THE LIZARDS OF THE ISLANDS VISITED BY FIELD CLUB A REVISION WITH SOME ADDITIONS By D. R. Towns*

Transcription

1 Tane (1971) 17: THE LIZARDS OF THE ISLANDS VISITED BY FIELD CLUB A REVISION WITH SOME ADDITIONS By D. R. Towns* SUMMARY The taxonomy of the lizards of the islands visited by Field Club (Hard, 1954) is updated according to McCann (1955). Suggested alterations are as follows: Hoplodactylus duvaucellii Lygosoma omatum Lygosoma moco Lygosoma grande Lygosoma smithii Lygosoma lineo-ocellatum = H. duvauceli plus H. pacificus = Sphenomorphus pseudornatus = Leiolopisma smithi = Leiolopisma suteri = Leiolopisma smithi = Leiolopisma moco INTRODUCTION The records of sightings and collection of reptiles by Field Club members from Hen, Little Barrier, Mayor, Great Barrier and Rangitoto Islands as published by Hard (1954) are greatly in need of revision, especially as it appears that many of Hard's identifications were based on the work of Lucas and Frost (1896). The suggested alterations to Hard's identifications, however, can only be inferred from his descriptions and other workers' observations in the areas he visited. The revised taxonomy of these lizards follows McCann (1955) who gives the fullest account of the families, genera and species of the lizards of New Zealand so far published, along with some unravelling of their complex synomies. THE LIZARDS Family Gekkonidae Genus Hoplodactylus Fitzinger H. duvaucellii (syn. H. duvauceli). Confusion over the identification of this gecko may have arisen owing to debate as to whether H. duvauceli was synonomous with H. pacificus (McCann, ibid.). It is now accepted that these are two separate species. With this in mind it seems that Hard's "//. duvaucellii" is actually H. duvauceli plus H. pacificus. This is suggested by the fact that although Hard's identification of H. duvauceli from Hen and Little Barrier Islands may be correct, much searching by the author on Mayor Island (Nov. 1969), from which Hard also reports this animal, only produced one small //. pacificus. Hard states that H. duvauceli * Department of Zoology, University of Auckland.

2 92 "was found to be common on Little Barrier, Specimens were seen on the tea-tree scrub or in the coastal fringe..." In this context it is important to note that on many islands, where H. pacificus and H. duvauceli are found together (including Hen and Little Barrier), H. pacificus is more common than H. duvauceli (Robb, pers. comm.). Family Scincidae Genus Lygosoma Hardwick and Gray. Since Hard's publication this generic name for the New Zealand skinks has been abolished in favour of Leiolopisma Dum. and Bibr., and one genus added, this being Sphenomorphus Fitzinger. Lygosoma omatum /syn. Leiolopisma ornata) = Sphenomorphus pseudornatus. Hard records this skink from Hen Island and states that it is "smaller than the mainland form which is abundant beneath rocks on Mt. Mangere." If this is so, the animal he saw is undoubtedly what is now known as Sphenomorphus pseudornatus McCann (Fawcett, 1964, Chard, 1967). However the synonomy of Sphenomorphus is closely linked with that of/,, ornata. In 1843 Gray described a new species of New Zealand skink, Tiliqua ornata with the type locality described as "Cook's Straits." Two years later he described Hinula ornata which he distinguished by "scaley character of the lower eyelid" (McCann, 1955), giving the type locality as "New Zealand". Gray later relegated his T. ornata to synonomy with//, ornata and they remained thus until re-examined by McCann (1955). The difference in range, scale counts and other factors especially the scaley eyelid of H. ornata resulted in McCann separating Gray's T. ornata (syn. Leiolopisma ornata), which is found south of 38 S (McCann, 1955) from Hinula ornata which he placed in the genus Sphenomorphus. This animal, which is confined to the northern North Island is now called Sphenomorphus pseudornatus. Lygosoma moco (syn. Leiolopisma moco) = Leiolopisma smithi. This lizard also has a complex synonomy. Some authors refer to this animal as the common garden skink e.g. Powell (1951) calls Lygosoma moco "the little lizard of our gardens" and Natusch (1967) says that "Aucklanders will be familiar with L. moco." Boulenger's (1887) Lygosoma moco is regarded by McCann (1955) as being a composite species containing Leiolopisma moco (Dum. & Bibr.) and L. zelandica (Gray). As L. zelandica is the common garden skink of the southern North Island and the South Island it is possible that the Auckland species has been confused with it. Hard records "Lygosoma moco " (sensu lato) from Little Barrier Island and says "the brown skink was recorded as occurring in abundance on Rangitoto Island by Hutton 1871, and today occurs beneath rocks on the upper scoriae-

3 93 eous zone of the island. This species is abundant in many Auckland gardens." This description fits Leiolopisma smithi which, along with Sphenomorphus pseudornatus may be present in Auckland, (pers. obs.). Leiolopisma moco (sensu stricto) is a bush and scrub dwelling form and there does riot appear to be any record of it from Auckland city or suburbs. Lygosoma grande (syn. Leiolopisma grandej = Leiolopisma suteri. Hard calls this the "Black Shore Skink" and records it from Hen, Rangitoto and Great Barrier Islands. He states that "doubt exists as to the true identity of this species," noting that "Hutton in 1871 recorded that Mr T. Kirk and himself had collected specimens of a black skink from Flat Island, a rock off Great Barrier and also from Little Barrier and gave it the name Mocoa grandis. " Hard goes on to say that "Lucas and Frost in 1896 included this new species in their Lygosoma (Liolepisma - L. & F., 1896) grande and recorded its distribution as South Island, among rocks." It appears that Hard has confused two completely different species in this case. His and Hutton's (1871) description of the "Black Shore Skink" is most likely to fit that of Leiolopisma suteri (Boulenger) which has been reported from all of the localities Hard mentions (Whitaker, 1968 a, b; McCann, 1955; Robb, pers, comm.), while Leiolopisma grande is probably confined to the South Island (McCann, 1955). Lygosoma smithii (syn. Leiolopisma smithi) Since Hard's publication, this species has been split into two subspecies: Leiolopisma smithi numerate McCann Leiolopisma smithi smithi (Gray). Hard is probably correct in his description of L. smithi from Little Barrier Island, but which of the two subspecies he encountered is not clear from his report. Leiolopisma s. numerate and L. s. smithi are often difficult to tell apart, especially as their colour and markings vary greatly. At Ruamahunga Beach, on the coast of the Coromandel Peninsula, a population of L. smithi (s.l.) sampled by the author consisted of large brown skinks, with a wide, broken, black lateral band and a broken black mid-dorsal line. At Port Jackson, further along the same coast, the animals were green in colour, retaining the broken black lateral line, but with various amounts of black speckling on the dorsal surface. Mid-body scale counts (38 in both cases) and head scalation checks showed that these were both L. s. numerate. A population of similar brown skinks from Matauri Bay (Northland) had markings like the skinks from Ruamahunga. Thirty-eight scales about the mid-body suggested that these animals were alsol.s. numerate. Smaller green skinks collected from the same area had 34 mid-body scales which suggested them to be L. s. smithi. This indicates that there may be considerable confusion if colour is used as the main means of identification of these animals.

4 FIG. 2 Leiolopisma moco (female) from Mayor Island. Photo C.G. Quilter.

5 Lygosoma lineo-ocellatum /'syn. Leiolopisma lineo-ocellatum). = Leiolopisma moco. 95 Hard admits that "the identity of this skink is not definite," recording it from Little Barrier Island and Mayor Island. However, as L. lineo-ocellatum is probably restricted to South and Stewart Islands (McCann, 1955), it is more likely that the animals Field Club sighted on Mayor Island were L. moco (s.s.). as one female of that species was collected there in November 1969 (pers. obs.). This animal, with a mid-body scale count of 32 closely follows the description of L. moco given by McCann (1955). Hard describes the specimen from Little Barrier Island as being "somewhat similar to L. moco, it was much larger and stouter and measured 6%ins. The specimen was a chocolate brown in colour with white, black-edged spots dorsally." Remembering that Hard's "L. moco"is actually L. smithi, it is possible that he saw a large specimen of the latter. Leiolopisma moco as it is known today is a handsome lizard with two distinctive lateral cream stripes running down the body and tail, one stripe also runs along each leg. Leiolopisma smithi, however with its variable colour scheme (green to brown, with various amounts of black speckling and sometimes a single lighter coloured dorso-lateral stripe) and pointed snout can be seen from the photograph (fig. 1) to be quite different from L. moco (fig. 2). The two animals also occupy different habitats, L. smithi tending to be a coastal dweller (often under rocks on boulder beaches), while L. moco is often found in small cleared areas where good cover in the form of bush, scrub, or thick grass is present nearby. This attempted revision of Hard's work may, in time, need to be revised itself as many New Zealand lizards (especially the skinks) are extremely difficult to identify. "Diagnostic" characters of one species often overlap with those of another, e.g. mid-body scale counts may be very variable. This prompted McCann (citing Smith, 1935) to note for the genus Leiolopisma: "The determination of species grouped under the genus is often extremely puzzling. Two forms that in one area seem quite distinct, in another area appear to intergrade. Comparison in such cases depends upon very trivial characters and morphological differences; colour pattern, geographical distribution, and even habits have all to be taken into account. They are perhaps species in the making, and until a more exact conception of what a species is, they will continue to confound us." ACKNOWLEDGEMENTS I would like to thank the following people for the help they have given; Assoc. Prof. J. Robb and Miss E.M. Dickson for criticism of the script, Mr C. G. Quilter for the photography and Mr A.H. Whitaker for his helpful suggestions.

6 96 REFERENCES BOULENGER, G.A "Catalogue of the lizards in the British Museum" 3; CHARD, W.G. FAWCETT, J.D. GRAY, I.E Thermoregulation in Sphenomorphus pseudornatus and Leiolopisma fallai. Unpublished Zoology IIIB Project, University of Auckland The life history and ecology of Sphenomorphus pseudornatus McCann (Lacertalia: Scincidae) Unpublished MSc Thesis, University of Auckland "Descriptions of the Reptiles and Amphibia hitherto observed in New Zealand." In Dieffenbach, E. "Travels in New Zealand" 2: HARD, G Notes on the Reptilia of islands visited by Field Club Tane 6: HUTTON, F.W. LUCAS, A.H.S., FROST, C. McCANN, C. NATUSCH, S. POWELL, A.W.B. WHITAKER, A.H Notes on the lizards of New Zealand with descriptions of two new species. Trans. N.Z. Inst. 4: The lizards (Lacertalia) indigenous to New Zealand. Trans N.Z. Inst. 29: "The lizards of New Zealand." Dom. Mus. Bull. 17, Wellington "Animals of New Zealand." Whitcombe and Tombs, Christchurch "Native animals of New Zealand" Auck. Mus. Hdbk. Zoo. 1968(a) Leiolopisma suteri (Boulenger). An oviparous skink in New Zealand. N.Z.JISci. 11: (b) Lizards of the Poor Knights Islands. N.Z. Jl. Sci. 11: