Jump to content

Canterbury spotted skink: Difference between revisions

From Wikipedia, the free encyclopedia
Browse history interactively
← Previous edit
Content deleted Content added
VisualWikitext
m v2.05 - Fix errors for CW project (Reference list missing)
SdkbBot (talk | contribs)
Bots
355,259 edits
m Removed erroneous space and general fixes (task 1)
 
(5 intermediate revisions by 3 users not shown)
Line 1: Line 1:
{{Short description|Species of lizard}}
{{Short description|Species of lizard}}
{{Short description|Species of lizard}}
{{Use New Zealand English|date=July 2024}}

{{Speciesbox
{{Speciesbox
| name = Canterbury spotted skink
| name = Canterbury spotted skink
| image = CanterburySpottedSkink.jpg
| image = Oligosoma lineoocellatum (New Zealand spotted skink) at Zealandia Ecosanctuary in Wellington.jpg
| status = EN
| status = EN
| status_system = IUCN3.1
| status_system = IUCN3.1
| status_ref = <ref name=IUCN1>{{cite iucn |author=Hitchmough, R. |author2=van Winkel, D. |author3=Lettink, M. |author4=Chapple, D. |year=2019 |title=''Oligosoma lineoocellatum'' |volume=2019 |page=e.T120189599A120192619 |doi=10.2305/IUCN.UK.2019-2.RLTS.T120189599A120192619.en |access-date=20 March 2020}}</ref>
| status_ref = <ref>{{Cite report |url=https://www.iucnredlist.org/species/120189599/120192619 |title=''Oligosoma lineoocellatum'': Hitchmough, R., van Winkel, D., Lettink, M. & Chapple, D.: The IUCN Red List of Threatened Species 2019: e.T120189599A120192619 |last=IUCN |date=2018-02-17 |publisher=International Union for Conservation of Nature |doi=10.2305/iucn.uk.2019-2.rlts.t120189599a120192619.en |language=en}}</ref>
| genus = Oligosoma
| genus = Oligosoma
| species = lineoocellatum
| species = lineoocellatum
Line 12: Line 15:
}}
}}


The Canterbury spotted skink is one of a species complex of several related spotted skink species from New Zealand.<ref name="Melzer2017">{{cite journal |last1=Melzer |first1=Sabine |last2=Bell |first2=Trent |last3=Patterson |first3=Geoff B. |title=Hidden conservation vulnerability within a cryptic species complex: taxonomic revision of the spotted skink (Oligosoma lineoocellatum; Reptilia: Scincidae) from New Zealand |journal=Zootaxa |date=3 August 2017 |volume=4300 |issue=3 |doi=10.11646/zootaxa.4300.3.2}}</ref>
'''''Oligosoma lineoocellatum''''', commonly known as the '''Canterbury spotted skink''', is one of a species complex of several related spotted skink species from New Zealand.<ref name="Melzer2017" />

==Taxonomy==
The Canterbury spotted skink ''Oligosoma lineoocellatum'' <ref>{{Cite book |last=Duméril |first=C |title=Catalogue methodique de la collection des reptiles |last2=Duméril |first2=A |date=1851 |publisher=Gide and Baudry |location=Paris |pages=124}}</ref> is one of a species complex of several related spotted skink species in New Zealand.<ref name="Melzer2017">{{cite journal |last1=Melzer |first1=S |last2=Bell |first2=T |last3=Patterson |first3=G. B. |date=3 August 2017 |title=Hidden conservation vulnerability within a cryptic species complex: taxonomic revision of the spotted skink (''Oligosoma lineoocellatum''; Reptilia: Scincidae) from New Zealand |journal=Zootaxa |volume=4300 |issue=3 |doi=10.11646/zootaxa.4300.3.2}}</ref>

The four species within this complex are the Canterbury spotted skink ''O. lineoocellatum'' sensu stricto, the [[Mackenzie skink]] ''Oligosoma'' ''prasinum'',<ref name="Melzer2017" /> the [[Marlborough spotted skink]] ''Oligosoma elium'',<ref name="Melzer2017" /> and the [[Northern spotted skink]] ''Oligosoma'' ''kokowai''.<ref name="Melzer2017" />

These species are very morphologically similar; however, are distinguished by their differences in geographic distribution and genetic differences.<ref name="Melzer2017" />

==Identification==
The Canterbury spotted skink is a large, eye-catching skink with a snout-vent length reaching up to 107mm.<ref name=":0">{{Cite book |last=Van Winkel |first=D |title=Reptiles and Amphibians of New Zealand: A Field Guide |last2=Baling |first2=M |last3=Hitchmough |first3=R |publisher=Auckland University Press |year=2018 |isbn=9781869409371 |location=Auckland, New Zealand}}</ref> Individuals typically have an olive-green, brown or brown-grey dorsal (upper side) surface with light and dark coloured spots ([[ocelli]]) which extend almost to the tail tip.<ref name=":0" /><ref name=":1">{{Cite book |last=Purdie |first=S |title=A Naturalist’s Guide to the Reptiles & Amphibians of New Zealand |publisher=John Beaufoy Publishing |year=2022 |isbn=9781913679316 |location=Oxford, England}}</ref> Some individuals have also been found to have light dorsolateral stripes stretching from above the eye to the beginning of the tail.<ref name=":0" /><ref name=":1" /> The lateral (side) surface exhibits a dark brown or brown-black lateral band with specks and white edges notched, extending from the front of the eyes to the tail tip.<ref name=":0" /> A thin pale stripe runs beneath this, transitioning into intermittent patches of cream and dark brown on the lower side surface.<ref name=":0" /><ref name=":1" /> The ventral (underside) surface of the skink is grey in uniform, flushed with orange or pink, with a pale chin and throat covered in dark spots.<ref name=":0" /><ref name=":1" /> Individuals have dark brown eyes with an intact tail longer than the snout-vent length.<ref name=":0" /> The Canterbury spotted skink has cream or grey soles on its feet with 21–25 subdigital [[Lamella (surface anatomy)|lamellae]] (scales underneath fingers or toes).<ref name=":0" />

There are a several skinks that closely resemble the Canterbury spotted skink which can make it more challenging to identify them. The [[Mackenzie skink]] and [[Marlborough spotted skink]] are similar species; however, this is differentiated by the Canterbury spotted skink usually having more than 24 subdigital [[Lamella (surface anatomy)|lamellae]] and the [[ocelli]] markings on the dorsal surface running down the tail.<ref name=":0" /> The uniformly grey underside, the greater ratio of snout-vent length to head-width and the different geographic locations differentiate the Canterbury spotted skink from the [[Northern spotted skink]].<ref name=":0" /> Members of the ''[[Oligosoma chloronoton]]''<ref>{{Cite journal |last=Hardy |first=G. S. |date=1977 |title=The New Zealand Scincidae (Reptilia: Lacertilia); a taxonomic and zoogeographic study |url=http://www.tandfonline.com/doi/abs/10.1080/03014223.1977.9517956 |journal=New Zealand Journal of Zoology |language=en |volume=4 |issue=3 |pages=221–325 |doi=10.1080/03014223.1977.9517956 |issn=0301-4223}}</ref> species complex (green skinks) also appear similar to the Canterbury spotted skink; however, the Canterbury spotted skink usually has more than 22 subdigital lamellae compared to the green skinks and features fewer anterior [[subocular scales]] (below the eyes) of similar sizes.<ref name=":0" />

==Geographic distribution and habitat==
The Canterbury spotted skink is an [[Endemism|endemic]] species of skink only found in the [[Canterbury Region|Canterbury]] region of New Zealand.<ref name=":0" /> This distribution spreads from [[Mount Grey]] in the north, [[Banks Peninsula]] in the east, and the [[Rangitata River]] in the south.<ref name=":0" /><ref name=":1" /> This species may also be seen further south in Canterbury.<ref name=":0" /><ref name=":1" /> ''O. lineoocellatum'' can be found in various environments including lowland, coastal, montane/subalpine and alpine.<ref name=":0" /> These also vary in altitude from sea level up to 1400m.<ref>{{Cite book |last=Mark |first=A. F. |title=Above the Treeline: a Nature Guide to Alpine New Zealand |publisher=Craig Potton Publishing |year=2012 |isbn=9781877517761 |location=Nelson, New Zealand}}</ref> In these environments, the Canterbury spotted skink has been found in a wide range of habitats. These are grasslands, rock piles, boulder and cobble beaches,<ref>{{Cite book |last=Jewell |first=T |title=A Photographic Guide to Reptiles & Amphibians of New Zealand |publisher=New Holland Publishers (NZ) Ltd |year=2008 |isbn=9781869662035 |location=Auckland, New Zealand}}</ref><ref name=":0" /><ref name=":1" /> dune shrubland,<ref name=":0" /><ref name=":1" /> flaxland,<ref name=":0" /><ref name=":1" /> edges of forest <ref name=":1" /> scree slopes, fellfields,<ref name=":0" /><ref name=":1" /> stony coasts and riverbeds,<ref name=":0" /><ref name=":1" /> herbfields,<ref name=":1" /> and vinelands.<ref name=":0" />

==Life cycle and phenology==
The Canterbury spotted skink is [[Diurnality|diurnal]]<ref name=":0" /><ref name=":1" /> meaning it is active during the day. It is also heliothermic (gains heat from the sun) so spends a lot of time basking in the sun.<ref name=":0" /> Mating occurs at the beginning of autumn<ref>{{Cite journal |last=Molinia |first=F. C. |last2=Bell |first2=T |last3=Norbury |first3=G |last4=Cree |first4=A |last5=Gleeson |first5=D.M. |date=2010 |title=Assisted breeding of skinks or how to teach a lizard old tricks! |url=https://www.herpconbio.org/Volume_5/Issue_2/Molinia_etal_2010.pdf |journal=Herpetological Conservation and Biology |volume=5 |issue=2 |pages=311–319}}</ref> and females are [[Viviparity|viviparous]] (live bearing). Breeding occurs once per year with pregnancies lasting 4–5 months <ref>{{Citation |last=Cree |first=A |title=Reproduction and Life History of New Zealand Lizards |date=2016 |work=New Zealand Lizards |pages=169–206 |editor-last=Chapple |editor-first=David G. |url=https://doi.org/10.1007/978-3-319-41674-8_5 |access-date=2024-05-10 |place=Cham |publisher=Springer International Publishing |language=en |doi=10.1007/978-3-319-41674-8_5 |isbn=978-3-319-41674-8 |last2=Hare |first2=K. M.}}</ref> ending between February and March.<ref name=":0" /> The average clutch size (number of offspring produced) of 3.82 (+/-0.18).<ref name=":2">{{Cite journal |last=Spencer |first=N. J. |last2=Thomas |first2=B. W. |last3=Mason |first3=R. F. |last4=Dugdale |first4=J. S. |date=1998 |title=Diet and life history variation in the sympatric lizards ''Oligosoma nigriplantare polychroma'' and ''Oligosoma lineoocellatum'' |url=http://www.tandfonline.com/doi/abs/10.1080/03014223.1998.9518169 |journal=New Zealand Journal of Zoology |language=en |volume=25 |issue= |pages=457–463 |doi=10.1080/03014223.1998.9518169 |issn=0301-4223}}</ref> The mating system of the Canterbury spotted skink is widely unknown.<ref name=":3">{{Citation |last=Hare |first=K. M. |title=The Ecology of New Zealand’s Lizards |date=2016 |work=New Zealand Lizards |pages=133–168 |editor-last=Chapple |editor-first=D. G. |url=https://doi.org/10.1007/978-3-319-41674-8_6 |access-date=2024-05-10 |place=Cham |publisher=Springer International Publishing |language=en |doi=10.1007/978-3-319-41674-8_6 |isbn=978-3-319-41674-8 |last2=Chapple |first2=D. G. |last3=Towns |first3=D. R. |last4=van Winkel |first4=D}}</ref> Research has been done on ''[[Oligosoma grande]]''<ref>{{Cite book |last=Gray |first=J. E. |title=Catalogue of the Specimens of Lizards in the Collection of the British Museum |date=1845 |publisher=Edward Newman |location=London |pages=171}}</ref> where observations suggested mating was [[Polygyny|polygynous]] (one male with multiple females)<ref>{{Cite journal |last=Eifler |first=D. A. |last2=Eifler |first2=M. A. |date=1999 |title=Foraging behavior and spacing patterns of the lizard ''Oligosoma grande'' |url=https://www.jstor.org/stable/1565580 |journal=Journal of Herpetology |volume=33 |issue=4 |pages=632–639 |doi=10.2307/1565580 |issn=0022-1511}}</ref> However, genetic studies of this species found that over one breeding season, both males and females had more than one partner using a promiscuous mating system.<ref>{{Cite journal |last=Berry |first=O. F. |date=2006-06-01 |title=Inbreeding and promiscuity in the endangered grand skink |url=https://doi.org/10.1007/s10592-005-9054-0 |journal=Conservation Genetics |language=en |volume=7 |issue=3 |pages=427–437 |doi=10.1007/s10592-005-9054-0 |issn=1572-9737}}</ref>

Population modelling has been done on a population of the [[McCann's skink|McCann’s skink]] ''Oligosoma maccanni'',<ref>{{Cite journal |last=Patterson |first=G. B. |last2=Daugherty |first2=C.H. |date=1990 |title=Four new species and one new subspecies of skinks, genus ''Leiolopisma'' (Reptilia: Lacertilia: Scincidae) from New Zealand |url=http://www.tandfonline.com/doi/abs/10.1080/03036758.1990.10426733 |journal=Journal of the Royal Society of New Zealand |language=en |volume=20 |issue=1 |pages=65–84 |doi=10.1080/03036758.1990.10426733 |issn=0303-6758}}</ref> at [[Kaitorete Spit]] in Canterbury.<ref name=":5">{{Cite book |last=Lettink |first=M |title=Monitoring and restoration options for lizards on Kaitorete Spit, Canterbury |last2=Cree |first2=A |last3=Norbury |first3=G |last4=Seddon |first4=P. J. |publisher=Department of Conservation |year=2008 |isbn=9780478145007 |location=Wellington, New Zealand}}</ref> This study categorised the different life stages of the skink based on their snout-vent-length (SVL). [[McCann's skink|McCann’s skinks]] born within the same year have an SVL between 25-39mm, juveniles were between 40-48mm SVL, and adults had an SVL greater than 49mm, respectively.<ref>{{Cite journal |last=Freeman |first=A |date=1997 |title=The conservation status of a coastal duneland lizard fauna at Kaitorete Spit, Canterbury, New Zealand |url=https://www.researchgate.net/publication/271508492_The_conservation_status_of_a_coastal_duneland_lizard_fauna_at_Kaitorete_Spit_Canterbury_New_Zealand |journal=Herpetofauna |volume=27 |issue=1 |pages=25–30}}</ref><ref>{{Cite book |last=Lettink |first=M |title=Adding to Nature: Can Artificial Retreats be Used to Monitor and Restore Lizard Populations? |date=2007 |publisher=University of Otago |location=Dunedin, New Zealand |type=Unpublished PhD thesis}}</ref><ref name=":5" /> For ''O. lineoocellatum'', it has been assumed the age of maturity is 4 years, with a life expectancy of 10 years.<ref name=":4">{{Cite book |last=Hitchmough |first=R |title=Conservation status of New Zealand reptiles, 2021 |last2=Barr |first2=B |last3=Knox |first3=C |last4=Lettink |first4=M |last5=Monks |first5=J. M. |last6=Patterson |first6=G. B. |last7=Reardon |first7=J. T. |last8=Van Winkel |first8=D |last9=Rolfe |first9=J |last10=Michel |first10=P|publisher=Department of Conservation |year=2021 |isbn=978-1-7386283-0-8 |edition=New Zealand Threat Classification Series 35 |location=Wellington, New Zealand}}</ref> Monitored populations have shown an ongoing decline with a predicted decline of more than 70% over the next 10 years or three generations.<ref name=":4" />

==Diet, prey and predators==
Individuals of ''O. lineoocellatum'' display an active foraging behaviour meaning they are actively searching for prey instead of waiting for it to come to them.<ref>{{Cite web |last=Patterson |first=G. B. |date=1985 |title=The Ecology and taxonomy of the common skink ''Leiolopisma nigriplantare maccanni'' in tussock grasslands in Otago |url=https://ourarchive.otago.ac.nz/handle/10523/124}}</ref><ref>{{Cite book |last=Towns |first=D. R. |title=Biology of Australasian frogs and reptiles |last2=Daugherty |first2=C. H. |last3=Newman |first3=D. G. |publisher=Surrey Beatty, Chipping Norton, NSW, with Royal Zoological Society of NSW |year=1985 |isbn=9780949324030 |editor-last=Grigg |editor-first=G |location=Chipping Norton, New South Wales |pages=107–115 |chapter=An overview of the ecological biogeography of the New Zealand lizards (Gekkonidae, Scincidae) |editor-last2=Shine |editor-first2=R |editor-last3=Ehmann |editor-first3=H}}</ref><ref>{{Cite journal |last=East |first=K. T. |last2=East |first2=M. R. |last3=Daugherty |first3=C. H. |date=1995 |title=Ecological restoration and habitat relationships of reptiles on Stephens Island, New Zealand |url=http://www.tandfonline.com/doi/abs/10.1080/03014223.1995.9518040 |journal=New Zealand Journal of Zoology |language=en |volume=22 |issue=3 |pages=249–261 |doi=10.1080/03014223.1995.9518040 |issn=}}</ref><ref name=":2" /> The Canterbury spotted skink is [[Omnivore|omnivorous]] feeding on both plant and animal material.<ref name=":0" /> A study found [[Oligochaeta]] (earthworms), [[Beetle|Coleoptera]] (beetles), [[Hymenoptera]] (wasps and bees), [[Millipede|Diplopoda]] (millipedes) and [[Lepidoptera]] (butterflies and moths) were the highest sources of prey for ''O. lineoocellatum''.<ref name=":2" /> Seeds and fruit were also found in their diet, but were present in a lower percent of stomachs of the skinks surveyed.<ref name=":2" /> Other sources of food include nectar and smaller lizards including other Canterbury spotted skinks.<ref name=":0" /> Although ''O. lineoocellatum'' is [[Diurnality|diurnal]], the findings from the study show their main prey species are [[Nocturnality|nocturnal]] suggesting they may also forage at night.<ref name=":2" />

In New Zealand, 50 species have been recorded predating on lizards with 51% of these being birds.<ref name=":3" /> Introduced mammals such as rats, hedgehogs and cats are also major predators of lizards.<ref name=":3" />

Researchers have recorded multiple parasites on skinks within the spotted skink species complex.<ref name="Melzer2017" /> However, they have not yet determined exactly with which skink species each parasite is associated.<ref name="Melzer2017" /> These parasites recorded include [[Trematoda|trematodes]]: ''Dolichosaccus (Lecithopyge) leiolopismae'',<ref>{{Cite journal |last=Allison |first=B |last2=Blair |first2=D |date=1987 |title=The genus ''Dolichosaccus'' (Platyhelminthes: Digenea) from amphibians and reptiles in New Zealand, with a description of ''Dolichosaccus (Lecithopyge) leiolopismae'' n. sp. |url=https://www.tandfonline.com/doi/full/10.1080/03014223.1987.10423007 |journal=New Zealand Journal of Zoology |language=en |volume=14 |issue=3 |pages=367–374 |doi=10.1080/03014223.1987.10423007 |issn=0301-4223}}</ref> ''Paradisomum pacificus'', [[Cestoda|cestodes]]: ''Oochoristica novaezealandicae'', [[nematode]]s: ''Parathelandros'' sp.; ''Skrjabinodon trimorphi'' and [[protozoa]]ns: ''Haemogregarina'' sp.<ref name="Melzer2017" />

==Other information==
The Canterbury spotted skink is classified as “threatened- nationally critical” under the [[New Zealand Threat Classification System|New Zealand Threat Classification system]].<ref name=":4" /> Population estimates suggest there are between 1,000 – 5,000 mature individuals left and this is predicted to decline over three generations by 10-50%.<ref>{{Cite book |last=Hitchmough |first=R |title=Conservation status of New Zealand reptiles, 2015 |last2=Barr |first2=B |last3=Lettink |first3=M |last4=Monks |first4=J |last5=Reardon |first5=J |last6=Tocher |first6=M |last7=Van Winkel |first7=D |last8=Rolfe |first8=J |publisher=Department of Conservation |year=2016 |isbn=9781988514000 |edition=New Zealand Threat Classification Series 17 |location=Wellington, New Zealand}}</ref> The biggest threats to the Canterbury spotted skink are invasive mammalian predators and habitat loss due to land use change.<ref name="Melzer2017" />

New Zealand lizards are important seed dispersers and can assist with dispersal in areas where [[Frugivore|fruigivorous]] (feeding on fruit) birds are not present.<ref>{{Cite journal |last=Whitaker |first=A. H. |date=1987 |title=The roles of lizards in New Zealand plant reproductive strategies |url=http://www.tandfonline.com/doi/abs/10.1080/0028825X.1987.10410078 |journal=New Zealand Journal of Botany |language=en |volume=25 |issue=2 |pages=315–328 |doi=10.1080/0028825X.1987.10410078 |issn=0028-825X}}</ref><ref>{{Cite journal |last=Wotton |first=D. M. |last2=Drake |first2=D. R. |last3=Powlesland |first3=R. G. |last4=Ladley |first4=J. J. |date=2016 |title=The role of lizards as seed dispersers in New Zealand |url=http://www.tandfonline.com/doi/full/10.1080/03036758.2015.1108924 |journal=Journal of the Royal Society of New Zealand |language=en |volume=46 |issue=1 |pages=40–65 |doi=10.1080/03036758.2015.1108924 |issn=0303-6758}}</ref> Studies have also found that lizards can be effective [[pollinator]]s.<ref>{{Cite journal |last=Traveset |first=A |last2=Sáez |first2=E |date=1997 |title=Pollination of ''Euphorbia dendroides'' by lizards and insects: Spatio-temporal variation in patterns of flower visitation |url=http://link.springer.com/10.1007/PL00008816 |journal=Oecologia |language=en |volume=111 |issue=2 |pages=241–248 |doi=10.1007/PL00008816 |issn=0029-8549}}</ref><ref>{{Cite journal |last=Nyhagen |first=D. F. |last2=Kragelund |first2=C |last3=Olesen |first3=J. M. |last4=Jones |first4=C. G. |date=2001 |title=Insular interactions between lizards and flowers: flower visitation by an endemic Mauritian gecko |url=https://www.cambridge.org/core/product/identifier/S0266467401001560/type/journal_article |journal=Journal of Tropical Ecology |language=en |volume=17 |issue=5 |pages=755–761 |doi=10.1017/S0266467401001560 |issn=0266-4674}}</ref>


==References==
==References==
{{reflist}}
{{Reflist}}


{{Taxonbar|from=Q5087209}}
{{Taxonbar|from=Q5087209}}
Line 24: Line 59:
[[Category:Taxa named by Auguste Duméril]]
[[Category:Taxa named by Auguste Duméril]]
[[Category:Endemic reptiles of New Zealand]]
[[Category:Endemic reptiles of New Zealand]]


{{Lygosominae-stub}}

Latest revision as of 11:33, 3 October 2024

Canterbury spotted skink
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Squamata
Family: Scincidae
Genus: Oligosoma
Species:
O. lineoocellatum
Binomial name
Oligosoma lineoocellatum
Dumeril, 1851

Oligosoma lineoocellatum, commonly known as the Canterbury spotted skink, is one of a species complex of several related spotted skink species from New Zealand.[2]

Taxonomy

[edit]

The Canterbury spotted skink Oligosoma lineoocellatum [3] is one of a species complex of several related spotted skink species in New Zealand.[2]

The four species within this complex are the Canterbury spotted skink O. lineoocellatum sensu stricto, the Mackenzie skink Oligosoma prasinum,[2] the Marlborough spotted skink Oligosoma elium,[2] and the Northern spotted skink Oligosoma kokowai.[2]

These species are very morphologically similar; however, are distinguished by their differences in geographic distribution and genetic differences.[2]

Identification

[edit]

The Canterbury spotted skink is a large, eye-catching skink with a snout-vent length reaching up to 107mm.[4] Individuals typically have an olive-green, brown or brown-grey dorsal (upper side) surface with light and dark coloured spots (ocelli) which extend almost to the tail tip.[4][5] Some individuals have also been found to have light dorsolateral stripes stretching from above the eye to the beginning of the tail.[4][5] The lateral (side) surface exhibits a dark brown or brown-black lateral band with specks and white edges notched, extending from the front of the eyes to the tail tip.[4] A thin pale stripe runs beneath this, transitioning into intermittent patches of cream and dark brown on the lower side surface.[4][5] The ventral (underside) surface of the skink is grey in uniform, flushed with orange or pink, with a pale chin and throat covered in dark spots.[4][5] Individuals have dark brown eyes with an intact tail longer than the snout-vent length.[4] The Canterbury spotted skink has cream or grey soles on its feet with 21–25 subdigital lamellae (scales underneath fingers or toes).[4]

There are a several skinks that closely resemble the Canterbury spotted skink which can make it more challenging to identify them. The Mackenzie skink and Marlborough spotted skink are similar species; however, this is differentiated by the Canterbury spotted skink usually having more than 24 subdigital lamellae and the ocelli markings on the dorsal surface running down the tail.[4] The uniformly grey underside, the greater ratio of snout-vent length to head-width and the different geographic locations differentiate the Canterbury spotted skink from the Northern spotted skink.[4] Members of the Oligosoma chloronoton[6] species complex (green skinks) also appear similar to the Canterbury spotted skink; however, the Canterbury spotted skink usually has more than 22 subdigital lamellae compared to the green skinks and features fewer anterior subocular scales (below the eyes) of similar sizes.[4]

Geographic distribution and habitat

[edit]

The Canterbury spotted skink is an endemic species of skink only found in the Canterbury region of New Zealand.[4] This distribution spreads from Mount Grey in the north, Banks Peninsula in the east, and the Rangitata River in the south.[4][5] This species may also be seen further south in Canterbury.[4][5] O. lineoocellatum can be found in various environments including lowland, coastal, montane/subalpine and alpine.[4] These also vary in altitude from sea level up to 1400m.[7] In these environments, the Canterbury spotted skink has been found in a wide range of habitats. These are grasslands, rock piles, boulder and cobble beaches,[8][4][5] dune shrubland,[4][5] flaxland,[4][5] edges of forest [5] scree slopes, fellfields,[4][5] stony coasts and riverbeds,[4][5] herbfields,[5] and vinelands.[4]

Life cycle and phenology

[edit]

The Canterbury spotted skink is diurnal[4][5] meaning it is active during the day. It is also heliothermic (gains heat from the sun) so spends a lot of time basking in the sun.[4] Mating occurs at the beginning of autumn[9] and females are viviparous (live bearing). Breeding occurs once per year with pregnancies lasting 4–5 months [10] ending between February and March.[4] The average clutch size (number of offspring produced) of 3.82 (+/-0.18).[11] The mating system of the Canterbury spotted skink is widely unknown.[12] Research has been done on Oligosoma grande[13] where observations suggested mating was polygynous (one male with multiple females)[14] However, genetic studies of this species found that over one breeding season, both males and females had more than one partner using a promiscuous mating system.[15]

Population modelling has been done on a population of the McCann’s skink Oligosoma maccanni,[16] at Kaitorete Spit in Canterbury.[17] This study categorised the different life stages of the skink based on their snout-vent-length (SVL). McCann’s skinks born within the same year have an SVL between 25-39mm, juveniles were between 40-48mm SVL, and adults had an SVL greater than 49mm, respectively.[18][19][17] For O. lineoocellatum, it has been assumed the age of maturity is 4 years, with a life expectancy of 10 years.[20] Monitored populations have shown an ongoing decline with a predicted decline of more than 70% over the next 10 years or three generations.[20]

Diet, prey and predators

[edit]

Individuals of O. lineoocellatum display an active foraging behaviour meaning they are actively searching for prey instead of waiting for it to come to them.[21][22][23][11] The Canterbury spotted skink is omnivorous feeding on both plant and animal material.[4] A study found Oligochaeta (earthworms), Coleoptera (beetles), Hymenoptera (wasps and bees), Diplopoda (millipedes) and Lepidoptera (butterflies and moths) were the highest sources of prey for O. lineoocellatum.[11] Seeds and fruit were also found in their diet, but were present in a lower percent of stomachs of the skinks surveyed.[11] Other sources of food include nectar and smaller lizards including other Canterbury spotted skinks.[4] Although O. lineoocellatum is diurnal, the findings from the study show their main prey species are nocturnal suggesting they may also forage at night.[11]

In New Zealand, 50 species have been recorded predating on lizards with 51% of these being birds.[12] Introduced mammals such as rats, hedgehogs and cats are also major predators of lizards.[12]

Researchers have recorded multiple parasites on skinks within the spotted skink species complex.[2] However, they have not yet determined exactly with which skink species each parasite is associated.[2] These parasites recorded include trematodes: Dolichosaccus (Lecithopyge) leiolopismae,[24] Paradisomum pacificus, cestodes: Oochoristica novaezealandicae, nematodes: Parathelandros sp.; Skrjabinodon trimorphi and protozoans: Haemogregarina sp.[2]

Other information

[edit]

The Canterbury spotted skink is classified as “threatened- nationally critical” under the New Zealand Threat Classification system.[20] Population estimates suggest there are between 1,000 – 5,000 mature individuals left and this is predicted to decline over three generations by 10-50%.[25] The biggest threats to the Canterbury spotted skink are invasive mammalian predators and habitat loss due to land use change.[2]

New Zealand lizards are important seed dispersers and can assist with dispersal in areas where fruigivorous (feeding on fruit) birds are not present.[26][27] Studies have also found that lizards can be effective pollinators.[28][29]

References

[edit]
  1. ^ IUCN (2018-02-17). Oligosoma lineoocellatum: Hitchmough, R., van Winkel, D., Lettink, M. & Chapple, D.: The IUCN Red List of Threatened Species 2019: e.T120189599A120192619 (Report). International Union for Conservation of Nature. doi:10.2305/iucn.uk.2019-2.rlts.t120189599a120192619.en.
  2. ^ a b c d e f g h i j Melzer, S; Bell, T; Patterson, G. B. (3 August 2017). "Hidden conservation vulnerability within a cryptic species complex: taxonomic revision of the spotted skink (Oligosoma lineoocellatum; Reptilia: Scincidae) from New Zealand". Zootaxa. 4300 (3). doi:10.11646/zootaxa.4300.3.2.
  3. ^ Duméril, C; Duméril, A (1851). Catalogue methodique de la collection des reptiles. Paris: Gide and Baudry. p. 124.
  4. ^ a b c d e f g h i j k l m n o p q r s t u v w x y z Van Winkel, D; Baling, M; Hitchmough, R (2018). Reptiles and Amphibians of New Zealand: A Field Guide. Auckland, New Zealand: Auckland University Press. ISBN 9781869409371.
  5. ^ a b c d e f g h i j k l m n Purdie, S (2022). A Naturalist’s Guide to the Reptiles & Amphibians of New Zealand. Oxford, England: John Beaufoy Publishing. ISBN 9781913679316.
  6. ^ Hardy, G. S. (1977). "The New Zealand Scincidae (Reptilia: Lacertilia); a taxonomic and zoogeographic study". New Zealand Journal of Zoology. 4 (3): 221–325. doi:10.1080/03014223.1977.9517956. ISSN 0301-4223.
  7. ^ Mark, A. F. (2012). Above the Treeline: a Nature Guide to Alpine New Zealand. Nelson, New Zealand: Craig Potton Publishing. ISBN 9781877517761.
  8. ^ Jewell, T (2008). A Photographic Guide to Reptiles & Amphibians of New Zealand. Auckland, New Zealand: New Holland Publishers (NZ) Ltd. ISBN 9781869662035.
  9. ^ Molinia, F. C.; Bell, T; Norbury, G; Cree, A; Gleeson, D.M. (2010). "Assisted breeding of skinks or how to teach a lizard old tricks!" (PDF). Herpetological Conservation and Biology. 5 (2): 311–319.
  10. ^ Cree, A; Hare, K. M. (2016), Chapple, David G. (ed.), "Reproduction and Life History of New Zealand Lizards", New Zealand Lizards, Cham: Springer International Publishing, pp. 169–206, doi:10.1007/978-3-319-41674-8_5, ISBN 978-3-319-41674-8, retrieved 2024-05-10
  11. ^ a b c d e Spencer, N. J.; Thomas, B. W.; Mason, R. F.; Dugdale, J. S. (1998). "Diet and life history variation in the sympatric lizards Oligosoma nigriplantare polychroma and Oligosoma lineoocellatum". New Zealand Journal of Zoology. 25: 457–463. doi:10.1080/03014223.1998.9518169. ISSN 0301-4223.
  12. ^ a b c Hare, K. M.; Chapple, D. G.; Towns, D. R.; van Winkel, D (2016), Chapple, D. G. (ed.), "The Ecology of New Zealand's Lizards", New Zealand Lizards, Cham: Springer International Publishing, pp. 133–168, doi:10.1007/978-3-319-41674-8_6, ISBN 978-3-319-41674-8, retrieved 2024-05-10
  13. ^ Gray, J. E. (1845). Catalogue of the Specimens of Lizards in the Collection of the British Museum. London: Edward Newman. p. 171.
  14. ^ Eifler, D. A.; Eifler, M. A. (1999). "Foraging behavior and spacing patterns of the lizard Oligosoma grande". Journal of Herpetology. 33 (4): 632–639. doi:10.2307/1565580. ISSN 0022-1511.
  15. ^ Berry, O. F. (2006-06-01). "Inbreeding and promiscuity in the endangered grand skink". Conservation Genetics. 7 (3): 427–437. doi:10.1007/s10592-005-9054-0. ISSN 1572-9737.
  16. ^ Patterson, G. B.; Daugherty, C.H. (1990). "Four new species and one new subspecies of skinks, genus Leiolopisma (Reptilia: Lacertilia: Scincidae) from New Zealand". Journal of the Royal Society of New Zealand. 20 (1): 65–84. doi:10.1080/03036758.1990.10426733. ISSN 0303-6758.
  17. ^ a b Lettink, M; Cree, A; Norbury, G; Seddon, P. J. (2008). Monitoring and restoration options for lizards on Kaitorete Spit, Canterbury. Wellington, New Zealand: Department of Conservation. ISBN 9780478145007.
  18. ^ Freeman, A (1997). "The conservation status of a coastal duneland lizard fauna at Kaitorete Spit, Canterbury, New Zealand". Herpetofauna. 27 (1): 25–30.
  19. ^ Lettink, M (2007). Adding to Nature: Can Artificial Retreats be Used to Monitor and Restore Lizard Populations? (Unpublished PhD thesis). Dunedin, New Zealand: University of Otago.
  20. ^ a b c Hitchmough, R; Barr, B; Knox, C; Lettink, M; Monks, J. M.; Patterson, G. B.; Reardon, J. T.; Van Winkel, D; Rolfe, J; Michel, P (2021). Conservation status of New Zealand reptiles, 2021 (New Zealand Threat Classification Series 35 ed.). Wellington, New Zealand: Department of Conservation. ISBN 978-1-7386283-0-8.
  21. ^ Patterson, G. B. (1985). "The Ecology and taxonomy of the common skink Leiolopisma nigriplantare maccanni in tussock grasslands in Otago".
  22. ^ Towns, D. R.; Daugherty, C. H.; Newman, D. G. (1985). "An overview of the ecological biogeography of the New Zealand lizards (Gekkonidae, Scincidae)". In Grigg, G; Shine, R; Ehmann, H (eds.). Biology of Australasian frogs and reptiles. Chipping Norton, New South Wales: Surrey Beatty, Chipping Norton, NSW, with Royal Zoological Society of NSW. pp. 107–115. ISBN 9780949324030.
  23. ^ East, K. T.; East, M. R.; Daugherty, C. H. (1995). "Ecological restoration and habitat relationships of reptiles on Stephens Island, New Zealand". New Zealand Journal of Zoology. 22 (3): 249–261. doi:10.1080/03014223.1995.9518040.
  24. ^ Allison, B; Blair, D (1987). "The genus Dolichosaccus (Platyhelminthes: Digenea) from amphibians and reptiles in New Zealand, with a description of Dolichosaccus (Lecithopyge) leiolopismae n. sp". New Zealand Journal of Zoology. 14 (3): 367–374. doi:10.1080/03014223.1987.10423007. ISSN 0301-4223.
  25. ^ Hitchmough, R; Barr, B; Lettink, M; Monks, J; Reardon, J; Tocher, M; Van Winkel, D; Rolfe, J (2016). Conservation status of New Zealand reptiles, 2015 (New Zealand Threat Classification Series 17 ed.). Wellington, New Zealand: Department of Conservation. ISBN 9781988514000.
  26. ^ Whitaker, A. H. (1987). "The roles of lizards in New Zealand plant reproductive strategies". New Zealand Journal of Botany. 25 (2): 315–328. doi:10.1080/0028825X.1987.10410078. ISSN 0028-825X.
  27. ^ Wotton, D. M.; Drake, D. R.; Powlesland, R. G.; Ladley, J. J. (2016). "The role of lizards as seed dispersers in New Zealand". Journal of the Royal Society of New Zealand. 46 (1): 40–65. doi:10.1080/03036758.2015.1108924. ISSN 0303-6758.
  28. ^ Traveset, A; Sáez, E (1997). "Pollination of Euphorbia dendroides by lizards and insects: Spatio-temporal variation in patterns of flower visitation". Oecologia. 111 (2): 241–248. doi:10.1007/PL00008816. ISSN 0029-8549.
  29. ^ Nyhagen, D. F.; Kragelund, C; Olesen, J. M.; Jones, C. G. (2001). "Insular interactions between lizards and flowers: flower visitation by an endemic Mauritian gecko". Journal of Tropical Ecology. 17 (5): 755–761. doi:10.1017/S0266467401001560. ISSN 0266-4674.
Retrieved from "https://en.wikipedia.org/w/index.php?title=Canterbury_spotted_skink&oldid=1249137610"