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opennotspecifiedJun 2020View details →

FIGURE 3 in A new species of Sphenomorphus (Squamata: Scincidae) from Phu Quoc Island Vietnam with a discussion of biogeography and character state evolution in the S stellatus group

FIGURE 3. Maximum clade credibility BEAST tree depicting the relationships of species of the Sphenomorphus stellatus group.

opencc-zeroDec 2020View details →

Data from: Biogeography and anthropogenic impact shape the success of invasive wasps on New Zealand's offshore islands

Aim The theory of island biogeography predicts that the susceptibility of an island to invasion is determined by its isolation and size. However, many island ecosystems have been intensely modified by humans. Here, we investigated the biogeographic, biotic and anthropogenic drivers of invasive social wasps on 36 offshore islands. Location Islands off the east coast of New Zealand's North Island. Taxa Vespula germanica (Fabricius, 1793), Vespula vulgaris (Linnaeus, 1758) and Polistes chinensis antennalis (Fabricius, 1793), Polistes humilis (Fabricius, 1781). Methods We used GIS software for in situ randomisation of plots on each island (36 islands, 409 plots) and conducted 5-minute wasp counts to estimate wasp abundance. Wasp abundance and canopy cover were recorded at each plot. Island isolation was measured using GIS software. Data on island size, human settlement and the presence of introduced rats (Rattus spp.) were collated from the literature and island managers. The number of boat docks per island was counted from satellite images. A generalised linear mixed effect model (GLMM) was fitted to identify drivers of Vespula and Polistes abundance on offshore islands. Results The abundance of Vespula was negatively correlated with island isolation and canopy cover, yet positively correlated with island size. Vespula were also more abundant on islands that have been settled by humans. The abundance of Polistes was negatively correlated with canopy cover. Finally, results did not support the notion that invasive wasps were associated with introduced rats on New Zealand's offshore islands. Conclusions Our findings highlight the importance of biogeographic factors, such as island size and isolation, for species invasions, and suggest that intact forest cover could contribute to biotic resistance to invasive wasps in island ecosystems. Studies of invasive species should consider the joint effects of biogeographic, biotic and anthropogenic factors to best inform conservation management.ealand's North Island.

opencc-zeroDec 2017View details →

Data from: The theory of island biogeography, the sample-area effect, and the habitat diversity hypothesis: complementarity in a naturally fragmented landscape of lake islands

Aim: Investigate relationships between fragmentation and species diversity in the context of the theory of island biogeography, sample-area effect, and habitat diversity hypothesis. Location: Lake of the Woods, Canada. Taxon: Vascular plants Methods: Vascular plant species diversity was inventoried on 30 islands, organized into two island sets. Each island set contained four size classes that varied in degree of fragmentation while controlling for the sample-area effect (small island set: 8×0.1-ha, 4×0.2-ha, 2×0.4-ha, and 1×0.8-ha islands; large island set: identical pattern utilizing 1.0-ha to 8.0-ha islands). Fragmentation effects were then examined using SLOSS-based analyses, addressing whether single large or several small islands contained more species: (1) direct comparisons of species and habitat richness across size classes; (2) extrapolations of species-area relationships; and (3) analyses of species and habitat accumulation curves. Multigroup path analysis was next used to quantify effects of habitat diversity, island area, and isolation on species richness for both island sets. Finally, pairwise and multiple-site dissimilarity was estimated for both species and habitats across 0.1-ha and 1.0-ha islands to investigate whether: (1) variation in species composition was related to habitat composition; and (2) species dissimilarity increased with inter-island distance. Results: SLOSS-based analyses indicated that several small islands contained more species than single large islands in both island sets. This pattern was also observed for habitats, but only in the small islands set. Path analysis suggested that island area had significant direct and indirect effects (mediated by habitat diversity) on species richness. Habitat diversity and island isolation had significant positive and negative effects on species richness, respectively, independent of island area. Species and habitat dissimilarities were significantly related across 0.1-ha but not 1.0-ha islands, and showed no relationship to inter-island distance. Main Conclusions: The overall positive relationship between fragmentation and species richness may be attributed to greater habitat diversity and increased species dissimilarity across smaller islands relative to larger islands. However, negative isolation effects indicate that landscape configuration is still an important conservation consideration. These results each align with different predictions of the theory of island biogeography, sample-area effect, and habitat diversity hypothesis, questioning the exclusivity of these theoretical frameworks.

opencc-zeroDec 2010View details →

Data from: Biogeography in a continental island: population structure of the relict endemic centipede Craterostigmus tasmanianus (Chilopoda, Craterostigmomorpha) in Tasmania using 16S rRNA and COI

We used 16S ribosomal RNA (rRNA) and cytochrome c oxidase subunit I (COI) sequence data to investigate the population structure in the centipede Craterostigmus tasmanianus Pocock, 1902 (Chilopoda: Craterostigmomorpha: Craterostigmidae) and to look for possible barriers to gene flow on the island of Tasmania, where C. tasmanianus is a widespread endemic. We first confirmed a molecular diagnostic character in 28S rRNA separating Tasmanian Craterostigmus from its sister species Craterostigmus crabilli (Edgecombe and Giribet 2008) in New Zealand and found no shared polymorphism in this marker for the 2 species. In Tasmania, analysis of molecular variance analysis showed little variation at the 16S rRNA and COI loci within populations (6% and 13%, respectively), but substantial variation (56% and 48%, respectively) among populations divided geographically into groups. We found no clear evidence of isolation by distance using a Mantel test. Bayesian clustering and gene network analysis both group the C. tasmanianus populations in patterns which are broadly concordant with previously known biogeographical divisions within Tasmania, but we did not find that genetic distance varied in a simple way across cluster boundaries. The coarse-scale geographical sampling on which this study was based should be followed in the future by sampling at a finer spatial scale and to investigate genetic structure within clusters and across cluster boundaries.

opencc-zeroDec 2011View details →

Data from: The biogeography of Sulawesi revisited: is there evidence for a vicariant origin of taxa on Wallace's "anomalous island"?

Sulawesi, the largest island in the Indonesian biodiversity hotspot region Wallacea, hosts a diverse endemic fauna whose origin has been debated for more than 150 years. We use a comparative approach based on dated phylogenies and geological constraints to test the role of vicariance versus dispersal in the origin of Sulawesi taxa. Most divergence time estimates for the split of Sulawesi lineages from their sister groups postdate relevant tectonic vicariant events, suggesting that the island was predominantly colonized by dispersal. Vicariance cannot be refuted for 20 % of the analyzed taxa, though. While vicariance across Wallace's Line was only supported for one arthropod taxon, divergence time estimates were consistent with a "tectonic dispersal" vicariance hypothesis from the East in three (invertebrate and vertebrate) taxa. Speciation on Sulawesi did not occur before the Miocene, which is consistent with geological evidence for more extensive land on the island from that time. The Pliocene onset of periodic sea-level changes may have played a role in increasing the potential for dispersal to Sulawesi. A more extensive taxon sampling in Wallacea will be crucial for refining our understanding of the region's biogeography and for testing hypotheses on the origin of taxa on its most important island.

opencc-zeroDec 2015View details →

Data from: A hierarchical model of whole assemblage island biogeography

Island systems have long played a central role in the development of ecology and evolutionary biology. However, while many empirical studies suggest species differ in vital biogeographic rates, such as dispersal abilities, quantitative methods have had difficulty incorporating such differences into analyses of whole-assemblages. In particular, differences in dispersal abilities among species can cause variation in the spatial clustering and localization of species distributions. Here, we develop a single, hierarchical Bayes, assemblage-wide model of 252 bird species distributions on the islands of Northern Melanesia and use it to investigate a) whether dispersal limitation structures bird assemblages across the archipelago, b) whether species differ in dispersal ability, and c) test the hypothesis that wing aspect ratio, a trait linked to flight efficiency, predicts differences inferred by the model. Consistent with island biogeographic theory, we found that individual species were more likely to occur on islands with greater area, and on islands near to other islands where the species also occurred. However, species showed wide variation in the importance and spatial scale of these clustering effects. The importance of clustering in distributions was greater for species with low wing aspect ratios, and the spatial scale of clustering was also smaller for low aspect ratio species. These findings suggest that the spatial configuration of islands interacts with species dispersal ability to affect contemporary distributions, and that these species differences are detectable in occurrence patterns. More generally, our study demonstrates a quantitative, hierarchical approach that can be used to model the influence of dispersal heterogeneity in diverse assemblages and test hypotheses for how traits drive dispersal differences, providing a framework for deconstructing ecological assemblages and their drivers.

FIGURE 10 in Simuliidae (Diptera) of the Solomon Islands: new records and species, ecology, and biogeography

FIGURE 10. Simulium (M.) nr. selwynense, Makira (Santa Cristobal). Penultimate/early lastinstar larva. a, left lateral view. b, pharate pupal gill. c, hypostomal teeth. d, mandible teeth, sensillum, and serrations. e, dorsal view of head, probably female. f, hypostoma and postgenal cleft. g, anal sclerite and circlet of hooks.

FIGURE 5a–c in Simuliidae (Diptera) of the Solomon Islands: new records and species, ecology, and biogeography

FIGURE 5a–c. Simulium (M.) nr. selwynense, Santa Isobel. Lastinstar larvae. a, left lateral views, female upper, male lower. b, dorsal view of female larva head. c, dorsal view of male larva head.

FIGURE 7 in Simuliidae (Diptera) of the Solomon Islands: new records and species, ecology, and biogeography

FIGURE 7. Simulium (G.) rhopaloides n. sp. Guadalcanal. Early last instar larva, Holotype. a, left lateral view. b, pharate pupal gill. c, hypostomal teeth. d, mandible teeth, sensillum, and serrations. e, dorsal view of head. f, hypostoma and postgenal cleft. g, anal sclerite and circlet of hooks.

FIGURE 4 in Simuliidae (Diptera) of the Solomon Islands: new records and species, ecology, and biogeography

FIGURE 4. Simulium (M.) nr. selwynense, Rendova, New Georgia Islands. Lastinstar larva. a, left lateral view. b, pharate pupal gill. c, hypostomal teeth. d, mandible teeth, sensillum, and serrations. e, dorsal view of head. f, hypostoma and postgenal cleft. g, anal sclerite and circlet of hooks.

FIGURE 1 in Simuliidae (Diptera) of the Solomon Islands: new records and species, ecology, and biogeography

FIGURE 1. Bougainville (PNG) and the Solomon Islands. The 200m bathymetric contour is indicated. Numbers and letters associated with islands are number of recognised species and subgenus (M = Morops, G = Gomphostilbia).

FIGURE 5 in Simuliidae (Diptera) of the Solomon Islands: new records and species, ecology, and biogeography

FIGURE 5. Simulium (M.) nr. selwynense, Santa Isobel. Lastinstar larvae. d, pharate pupal gill. e, hypostomal teeth. f, anal sclerite and circlet of hooks. g, hypostoma and postgenal cleft. h, mandible teeth, sensillum, and serrations.

FIGURE 9a–c in Simuliidae (Diptera) of the Solomon Islands: new records and species, ecology, and biogeography

FIGURE 9a–c. Simulium (M.) nr. pohaense, Malaita. Last instar larva. a, left lateral view, male. b, dorsal view, female larva head. c, dorsal view, male larva head.

FIGURE 3 in Simuliidae (Diptera) of the Solomon Islands: new records and species, ecology, and biogeography

FIGURE 3. Simulium (G.) noroense, New Georgia, New Georgia Islands. Penultimate instar larva. a, left lateral view. b, pharate pupal gill. c, hypostomal teeth. d, mandible teeth, sensillum, and serration. e, dorsal view of head. f, hypostoma and postgenal cleft. g, anal sclerite and circlet of hooks.

FIGURE 2 in Simuliidae (Diptera) of the Solomon Islands: new records and species, ecology, and biogeography

FIGURE 2. Simulium (G.) noroense, Kolumbangara, New Georgia Islands. Penultimate instar larva. a, left lateral view. b, pharate pupal gill. c, hypostomal teeth. d, mandible teeth, sensillum, and serration. e, dorsal view of head. f, hypostoma and postgenal cleft. g, anal sclerite and circlet of hooks.

FIGURE 11 in Simuliidae (Diptera) of the Solomon Islands: new records and species, ecology, and biogeography

FIGURE 11. Localities of new Simuliidae material from the Solomon Islands. a, Stream near Ringgi, Kolumbangara, New Georgia Islands. b, Upper Sakumbare River, New Georgia, New Georgia Islands. c, Upper Toropi River, Rendova, New Georgia Islands (J. Polhemus in background). d, Garana River (3 km inland), Santa Isabel. e, Charovuga River, Guadalcanal. f, Aluta River, cascade, Malaita (R. Englund in background). g, Puepue River, Makira.

FIGURE 8 in Simuliidae (Diptera) of the Solomon Islands: new records and species, ecology, and biogeography

FIGURE 8. Simulium (G.) hiroshii, Malaita. Female adult. a, left lateral view. b, frontal view of head. Specimen in alcohol.

FIGURE 9d–h in Simuliidae (Diptera) of the Solomon Islands: new records and species, ecology, and biogeography

FIGURE 9d–h. Simulium (M.) nr. pohaense, Malaita. Last instar larva. d, pharate pupal gill. e, hypostomal teeth. f, anal sclerite and circlet of hooks. g, hypostoma and postgenal cleft. h, mandible teeth, sensillum, and serrations

opennotspecifiedDec 2010View details →

FIGURE 8. Bothridia a in New species of Crotonia (Acari: Oribatida: Crotoniidae) from Lord Howe and Norfolk Islands: further evidence of long-distance dispersal events in the biogeography of a genus of Gondwanan relict oribatid mites

FIGURE 8. Bothridia a) Crotonia gorgonia sp. nov.; b) Crotonia norfolkensis sp. nov.; c) Crotonia utricularia sp. nov.