Island Endemic Species Research Articles

Systematic significance and evolutionary dynamics of the achene twin hairs in Filago (Asteraceae, Gnaphalieae) and related genera: further evidence of morphological homoplasy

The variation and evolutionary dynamics of the twin hairs covering the achenes of the external female florets in Filago and related genera are studied using scanning electron microscope (SEM) and a Bayesian reconstruction of ancestral character states. A molecular phylogenetic hypothesis based on sequences of ITS and ETS (nuclear ribosomal DNA) and plastid rpl32-trnL intergenic spacer regions was used as a framework to test the phylogenetic, evolutionary and taxonomic significance of this character in the study group. The phylogenetic position of three island-endemic species (F. petro-ianii, F. tyrrhenica and F. wagenitziana) is explored. Three types of twin hairs are described, which alone or combined define five different types of indumentum. The results suggest that glabrous achenes are the ancestral condition for “Filago group s.str.”, while the presence of long-clavate twin hairs on the achene represents the ancestral character state for the genus Filago. Several cases of parallelisms are detected. With regard to taxonomy, twin hairs provide additional support for the recognition of Bombycilaena and Logfia at the generic level and allow the taxonomic re-evaluation of F. lutescens subsp. atlantica and F. crocidion. Finally, the utility of a Bayesian Binary MCMC approach (using the software RASP) for evolutionary reconstruction of morphological characters is demonstrated.

Deforestation and fragmentation of natural forests in the upper Changhua watershed, Hainan, China: implications for biodiversity conservation.

Hainan, the largest tropical island in China, belongs to the Indo-Burma biodiversity hotspot. The Changhua watershed is a center of endemism for plants and birds and the cradle of Hainan's main rivers. However, this area has experienced recent and ongoing deforestation and habitat fragmentation. To quantify habitat loss and fragmentation of natural forests, as well as the land-cover changes in the Changhua watershed, we analyzed Landsat images obtained in 1988, 1995, and 2005. Land-cover dynamics analysis showed that natural forests increased in area (97,909 to 104,023ha) from 1988 to 1995 but decreased rapidly to 76,306ha over the next decade. Rubber plantations increased steadily throughout the study period while pulp plantations rapidly expanded after 1995. Similar patterns of land cover change were observed in protected areas, indicating a lack of enforcement. Natural forests conversion to rubber and pulp plantations has a general negative effect on biodiversity, primarily through habitat fragmentation. The fragmentation analysis showed that natural forests area was reduced and patch number increased, while patch size and connectivity decreased. These land-cover changes threatened local biodiversity, especially island endemic species. Both natural forests losses and fragmentation should be stopped by strict enforcement to prevent further damage. Preserving the remaining natural forests and enforcing the status of protected areas should be a management priority to maximize the watershed's biodiversity conservation value.

Genetic connectivity of the moth pollinated tree Glionnetia sericea in a highly fragmented habitat.

Long-distance gene flow is thought to be one prerequisite for the persistence of plant species in fragmented environments. Human influences have led to severe fragmentation of native habitats in the Seychelles islands, with many species surviving only in small and isolated populations. The endangered Seychelles endemic tree Glionnetia sericea is restricted to altitudes between 450 m and 900 m where the native forest vegetation has been largely lost and replaced with exotic invasives over the last 200 years. This study explores the genetic and ecological consequences of population fragmentation in this species by analysing patterns of genetic diversity in a sample of adults, juveniles and seeds, and by using controlled pollination experiments. Our results show no decrease in genetic diversity and no increase in genetic structuring from adult to juvenile cohorts. Despite significant inbreeding in some populations, there is no evidence of higher inbreeding in juvenile cohorts relative to adults. A Bayesian structure analysis and a tentative paternity analysis indicate extensive historical and contemporary gene flow among remnant populations. Pollination experiments and a paternity analysis show that Glionnetia sericea is self-compatible. Nevertheless, outcrossing is present with 7% of mating events resulting from pollen transfer between populations. Artificial pollination provided no evidence for pollen limitation in isolated populations. The highly mobile and specialized hawkmoth pollinators (Agrius convolvuli and Cenophodes tamsi; Sphingidae) appear to promote extensive gene flow, thus mitigating the potential negative ecological and genetic effects of habitat fragmentation in this species. We conclude that contemporary gene flow is sufficient to maintain genetic connectivity in this rare and restricted Seychelles endemic, in contrast to other island endemic tree species with limited contemporary gene flow.

Characterization of microsatellite markers for Saxicola species

We characterized 28 unique African stonechat (Saxicola torquata) microsatellite loci. Seventeen loci characterized in 24 unrelated Saxicola torquata axillaris individuals sampled at Mount Meru, Tanzania displayed 2–26 alleles per locus and observed heterozygosities ranged from 0.29 to 0.92. Heterozygous females and sequence similarity suggested all 17 loci were autosomal. All markers also successfully amplified in nine different species ranging from Europe to Asia, including three endemic Island species. These microsatellite markers will be useful to assess the genetic diversity of the large and widely distributed genus Saxicola, a group comprising 11 recognized species with evidences of cryptic diversification. Several species show a narrow range distribution and are of conservation concern.

Genome diversity and divergence in Drosophila mauritiana: multiple signatures of faster X evolution.

Drosophila mauritiana is an Indian Ocean island endemic species that diverged from its two sister species, Drosophila simulans and Drosophila sechellia, approximately 240,000 years ago. Multiple forms of incomplete reproductive isolation have evolved among these species, including sexual, gametic, ecological, and intrinsic postzygotic barriers, with crosses among all three species conforming to Haldane’s rule: F1 hybrid males are sterile and F1 hybrid females are fertile. Extensive genetic resources and the fertility of hybrid females have made D. mauritiana, in particular, an important model for speciation genetics. Analyses between D. mauritiana and both of its siblings have shown that the X chromosome makes a disproportionate contribution to hybrid male sterility. But why the X plays a special role in the evolution of hybrid sterility in these, and other, species remains an unsolved problem. To complement functional genetic analyses, we have investigated the population genomics of D. mauritiana, giving special attention to differences between the X and the autosomes. We present a de novo genome assembly of D. mauritiana annotated with RNAseq data and a whole-genome analysis of polymorphism and divergence from ten individuals. Our analyses show that, relative to the autosomes, the X chromosome has reduced nucleotide diversity but elevated nucleotide divergence; an excess of recurrent adaptive evolution at its protein-coding genes; an excess of recent, strong selective sweeps; and a large excess of satellite DNA. Interestingly, one of two centimorgan-scale selective sweeps on the D. mauritiana X chromosome spans a region containing two sex-ratio meiotic drive elements and a high concentration of satellite DNA. Furthermore, genes with roles in reproduction and chromosome biology are enriched among genes that have histories of recurrent adaptive protein evolution. Together, these genome-wide analyses suggest that genetic conflict and frequent positive natural selection on the X chromosome have shaped the molecular evolutionary history of D. mauritiana, refining our understanding of the possible causes of the large X-effect in speciation.

Taxonomic revision of the semi-aquatic skink Parvoscincus leucospilos (Reptilia: Squamata: Scincidae), with description of three new species.

We review the recent discovery of multiple populations of the enigmatic, semi-aquatic Sphenomorphus Group skink, Parvoscincus leucospilos Peters, and investigate the morphological and genetic diversity of isolated, allopatric populations of this unique skink. Our investigations support the recognition of four unique evolutionary lineages distributed across Luzon Island in the Philippines, three of which are herein described as new species (P. tikbalangi sp. nov., P. manananggalae sp. nov., and P. duwendorum sp. nov.). All four recognized species are genetically divergent in both mitochondrial and nuclear DNA sequences, and morphologically distinct. The description of three new Luzon Island endemic species adds to the growing body of literature suggesting that mechanisms driving the accumulation of vertebrate diversity in the Philippines may vary regionally across the archipelago.

Population structure and management of invasive cats on an Australian Island

Invasive predators have a major impact on endemic island species; therefore, information about invasion dynamics are essential for implementing successful control measures. The introduction of feral cats onto Dirk Hartog Island, Western Australia, has had devastating effects, with presumably 10 of 13 native terrestrial mammal species being lost because of predation. Detailed records of historical introduction events were lacking; therefore, we analyzed genetic variation of the current population to gain information about past invasion dynamics and current gene-flow patterns. We analyzed the genetic structure and diversity of feral cats on the island and 2 mainland populations (Peron Peninsula and Steep Point). Analysis of mitochondrial DNA (ND5 and ND6) showed 2 primary haplotypes that we attribute to 2 main introduction events. Pairwise G 00 ST values indicated high connectivity on the island but some isolation to the mainland populations. Mitochondrial and nuclear data showed no evidence for genetic differentiation of island and mainland populations; however, kinship analyses rejected evidence for on-going immigration of members of the current cat populations. Overall, our data suggested that gene flow following the main introduction events ceased some years ago. Because current island populations appear to be reproductively isolated from mainland populations, a sufficiently large-scale eradication measure might successfully diminish feral cat populations long-term. 2014 The Wildlife Society.

Dispersal ability of island endemic plants: What can we learn using multiple dispersal traits?

Island endemic species are expected to have lower dispersal ability than their non-endemic congeners. Several studies have demonstrated differences in diaspore morphology between endemic species and their non-endemic congeners. It is, however, relatively difficult to translate the differences in morphology of the diaspores into differences in dispersal ability. To avoid this problem, we measured directly dispersal values (anemo-, hydro-, exozoo- and endozoo-chory) of 27 pairs of closely related endemic and non-endemic species from Canary Islands. We did not explicitly support the hypothesis about the loss of dispersal ability of island species. The comparison of pairs of endemic and non-endemic species showed the reduction in dispersal potential only for endozoochory. In many cases, endemic species had, in fact, the same or better dispersal ability than their non-endemic congeners. Higher dispersal ability of endemic species could have been evolved as a consequence of species subsequent dispersal to neighboring islands. As a support for this we found that the endemic species dispersing better than their non-endemic congeners also occupy more islands within the archipelago. We conclude that reduction of dispersal ability of species on islands may not be as general as previously expected and we need to take into account multiple species traits to understand the possible evolution of species dispersal potential.

Can Management Improve the Value of Shade Plantations for the Endemic Species of São Tomé Island?

AbstractCocoa and coffee are among the most valuable tropical crops, with much of their production in areas of high biodiversity. Although this could suggest a conflict between agricultural expansion and biodiversity conservation, these crops are normally grown in shade plantations—a more biodiversity‐friendly agroforestry system. Using São Tomé Island as a case study, we examined if shade plantation can benefit biodiversity by protecting extinction‐prone island endemic species. We found that shade plantations held rich assemblages, even in comparison with forest: we estimated 30 bird and 74 tree species occurring in plantations compared to 24 bird and 108 tree species in forests. However, the structure of the assemblages was significantly different between ecosystems, with an average dissimilarity of 33.8 percent and 87.9 percent for birds and trees, respectively. Shade plantations had consistently less endemic species than the forest; we estimated a drop from 17 to 13 in birds and from 17 to 3 in trees. We also found that despite marked differences in the response of bird species to the vegetation characteristics of shade plantations, there was a strong positive link between aboveground tree biomass and endemic species richness and abundance. These results show that shade plantations hold assemblages impoverished in endemic species, but that management can improve their value for the conservation of these species. Finally, we suggest that biodiversity‐friendly certification and carbon markets are used to implement and guarantee the long‐term economical sustainability of practices that favor the endemic species in São Tomé's shade plantations.

Molecular Systematics of Threatened Seed Plant Species Endemic in the Caribbean Islands

A review of available Caribbean Island red-lists species (CR and EN categories based on the IUCN guidelines from 2001, and E category established according to the IUCN guidelines from 1980) is presented. A database of over 1,300 endemic species that are either Critically Endangered or Endangered sensu IUCN was created. There are molecular systematic studies available for 112 of them. Six of these species (in six genera) are the only members of early divergent lineages that are sister to groups composed of a large number of clades. Seven of the species (in seven genera) belong to clades that have a small number of taxa but are sister to species/genus-rich clades. Ten of the species (in six genera) are sister to taxa restricted to South America or nested in clades endemic to this region. Fifty-seven of the species (in 35 genera) are sister to Caribbean Island endemic species. Erigeron belliastroides, an Endangered (EN) Cuban endemic, is sister to the Galapagos genus Darwiniothamnus. The phylogenetic placement of four of the threatened species resulted in changes in their taxonomic placement; they belong to polyphyletic or paraphyletic genera.

Alfred Russel Wallace and the destruction of island life: the Iguana tragedy

The Galápagos Islands (Ecuador) are usually associated with the explorations and theoretical deductions of Charles Robert Darwin (1809-1882), but Alfred Russel Wallace (1823-1913) also investigated these islands and published several reports on the living world of this unique archipelago. In contrast to Darwin, Wallace described the destruction of natural ecosystems by humans and foresaw the resulting extinction of species. Here, we outline two case studies pertinent to Wallace's prediction. First, we summarize the behavior of the predator-naive marine iguanas (Amblyrhynchus cristatus) on the Galápagos Islands, which are threatened by feral dogs and cats imported by humans. We also describe the unique life cycle of the spiny-tailed iguana (Ctenosaura bakeri) from the island of Utila (Honduras), a rare species whose populations are declining because of habitat destructions. In contrast to these threatened, endemic island species, the Green iguana (Iguana iguana) is still widely distributed, although, as a result of de-forestation, in some areas of South America local populations have disappeared. We conclude that Wallace was correct in his prediction that, because of human activities, numerous species of animals and plants will be driven to extinction, notably on islands.

Elevation-driven ecological isolation promotes diversification on Mediterranean islands

The percentage of single island neo-endemic species (an indicator for evolutionary diversification) was found to be independent of geographic distance to the continent in the case of the Aegean archipelago. It was concluded that speciation is independent of geographic isolation, while evolutionary processes are rather enhanced by habitat heterogeneity. An island's maximum elevation was used as an indicator for habitat heterogeneity. In contrast, we argue that habitat heterogeneity (=habitat diversity, i.e. the richness in different habitats) may be positively related to biotic richness, but a positive effect on speciation is yet to be proven. For any other type of heterogeneity, we propose a precise wording, especially when assessing its effect on speciation processes.Alternatively, we propose that elevation-driven ecological isolation causes the pattern of endemic species on high-elevation islands. Environmental filtering along an elevational gradient differentiates ecosystems, leading to an increase of isolation with elevation. The reason is that comparable ecosystems are much farther apart than is the case for lowland ecosystems. In addition, ecosystems on neighboring islands or on the continent that may be source regions for colonizing species are small in area in high elevations in comparison with low elevation ecosystems. Consequently, an increased speciation rate resulting in a larger percentage of single island endemic species can be expected for higher elevations on islands and high mountains. Support for this elevation-driven ecological isolation hypothesis comes from other islands in the Mediterranean region (e.g. Crete and Corsica), where an increase of the percentage of endemic species with elevation has been observed. Thus, the assessment of (genetic-) isolation should incorporate the distance to similar habitats instead of simple land-to-land connections.

Population genomics of the endangered giant Galápagos tortoise.

BackgroundThe giant Galápagos tortoise, Chelonoidis nigra, is a large-sized terrestrial chelonian of high patrimonial interest. The species recently colonized a small continental archipelago, the Galápagos Islands, where it has been facing novel environmental conditions and limited resource availability. To explore the genomic consequences of this ecological shift, we analyze the transcriptomic variability of five individuals of C. nigra, and compare it to similar data obtained from several continental species of turtles.ResultsHaving clarified the timing of divergence in the Chelonoidis genus, we report in C. nigra a very low level of genetic polymorphism, signatures of a weakened efficacy of purifying selection, and an elevated mutation load in coding and regulatory sequences. These results are consistent with the hypothesis of an extremely low long-term effective population size in this insular species. Functional evolutionary analyses reveal a reduced diversity of immunity genes in C. nigra, in line with the hypothesis of attenuated pathogen diversity in islands, and an increased selective pressure on genes involved in response to stress, potentially related to the climatic instability of its environment and its elongated lifespan. Finally, we detect no population structure or homozygosity excess in our five-individual sample.ConclusionsThese results enlighten the molecular evolution of an endangered taxon in a stressful environment and point to island endemic species as a promising model for the study of the deleterious effects on genome evolution of a reduced long-term population size.

Molecular systematics and historical biogeography of tree boas (Corallus spp.)

Inferring the evolutionary and biogeographic history of taxa occurring in a particular region is one way to determine the processes by which the biodiversity of that region originated. Tree boas of the genus Corallus are an ancient clade and occur throughout Central and South America and the Lesser Antilles, making it an excellent group for investigating Neotropical biogeography. Using sequenced portions of two mitochondrial and three nuclear loci for individuals of all recognized species of Corallus, we infer phylogenetic relationships, present the first molecular analysis of the phylogenetic placement of the enigmatic C. cropanii, develop a time-calibrated phylogeny, and explore the biogeographic history of the genus. We found that Corallus diversified within mainland South America, via over-water dispersals to the Lesser Antilles and Central America, and via the traditionally recognized Panamanian land bridge. Divergence time estimates reject the South American Caribbean-Track as a general biogeographic model for Corallus and implicate a role for events during the Oligocene and Miocene in diversification such as marine incursions and the uplift of the Andes. Our findings also suggest that recognition of the island endemic species, C. grenadensis and C. cookii, is questionable as they are nested within the widely distributed species, C. hortulanus. Our results highlight the importance of using widespread taxa when forming and testing biogeographic hypotheses in complex regions and further illustrate the difficulty of forming broadly applicable hypotheses regarding patterns of diversification in the Neotropical region.

Anagenetic speciation in Ullung Island, Korea: genetic diversity and structure in the island endemic species, Acer takesimense (Sapindaceae)

Anagenetic speciation is an important mode of speciation in oceanic islands; one-fourth of the endemic plants are estimated to have been derived via this process. Few studies, however, have critically examined the genetic consequences of anagenesis in comparison with cladogenesis (involved with adaptive radiation). We hypothesize that endemic species originating via anagenetic speciation in a relatively uniform environment should accumulate genetic variation with limited populational differentiation. We undertook a population genetic analysis using nine nuclear microsatellite loci of Acer takesimense, an anagenetically derived species endemic to Ullung Island, Korea, and its continental progenitor A. pseudosieboldianum on the Korean Peninsula. Microsatellite data reveal a clear genetic distinction between the two species. A high F value in the cluster of A. takesimense was found by Bayesian clustering analysis, suggesting a strong episode of genetic drift during colonization and speciation. In comparison with A. pseudosieboldianum, A. takesimense has slightly lower genetic diversity and possesses less than half the number of private and rare alleles. Consistent with predictions, weak geographical genetic structure within the island was found in A. takesimense. These results imply that anagenetic speciation leads to a different pattern of specific and genetic diversity than often seen with cladogenesis.

New hope for the critically endangered São Tomé Grosbeak Neospiza concolor and an alert to protect Obô Natural Park surroundings

The São Tomé Grosbeak Neospiza concolor is critically endangered, with an area of occurrence smaller than 16 km2 and an adult population under 50 individuals. It was previously thought to be restricted to old-growth forest in the southern lowlands of the island, but here we describe its presence at altitude over a long period, using young secondary forests and feeding on plants characteristic of disturbed areas. By extending the grosbeak's area of occurrence and what is known about its ecology, these observations raise new hope for the survival of this threatened bird. However, this new site lies outside the Ôbo Natural Park, São Tomé's only protected area, for which we alert the need to better protect its surroundings, which are relevant for many of the island's endemic species.

Evolution of Nesting Height in an Endangered Hawaiian Forest Bird in Response to a Non‐Native Predator

The majority of bird extinctions since 1800 have occurred on islands, and non-native predators have been the greatest threat to the persistence of island birds. Island endemic species often lack life-history traits and behaviors that reduce the probability of predation and they can become evolutionarily trapped if they are unable to adapt, but few studies have examined the ability of island species to respond to novel predators. The greatest threat to the persistence of the Oahu Elepaio (Chasiempis ibidis), an endangered Hawaiian forest bird, is nest predation by non-native black rats (Rattus rattus). I examined whether Oahu Elepaio nest placement has changed at the individual and population levels in response to rat predation by measuring nest height and determining whether each nest produced offspring from 1996 to 2011. Average height of Oahu Elepaio nests increased 50% over this 16-year period, from 7.9 m (SE 1.7) to 12.0 m (SE 1.1). There was no net change in height of sequential nests made by individual birds, which means individual elepaios have not learned to place nests higher. Nests ≤3 m off the ground produced offspring less often, and the proportion of such nests declined over time, which suggests that nest-building behavior has evolved through natural selection by predation. Nest success increased over time, which may increase the probability of long-term persistence of the species. Rat control may facilitate the evolution of nesting height by slowing the rate of population decline and providing time for this adaptive response to spread through the population.

Habitat selection and conservation status of the endemic Ninox hawk-owl on Cebu, Philippines

SummaryThe largely deforested island of Cebu, Philippines, hosts a forest-dwelling hawk-owl identified in the literature as Ninox philippensis spilonota but which is in fact a Cebu island endemic species, soon to be named. To determine the current distribution and habitat requirements of this hawk-owl, the five largest of 11 remaining forest patches on Cebu were surveyed between March and June 2011, involving 64 post-sunset 500-m walked transects with playback and habitat assessments. Radio-telemetry studies were also conducted on 10 owls but only for 3–5 days per owl as they removed the transmitters. A total of 52 owls were located across all five forests (at 16 sites two owls responded together to playback) but only the largest forest, Alcoy, contained enough transects for analyses of habitat in relation to owl distribution. Alcoy stands on steep-sided hills and some planting of exotic species occurs within it. Owls were detected in forest interior, forest edge and forest-plantation mix in Alcoy, and on ridges and in gullies despite lower tree densities and greater proximity to clearings in the gullies. However, parts of Alcoy experience strong winds, and owl occupancy decreased significantly with increasing wind speed. Home ranges for the 10 radio-tagged owls were estimated to cover ∼10 ha, although given the short tracking periods this may be an underestimate. Suitable forest studied covers roughly 1,670 ha, with six unstudied forests totalling 250 ha, so assuming a pair every 10 ha would give a tentative global population estimate of ∼ 200 pairs of Cebu Hawk-owls, and even fewer if home ranges are larger than estimated. This, coupled with continuing habitat degradation, triggers the IUCN Red List category ‘Endangered’. Tree cavities suitable for nests may be limiting, and nest-box provision could be explored, provided this does not increase predator pressure on other rare species.

An 11‐yr exclosure experiment in a high‐elevation island ecosystem: introduced herbivore impact on shrub species richness, seedling recruitment and population dynamics

AbstractQuestionsDo introduced herbivores and fire explain the mono‐dominance of one legume shrub (Adenocarpus viscosus subsp. spartioides) above the tree line on an oceanic island, given the fact that a number of other legume shrub species are potentially present? What drives the observed landscape‐scale life–death pattern within the mono‐dominant shrub species population?LocationThe sub‐alpine scrub vegetation of La Palma (Canary Islands, Atlantic Ocean).MethodsAn 11‐yr exclosure experiment with sites distributed along an elevation and orientation gradient was used to identify the influence of introduced herbivore pressure on four endemic shrub species and their seedling recruitment. Further, we assessed the population dynamics and spatial pattern of the dominant shrub species A. viscosus subsp. spartioides. Habitat and vitality characteristics were investigated, assessing spatial topographic features and tree ring‐based age estimates. Linear mixed models, ANOVAs, linear regression and variation partitioning were used as statistical analysis tools.ResultsOutside of the exclosures A. viscosus subsp. spartioides was virtually mono‐dominant in the study area, even though other shrub species seem better suited in the absence of introduced herbivores. The presence of introduced herbivores significantly reduced seedling recruitment within all target species, except for A. viscosus subsp. spartioides. Mean age of A. viscosus subsp. spartioides increased with elevation, although vitality analyses indicated that the sub‐alpine scrub is elevated above its growth optimum. Three out of four investigated shrub species showed differences in growth height depending on elevation and island orientation.ConclusionIntroduced herbivores and fire are identified as key disturbances enhancing the occurrence of A. viscosus subsp. spartioides, a commonly less competitive species. However, Genista benehoavensis, a single island endemic shrub species, seems to be better adapted to the harsh climate conditions of the sub‐alpine scrub in the absence of introduced herbivores than any other shrub species.

A new skink fauna from Caribbean islands (Squamata, Mabuyidae, Mabuyinae)

Neotropical skinks are unique among lizards and other vertebrates in their degree of convergence, in reproductive traits,with eutherian mammals. They have also been famously difficult to classify into species, largely because of a conservativebody plan and paucity of conventional diagnostic characters. Currently there are 26 recognized species, six of which occuronly on Caribbean islands. All are placed in a single genus, Mabuya. We conducted a systematic revision of Neotropicalskinks using both conventional and unconventional morphological characters, supplemented by DNA sequence analyses.We define 61 species grouped into 16 clades, recognized here as genera. They include three available generic names(Copeoglossum, Mabuya, and Spondylurus) and 13 new genera: Alinea gen. nov., Aspronema gen. nov., Brasiliscincusgen. nov., Capitellum gen. nov., Exila gen. nov., Manciola gen. nov., Maracaiba gen. nov., Marisora gen. nov., Noto-mabuya gen. nov., Orosaura gen. nov., Panopa gen. nov., Psychosaura gen. nov., and Varzea gen. nov. These 16 generaof skinks form a monophyletic group and are placed in the Subfamily Mabuyinae of the skink Family Mabuyidae. Sixother skink families are recognized: Acontidae, Egerniidae, Eugongylidae, Lygosomidae, Scincidae, and Sphenomorphi-dae. We describe three new subfamilies of Mabuyidae: Chioniniinae subfam. nov., Dasiinae subfam. nov., and Trachyl-epidinae subfam. nov. We describe 24 new species of mabuyines: Capitellum mariagalantae sp. nov., Capitellumparvicruzae sp. nov., Copeoglossum aurae sp. nov., Copeoglossum margaritae sp. nov., Copeoglossum redondae sp.nov., Mabuya cochonae sp. nov., Mabuya desiradae sp. nov., Mabuya grandisterrae sp. nov., Mabuya guadeloupae sp.nov., Mabuya hispaniolae sp. nov., Mabuya montserratae sp. nov., Marisora aurulae sp. nov., Marisora magnacornaesp. nov., Marisora roatanae sp. nov., Spondylurus anegadae sp. nov., Spondylurus culebrae sp. nov., Spondylurus caico-sae sp. nov., Spondylurus haitiae sp. nov., Spondylurus magnacruzae sp. nov., Spondylurus martinae sp. nov., Spondy-lurus monae sp. nov., Spondylurus monitae sp. nov., Spondylurus powelli sp. nov., and Spondylurus turksae sp. nov. Wealso resurrect 10 species from synonymies: Alinea lanceolata comb. nov., Alinea luciae comb. nov., Capitellum metalli-cum comb. nov., Mabuya dominicana, Marisora alliacea comb. nov., Marisora brachypoda comb. nov., Spondylurusfulgidus comb. nov., Spondylurus nitidus comb. nov., Spondylurus semitaeniatus comb. nov., and Spondylurus spilonotuscomb. nov. Of the 61 total species of mabuyine skinks, 39 occur on Caribbean islands, 38 are endemic to those islands,and 33 of those occur in the West Indies. Most species on Caribbean islands are allopatric, single-island endemics, al-though three species are known from Hispaniola, three from St. Thomas, and two from Culebra, St. Croix, Salt Island,Martinique, the southern Lesser Antilles, Trinidad, and Tobago. Co-occurring species typically differ in body size and be-long to different genera. Three ecomorphs are described to account for associations of ecology and morphology: terrestri-al, scansorial, and cryptozoic. Parturition occurs at the transition between the dry and wet seasons, and the number ofyoung (1–7) is correlated with body size and taxonomic group. Molecular phylogenies indicate the presence of many un-named species in Middle and South America. A molecular timetree shows that mabuyines dispersed from Africa to SouthAmerica 18 (25–9) million years ago, and that diversification occurred initially in South America but soon led to coloni-zation of Caribbean islands and Middle America. The six genera present on Caribbean islands each represent separate dis-persals, over water, from the mainland during the last 10 million years. Considerable dispersal and speciation alsooccurred on and among Caribbean islands, probably enhanced by Pleistocene glacial cycles and their concomitant sea lev-el changes. Based on IUCN Redlist criteria, all of the 38 endemic Caribbean island species are threatened with extinction.Twenty-seven species (71%) are Critically Endangered, six species (16%) are Endangered, and five species (13%) are Vul-nerable. Sixteen of the Critically Endangered species are extinct, or possibly extinct, because of human activities duringthe last two centuries. Several of the surviving species are near extinction and in need of immediate protection. Analysisof collection records indicates that the decline or loss of 14 skink species can be attributed to predation by the Small IndianMongoose. That invasive predator was introduced as a biological control of rats in sugar cane fields in the late nineteenthcentury (1872–1900), immediately resulting in a mass extinction of skinks and other reptiles. The ground-dwelling and diurnal habits of skinks have made them particularly susceptible to mongoose predation.