, breathes fire and kills people". According to the locals, he is also supposed to kill and eat people; there is no proof of this. The inhabitants of the Arfak Mountains on the Vogelkopf Peninsula, in turn, hunt the Papuan dragon for its meat.
Nothing is known about the population of the Papuan dragon, in 1994 the number of all specimens ever exported to zoos and museums was estimated at 30 to 50. So far, the stocks have hardly been influenced by humans. The species is listed in the Washington Convention on the Protection of Species in Appendix II.
swell
- H.-G. Horn: Varanus salvadorii. In: ER Pianka, DR King (Ed.): Varanoid Lizards of the World. Indiana University Press, Bloomington / Indianapolis 2004, ISBN 0-253-34366-6 , pp. 234-243.
- ↑ H.-G. Horn, SS Sweet, KM Philipp: On the distribution of the Papuan monitor (Varanus salvadorii Peters & Doria, 1878) in New Guinea. In: Mertensiella. Volume 16 ( Advances in Monitor Research III ), 2007, pp. 25-43.
- ↑ a b c F. Pattiselanno, E. Rahayu, J. Wanggai: Varanus Species at The Arfak Strict Nature Reserve. In: Biodiversitas. Volume 8, No. 1, 2007, pp. 114-117.
