Seasonal and Daily Shifts in Substrate Use by Settling Butterflies: Conserving Resources for Invertebrates has a Behavioral Dimension

Arthropod habitats comprise utilities, such as places to rest, roost, locate mates, avoid enemies and thermoregulate, as well as consumables such as food supplies. We investigate the value of incorporating behavioral observations on substrate use within the standard mapping programme of the UK Millennium Atlas for expanding knowledge on resource use in butterflies. We find large differences among species and butterfly families in substrate use, including non-vegetation surfaces and human artefacts, when settled. Substantial differences in substrate use when settled and in settling height also occur seasonally and diurnally; settling height is at a minimum during the mid part of the day, whereas throughout the season there is an increase from spring to summer followed by a levelling off in autumn. Significant seasonal and or diurnal patterns occur for eight of the 13 species for which N≥30. Distinctions in settling height are affected by thermal environment and are related to two aspects of thermoregulation behavior, basking and wing appression, the latter both having seasonal components. These findings demonstrate the wide variety of surfaces required by butterfly species as habitat components over time. They also establish the importance of determining the behavior of individuals in relation to substrate use, biotope and vegetation units during standard recording surveys in order to determine the status of individuals located in recording units such as grid squares.     

Relationships between tree component structure,topography and soils of a riverside forest,Rio Botucaraí, Southern Brazil

The relationships among floristic, structural and physiognomic variables of the tree component, flooding regime variations and soil fertility were investigated in a riparian forest fragment (ca. 43 ha) in the Rio Botucaraí watershed near the confluence with the Rio Jacuí, southern Brazil. All the trees with a dbh ≥ 15 cm were surveyed in 100 contiguous 10 × 10 m plots and soil chemical and textural variables were obtained from the analyses of 15 topsoil samples (0–20 cm depth) collected at different locations. The sample sites encompass all the topographic variation of the area. We used canonical correspondence analysis (CCA) to seek correlations between environmental variables and tree component distribution. The 1,547 surveyed individuals belonged to 30 species and 16 botanical families. The Shannon diversity index (H′) and the Pielou equability (J′) were 1.995 and 0.586 nats ind.⁻¹, respectively. Sebastiania commersoniana, Casearia sylvestris, Eugenia uniflora and Eugenia hyemalis presented the highest importance values. Species’ densities chiefly correlated with site elevation, flooding regime and soil chemical fertility. The analyses of ecological categories (EC) revealed that most species are heliophylous and typical of early successional stages. Richness and diversity (P < 0.001) variations from different topographic positions reflect that at the local scale, flooding was a limiting factor for the establishment of certain species suggesting that local processes control species richness and diversity.     

Predation Hot Spots: Large Scale Impact of Local Aggregations

Abstract   Broad scale survey distributions of fish are dominated by some extremely high catches. With a novel survey design we resolved the small-scale fish distribution in the spatio-temporal vicinity of these extreme hauls and showed that in the North Sea they generally do not occur in isolation. An additional case study where stomach contents of fish predators were analyzed revealed that they actually indicate aggregations of piscivorous fish predators on prey aggregations. We show that the predation impact can reach immense dimensions, an aggregation of more than 50 million juvenile cod (Gadus morhua) was entirely wiped out in 5 days by predatory whiting (Merlangius merlangus), aggregating on these juveniles in an area of approximately 18 km². The consumption of only 32 hot spots of similar magnitude as observed in our study adds up to the average size of an incoming North Sea cod year class. These findings support the hypothesis of predation as the major source of mortality in young-of-the-year demersal fish species and questions the generality of fish aggregation as an effective anti-predator strategy. This study highlights the system-wide structuring force of small-scale predation hot spots and further points to the importance of a more realistic implementation of local high-intensity predation events in food web models. Electronic supplementary material:   The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

澳门翼手目物种多样性补充调查及其保护现状

<正>翼手目为哺乳动物中的第二大目,中国的翼手目多样性也在不断更新,Smith和解焱(2009)统计中国翼手目118种,蒋志刚等(2015)则认为中国翼手目有7科34属134种。广东省翼手目有6科24属55种(邹发生和叶冠锋,2016),此后也仍陆续有新纪录,如长指鼠耳蝠(Myotis longipes)(张琴等,2017)、卡氏伏翼(Hypsugo cadornae)(Xie et al., 2021);我们前期对澳门翼手目的调查,发现5科8属10种(黄继展等,2013)。     

Inferring trackline detection probabilities,g(0), for cetaceans from apparent densities in different survey conditions

Visual line‐transect surveys are commonly used to estimate cetacean abundance. A key parameter in such studies is g(0), the probability of detecting an animal that is directly on the transect line. This is typically considered to be constant for a species across survey conditions. A method is developed to estimate the relative values of g(0) in different survey conditions (Beaufort state) by comparing Beaufort‐specific density estimates. The approach is based on fitting generalized additive models, with the presence of a sighting on a survey segment as the dependent variable, Beaufort state as the key explanatory variable, and year, latitude, and longitude as nuisance variables to control for real differences in density over time and space. Values of relative g(0) are estimated for 20 cetacean taxa using 175,000 km of line‐transect survey data from the eastern and central Pacific Ocean from 1986 to 2010. Results show that g(0) decreases as Beaufort state increases, even for visually conspicuous species. This effect is greatest for the least conspicuous species (rough‐toothed dolphins, beaked whales, minke whales, and dwarf and pygmy sperm whales). Ignoring these large effects results in a nontrivial bias in cetacean abundance estimates.     

Xylem Sap Flux Affects Conventional Stem CO2 Efflux Measurements in Tropical Trees

The relationship between sap flux and stem CO₂ efflux was assessed for three mango trees. We observed higher than expected CO₂ effluxes at the place of measurement under intermediate sap flux velocities and lower fluxes under high sap flux velocity. This variation disappeared after removing the tree crown.     

Oil Spill Response Risk Judgments,Decisions, and Mental Models: Findings from Surveying U.S. Stakeholders and Coastal Residents

This study applies a mental models survey approach to assess public thinking about oil spills and oil spill response. Based on prior interdisciplinary oil spill response research, the study first applies qualitative interview results and a response risk decision model to the design of a survey instrument. The decision model considers controlled burning, public health, and seafood safety. Surveying U.S. coastal residents (36,978 pairs of responses) through Google Insights identifies beliefs and gaps in understanding as well as related values and preferences about oil spills, and oil spill responses. A majority of respondents are concerned about economic impacts of major oil spills, and tend to see ocean ecosystems as fragile. They tend to see information about chemical dispersants as more important than ecological baseline information, and dispersants as toxic, persistent, and less effective than other response options. Although respondents regard laboratory studies as predictive of the effects of oil and of controlled burning, they are less confident that scientists agree on the toxicity and effectiveness of dispersants. The results illustrate opportunities to reframe discussions of oil spill response in terms of tradeoffs between response options, and new possibilities for assessing public opinions and beliefs during events.     

DNA barcoding of euryglossine bees and the description of new species of Euhesma Michener (Hymenoptera,Colletidae, Euryglossinae)

This paper launches an open access DNA barcoding project “AUSBS” under the Barcoding of Life Datasystems (BOLD). The aims of the project are to help scientists who lack the necessary morphological knowledge to identify known species using molecular markers, to aid native bee specialists with the recognition of species groups that morphologically are difficult to define, and, eventually, to assist with the recognition of new species among known species. Using integrative taxonomy, i.e. morphological comparison to type specimens in Australian museum collections combined with phylogenetic analysis of a fragment of the mitochondrial DNA cytochrome c oxidase subunit I (mtCOI) gene sequences led to the recognition of four new species of Euhesma Michener (Hymenoptera: Colletidae: Euryglossini) collected during intensive surveys in remote Australian conservation areas, which are described. The new species are Euhesma micans, Euhesma lyngouriae, and Euhesma aulaca in a species group associated with Eremophila flowers, and Euhesma albamala in the walkeriana species group.