Pollen foraging behaviour of solitary Hawaiian bees revealed through molecular pollen analysis

Obtaining quantitative information concerning pollinator behaviour has become a primary objective of pollination studies, but methodological limitations hinder progress towards this goal. Here, we use molecular genetic methods in an ecological context to demonstrate that endemic Hawaiian Hylaeus bees (Hymenoptera: Colletidae) selectively collect pollen from native plant species in Haleakala and Hawaii Volcanoes National Parks. We identified pollen DNA from the crops (internal storage organs) of 21 Hylaeus specimens stored in ethanol for up to 3 years. Genetic analyses reveal high fidelity in pollen foraging despite the availability of pollen from multiple plant species present at each study site. At high elevations in Haleakala, pollen was available from more than 12 species of flowering plants, but Hawaiian silversword (Argyroxiphium sandwicense subsp. macrocephalum) comprised 86% of all pollen samples removed from bee crops. At lower elevations in both parks, we only detected pukiawe (Leptecophylla (Styphelia) tameiameiae) pollen in Hylaeus crops despite the presence of other plant species in flower during our study. Furthermore, 100% of Hylaeus crops from which we successfully identified pollen contained native plant pollen. The molecular approaches developed in this study provide species-level information about floral visitation of Hawaiian Hylaeus that does not require specialized palynological expertise needed for high-throughput visual pollen identification. Building upon this approach, future studies can thus develop appropriate and customized criteria for assessing mixed pollen loads from a broader range of sources and from other global regions.     

Occurrence and social structure of Baird's beaked whales,Berardius bairdii,in the Commander Islands,Russia

The social structure of Baird's beaked whales is completely unstudied, and it is unknown if either females or males form long‐term social associations or occur in stable groups. In this paper we summarize our observations of individually identified animals over the span of 6 yr to provide insight on their long‐term social structure. We have identified 122 whales, with 28 of them encountered three times or more and thus included in the analysis of social structure. We found that the whales exhibited nonrandom patterns of social associations with some individuals preferentially associating with each other. Whales with more scarred skin had higher maximum association coefficients, which indicates that older animals and/or males were more inclined to form stable associations. Cluster analysis with a modularity test for gregariousness divided the whales into four clusters. Whales from the same clusters did not always occur together, but some individuals retained stable associations over several years. The strength of social relationships decayed over periods of months, with between‐year relationships showing little deviation from what would be expected if association was random. Generally these findings do not correspond to a stable society with fixed groups but instead suggest a fission‐fusion society with some stable alliances.     

医学检验服务支撑平台在区域医联体中的作用

自2013年以来,北京地区构建了多个区域医联体。在中日友好医院医联体运行的半年多时间里,针对遇到的问题,医联体内各医疗机构采取了许多相应的措施。针对医学检验信息互通,结果互认,样本转运等方面的问题,中日友好医院联合医联体内各成员单位引入医学检验服务支撑平台,探索一种“互助式”的新型医学检验服务模式,力求达到“六统一”的要求,实现医联体的优势互补、资源优化配置作用。     

Will a warmer and wetter future cause extinction of native Hawaiian forest birds?

Isolation of the Hawaiian archipelago produced a highly endemic and unique avifauna. Avian malaria (Plasmodium relictum), an introduced mosquito‐borne pathogen, is a primary cause of extinctions and declines of these endemic honeycreepers. Our research assesses how global climate change will affect future malaria risk and native bird populations. We used an epidemiological model to evaluate future bird–mosquito–malaria dynamics in response to alternative climate projections from the Coupled Model Intercomparison Project. Climate changes during the second half of the century accelerate malaria transmission and cause a dramatic decline in bird abundance. Different temperature and precipitation patterns produce divergent trajectories where native birds persist with low malaria infection under a warmer and dryer projection (RCP4.5), but suffer high malaria infection and severe reductions under hot and dry (RCP8.5) or warm and wet (A1B) futures. We conclude that future global climate change will cause significant decreases in the abundance and diversity of remaining Hawaiian bird communities. Because these effects appear unlikely before mid‐century, natural resource managers have time to implement conservation strategies to protect this unique avifauna from further decimation. Similar climatic drivers for avian and human malaria suggest that mitigation strategies for Hawai'i have broad application to human health.     

PACT in practice: comparative historical biogeographic patterns and species–area relationships of the Greater Antillean and Hawaiian Island terrestrial biotas

Aim To compare the evolutionary and ecological patterns of two extensively studied island biotas with differing geological histories (the Hawaiian Islands and the Greater Antilles). We evaluated the results from PACT (phylogenetic analysis for comparing trees), an innovative approach that has been proposed to reveal general patterns of biotic expansion (between regions) and in situ (within a region) diversification, as well as species–area relationships (SAR) and the taxon pulse dynamic. Location The Hawaiian Islands and Greater Antilles. Methods We used the PACT algorithm to construct general area cladograms and identified biotic expansion and in situ nodes. We analysed the power‐law SAR and relative contribution of biotic expansion and in situ diversification events using power‐law and linear regression analyses. Results Both biotic expansion and in situ nodes were prevalent throughout the PACT general area cladograms (Greater Antilles, 55.9% biotic expansion, 44.1% in situ; Hawaiian Islands, 40.6% biotic expansion, 59.4% in situ). Of the biotic expansion events, both forward and backward events occurred in both regions (Greater Antilles, 85.1% forward, 14.9% backward; Hawaiian Islands, 65% forward, 35% backward). Additionally, there is a power‐law SAR for the Greater Antilles but not for the Hawaiian Islands. However, exclusion of Hawai'i (the youngest, largest Hawaiian Island) produced a power‐law SAR for the Hawaiian Islands. Main conclusions The prevalence of in situ events as well as forward and backward biotic expansion events reveals that both Hawaiian and Greater Antillean biotas have evolved through alternating episodes of biotic expansion and in situ diversification. These patterns are characteristic of the taxon pulse dynamic, for which few data have previously been recorded on islands. Additionally, our analysis revealed that historical influences on the power‐law SARs are pronounced in both assemblages: old, small islands are relatively species rich and young, large islands are relatively species poor. Thus, our PACT results are consistent with hypotheses of geological influence on the evolution of island biotas and also provide greater insight into the role of the taxon pulse dynamic in the formation of island equilibria.     

Indigenous Studies in the Elementary Curriculum: A Cautionary Hawaiian Example

This article uses a Native Hawaiian example to raise difficult questions about the role and responsibility of non-Indigenous educators in teaching and supporting Indigenous studies. It challenges educators and educational researchers to think closely about how they might serve as allies in Indigenous struggles for self-determination.     

Biotic resistance to an invasive spider conferred by generalist insectivorous birds on Hawai’i Island

A central problem for ecology is to understand why some biological invasions succeed while others fail. Species interactions frequently are cited anecdotally for establishment failure, but biotic resistance is not well supported by quantitative experimental studies in animal communities. In a 33-month experiment on Hawaii Island, exclusion of native and alien forest birds resulted in a 25- to 80-fold increase in the density of a single non-indigenous spider species (Theridiidae: Achaearanea cf. riparia). Caged plots held large aggregations of juveniles and more large-bodied individuals, suggesting potential reproductive individuals are more susceptible to bird predation. Most examples of biotic resistance involve competition for limiting resources among sessile marine animals or terrestrial plants. The present results show that generalist predators can limit the success of introductions, even on oceanic islands, generally assumed less resistant to invasion.     

Population divergence and gene flow in an endangered and highly mobile seabird

Seabirds are highly vagile and can disperse up to thousands of kilometers, making it difficult to identify the factors that promote isolation between populations. The endemic Hawaiian petrel (Pterodroma sandwichensis) is one such species. Today it is endangered, and known to breed only on the islands of Hawaii, Maui, Lanai and Kauai. Historical records indicate that a large population formerly bred on Molokai as well, but this population has recently been extirpated. Given the great dispersal potential of these petrels, it remains unclear if populations are genetically distinct and which factors may contribute to isolation between them. We sampled petrels from across their range, including individuals from the presumably extirpated Molokai population. We sequenced 524 bp of mitochondrial DNA, 741 bp from three nuclear introns, and genotyped 18 microsatellite loci in order to examine the patterns of divergence in this species and to investigate the potential underlying mechanisms. Both mitochondrial and nuclear data sets indicated significant genetic differentiation among all modern populations, but no differentiation was found between historic samples from Molokai and modern birds from Lanai. Population-specific nonbreeding distribution and strong natal philopatry may reduce gene flow between populations. However, the lack of population structure between extirpated Molokai birds and modern birds on Lanai indicates that there was substantial gene flow between these populations and that petrels may be able to overcome barriers to dispersal prior to complete extirpation. Hawaiian petrel populations could be considered distinct management units, however, the dwindling population on Hawaii may require translocation to prevent extirpation in the near future.     

Invertebrate Community Associated with the Macroalga Halimeda kanaloana Meadow in Maui,Hawaii

An expansive meadow of the native macroalga Halimeda kanaloana has been found in west Maui, Hawaii. This study examined the invertebrate community associated with the H. kanaloana meadow. Analyses of samples collected by SCUBA divers found that the meadow supports a diverse and unique benthic community. The meadow provides a suitable habitat for a variety of epibenthic and epifaunal invertebrates in the otherwise homogeneous sandy habitat. Infaunal polychaete abundances, species richness and Shannon‐Wiener diversity index were also higher inside the meadow. Abundances of epibenthic organisms, and dissimilarities of the polychaete assemblage, inside and outside the meadow were greater at deeper stations. This might be due to an effect of the Halimeda density rather than depth, suggesting that the macroalgal density might play an important role in shaping the benthic community. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)