Genetic variation in three species in the Lampropholis delicata (Lacertilia: Scincidae) complex

The Lampropholis delicata complex consists of three closely related species, which have very different habitat requirements and geographic distributions. Percentage polymorphism and average heterozygosity per population are lowest in the species with the narrowest habitat requirements. Genetic differentiation between populations is also lowest in this species, which had a very limited and almost continuous distribution. For one species, which occurs in a very wide range of habitats, both natural and disturbed, genetic variability is compared between samples from disturbed and undisturbed habitats. Average heterozygosity is significantly lower in samples from disturbed than in those from undisturbed sites.     

Investigating the origin of transoceanic distributions: Mtdna shows Mabuya lizards (Reptilia,Scincidae) crossed the Atlantic twice

Phylogenies with even a rough time scale can be used to investigate the history of non‐volant taxa with disjunct distributions in widely separated land areas that were once connected. Basic methods for doing this are discussed. A partial phylogeny of Mabuya based on mtDNA (305 bp cytochrome b, 379 bp 12S rRNA and 388 bp 16S rRNA) is used to show that this genus invaded tropical America from Africa twice in the last 9 Myr, once reaching the American mainland and once the oceanic island of Fernando de Noronha, two journeys each of at least 3000 km. In general, phylogenetic evidence for multiple invasions is less equivocal than that suggesting a single invasion, which is more prone to sampling artefacts. Two alternative hypotheses explaining the presence of Mabuya in both Africa and tropical America are refuted on the basis of molecular clock considerations, namely that the occurrence of Mabuya in these continents pre‐dated their separation over 100 My ago and that it was introduced from one continent to the other by human activities. Like several other lizard groups that have made successful long‐distance transmarine colonizations, Mabuya has done this on many occasions. Phylogenetic results are also compatible with a SE Asian or Australasian origin of Mabuya followed by westward expansion.     

Fragmented landscapes, habitat specificity, and conservation genetics of three lizards in Florida scrub

Dry, sandy scrub habitats of the Floridapeninsula represent naturally fragmentedremnants of xeric ecosystems that werewidespread during the Pliocene and earlyPleistocene. This habitat is characterized byhigh endemism, and distribution of genetic andevolutionary diversity among scrub ``islands' isof compelling interest because Florida scrub israpidly disappearing under human development. We compare range-wide diversity inmitochondrial cytochrome b sequences forthree scrub-associated lizards with contrastinglevels of habitat specificity. All speciesshow strong geographic partitioning of geneticdiversity, supporting the hypothesis that scrubfauna is highly restricted by vicariantseparations. The mole skink (Eumecesegregius), the least habitat specific, has thelowest phylogeographic structure among thelizards (_st = 0.631). The mtDNAgeneology for E. egregius is not entirelyconcordant with the five recognized subspeciesand supports a link between populations incentral Florida (E. e. lividus) and theFlorida Keys (E.e. egregius) rather thana previously proposed affiliation betweennorthern and southern populations. The Floridascrub lizard (Sceloporus woodi) is themost habitat specific of the lizards and hasthe strongest phylogeographic structure (_st = 0.876). The sand skink (Neosepsreynoldsi) falls between the moleskink and scrub lizard in terms of habitatspecificity and phylogeographic structure (_st = 0.667). For all three species,networks of mtDNA haplotypes coalesce on twocentral ridges that contain the oldest scrub. The geographic structure and deep evolutionarylineages observed in these species have strongimplications for conservation, includingstrategies for translocation, reserve design,and management of landscape connectivity.     

Highly polymorphic microsatellite loci for the Gran Canarian skink (Chalcides sexlineatus) and their applicability in other Canarian Chalcides

The scincid lizard Chalcides sexlineatus is endemic to the island of Gran Canaria, within which it shows a pronounced phylogeographical pattern. Understanding the maintenance of this pattern requires knowledge of nuclear DNA structuring. Eleven polymorphic tetranucleotide microsatellite loci were isolated from a library constructed from genomic DNA enriched for AAAG repeat sequence. The number of alleles per locus ranged from 12 to 19, and expected heterozygosities spanned from 0.738 to 0.933 (n = 30). The majority of these could be cross‐amplified in other endemic Canarian Chalcides. The loci will be used to investigate gene flow between the principal mitochondrial clades within C. sexlineatus.     

Sex,androgens, and whole‐organism performance in an Australian lizard

Understanding underlying physiological differences between the sexes in circulating androgens and how hormonal variation affects morphology–performance relationships may help clarify the evolution of sexual dimorphism in diverse taxa. Using a widely distributed Australian lizard (Eulamprus quoyii) with weak sexual dimorphism and no dichromatism, we tested whether circulating androgens differed between the sexes and whether they covaried with morphological and performance traits (bite force, sprint speed, endurance). Males had larger head dimensions, stronger bite force, faster sprint speed, and longer endurance compared to females. We found that the sexes did not differ in androgen concentrations and that androgens were weakly associated with both morphological and performance traits. Interestingly, high circulating androgens showed a nonlinear relationship with bite force in males and not females, with this relationship possibly being related to alternative male reproductive tactics. Our results suggest that androgens are not strongly correlated with most performance and morphological traits, although they may play an important organizational role during the development of morphological traits, which could explain the differences in morphology and thus performance between the sexes. Differences in performance between the sexes suggest differential selection on these functional traits between males and females. © 2014 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 111, 834–849.     

Extinct,obscure or imaginary: The lizard species with the smallest ranges

Aim

Small geographic ranges make species especially prone to extinction from anthropogenic disturbances or natural stochastic events. We assemble and analyse a comprehensive dataset of all the world's lizard species and identify the species with the smallest ranges—those known only from their type localities. We compare them to wide‐ranging species to infer whether specific geographic regions or biological traits predispose species to have small ranges.

Location

Global.

Methods

We extensively surveyed museum collections, the primary literature and our own field records to identify all the species of lizards with a maximum linear geographic extent of <10 km. We compared their biogeography, key biological traits and threat status to those of all other lizards.

Results

One in seven lizards (927 of the 6,568 currently recognized species) are known only from their type localities. These include 213 species known only from a single specimen. Compared to more wide‐ranging taxa, they mostly inhabit relatively inaccessible regions at lower, mostly tropical, latitudes. Surprisingly, we found that burrowing lifestyle is a relatively unimportant driver of small range size. Geckos are especially prone to having tiny ranges, and skinks dominate lists of such species not seen for over 50 years, as well as of species known only from their holotype. Two‐thirds of these species have no IUCN assessments, and at least 20 are extinct.

Main conclusions

Fourteen per cent of lizard diversity is restricted to a single location, often in inaccessible regions. These species are elusive, usually poorly known and little studied. Many face severe extinction risk, but current knowledge is inadequate to properly assess this for all of them. We recommend that such species become the focus of taxonomic, ecological and survey efforts.

     

The relative influence of in situ and neighborhood factors on reptile recolonization in post‐mining restoration sites

Restoration can be important in slowing, or reducing, rates of biodiversity loss, but needs to consider the factors influencing fauna recolonization as part of the recovery process. Although many studies of factors influencing faunal recolonization have examined the influence of in situ site factors, fewer have examined the influence of neighborhood landscape factors, especially in landscapes with permeable matrices. To assess the relative influence of landscape and site factors on reptile recolonization in a production landscape with a permeable matrix, we surveyed reptiles at intact reference sites and post‐mining restoration sites (3–20 years post‐mining [YPM]) in a forest ecosystem in southwestern Australia. Reptile assemblages in restoration sites never converged on those in reference habitat. Reptile species composition and individual species abundances (>20 detections) in restoration sites were primarily influenced by site factors such as canopy height, litter cover, and coarse woody debris volume, and not by landscape factors. We suggest that the most common reptile species in our study area are primarily influenced by site factors, not landscape factors, and most reptiles detected in restoration sites were present by 3–4 YPM. Therefore, it is likely that habitat suitability is the main barrier to most species' recolonization of restoration sites in landscapes with permeable matrices. Management should continue to focus on restoring microhabitats and vegetation structure, which is similar to reference habitat to promote recolonization of restoration sites by reptiles.     

Ecological factors influencing the antipredator behaviors of the ground skink, Scincella lateralis

I tested several hypotheses regarding the antipredator behaviorsof ground skinks (Scincella lateralis) based on a simple-optimalitymodel for avoiding predation. Field studies demonstrated thatS. lateralis with lower body temperatures fled earlier in predatoryevents when the predator was farther away than did warmer animal.This may reflect a compensatory shift in behavior related todecreased sprint speeds observed at lower temperatures. Thesedifferences in maximum sprint speeds at five substrate temperatureswere not linked to morphological characteristics such as mass,snout-vent length, or tail length. Body temperatures of S. lateraliswere highly correlated with substrate temperatures in the field,and these environmental temperatures correlated with the dailyand seasonal activity schedules of S. lateralis. The thermoregulatorystrategy of ground skinks closely parallels theoretical predictionsfor forest-dwelling lizards based on optimum performance curves.In the laboratory, S. lateralis did not alter flight responsesbased on the availability of cover objects or tail conditionof the lizards. Escape behaviors of males and females did notdiffer. Likewise, S. lateralis. showed no differences in responseto differently sized predator models. Differences were foundbetween the reactions of adult and juvenile skinks to an approachingpredator model. Also, S. lateralis collected in Louisiana fledfrom the same predator model with greater frequency than S.lateralis collected in Oklahoma     

The formulation of a national strategy for biological control of possums and bovine Tb

Abstract

The Government has designated the control of possums and bovine Tb a National Science Strategy (NSS) research area. An NSS Committee has been appointed by the Ministry of Research Science and Technology, commissioned to “identify, coordinate and promote national priorities for possum and tuberculosis (Mycobacterium bovis) related research in order that threats both to New Zealand's export markets and to conservation values can be eliminated”.