"Laboratory" Animals

Lampropholis: the new "laboratory" animals

Shelley Burgin Faculty of Science and Technology, University of Western Sydney — Hawkesbury, Richmond, NSW 2753

ABSTRACT

Two spsciGs of Lsmpropholis skinks, LQmpropholis dslicdtd and Lsmpropholis guichenoti, commonly referred to as Penny or Garden skinks, have a predilection for disturbed areas. Both species have a widespread distribution over much of eastern Australia. Throughout most of their ranges they occur in overlap in a variety of habitats both disturbed and undisturbed, including suburban gardens. It is proposed that these species would make appropriate "laboratory" animals for undergraduate teaching, particularly animal ecology. They adapt well to captivity providing they are provided with adequate space and cover, food, water, and other appropriate environmental conditions such as light

and temperature. Their attributes include adaptive capacity to captivity, small size, ease of capture Downloaded from http://meridian.allenpress.com/rrimo/book/chapter-pdf/2644390/rzsnsw_1993_041.pdf by guest on 24 September 2021 and abundance. Also addressed are animal welfare issues of captive housing and use of native species in teaching.

INTRODUCTION As "laboratory" animals they are ideal. Their small size, abundance, ease of capture either Past generations of Australian biologists are by hand or pitfall traps, and adaptation to familiar with both the ubiquitous laboratory rat artificial housing make them appropriate Rattus norvegicus and Cane Toad Bufo marinus. animals for a range of undergraduate studies Their dissection has generally been a basic encompassing animal behaviour and ecology. component of first year undergraduate train- ing. Subjects taught in subsequent years also They adapt readily to life in an aquarium (or have their "typical" animals. It is inconceivable other appropriate "cage"), providing they have to imagine that anyone could call themselves a sufficient space, cover, food in the form of Genetics student without having handled large Drosophila sp. and water. If they are only being numbers of Drosophila melanogaster; while many kept short-term, no special arrangements are of us learned all we know about mark, release, required to control temperature and light. recapture techniques using a tray of flour However, if kept in captivity for extended swarming with Tribolium sp. periods of time, they need to have access to direct sunlight or heat lamps, otherwise they With appropriate technical support, estab- may encounter problems moulting. They lished animal houses and/or assured supply, also need to have appropriate lighting and the approach was safe, but boring. In recent temperature regimes for follicular develop- years, with greater concern about ethics, ment since it is associated with day-length financial constraints and increased numbers of cycles and a minimum temperature of 20°C is students, it has become increasingly difficult required for their development. and expensive to ensure our yearly supply of laboratory animals. I also perceive another Two species, Lampropholis delicata (De Vis "problem" with this traditional approach: none 1888) and Lampropholis guichenoti (Dumeril and of these species are Australian natives. Austra- Bibron 1839), are better known than their lian alternatives exist, for example the small congeners and are abundant in urban areas of reptiles. the Australian east coast (Burgin 1989).

SCINCID LIZARDS BIOLOGY OF AS "LABORATORY" ANIMALS LAMPROPHOLIS DELICATA Small diurnal scincid lizards are widely Lamoropholis delicata is small, animals distributed throughout eastern Australia. One observed in Sydney weighed as much as 1.1 such group, the Lampropholis, are sufficiendy gm with a maximum total length of 82.5 mm. abundant to have gained the common names They occur in open forest types from south- Garden or Penny Skinks. Due to their pre- eastern South Australia through southern dilection for disturbed areas, Lampropholis are Victoria and eastern New South Wales to frequently abundant in areas of human habita- northeastern Queensland (Cogger 1992). In tion, including parklands, urban gardens and addition the species occurs in eastern Tasmania adjacent bushland. (Green 1981) and has been introduced to

Herpetology in Australia 279 Hawaii (Baker 1979; Loveridge 1934; Oliver Clutch size in oviparous species is known to and Shaw 1953) and New Zealand (Hardy be correlated with female size. Baker (1979) 1977). This species will therefore be endemic suggested that the relatively smaller size to the campuses of most universities in Queens- attained by female L. delicata on Oahu Island land, eastern New South Wales, Victoria and (Hawaiian group) may have been a result of South Australia. greater competition (both intra- and inter- specific), than occurred on the islands of Kauai Baker (1979) commented that L. delicata was or Hawaii. Since individuals from the Hawaiian widely distributed in urban habitat, from dry Islands grow to a significantly larger body size lowlands to wet upland regions. As with other than Australian L. delicata, this phenomenon species of the genus, its preferred microhabitat may be attributed to lower predation pressure varies with prevailing weather conditions. In on the exotic populations, allowing individuals general the species tends to be associated with to live longer and therefore attain a greater sun flecks under canopy in areas with relatively body size and consequently larger clutch size. uniform, although open, cover. However, in Observations of predation give some basis for cooler areas, such as the Notophagus moorei rain- the prediction that larger females are at greater forests on the New South Wales/Queensland Downloaded from http://meridian.allenpress.com/rrimo/book/chapter-pdf/2644390/rzsnsw_1993_041.pdf by guest on 24 September 2021 boarder, individuals are more commonly predatory risk, at least immediately preceding observed in the open, along road and track oviposition (Burgin 1989). verges, rather than in more sheltered areas. This behaviour is also common during the BIOLOGY OF cooler months in warmer parts of the species' LAMPROPHOLIS GUICHENOTI range, although in cooler areas they will Lampropholis guichenoti is the larger of the two hibernate during cold periods. Outside of closed forest habitats, L. delicata tends to species. Animals from the Sydney population be restricted to areas of permanent cover may weigh as much as 1.4 gm and have a representing relatively moist microclimates, maximum total length of 86 mm. Their range such as logs and rock piles (Belmont 1977). It extends from southeastern South Australia is also frequently observed in more open through most of Victoria and eastern New habitat (including urban gardens and park- South Wales to southeastern Queensland. lands) in association with relatively deep litter, Within this range the species is broadly in over- such as at the base of mature eucalypts or in lap with L. delicata, although L. guichenoti tends other appropriately moist areas (Burgin 1989). to tolerate a drier micro-climate than L. delicata. Both achieve similar body temperatures in the Clarke (1965) recorded that the young hatch field, despite L. guichenoti preferring air in summer and reach maturity in the following temperatures approximately one degree year. Joss and Minard (1985) studied a Sydney warmer than L. delicata (Graham 1987). Where L. delicata population. They confirmed that the habitats of the two species overlap, L. oviposition occurred in summer while ovaries guichenoti is invariably in more open areas than were quiescent during autumn and winter (i.e., L. delicata, although frequently both species are February to July). Between August and October associated with disturbed areas (Burgin 1989). follicles grew, with one or two per ovary Joss and Minard (1985) observed that in the becoming vitellogenic, and these were ovulated Sydney region L. guichenoti had a similar repro- in October or November. After eggs were laid ductive cycle to L. delicata. However, (approximately one month later), a second wave of vitellogenic follicles occurred, subsequently in seasons of high rainfall, L. guichenoti may these regressed, post-mating in late summer. produce two clutches of eggs in a single season. Males produced mature sperm during October Other observations also indicate that this may and November, and again in February. Testes be the case (Milton 1980, Brisbane area; are depleted of sperm by the end of autumn. Pengilley 1972, southeastern Highlands of The females thus carry sperm over-winter and New South Wales), although Milton (1980) developed eggs are fertilized in spring. suggested that his observations coulcl also be explained in terms of the species breeding While small individuals occasionally have a later in southeastern Queensland. On the New single egg, two is more common. Within Aust- England Tableland (northern New South Wales), ralia females generally carry three eggs, with however, the species apparently produces only large individuals occasionally producing up to one clutch annually with recruitment begin- five (Burgin 1989). However in Hawaii female ning in February, subsequently juveniles grow L. delicata may produce as many as seven eggs rapidly and both sexes reach maturity in eight (mean clutch size on Hawaii 4.7; range 3-7) to nine months (Simbotwe 1985), growth rate although among islands, female egg numbers then decreases (Heatwole 1976; Simbotwe vary (Baker 1979). 1985). Egg incubation requirements of the two 280 Herpetology in Australia species, L. delicata and L. guichenoti, are similar Under such conditions the animals appear to and communal nesting occurs (Mitchell 1959; suffer no ill effects, for example no behaviour Wells 1979, 1981; Burgin 1989). change or disease has been observed. Since males are aggressive and territorial, to ensure ECOLOGICAL STUDIES OF that stress is minimized adequate space and cover LAMPROPHOLIS (ideally in the form of leaf litter) needs to be maintained. These species are opportunistic As discussed above, attributes such as wide- feeders, feeding on a variety of small inverte- spread distribution, small (but not microscopic) brates. Nutritional problems may therefore size, abundance, ease of capture and main- occur if their diet was restricted to Drosophila tenance make Lampropholis species a useful sp. for extended periods. One mechanism for "tool" for a variety of class activities involving overcoming this problem is to add additional animal ecology. An additional advantage is that leaf-litter cover from the species' environment there is sexual dimorphism in L. guichenoti: at regular intervals. Since this will include a both head width and height are significantly diversity of small invertebrates, it is an effective larger in males than in females (Simbotwe

way to introduce the animal's natural food. Downloaded from http://meridian.allenpress.com/rrimo/book/chapter-pdf/2644390/rzsnsw_1993_041.pdf by guest on 24 September 2021 1985). Colour pattern also varies between sexes, as it does in some populations of L. The ease with which it is possible to duplicate delicata (Burgin 1989). This sexual dimorphism the natural environment of Lampropholis sp. in and the significant overlap between the two the laboratory is in sharp contrast to that of species, makes it feasible to undertake projects common laboratory animals. It is the norm to involving intra- and inter-specific comparisons. house rats in totally artificial surroundings and feed them artificial diets while toads are Using L. delicata and L. guichenoti in mark, frequently transported and stored without release and recapture studies instead of food or water, under crowded conditions. Dis- simulating a population using beans, or flour section invariably reveals grossly over-weight weevils has the advantage of allowing students rats and starved toads. Captive maintenance of the opportunity of undertaking "fieldwork" small reptiles is therefore considered much economically (i.e., generally without leaving more humane than holding toads or breeding the campus). However, there are also draw- rats in captivity. backs to using Lampropholis. When conditions As stated previously, unnecessary cruelty to are cool or heavily overcast, the skinks will not any animal (vertebrate or invertebrate) is con- be active but flexibility within the week-to-week sidered unacceptable. I also see no more justifi- practical programme will usually overcome any cation for treating introduced species with any associated problems. less respect than native animals. PERMITS AND APPROVALS The Lampropholis are common inhabitants of gardens throughout much of Australia and are Before collecting any animals, however, it is the prey for many birds, snakes, lizards and necessary to obtain a licence from National other animals. However, the local pest control Parks and Wildlife Service as reptiles are person or pesticide- and/or herbicide-happy protected in all states of Australia. It is also gardener kills large numbers of these small essential to have ethics approval from the animals without thought. Predators prey on appropriate body. In obtaining such approvals the skinks and in doing so, the poison is passed it is necessary to justify the use of animals for up the food chain. Teaching students to notice scientific inquiry. In considering using these and respect such animals can only help to species more widely for teaching, it is desirable encourage the conservation of the species. The to address the animal's welfare and their exposure to reptiles may also enthuse some to appropriateness for the proposed study. join the field of herpetology so that we can improve our knowledge of our most diverse Unnecessary cruelty to any animal (vertebrate reptile fauna. At the very least it will help to or invertebrate) is unacceptable, and therefore overcome the community's fear of reptiles. if it is not possible to provide the species with an acceptable environment, it should not be REFERENCES retained in captivity. Providing an environment for L. delicata and L. guichenoti which BAKER, J. K., 1979. The rainbow skink, Lampropholis delicata in Hawaii. Pac. Sci. 33: 207-12. mimics their natural habitat is not difficult. To BELMONT, C. M., 1977. Resource partitioning and habitat do this it is necessary to retain the animals at selection in the ground skinks. Honours Thesis, appropriate temperatures, in conditions of University of New England: Armidale. adequate light with appropriate diurnal patterns, BURGIN, S., 1989. The taxonomic and phylogenetic relation- well fed and watered, with appropriate space ships of some Australian scincid lizards (Scincid: and cover, away from major interruptions. Lygosominae), PhD, Macquarie University: Sydney. Herpetology in Australia 281 CLARKE, C. J., 1965. A comparison between some Australian MILTON, D. A., 1980. Some aspects of the population five-fingered lizards of the genus Leiolopisma Dumeril dynamics of Lampropholis guichenoti in Toohey Forest and Bibron (Lacertilia: Scincidae). Aust, J. Zool. 13: near Brisbane. Herpetofauna 11: 19-23. 577-92. MITCHELL, F. J., 1959. Communal egg-laying in the lizard COGGER, H. G., 1992. Reptiles and amphibians of Australia. Leiolopisma guichenoti (Dumiril and Bibron). Trans. Roy. Reed International Books: Chatswood, New South Soc. S. Aust. 82: 121-22. Wales. OLIVE, J. A. AND SHAW, C. E." 1953. The amphibians and GRAHAM, A., 1987. Habitat selection in Lampropholis delicata reptiles of the Hawaiian Islands. Zoologica 32(2): 65-95. and L. guichenoti (Squamata: Scincidae). Honours PENGILLEY, R., 1972. Systematic relationships and ecology of Thesis, Macquarie University: Sydney. some lygosomine lizards from Southeastern Australia. GREEN, R. H., 1981. Distribution of the delicata skink. Tas. PhD, Australian National University: Canberra. Nat. 68 Dec. 1981: 8. SIMBOTWE, M. P., 1985. Sexual dimorphism and reproduction HARDY, G. S., 1977. The New Zealand Scincidae (Reptilia: of Lampropholis guichenoti (Lacertilia: Scincidae). Pp. Lacertilia): A taxonomic and zoogeography study. N.Z. 11-16. in Biology of Australasian frogs and reptiles ed by G. J. Zool. 4: 221-25. Grigg, R. Shine and H. Ehmann. Surrey Beatty & Sons: Sydney. HEATWOLE, H., 1976. Reptile ecology. University of Queens-

land Press: Brisbane. WELLS, R., 1979. A large aggregation of skink eggs. Herpeto- Downloaded from http://meridian.allenpress.com/rrimo/book/chapter-pdf/2644390/rzsnsw_1993_041.pdf by guest on 24 September 2021 fauna 11(1): 19-20. Joss, J. M. P. AND MINARD, J. A., 1985. On the reproductive cycles of Lampropholis guichenoti and L. delicata WELLS, R., 1981. Utilization of the same site for communal (Squamata: Scincidae) in the Sydney region. Aust. J. egg-laying by Lampropholis delicata and L. guichenoti. Zool. 33: 699-704. Aust. J. Herpet. 1: 35-36.

LOVERIDGE, A., 1934. Australian reptiles in the Museum of Comparative Zoology, Harvard. Bull. Mus. Camp. Zool. Harv. 77: 243.

This response was sought following Is it appropriate, if there is already an comments by the referees that the above paper experimental model which has been developed at raises issues of animal care and ethics. The great cost to that species, to start a new one? How author has since revised the paper drawing can Burgin justify re-investing the same type more attention to the ethical issues, but the view- of effort (i.e., suffering) entailed in the develop- point presented here still stands. (Editors). ment of exiting models? Further, I would ask the author, from a research point of RESPONSE: LAMPROPHOLIS: THE view: NEW LABORATORY ANIMAL i) Is the animal a more proper laboratory animal than rats and cane toads; that is, will Karen Stiles it give better results? Member Animal Research Review Panel, NSW representing the ii) Is this animal more easily managed in Animal Societies Federation (NSW) captivity? What thought has been given to parasites, diseases, distress et al. resulting This paper gives me cause for great alarm. from the artificial confinement of this Although apparently innocuous, it in fact has animal? the potential to open the floodgates on iii) What thought has been given to setting enormous ongoing suffering. Just when it criteria for recognizing, monitoring and seemed a more humane, forward-thinking alleviating distress and pain, means of approach was being taken by scientists, yet euthanasia, agreed endpoints . . . the list another animal has been targeted as the cheap goes on and brings me back to my opening and easy answer to deep phiolosophical statement. questions. In summary, I believe the current trend is Supposing for the moment that live animals for redwing animal usage in research and in undergraduate (or in fact any) research are teaching. Bearing in mind that economics justifiable, and that this hypothesis could should not be a part of the greater ethical argu- become reality, I put forward that there is ment, what possible advantage does Burgin see already an established model with well known in the use of Lampropholis} I invite the author parameters. to provide rmZ justification for this paper.

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