Improving search strategies for the cryptic New Zealand striped skink (

The striped skink (Oligosoma striatum) is a poorly known New Zealand endemic species rarely seen in the wild despite ongoing efforts to locate specimens. It is uncertain whether its threatened status is due to low numbers, or to unusual habitat use and activity patterns that make it difficult to detect. Anecdotal reports indicate the species may be partly arboreal. We carried out captive-based behavioural comparisons between striped skinks and the common terrestrial brown skink (Oligosoma zelandicum). Brown skinks are of similar mass to striped skinks and overlap in geographic range and habitat, but are easily captured by hand and pitfall trapping in the wild. They were therefore a suitable comparison from which to assess activity levels and arboreal tendencies in striped skinks, with the aim of improving survey methods. Point samples and total frequencies of behaviours were collected using time-lapse video recordings taken concurrently of individuals of each species occupying identical enclosures. Striped skinks had significantly higher levels of diurnal activity than brown skinks. They also showed periods of nocturnal activity associated with high moisture levels. When active, the types of behaviours carried out by each species were very similar, as were the proportions of active time spent carrying out each behaviour. Striped skinks spent significantly longer periods at greater heights within the enclosure than brown skinks, indicating stronger arboreal tendencies. High levels of arboreal activity and in particular nocturnal activity may make striped skinks more vulnerable to introduced predators such as rodents and possums. In order to accurately assess the status and carry out long-term monitoring of the striped skink, new survey and capture techniques will be required. Arboreal traps, visual canopy surveys and surveying felled trees are recommended.     

Habitat use by chevron skinks (

Habitat use of the endangered chevron skink (Oligosoma homalonotum) was investigated between 1997 and 2002 at three sites on Great Barrier Island, New Zealand. Habitat preferences were determined by pitfall trapping and radio-tracking studies, and a comparison of catchments with and without chevron skinks. Over the course of the research, 88 skinks were encountered. Significantly more skinks were caught in pitfall traps set in stream habitat than in alluvial terrace, boulder bank or ridge habitat. Eight chevron skinks were radio-tracked for periods between three and eight days, and 118 fixes were taken from 55 different retreat sites. When compared with randomly selected sites, chevron skinks were more likely to be found at sites that had crevices, debris dams and trees than those that did not. The further a site was away from the stream edge, the less likely it was to be a chevron skink retreat site. Chevron skinks were more likely to be found in catchments with narrow streams with rocky, as opposed to silty, substrates. We recommend that future management of chevron skinks incorporate sites that contain mature forest and rocky streams. While forest habitats on Great Barrier Island appear to be increasing in area, chevron skinks may still be declining due to the effects of introduced predators.     

Ectoparasite and hemoparasite infection in a diverse temperate lizard assemblage at Macraes Flat, South Island, New Zealand

A lizard assemblage at Macraes Flat, New Zealand, comprising the common skinks Oligosoma maccanni and Oligosoma nigriplantare polychroma, the endangered species Oligosoma grande and Oligosoma otagense, and the common gecko Hoplodactylus maculatus, was studied to determine the prevalence of ectoparasites and hemoparasites. The mites Odontacarus lygosomae and Ophionyssus scincorum infected all Oligosoma spp. only, and the mite Neotrombicula naultini infected only H. maculatus. The hemoparasite Hepatozoon lygosomarum infected all Oligosoma skinks, except O. n. polychroma. Oligosoma otagense had the highest infection levels of all parasites by several orders of magnitude. For all lizard species, there was no difference in mite prevalence between adult males and adult females, but juveniles were less often infected. For all skink species, there was a significant relationship between presence of the hemoparasite He. lygosomarum and infection intensity of the supposed vector, O. scincorum. It is unclear if patterns of parasite infection reflect species-specific susceptibility, host-parasite species-specific spatial ecology, or environmentally induced host physiological impairment. Considering the threatened nature of O. otagense, evidence of high parasitemia should stimulate further investigation.     

Accuracy and precision of skink counts from artificial retreats

Index counts are commonly used to detect spatial and temporal changes in the size of wildlife populations. For indices to be valid there must be a constant (usually linear) relationship between the index and population size. In a study conducted in the Eglinton Valley (Fiordland, South Island, New Zealand), single-day index counts of common skinks (Oligosoma polychroma) from artificial retreats were compared with capture?mark?recapture (CMR) estimates of population size (N?) obtained by pitfall trapping. Generalised linear models revealed that skink counts from artificial retreats provided a reasonably accurate (P??1, which was high compared with other common skink populations. We recommend: (1) long-term monitoring of common skinks in the Eglinton Valley, using the index method described herein; (2) calibration of index counts against population size estimates collected from other habitats and species.     

Short-term success of a translocation of Otago skinks (Oligosoma otagense) to Orokonui Ecosanctuary

Natural habitat is not always available for translocations due to habitat modification or pressure from introduced predators. We followed the release of 30 captive-bred Otago skinks (Oligosoma otagense) into a 109?m² outdoor enclosure of artificial habitat at Orokonui Ecosanctuary in southeastern New Zealand. We evaluated the short-term success of the translocation by assessing visibility and survival of the skinks over the 3 summer months following release in spring 2013, plus survival the following spring. Skinks were visible most days, especially in warm, dry conditions. Survival was high over the first summer; 80% of skinks were seen at least once during February 2014. The following spring 63% of skinks were resighted during three surveys and breeding has since been reported. Thus, it is feasible to maintain captive-bred adults of this Nationally Endangered skink in artificially constructed, outdoor habitat in a coastal location. However, to avoid predation of juveniles by adult skinks, future translocations should avoid releasing juveniles close to adults.     

Molecular phylogeny of the scincid lizards of New Caledonia and adjacent areas: evidence for a single origin of the endemic skinks of Tasmantis

We use approximately 1900bp of mitochondrial (ND2) and nuclear (c-mos and Rag-1) DNA sequence data to recover phylogenetic relationships among 58 species and 26 genera of Eugongylus group scincid lizards from New Caledonia, Lord Howe Island, New Zealand, Australia and New Guinea. Taxon sampling for New Caledonian forms was nearly complete. We find that the endemic skink genera occurring on New Caledonia, New Zealand and Lord Howe Island, which make up the Gondwanan continental block Tasmantis, form a monophyletic group. Within this group New Zealand and New Zealand+Lord Howe Island form monophyletic clades. These clades are nested within the radiation of skinks in New Caledonia. All of the New Caledonian genera are monophyletic, except Lioscincus. The Australian and New Guinean species form a largely unresolved polytomy with the Tasmantis clade. New Caledonian representatives of the more widespread genera Emoia and Cryptoblepharus are more closely related to the non-Tasmantis taxa than to the endemic New Caledonian genera. Using ND2 sequences and the calibration estimated for the agamid Laudakia, we estimate that the diversification of the Tasmantis lineage began at least 12.7 million years ago. However, using combined ND2 and c-mos data and the calibration estimated for pygopod lizards suggests the lineage is 35.4-40.74 million years old. Our results support the hypothesis that skinks colonized Tasmantis by over-water dispersal initially to New Caledonia, then to Lord Howe Island, and finally to New Zealand.     

A significant range extension and sanctuary for the rare Open Bay Island skink (Oligosoma taumakae)

Abstract

The Open Bay Island skink (Oligosoma taumakae) is one of New Zealand's rarest lizard species. Until 2010, it was known only from two small islands in the Open Bay Island Group, a Māori-owned wildlife sanctuary in South Westland, New Zealand. Skinks on these islands are threatened by predation from weka (Gallirallus australis), a flightless native rail thought to have been introduced to the Open Bay Islands c. 100 years ago. Here, we describe the discovery of Open Bay Island skinks on two vegetated rock stacks located off the coast of Barn Bay, 52 km southwest of the Open Bay Islands. Although small (c. 0.10 and 0.36 ha), the Barn Islands appear to be predator-free, providing an important sanctuary for the skinks. We recommend: (1) a survey of mainland sites with suitable habitat; and (2) an evaluation of the need for island biosecurity measures for detecting and responding to incursions of small mammals.     

A SINE of restricted gene flow across the Alpine Fault: phylogeography of the New Zealand common skink (Oligosoma nigriplantare polychroma)

New Zealand has experienced a complex climatic and geological history since the Pliocene. Thus, identifying the processes most important in having driven the evolution of New Zealand's biota has proven difficult. Here we examine the phylogeography of the New Zealand common skink ( Oligosoma nigriplantare polychroma ) which is distributed throughout much of New Zealand and crosses many putative biogeographical boundaries. Using mitochondrial DNA sequence data, we revealed five geographically distinct lineages that are highly differentiated (pairwise Φ_ST 0.54–0.80). The phylogeographical pattern and inferred age of the lineages suggests Pliocene mountain building along active fault lines promoted their divergence 3.98–5.45 million years ago. A short interspersed nuclear element (SINE) polymorphism in the myosin gene intron ( MYH-2 ) confirmed a pattern of restricted gene flow between lineages on either side of the mountain ranges associated with the Alpine Fault that runs southwest to northeast across the South Island of New Zealand. An analysis of molecular variance confirmed that ~40% of the genetic differentiation in O. n. polychroma is distributed across this major fault line. The straits between the main islands of New Zealand accounted for much less of the variation found within O. n. polychroma , most likely due to the repeated existence of landbridges between islands during periods of the Pleistocene that allowed migration. Overall, our findings reveal the relative roles of different climatic and geological processes, and in particular, demonstrate the importance of the Alpine Fault in the evolution of New Zealand's biota.     

Effects of habitat structure on distribution and abundance of lizards at Pukerua bay, Wellington, New Zealand

The distribution and abundance of lizards relative to habitat structure were studied at Pukerua Bay, Wellington between December 1982 and March 1988 in order to identify options for management of the habitat of the five species of lizards present. One species, Whitaker's skink (Cyclodina whitakeri), is a threatened species with only one known mainland population. Pitfall traps were set for 23 667 trap-days and yielded 2897 lizard captures. Highest capture rate was for common skinks (Oligosoma nigriplantare polychroma) and lowest rate was for C. whitakeri. Of the five lizard species at Pukerua Bay, C. whitakeri had the narrowest habitat range and was most sensitive to temperature extremes. These features, combined with predation, and habitat disturbance and degradation, have resulted in critically low numbers of C. whitakeri. Assessment of management options to lessen the threats to C. whitakeri concluded that risks from disturbance, predation and fire could best be minimised through a managed revegetation programme.     

Community-wide character displacement in New Zealand skinks

Aim  To test for community-wide character displacement in New Zealand skinks.
Location  Four small islands in the New Zealand archipelago.
Methods  (1) We conducted a field experiment on a single island to evaluate whether prey size selection is correlated with lizard body size. We pitfall trapped 69 skinks from three species, measured several aspects of their morphology and presented each animal with a variety of different-sized prey in a food choice experiment. (2) We tested whether the morphological characteristics associated with prey size selection were evenly partitioned in four island skink communities using null models.
Results  Prey size selection was associated with skink morphology; larger skinks consumed larger prey. Null model analyses showed support for evenly displaced body sizes on one island, weak support on one island and no support on two islands.
Main conclusions  Results showed mixed support for community-wide character displacement in New Zealand skinks. Differences in body sizes appear to reflect the use of different-sized prey. Even differentiation in body sizes on one island suggests that species coexistence is facilitated by interspecific differences in prey size selection. However, little support was found on other islands, suggesting that other factors, such as interspecific differences in habitat selection and/or diurnal activity patterns, may interact with differences in prey size selection to promote coexistence among New Zealand skinks.     

Skink predation by hedgehogs at Macraes Flat, Otago, New?Zealand

The stomach contents of 158 hedgehogs captured at Macraes Flat, Otago, New Zealand, over two summers in 2000 and 2001 were examined for the occurrence of lizards. The remains of at least 43 skinks (both Oligosoma nigriplantare polychroma and O.?maccanni) and one gecko (Hoplodactylus sp.) were found. Twenty-one percent (n?=?33; 8 males and 25 females) of the examined hedgehogs had fed on skinks. Female hedgehogs ate significantly more skinks than did males. Our results suggest that the presence of large numbers of hedgehogs can have a high impact on native reptile populations in New Zealand and therefore they should be targeted in future trapping programmes.     

Lizards in the suburbs: a single-garden study of a small endemic New Zealand skink (Oligosoma aeneum)

Detailed investigations of ecology and life history of lizards in New Zealand/Aotearoa are needed to inform their conservation and management. An early demographic study of copper skinks (Oligosoma aeneum) in a suburban garden was undertaken in Lower Hutt using mark–recapture methods, sampling weekly from March 1971 to December 1973. Oligosoma aeneum were seen on 1372 occasions, with 972 captures of 169 individuals. The maximum snout–vent length was 66 mm, 33% of skinks had complete tails, and colour differences suggested sexual signalling and warrant further study. Most captures occurred over November–March, with fewest over June–August. The estimated spring/summer population size in the garden (± SEM) was 83.6 (± 9.4) skinks, and the annual survival rate (± SEM) was 38.0% (± 16.0%). This is one of the few New Zealand lizard studies that have extended through all months of the year and it adds to limited information on lizard populations in suburban areas.     

DID TECTONIC ACTIVITY STIMULATE OLIGO–MIOCENE SPECIATION IN THE INDO‐WEST PACIFIC?

Analyses of molecular phylogenies of three unrelated tropical marine gastropod genera, Turbo, Echinolittorina , and Conus , reveal an increase in the rate of cladogenesis of some Indo-West Pacific (IWP) clades beginning in the Late Oligocene or Early Miocene between 23.7 and 21.0 million years ago. In all three genera, clades with an increased rate of diversification reach a maximum of diversity, in terms of species richness, in the central IWP. Congruence in both the geographical location and the narrow interval of timing suggests a common cause. The collision of the Australia and New Guinea plate with the southeast extremity of the Eurasian plate approximately 25 Mya resulted in geological changes to the central IWP, including an increase in shallow-water areas and length of coastline, and the creation of a mosaic of distinct habitats. This was followed by a period of rapid diversification of zooxanthellate corals between 20 and 25 Mya. The findings reported here provide the first molecular evidence from multiple groups that part of the present-day diversity of shallow-water gastropods in the IWP arose from a rapid pulse of speciation when new habitats became available in the Late Oligocene to Early Miocene. After the new habitats were filled, the rate of speciation likely decreased and this combined with high levels of extinction (in some groups), resulted in a slow down in the rate of diversification in the genera examined.     

After the deluge: mitochondrial DNA indicates Miocene radiation and Pliocene adaptation of tree and giant weta (Orthoptera: Anostostomatidae)

Aim New Zealand broke away from the margins of Gondwana c. 75 Ma. Since then, New Zealand taxa derived from the Gondwanan biota are thought to have been exposed first to a subtropical climate on a low lying terrain, then severe land reduction during the Oligocene marine transgression, followed by much cooler climates of the Pliocene and Pleistocene, at which time mountain ranges emerged. The biological consequence of New Zealand's geological and climatic history is not well understood, in particular the extent to which the Oligocene acted as a biological bottleneck remains unresolved. Methods We used mitochondrial cytochrome oxidase I and 12S DNA sequences to examine the extent of diversity and inferred timing of speciation of New Zealand weta (Anostostomatidae), a group of Orthoptera with a Gondwanan distribution generally thought to be ancient inhabitants of New Zealand. Main conclusions We hypothesize that at least three distinct groups of weta survived the Oligocene marine transgression and radiated subsequently. Speciation followed during the Miocene and radiation into new habitats occurred during the Pliocene when mountain building created novel environments. Patterns of genetic diversity within species reflect, in some instances, geographical subdivision in the Pliocene, and in other cases, Pleistocene range changes resulting from climate change.     

Dispersal and speciation of skinks among archipelagos in the tropical Pacific Ocean

Summary We examined the potential effects of geography on the distribution and speciation of skinks on tropical Pacific archipelagos. The entire tropical Pacific skink fauna was divided into continental (found also in continental areas), Pacific (endemic to the study area but found within more than one archipelago) and endemic (found within only one archipelago) species categories. The number and proportion of skinks within each species category were determined for each of the 27 archipelagos in the study area. Nine geographic variables reflecting archipelago size, isolation and elevation were estimated for each archipelago. Principal components analysis was used to reduce the nine variables to three uncorrelated composite variables that were interpreted as representing archipelago size, isolation and elevation. Numbers and proportions of skinks in each category within an archipelago were related to the composite geographic variables using multiple linear regression analysis. Archipelago size and isolation were important predictors of both skink diversity and endemism. Results were then compared to diversity and endemism of birds within the study area. Skinks showed an archipelago-wide level of endemism similar to that of birds. On an archipelago by archipelago basis, however, large differences between birds and skinks were evident. In particular, the New Caledonia skink fauna was much more endemic than that of birds. The bird faunas of Hawaii and the Marquesas were nearly completely endemic, while no endemic skinks occurred in these two archipelagos. These differences presumably reflect the relative dispersal powers of skinks and birds and, consequently, rates of colonization and speciation. Differences may also be due partly to morphological conservatism among isolated skink populations and the occurrence of cryptic species that have not yet been identified as separate species. The discovery of such cryptic species, however, is unlikely to increase the endemic skink fauna of Hawaii and other distant archipelagos to a level commensurate with that of birds. Differences in endemism between skinks and birds may also be due to unknown local ecological interactions.     

Maternal and environmental influences on reproductive success of a viviparous grassland lizard

Understanding the factors that drive population persistence and growth is fundamental to both conservation management and evolutionary biology. Internal (maternal) and external (environmental) factors can affect female reproductive output, and in oviparous reptiles both may strongly influence offspring phenotype and quality. However, the link between these effects, their importance for reproductive output and offspring characteristics of live-bearing lizards, and whether population declines are linked to these factors in modified versus native habitats are unknown. We used a common New Zealand skink species, Oligosoma maccanni (McCann?s skink), found in grazed native and exotic grassland to test whether differences in environmental or maternal characteristics influenced birth date, pregnancy success and offspring phenotype. In both grassland types the date of birth was c. 8 days earlier at lower altitudes (altitudinal range = 564?719 m a.s.l), and small females were less likely to have successful pregnancies. However, larger females had more weak or deformed offspring, suggesting that reproductive senescence may exist in this species. While other research shows that exotic grasslands do not support as many skinks as native tussock grassland, reproductive success of pregnant skinks (viable litter size) was not affected by habitat modification. However, neonates had greater body condition (mass for length) when from females with higher post-partum body condition, and these females were from the native tussock grasslands. In conjunction with previously published data on McCann?s skink, our data suggest that reduced offspring quality may contribute to the lower population numbers in the exotic habitats.     

Genetic diversity and gene flow in a rare New Zealand skink despite fragmented habitat in a volcanic landscape

Anthropogenic habitat fragmentation often restricts gene flow and results in small populations that are at risk of inbreeding. However, some endangered species naturally occupy patchy habitat where local population extinction and recolonization are normal. We investigated population fragmentation in the range‐restricted New Zealand small‐scaled skink (Oligosoma microlepis), documenting changes in habitat occupancy and analyzing mitochondrial, microsatellite, and morphological variation sampled across the geographical range of the species (approximately 100 km²). Small‐scaled skinks have a strong preference for rocky outcrops that exist in a mosaic of other habitat types. A metapopulation structure was indicated by both local extinction and colonization of new sites. We found relatively high mtDNA nucleotide site diversity within this narrow range (π = 0.004; 16S), evidence of inter‐patch gene flow, and no statistical support for inbreeding. Gene flow was limited by geographical distance, although the existence of pasture between habitat patches apparently has not prevented skink dispersal. Generalized linear models indicated an association between body size and location suggesting a local environmental influence on phenotype. Prior to human‐induced habitat modification, native forest probably separated preferred sites and, less than 2000 years ago, volcanic activity devastated much of the area currently occupied by O. microlepis. This skink appears able to re‐establish populations if other human‐linked factors such as agricultural intensification and introduced predators are limited. Although in contrast to expectations for a scarce and localized species living in a highly modified landscape, this lizard may have previously adapted to a dynamic, mosaic environment mediated by volcanism.     

Phylogeny and taxonomy of casebearer moths (Lepidoptera,Coleophoridae) based on morphological and molecular genetic data. 2. Reconstruction of divergence time for major taxa of Coleophoridae based on <Emphasis Type="Italic">COI</Emphasis> gene variability

Reconstruction of divergence time for major taxa of the family Coleophoridae showed casebearer moths to be evolutionarily young, probably due to the formation of the first taxa of the family in a specific environment of grassland ecosystems during the Eocene–Oligocene. Analysis of evolutionary divergence of species indicated that the ancestors of modern taxa of the subfamily Coleophorinae lived in the early Oligocene and were probably associated with herbaceous plants of the families Amaranthaceae, Fabaceae, and Asteraceae. In general, the most active speciation among casebearer moths occurred in the late Miocene, possibly due to the increasing diversity of habitats and active changes of woody and herbaceous plant formations in the Ancient Mediterranean during that historical period.     

The fossil history of palms (Arecaceae) in Africa and new records from the Late Oligocene (28–27 Mya) of north-western Ethiopia

The African palm fossil record is limited but the data provide an outline of palm evolution from the Late Cretaceous through the Neogene. Pollen attributed to palms is reported from the Aptian (125–112 Mya), but the earliest unequivocal record in Africa is Campanian (83.5–70.6 Mya). Palms diversified 83.5–65.5 Mya and became widespread, although most records are from the west and north African coasts. Many taxa were shared between Africa and northern South America at that time, but a few were pantropical. Extirpations occurred throughout the Palaeogene, including a notable species turnover and decline at the Eocene–Oligocene boundary (33.9 Mya), a change that resulted in the elimination of nypoid palms from Africa. The Neogene plant macrofossil record is better sampled than the Palaeogene, although few palms are documented. Thus, the low diversity of African palms today is more likely the result of Palaeogene, rather than Neogene extinctions. Newly discovered palm fossils of leaves, petioles and flowers from the Late Oligocene (27–28 Mya) of north-western Ethiopia document the abundance and dominance of palms in some communities at that time. The fossils represent the earliest records of the extant genera Hyphaene (Coryphoideae) and Eremospatha (Calamoideae).  © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 151 , 69–81.     

Origin and post-colonization evolution of the Chatham Islands skink (Oligosoma nigriplantare nigriplantare)

Island ecosystems provide an opportunity to examine a range of evolutionary and ecological processes. The Chatham Islands are an isolated archipelago situated approximately 800 km east of New Zealand. Geological evidence indicates that the Chatham Islands re-emerged within the last 1-4 million years, following a prolonged period of marine inundation, and therefore the resident flora and fauna is the result of long-distance overwater dispersal. We examine the origin and post-colonization evolution of the Chatham Islands skink, Oligosoma nigriplantare nigriplantare, the sole reptile species occurring on the archipelago. We sampled O. n. nigriplantare from across nine islands within the Chatham Islands group, and representative samples from across the range of its closest relative, the New Zealand mainland common skink (Oligosoma nigriplantare polychroma). Our mitochondrial sequence data indicate that O. n. nigriplantare diverged from O. n. polychroma 5.86-7.29 million years ago. This pre-dates the emergence date for the Chatham Islands, but indicates that O. n. nigriplantare colonized the Chatham Islands via overwater dispersal on a single occasion. Despite the substantial morphological variability evident in O. n. nigriplantare, only relatively shallow genetic divergences (maximum divergence approximately 2%) were found across the Chatham Islands. Our analyses (haplotypic diversity, Phi(ST), analysis of molecular variance, and nested clade phylogeographical analysis) indicated restricted gene flow in O. n. nigriplantare resulting in strong differentiation between islands. However, the restrictions to gene flow might have only arisen recently as there was also a significant pattern of isolation by distance, possibly from when the Chatham Islands were a single landmass during Pleistocene glacial maxima when sea levels were lower. The level of genetic and morphological divergence between O. n. nigriplantare and O. n. polychroma might warrant their recognition as distinct species.