Copper skink

Copper skink
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Squamata
Family: Scincidae
Genus: Oligosoma
Species: O. aeneum
Binomial name
Oligosoma aeneum
(Girard 1857)
Synonyms

Cyclodina aenea[1]

The copper skink, Oligosoma aeneum, is a skink of the family Scincidae, endemic to the North Island of New Zealand.

Taxonomy and Systematics

The number of skink species endemic to New Zealand is not yet known, as advancing molecular studies indicate genetic divergence amongst many groups previously considered a single species.[2] At present, there is estimated to be between 50-60 species, all of the family Scincidae.[3] Following a taxonomic revision of the species complex in 2008, the Copper Skink was assigned the scientific name of Cyclodina aenea, and found to be both genetically and morphologically diverged from 2 other skink species which were previously considered synonymic.[4]

Anatomy

The Copper Skink is New Zealand’s smallest indigenous skink, with a mature length of no more than 120mm.[5] Like most skinks, it has smooth skin covering a long body, with relatively short legs. The tail makes up a considerable proportion of the body length, and tapers to a point. The skink is capable of shedding its tail to distract predators when threatened, before regenerating a new one – a process known as caudal autotomy.[6] Copper skinks have small heads with round, lidded eyes, which they are capable of blinking.

Ecology and Behaviour

The Copper Skink occupies a range of habitats, from forested areas to urban gardens. Like many skinks, it has a largely carnivorous diet and feeds mostly on small insects and other invertebrates.[7] Copper skinks are viviparous, and mate in spring before giving birth to between 3-7 relatively large offspring in late summer.[8][9]

Distribution

The initial arrival of the Copper Skink (and indeed any other skink species) to New Zealand is somewhat uncertain, and is a topic of considerable debate. The level of genetic diversity between the Copper Skink and other indigenous species suggests strongly that they and their ancestors have been a part of New Zealand’s fauna for millions of years,[10] allowing time for many early species to diverge and become distinct from each other. One 2009 study by Chapple, Ritchie and Daugherty, investigating “the origin and diversification” of New Zealand’s skinks, produced a molecular phylogeny by analysing genetic sequences of all but one living species. It suggested that all indigenous NZ skinks form a monophyletic group with a single ancestor, and that they initially arrived during the early Miocene era, by clinging to floating debris from New Caledonia.[11] From this early colonisation they underwent adaptive radiation to fill a variety of ecological niches, spreading across New Zealand to form the numerous species known today.

Conservation

Despite the dramatic alteration of New Zealand’s landscape by humans, the Copper Skink has adapted relatively well to urbanisation of its environment. In 2012 the Department of Conservation (DOC) classified the Copper skink as Not Threatened under the New Zealand Threat Classification System.[12] It is a common sight in many Auckland gardens, due to its ability to thrive in a range of microhabitats.[13] However, the introduction of mammalian predators such as cats, rodents and hedgehogs has proven to reduce their population numbers in many regions.[14][15][16]

In addition to the threat of mammalian predators, there are concerns that the competition for resources between the Copper Skink and the introduced Rainbow Skink (Lampropholis delicata) may present a further threat to Copper Skink populations.[17] A prolific breeder, the Rainbow skink occupies a very similar niche to the Copper Skink in terms of habitat and diet, indicating a significant competition between the species. Despite the concern, there has been relatively little research conducted into the potential effects of Rainbow Skinks in New Zealand. One 2004 study did compare the condition of captive Copper and Rainbow skinks housed together with those housed separately, and did not find significant difference between the two.[18] However, due to the high overlap of the species’ resource requirements, the Rainbow Skink is still considered by many to be a potential threat to Copper Skink populations.

References

  1. ↑ Chapple, D.G., Ritchie, P.A. and Daugherty, C.H. (01/01/0001 00:00:00) Origin, diversification, and systematics of the New Zealand skink fauna (Reptilia: Scincidae). Molecular Phylogenetics and Evolution.
  2. ↑ Wilson, K. (2012). Lizards – Origins and Diversity. In Te Ara – the Encyclopedia of New Zealand.
  3. ↑ New Zealand Herpetological Society. (2014). NZ Reptiles. Retrieved from
  4. ↑ Chapple, D. G., Patterson, J. B., Bell, T., & Daugherty, C. H. (2008). Taxonomic Revision of the New Zealand Copper Skink (Cyclodina aenea: Squamata: Scincidae) Species Complex, with Descriptions of Two New Species. Journal of Herpetology 42(3), 437-452.
  5. ↑ (DoC) Department of Conservation. (n.d). Cyclodina Skink. Retrieved from
  6. ↑ Department of Biology and Program in Animal Behavior, Bucknell University. (2006). Caudal autotomy and regeneration in lizards. Retrieved from
  7. ↑ Peace, J. E. (2004). Distribution, habitat use, breeding and behavioural ecology of rainbow skinks (Lampropholis delicata) in New Zealand (University of Auckland, Auckland, New Zealand). Retrieved from
  8. ↑ Supporters of Tiritiri Matangi Inc. (2010). Copper Skink. Retrieved from
  9. ↑ Gill, B. and T. Whitaker. 2001. New Zealand Frogs and Reptiles. David Bateman. Auckland, New Zealand.
  10. ↑ Wilson, K. (2012). Lizards – Origins and Diversity. In Te Ara – the Encyclopedia of New Zealand.
  11. ↑ Chapple, D. G., Ritchie, P. A., & Daugherty, C. H. (2009). Origin, diversification, and systematics of the New Zealand skink fauna (Reptilia: Scincidae). Molecular Phylogenetics and Evolution, 52(2), 470-487. doi: 10.1016/j.ympev.2009.03.021
  12. ↑ Hitchmough, Rod; Anderson, Peter; Barr, Ben; Monks, Jo; Lettink, Marieke; Reardon, James; Tocher, Mandy; Whitaker, Tony. "Conservation status of New Zealand reptiles, 2012" (PDF). Department of Conservation. The Government of New Zealand. Retrieved 18 July 2015.
  13. ↑ Peace, J. E. (2004). Distribution, habitat use, breeding and behavioural ecology of rainbow skinks (Lampropholis delicata) in New Zealand (University of Auckland, Auckland, New Zealand). Retrieved from
  14. ↑ Norbury, G., Van den Munckhof, M., Neitzel, S., Hutcheon, A., Reardon, J., Ludwig, K. (2014). Impacts of invasive house mice on post-release survival of translocated lizards. New Zealand Journal of Ecology, 38(2), 322-327. Retrieved from
  15. ↑ Jones, C., Norbury, G., & Bell, T. (2013). Impacts of introduced European hedgehogs on endemic skinks and weta in tussock grassland. Wildlife Research, 40(1), 36-44. doi: 10.1071/WR12164
  16. ↑ Towns, C. R., Daugherty, C. H., & Cree, A. (2001). Raising the prospects for a forgotten fauna: a review of 10 years of conservation effort for New Zealand reptiles. Biological Conservation, 99(1), 3-16. doi: 10.1016/S0006-3207(00)00184-1
  17. ↑ Department of Conservation. (n.d). Rainbow Skinks. Retrieved from
  18. ↑ Peace, J. E. (2004). Distribution, habitat use, breeding and behavioural ecology of rainbow skinks (Lampropholis delicata) in New Zealand (University of Auckland, Auckland, New Zealand). Retrieved from


External links

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