Neighboring Islands Research Articles

Comparative phylogeography of two hemipteran species (Geisha distinctissima and Megacopta cribraria) in the Zhoushan Archipelago of China reveals contrasting genetic structures despite concordant historical demographies.

Continental islands are useful models to explore the roles of shared historical factors in the evolution of sympatric species. However, China's largest continental group of islands, the Zhoushan Archipelago, was neglected by most studies focusing on biodiversity hotspots. Here we investigated the phylogeographic patterns and the historical demography of two sympatric hemipteran insects (Geisha distinctissima and Megacopta cribraria), which shared historical factors in the Zhoushan Archipelago. The results based on mtDNA (COX1, COX2-COX3, and CYTB) and nDNA (28S and ITS2) showed that G. distinctissima diverged into three genetic lineages (L1-L3) ~8.9-13.7 thousand years ago (kya), which coincided with the period of island isolation. However, the three lineages exhibit no clear phylogeographic patterns for frequent asymmetrical gene flow (starting around 5 kya) from the mainland and adjacent islands to other distant islands due to subsequent human activities. In contrast, only one genetic lineage exists for M. cribraria, without any phylogeographic structures. The ancestral range in the mainland as well as in neighboring islands, together with the frequent asymmetrical gene flow of M. cribraria (from the mainland and neighboring islands to more distant islands) within the last 5000 years suggests that human activities may have lead to the colonization of this species in the Zhoushan Archipelago. The contrasting genetic structures indicate shared historical factors but independent evolutionary histories for the two sympatric species in the Zhoushan Archipelago. Our demographic analysis clearly showed that both species underwent population expansion before 5 kya during the post-LGM (Last Glacial Maximum), which indicates that the two species shared concordant historical demographies. This result suggests that the population size of the two species was affected similarly by the climatic oscillations of post-LGM in Eastern China. Together, our findings reveal that the two insect species in the Zhoushan Archipelago exhibit contrasting genetic structures despite concordant historical demographies, which provides an important framework for the exploration of the evolution patterns of sympatric species in the continental island.

The interaction between island geomorphology and environmental parameters drives Adélie penguin breeding phenology on neighboring islands near Palmer Station, Antarctica.

Despite many studies on Adélie penguin breeding phenology, understanding the drivers of clutch initiation dates (CIDs, egg 1 lay date) is limited or lacks consensus. Here, we investigated Adélie penguin CIDs over 25 years (1991–2016) on two neighboring islands, Torgersen and Humble (<1 km apart), in a rapidly warming region near Palmer Station, Antarctica. We found that sea ice was the primary large‐scale driver of CIDs and precipitation was a secondary small‐scale driver that fine‐tunes CID to island‐specific nesting habitat geomorphology. In general, CIDs were earlier (later) when the spring sea ice retreat was earlier (later) and when the preceding annual ice season was shorter (longer). Island‐specific effects related to precipitation and island geomorphology caused greater snow accumulation and delayed CIDs by ~2 days on Torgersen compared to Humble Island. When CIDs on the islands were similar, conditions were mild with less snow across breeding sites. At Torgersen Island, the negative relationship between CID and breeding success highlights detrimental effects of delayed breeding and/or snow on penguin fitness. Past phenological studies reported a relationship between air temperature and CID, assumed to be related to precipitation, but we found air temperature was more highly correlated to sea ice, revealing a misinterpretation of temperature effects. Finally, contrasting trends in CIDs based on temporal shifts in regional sea ice patterns revealed trends toward earlier CIDs (4–6 day advance) from 1979 to 2009 as the annual ice season shortened, and later CIDs (7–10 day delay) from 2010 to 2016 as the annual ice season lengthened. Adélie penguins tracked environmental conditions with flexible breeding phenology, but their life history remains vulnerable to subpolar weather conditions that can delay CIDs and decrease breeding success, especially on landscapes where geomorphology facilitates snow accumulation.

ANTS OF GRENADA (HYMENOPTERA, FORMICIDAE)

On West Indian islands, as elsewhere in the world, ants are a very important component of virtually every terrestrial ecosystem. Nonetheless, the ants of most West Indian islands have remained largely unknown and unstudied. Now several destructive exotic ant species are spreading through the region, threatening native biodiversity. Here, we have compiled published and unpublished ant records and collected new specimens to document the diversity of ants on the island of Grenada. Our investigations increased the list of ant taxa known from the island to 82 (65 New World and 17 Old World species). Of these, 71 species are represented among specimens we collected, whereas 11 are New World species known from Grenada solely on the basis of earlier records. Some species recorded earlier, including at least nine not seen for more than 100 years, may now be extinct on Grenada. Grenada has more New World ant species than are known for Barbados (46), a neighboring island that has 34% more land area. Factors that may contribute to this difference include: 1) during low sea levels 15,000 years ago, Grenada was part of a larger island about 10 times Grenada's current size; 2) Grenada is more mountainous than Barbados; and 3) Grenada has more remaining forest cover than Barbados (50.0% vs. 14.7%). Conversely, Grenada has fewer Old World ant species than are known for Barbados (24). Factors that may contribute to this difference include: 1) lower human population density, 2) lower levels of imported lumber products, and 3) lower tourism levels. Records for only four of the 17 Old World exotic ants found in Grenada date to before 1995. Major tramp ant species that are known from the West Indies but have not yet been recorded from Grenada include Old World species such as the pharaoh ant (Monomorium pharaonis), the African big-headed ant (Pheidole megacephala), and the difficult white-footed ant (Technomyrmex difficilis), as well as the red imported fire ant (Solenopsis invicta).

Facial aging trajectories: A common shape pattern in male and female faces is disrupted after menopause.

ObjectivesDespite variation in lifestyle and environment, first signs of human facial aging show between the ages of 20–30 years. It is a cumulative process of changes in the skin, soft tissue, and skeleton of the face. As quantifications of facial aging in living humans are still scarce, we set out to study age‐related changes in three‐dimensional facial shape using geometric morphometrics.Materials and methodsWe collected surface scans of 88 human faces (aged 26–90 years) from the coastal town Split (Croatia) and neighboring islands. Based on a geometric morphometric analysis of 585 measurement points (landmarks and semilandmarks), we modeled sex‐specific trajectories of average facial aging.ResultsAge‐related facial shape change was similar in both sexes until around age 50, at which time the female aging trajectory turned sharply. The overall magnitude of facial shape change (aging rate) was higher in women than men, especially in early postmenopause. Aging was generally associated with a flatter face, sagged soft tissue (“broken” jawline), deeper nasolabial folds, smaller visible areas of the eyes, thinner lips, and longer nose and ears. In postmenopausal women, facial aging was best predicted by the years since last menstruation and mainly attributable to bone resorption in the mandible.DiscussionWith high spatial and temporal resolution, we were able to extract a shared facial aging pattern in women and men, and its divergence after menopause. This fully quantitative three‐dimensional analysis of human facial aging may not only find applications in forensic and ancient human facial reconstructions, but shall include lifestyle and endocrinological measures, and also reach out to studies of social perception.

From gradual spreading to catastrophic collapse – Reconstruction of the 1888 Ritter Island volcanic sector collapse from high-resolution 3D seismic data

Volcanic island flank collapses have the potential to trigger devastating tsunamis threatening coastal communities and infrastructure. The 1888 sector collapse of Ritter Island, Papua New Guinea (in the following called Ritter) is the most voluminous volcanic island flank collapse in historic times. The associated tsunami had run-up heights of more than 20 m on the neighboring islands and reached settlements 600 km away from its source. This event provides an opportunity to advance our understanding of volcanic landslide-tsunami hazards. Here, we present a detailed reconstruction of the 1888 Ritter sector collapse based on high-resolution 2D and 3D seismic and bathymetric data covering the failed volcanic edifice and the associated mass-movement deposits. The 3D seismic data reveal that the catastrophic collapse of Ritter occurred in two phases: (1) Ritter was first affected by deep-seated, gradual spreading over a long time period, which is manifest in pronounced compressional deformation within the volcanic edifice and the adjacent seafloor sediments. A scoria cone at the foot of Ritter acted as a buttress, influencing the displacement and deformation of the western flank of the volcano and causing shearing within the volcanic edifice. (2) During the final, catastrophic phase of the collapse, about 2.4 km3 of Ritter disintegrated almost entirely and traveled as a highly energetic mass flow, which incised the underlying sediment. The irregular topography west of Ritter is a product of both compressional deformation and erosion. A crater-like depression underlying the recent volcanic cone and eyewitness accounts suggest that an explosion may have accompanied the catastrophic collapse. Our findings demonstrate that volcanic sector collapses may transform from slow gravitational deformation to catastrophic collapse. Understanding the processes involved in such a transformation is crucial for assessing the hazard potential of other volcanoes with slowly deforming flanks such as Mt. Etna or Kilauea.

Behavioral Response of Little Fire Ant, Wasmannia auropunctata (Hymenoptera: Formicidae), to Trail Chemicals Laid on Epiphytic Moss

The little fire ant (LFA), Wasmannia auropunctata (Hymenoptera: Formicidae), is native to the neotropics, but has become one of the world’s most widespread and destructive invasive ants. In Hawaii, LFA was first discovered in 1999 on the Big Island and since then has rapidly spread to neighboring islands, causing ecological and economic damage. LFA can develop fully functional nests on the ground and arboreally, and their foraging and retrieval of food resources is facilitated by a well-developed recruitment system. LFA were found to form recruitment trails on epiphytic moss growing on macadamia nut trees. As a first step to identify LFA recruitment pheromone components, we tested the LFA worker trail-following response to naturally marked epiphytic moss trails. Significantly more LFA workers placed on a natural trail followed the trail and made 90° turns to continue following the trail compared to when they were placed on a fake trail that had no trail marking substance(s). In laboratory choice assays using hexane extracts of moss with and without LFA trail, LFA workers preferred to follow a trail drawn with a hexane extract of moss that had a recruitment trail over a trail drawn with a hexane extract of moss only. Our results confirm that LFA workers readily follow a trail marking substance(s) laid down on epiphytic moss.

Cash Transfers and Migration: Theory and Evidence from a Randomized Controlled Trial

Will the fast expansion of cash-based programming in developing countries increase international migration? Theoretically, cash transfers may favor international migration by relaxing liquidity, credit, and risk constraints. But transfers, especially those conditional upon staying at home, may also increase the opportunity cost of migrating abroad. This paper evaluates the impact of a cash-for-work program on migration. Randomly selected households in Comoros were offered up to US$320 in cash in exchange for their participation in public works projects. We find that the program increased migration to Mayotte — the neighboring and richer French Island — by 38 percent, from 7.8% to 10.8%. The increase in migration is explained by the alleviation of liquidity and risk constraints, and by the fact that the program did not increase the opportunity cost of migration for likely migrants.

Anatomy of a late Quaternary carbonate island: Constraints on timing and magnitude of sea-level fluctuations, West Caicos, Turks and Caicos Islands, BWI

The data set of the island of West Caicos consists of a combination of high-resolution lidar and digital imagery, radiometric data, and amino acid racemization (AAR) D/L values as well as extraordinary preservation of sedimentary and bio-constructed deposits on the island. Together with a well-established regional stratigraphic framework from the neighboring Bahamian island chain and detailed field mapping, the West Caicos data set provides an opportunity to advance our understanding of the link between carbonate stratigraphy and the controlling parameters of sea level, sediment supply, tectonics, and climate. The exceptionally well-preserved stratigraphic record of the mid–late Pleistocene from West Caicos allows recognition of marine isotope stages (MIS) 9/11, 5e, and Holocene. The west coast of the island provides a continuous 8.4 km exposure of the MIS 5e record that enhances our understanding of the intra-MIS 5e bipartite succession in this region and supports a sea-level lowering that occurred during the last interglacial (LIG).West Caicos accreted as a series of eolian, foreshore–shoreface, barrier-reef, and fringing-reef facies. Shoreline positions for all but the MIS 7 and MIS 5a/c deposits are now captured in the sub-meter geodetic-quality topobathy lidar survey. The Star Town unit of MIS 9/11 age forms the southern margin of the island as well as the central karst-modified spine, with uranium–thorium (UTh) coral ages of between 368 and 365 thousand years ago (ka) and a D/L Glu average of >0.60. Early MIS 5e strata include the Railroad Ridge unit in the center of the island, which was previously identified as one of the older units. The Railroad Ridge unit is a north–south linear dune ridge that has a D/L Glu average of 0.52 and indicates the onset of sediment sources from the east associated with a flooded central Caicos Platform. Approximately synchronously, the early MIS 5e South Reef unit (+3.75–4 m sea-level elevation) nucleated on the western coast of West Caicos, attached to the middle Pleistocene Star Town unit. The South Reef corals yield an average coral UTh age of 126.5 ka, with an average D/L Glu from skeletal matrix of 0.46. This transitional barrier/fringing reef is unconformably overlain by the late MIS 5e Boat Cove unit. Corals in the basal transgressive phase of this upper MIS 5e Boat Cove unit yield an average 120.6 ka UTh and average D/L Glu of 0.45. Shallow-marine, foreshore, and eolian facies of the late MIS 5e rest on a wave-cut terrace that cuts the early MIS 5e South Reef unit by as much as 3 m down to a +0.5 m above present sea-level elevation. The upper MIS 5e Boat Cove unit displays a maximum of +4.5 m elevation above present-day sea level, measured from the middle of the foreshore. This estimate may be a minimum value as the exposures on the west coast are part of a forced regressive foreshore sequence. Last stages of the upper MIS 5e deposition are seen in a series of regressive dune-beach ridge deposits referred to as the Northeast Ridges unit, with sea-level positions ranging from +4.5 m early in the central part of West Caicos, to +0.5 m on the far northeast coast, eventually building down below present-day sea level. This sea-level history fits well with previously documented records in the Bahamas and globally, and the extensive erosion supports a short-lived (between 126 and 120 ka) intra-MIS 5e relative-sea-level fall. Holocene deposition on West Caicos is restricted to northern and eastern margins of the island as a combination of strandplain and dune ridge mixed skeletal–oolitic units.Using the high-resolution digital elevation model (DEM) and linked digital geologic map makes it possible to compare areas of the different Pleistocene and Holocene units quantitatively and to constrain volumetric assessments and accumulation rates on the island for different units. The peak sediment volume production/accumulation rate—between 6.5 and 8 × 106 m3 or between 2.2 and 2.7 × 106 m3 per ka—is observed in the upper MIS 5e unit. This rate is 5 times greater than the 0.5 × 106 m3 per ka estimated for the Holocene ooid dune-ridge/strandplain complex, suggesting that the combination of higher sea level, greater wave and wind energy, and warmer ocean temperatures may have fostered the higher rate of chemically precipitated sediment supply.

Reconciling molecules and morphology in North AmericanMartes

Molecular investigations recently resurrected the Pacific marten (Martes caurina) as a species distinct from the American pine marten (M. americana). Previously, 2 hybrid zones for these species were identified, 1 in the northern Rocky Mountains and another on Kuiu Island off the coast of Southeast Alaska. We test the molecular perspectives on species status and hybridization using geometric morphometrics to characterize size and shape differences between North American marten species from 6 genetically defined populations: M. americana from interior Alaska, insular M. caurina from Admiralty Island in Southeast Alaska, M. caurina from Colorado, the 2 previously identified hybrid populations, and a third suspected hybrid population on neighboring Kupreanof Island. We found significant differences in shape supporting the designation of 2 morphological species, with M. caurina exhibiting a broader cranial shape and shorter rostrum. We also found significant size differences between species, and also between insular and mainland populations of M. caurina. Morphological intergradation of M. americana and M. caurina in both insular and mainland hybrid zones identified potentially admixed individuals in 2 of the 3 examined contact zones. Under the general lineage concept, our results support specieslevel classification of both M. americana and M. caurina and suggest that hybridization is geographically limited in scope or may not be effectively detected with morphometrics.

Seasonal surveillance confirms the range expansion of Aedes japonicus japonicus (Theobald) (Diptera: Culicidae) to the Hawaiian Islands of Oahu and Kauai

Abstract The Asian bush mosquito, Aedes japonicus japonicus (Theobald) was not known to occur in the Hawaii archipelago until it was identified on the island of Hawaii in 2003. This mosquito species remained undetected on the neighboring islands for 8 years before it was discovered at the Honolulu International Airport on Oahu in 2012. By 2015, four Ae. j. japonicus mosquitoes were collected in the western mountains of Oahu and one was collected in the central mountains of Kauai. The collection of this invasive mosquito species across the neighboring Hawaiian Islands of Oahu and Kauai indicated the need for increased seasonal surveillance on these islands. Following nearly four years of surveillance, Ae. j. japonicus was also confirmed to occur in the eastern mountains of Oahu and in the central mountainous region of Kauai. To expand the knowledge of the spread of invasive mosquitoes species further surveillance is necessary to identify all possible areas where populations of Ae. j. japonicus and other invasive mosquito species occur in Hawaiian archipelago.

Comparative Phylogeography of Forest-Dependent Mammals Reveals Paleo-Forest Corridors throughout Sundaland.

The evolutionary history of the colugo, a gliding arboreal mammal distributed throughout Sundaland, was influenced by the location of and connections between forest habitats. By comparing colugo phylogenetic patterns, species ecology, sample distributions, and times of divergence to those of other Sundaic taxa with different life-history traits and dispersal capabilities, we inferred the probable distribution of paleo-forest corridors and their influence on observed biogeographic patterns. We identified a consistent pattern of early diversification between east and west Bornean lineages in colugos, lesser mouse deer, and Sunda pangolins, but not in greater mouse deer. This deep east-west split within Borneo has not been commonly described in mammals. Colugos on West Borneo diverged from colugos in Peninsular Malaysia and Sumatra in the late Pliocene, however most other mammalian populations distributed across these same geographic regions diverged from a common ancestor more recently in the Pleistocene. Low genetic divergence between colugos on large landmasses and their neighboring satellite islands indicated that past forest distributions were recently much larger than present refugial distributions. Our analysis of colugo evolutionary history reconstructs Borneo as the most likely ancestral area of origin for Sunda colugos, and suggests that forests present during the middle Pliocene within the Sunda Shelf were more evergreen and contiguous, while forests were more fragmented, transient, seasonal, or with lower density canopies in the Pleistocene.

Status of coral reefs of Upolu (Independent State of Samoa) in the South West Pacific and recommendations to promote resilience and recovery of coastal ecosystems

Coral reef ecosystems worldwide are immediately threatened by the impacts of climate change. Here we report on the condition of coral reefs over 83 km of coastline at the island of Upolu, Samoa in the remote South West Pacific in 2016 during the Tara Pacific Expedition. Despite the distance to large urban centers, coral cover was extremely low (<1%) at approximately half of the sites and below 10% at 78% of sites. Two reef fish species, Acanthurus triostegus and Zanclus cornutus, were 10% smaller at Upolu than at neighboring islands. Importantly, coral cover was higher within marine protected areas, indicating that local management action remains a useful tool to support the resilience of local reef ecosystems to anthropogenic impacts. This study may be interpreted as cautionary sign for reef ecosystem health in remote locations on this planet, reinforcing the need to immediately reduce anthropogenic impacts on a global scale.

Performance of the biocontrol agent Secusio extensa (Lepidoptera: Erebidae) on its target host, Senecio madagascariensis (Madagascar fireweed), on an alternate host, Delairea odorata (Cape ivy), and on non-target plants, in Hawaii

The lepidopteran herbivore Secusio extensa (Erebidae: Arctiinae) was purposefully released in Hawaii in 2013 to control Madagascar fireweed, Senecio madagascariensis (Asteraceae: Senecioneae), an invasive weed of rangelands and other open areas. In conjunction with this biocontrol effort, we conducted pre- and post-release monitoring of S. madagascariensis in field plots, and post-release monitoring of non-target plants. Secusio extensa successfully established on the two islands where it was released, dispersed widely, and even colonized a neighboring island. However, in the first three years after release, S. extensa could only be found sporadically and in low abundances on its target host. In contrast, it underwent population outbreaks on the related, alternative host, Cape ivy (Delairea odorata, Asteraceae: Senecioneae), which is also a noxious weed in Hawaii. In addition to D. odorata, we observed S. extensa to feed on only two other related non-target plants in the tribe Senecioneae, among 24 species monitored. In several microsites supporting higher densities of S. extensa on S. madagascariensis, larval abundances peaked during a short period in the spring, but were insufficiently high to cause substantial damage to affected plants. The causes for low larval densities of S. extensa on its target host are unclear. We found no strong evidence for parasitism or predation of S. extensa larvae. However, females preferred to oviposit on D. odorata over S. madagascariensis, and larvae exhibited a marginally significant preference for feeding on D. odorata over S. madagascariensis. This preference, along with lower nutritional quality of S. madagascariensis relative to D. odorata, may explain why S. extensa has been unable to build large populations on its intended target, but has done so on an alternate host. Clarifying the roles of these mechanisms may help predict the continuing performance of S. extensa in controlling S. madagascariensis.

Satellite image analysis and frozen cylinder experiments on thermal erosion of periglacial fluvial islands

AbstractFrozen islands in the Lena River, Siberia, experience rates of fluvial thermal erosion exceeding 10m/year. The islands erode differentially, with rates of frontal retreat exceeding those on island sides. We define the erosion ratio (ER) between the front and sides to estimate this differential erosion. A GIS‐based study of 19 islands from 1967 to 2010 indicated average erosion rates of 19.7 and 3.7 m/year for the island heads and sides, respectively. The average ER over the period was 4.7. An analytical model of local thermal erosion for a frozen cylinder of sand in a turbulent water flow is proposed, assuming an ablation process. Thermal erosion of 19 frozen cylinders was measured for water flows of different temperature and velocity in a cold chamber. As observed in the field, frontal erosion always exceeded lateral erosion, with an average ER of 1.6. The ER decreased with increasing temperature from 5 to 15°C. The higher value of ER in the field may be due to interactions with neighboring islands and banks. An empirical law including phase change and the process of erosion is proposed, and validates our model compared with previous laws that do not account for erosion. The erosion process enhances heat transfer.

Coordinated Responsive Arrays of Surface-Linked Polymer Islands-CORALs.

The concept of co-ordinated responsive arrays of surface-linked islands (polymer CORALs) is introduced. This study targets a responsive system capable of revealing or covering the substrate surface in response to environmental changes in a reversible way. A convenient method of fabrication of polymer CORALs is proposed. It is based on microphase separation that occurs in thin films of supramolecular assemblies of block copolymers with reactive blocks. Such blocks form nanometer-size domains that may serve as anchors for surface-linked polymer islands. Two characteristics of the islands are critically important for the switching function: high grafting density within the islands and small lateral separation that allows interactions between polymer chains grafted to the neighboring islands. This combination permits complete coverage of the substrate surface upon exposure to a good solvent (relaxed state). In a weak solvent, the chains collapse within the islands, thus revealing the substrate (compact state). The morphology of the CORALs in both states and some details of the switching process were studied with atomic force microscopy, grazing incidence small-angle scattering, and coarse-grained molecular dynamic simulations.

Self-Assembly of Metal Oxide Nanoparticles in Liquid Metal toward Nucleation Control for Graphene Single-Crystal Arrays

Summary We have achieved the spontaneous assembly of alumina nanoparticles on a liquid metal surface and further synthesized a very-large-scale graphene single-crystal array. The effective electrical field established as a result of the electrical charge of the alumina nanoparticles in the liquid metal ensures the ordered self-assembly of the alumina islands and lays the foundation for precise spatial control of graphene nucleation, leading to the formation of graphene single-crystal arrays. In addition, controlling the density of the alumina in the liquid metal can precisely tune the periodicity of the arrays. This simple strategy, which is unlike the usual solid/aqueous solution system, opens up new territory for nanoparticle assembly. Focusing on the origin of the nanoparticle interaction that drives the self-assembly of ordered structure in the liquid metal system is a promising avenue for triggering more interesting applications.

Geochemical characterization of mid-distal Nisyros tephra on Datça peninsula (southwestern Anatolia)

We present new distal records of tephra deposits that overly the Kos ignimbrite in seven locations of Datça peninsula. Tephra in one of these locations were previously associated with Nisyros Kyra sub-unit based only on the field characteristics. We use different proxies such as field observations, petrography, mineral, glass, and whole-rock chemistry in order to characterize and correlate the previously and recently identified pumice fall deposits on Datça. The total thickness of the fall deposit reaches to 3.5m. The size of the pumice clasts is generally within the range of lapilli, and they have vitrophyric texture consisting mainly of plagioclase (andesine to labradorite) with scarce clinopyroxene (diopside to augite), olivine (Fo48–50), amphibole (magnesio-hastingsite), and biotite crystals. Amphibole is a ubiquitous phenocryst in all Datça tephra units and used as a criterion for the correlation. Glass major element analyses by EMPA reveal two different groups with andesitic and dacitic compositions. Difference in silica content (up to ca. 4wt%) detected in the same specimen also designates the heterogeneity in pumice glass. This heterogeneity in glass composition is also supported by the frequent occurrence of banded pumice clasts in Datça tephra. Whole-rock composition of the pumice is mainly andesitic with calc-alkaline affinity. Multi-element patterns on primitive-mantle normalized diagram display typical arc-magmatism signature (i.e. depletion in Nb, Ta, Ti, and P).In order to check and eliminate the potential alternatives, we compared the distal deposits on Datça not only with Kyra, but also with other Nisyros tephra units. Yet, Kyra is the only unit that has comparable depositional characteristics, calcic amphibole crystals, andesitic-dacitic glass and whole-rock chemistry, and distal tephra deposits on neighboring islands (Tilos and Chalki). Therefore, we associate Datça tephra deposits with some proximal Kyra subunits of intermediate composition. However, if further geochemical (especially glass and mineral chemistry) data are provided for the Lakkí and Melisserí tephra units, a more thorough tephra correlation will be possible. Finally, our results may have implications on Nisyros tephra dispersal and geochemical characterization.

Niuean

Niuean (ISO 639-3 code niu) is a Polynesian language spoken on the island of Niue, with an additional population of speakers living in New Zealand. Figure 1 indicates where Niue is located with respect to other neighboring islands in the South Pacific. The 2011 Niue Census of Populations and Households cited the number of individuals who had either basic or fluent spoken abilities at 1121 (with 101 non-speakers) (Statistics Niue 2012). English is the second most widely used language on the island. The 2013 New Zealand census cited 4548 individuals living in New Zealand who listed Niuean as one of their languages (Statistics New Zealand 2013). Niuean is classified as ‘definitely endangered’ by UNESCO (Moseley 2010). There are historically two distinct dialects: the older Motu dialect from the northern area, and the more recent Tafiti from the southern area. These dialect differences were once reflected in slight phonological differences in vocabulary items, but the differences have since eroded in the modern language (see McEwen 1970: ix). Previous research on Niuean phonetics and phonology includes a brief outline in Seiter (1980: x), two dictionaries (McEwen 1970, Sperlich 1997), and an article on vowel length (Rolle &amp; Starks 2014). While these works provide an overview of some of the phenomena to be addressed below, this sketch attempts a more thorough documentation of the phonetic structures of Niuean, and provides novel acoustic and articulatory data from the language. Recordings accompanying this paper are of a male speaker (Mr. Krypton Okesene) and a female speaker (the second author).

Seed dispersal increases local species richness and reduces spatial turnover of tropical tree seedlings

Dispersal is thought to be a key process underlying the high spatial diversity of tropical forests. Just how important dispersal is in structuring plant communities is nevertheless an open question because it is very difficult to isolate dispersal from other processes, and thereby measure its effect. Using a unique situation, the loss of vertebrate seed dispersers on the island of Guam and their presence on the neighboring islands of Saipan and Rota, we quantify the contribution of vertebrate seed dispersal to spatial patterns of diversity of tree seedlings in treefall gaps. The presence of vertebrate seed dispersers approximately doubled seedling species richness within canopy gaps and halved species turnover among gaps. Our study demonstrates that dispersal plays a key role in maintaining local and regional patterns of diversity, and highlights the potential for ongoing declines in vertebrate seed dispersers to profoundly alter tropical forest composition.

Short and flat grass preferred by adults of the endangered dragonfly Sympetrum pedemontanum elatum (Odonata: Libellulidae)

Sympetrum pedemontanum (Muller in Allioni) (Odonata: Libellulidae) is widely distributed across the Eurasian continent and its neighboring islands. However, the populations of its subspecies S. pedemontanum elatum (Selys) in Japan have been rapidly decreasing with the loss of habitats in rural and suburban areas since the 1970s. For the conservation of this subspecies, which is now listed as endangered in many prefectures, it is important to understand the habitat preferences of the adults. Previous studies indicate that adult males of this species tend to fly on the flat surface of rice paddy fields. Thus, we hypothesized that they preferred short and flat grass. Field experiments in the Sakasegawa River, Hyogo Prefecture, Japan, showed that adult S. p. elatum significantly preferred the trimmed grass of Phragmites japonicus to untreated shaggy grass, regardless of sex. Our results indicate the importance of grass management for the conservation of this species, not only in and around paddy fields but also in fluvial habitats, which are abundant in Japan.