Salvadori's monitor, Crocodile monitor

Varanus salvadorii  Peters & Doria 1878

Salvadori's monitor is one of the world's most magnificent animals. Often cited as being "the longest lizard in the world" virtually nothing is known of its ecology and the species remains one of the world's greatest zoological enigmas. This species was first described from a specimen 50cm SVL (165cm TL) caught by Dr Odoardo Beccaris, supposedly at  Dorei in northwestern New Guinea. It was described by Wilhelm Peters (the owner of the Zoological Museum in Berlin) and Marchese Giacomo Doria (later the owner of the Natural History Museum in Genoa) and named after Conte Tommasso Salvadori, an eminent Italian ornithologist.

Salvadori's monitor does not appear to live anywhere other than the magical island of New Guinea. According to Whitaker et al (1982) it is found in Western, Gulf, East and West Sepik provinces of Papua New Guinea. Mertens (1958) records it from the Fly River whilst Mertens (1971) and/or Brandenberg (1983) examined specimens from Aird Hill, Kikori, Kokoni River, Kwari (Dore), Hollandia Bivak, Lake Sentani and the Jamoer River. According to MacKay (pers. comm.) they are found in mangrove and other estuarine swamps as well as drier forest from Port Moresby westward along the coastal regions as far as the Vogelkopf in Irian Jaya. Because they are restricted to the southern coast he considers records from Lake Sentani and other parts of northern New Guinea to be incorrect.

Salvadori's monitor is an excellent climber, able to support itself on vertical surfaces by hanging on with the hind feet alone. The tail is extremely long (up to 200% of the snout-vent length) and surprisingly prehensile; able to curl round branches to support the lizard when descending. It is also a formidable whip. Murphy & Mitchell (1974) describe how an adult male used the tail to make well-aimed strikes at its keeper's eyes. On the ground Salvadori's monitors tend to keep the tail tightly curled up in a spiral (Mertens 1960). In captivity males tend to be much bulkier than females, but there are no clear external differences. Indeed, several animals identified as males on the basis of hemipenal eversion have subsequently laid eggs (Madsen, pers. comm.).

According to the record books, Salvadori's monitor is indeed the longest lizard in the world. The record appears to be held by a specimen examined by Dr Michael Pope, a zoologist of Port Moresby, which measured 475cm from the tip of its nose to the tip of its tail (Wood 1982). Unfortunately neither the lizard nor Dr Pope can be traced. However reliable sources suggest that some very large monitor lizards do occur there. According to Menzies (pers. comm.) the largest ever seen at the University of Port Moresby could have been 500cm long, but it escaped before it could be measured. Another specimen of 427cm has been reported from the area of Kikori, Gulf Province, Papua New Guinea (MacKay, pers. comm.) and a captive specimen circa. 300cm TL was reported to be kept at Moitaka (Allison, pers. comm.). Despite these claims the specimens available for inspection are all much smaller. The largest known example measured 244cm TL (Mertens 1962).