Conservation status of the recently described Ecuadorian Amazon parrot Amazona lilacina

SummaryAmazona lilacina is a threatened species endemic to Ecuador, existing across a patchwork of mangroves, lowland coastal forests, agricultural and community owned land. The species was described in 2014 and listed as ‘Endangered’ on the IUCN Red List, however, full assessment of the population was lacking. Using a combination of field observations, roost surveys and community questionnaires, conducted over the last 20 years, we provide up-to-date information on the species’ Extent of Occurrence, estimate its global population size, and evaluate its level of threat. Our results suggest the species occurs across an area of 19,890 km2 in three distinct geographically isolated subpopulations. Roost surveys across the range estimate the minimum remaining population at 741–1,090 individuals and we present evidence to suggest a 60% decline over the past 19 years in one part of the species’ range. We conducted community questionnaires with 427 people from 52 communities. The presence of pet parrots was reported in 37 communities, including 17 communities which reported pet A. lilacina. From this we predict that over half of all communities within our study area keep parrots as pets and at least 96 communities keep A. lilacina. Our findings justify an IUCN Red Listing of at least ‘Endangered’ for this species and highlight the need for conservation support. In order to assess population health in more detail, further research is required to assess genetic diversity and roost dynamics, and to identify areas that may be important for feeding and nesting throughout the range. As many of these areas are likely to overlap with community owned land, we suggest that future conservation actions should revolve around, and be led by, these communities.

An experimental investigation of dimensional precision in uncertainty disclosures related to revenue recognition

Purpose The purpose of this paper is to investigate how managerial disclosure of imprecise information about revenue recognition affects investors’ perceptions of corporate and management performance. Specifically, the authors focus on how outcome and probability dimensions and their respective (im) precision interact with each other and jointly affect investors’ judgments and decision-making. Design/methodology/approach The authors conducted an experiment where the dimensions are manipulated (outcome vs probability) of disclosed revenue recognition information and its related precision (a point vs a range estimate). Findings Results from this study suggest that participants are sensitive to specific dimensions of uncertainty disclosure: participants were highly aware of the (im)precision in outcome information, were more likely to invest when both dimensions were vague and expected higher revenue when dimensional precision was consistent. Practical implications The results imply that dimensional precision is an important component in uncertainty disclosure and may have a significant impact on investors’ judgments and decision making. Regulators and managers should consider dimensional imprecision when they develop and implement disclosure strategy regarding revenue recognition. Social implications The results have practical value for regulators/managers, who are in the process of developing/implementing disclosure strategy regarding revenue recognition. Originality/value This is the first study to examine the interaction of dimensions of uncertainty in revenue disclosures.

Study on Model for Settlement Prediction of High-Filled Embankment in Mountainous Area

Mountain high-filled embankment settlement prediction methods need to do some research. With the analysis of the experimental observation’s results, obtained some factors that influence the settlement. Then through the comparison of these three kinds of calculation models with the measured data, obtained the results which are suitable for the construction of the medium range estimate are as follows: Hyperbolic curve method and Exponential curve method. As gray prediction theory method is suitable for the long-term prediction after construction. The comparisons the accuracy of these different methods can provide reference for the prediction of embankment for similar constructions.

Variation in the home-range size of the squirrel glider (Petaurus norfolcensis)

The home-range area of animals may vary geographically and in response to habitat quality. We investigated the size of squirrel glider (Petaurus norfolcensis) home ranges near Brisbane, Queensland, and at Tea Gardens on the central coast of New South Wales. Habitat at both sites had been partially cleared and had been subjected to grazing for several decades. Twelve gliders were tracked over an average of 3.5 months in Brisbane. The fixed kernel (FK95%) home-range estimate averaged 4.6 ± 0.7 (s.e.) ha while the minimum convex polygon (MCP100%) averaged 6.7 ± 1.5 ha. Six gliders were tracked over 1 month at Tea Gardens. The FK95% home-range estimate averaged 14.8 ± 2.4 ha while the MCP100% averaged 13.3 ± 3.1 ha. The Tea Gardens values are derived from relatively short periods and are likely to underestimate the areas used. This study demonstrates that home-range size can vary substantially in the squirrel glider. This has implications for understanding how this species responds to variation in habitat quality and highlights the need for site-specific studies to inform aspects of management.

Historical population assessment of Barents Sea harp seals (Pagophilus groenlandicus)

Skaug, H. J., Frimannslund, L., and Øien, N. I. 2007. Historical population assessment of Barents Sea harp seals (Pagophilus groenlandicus). – ICES Journal of Marine Science, 64: 1356–1365: –. Harp seals are an important component of the Barents Sea ecosystem. Population size is estimated to have been around 6 million seals in 1875, when large-scale exploitation by Norwegian and Russian hunters started. The estimate is obtained by fitting a population dynamics model to all available sources of data on Barents Sea harp seals, but because of a lack of information about several key parameters in the model, the uncertainty associated with the estimate is large. A sensitivity study involving three different mechanisms for density-dependence results in a range estimate of 3–7 million seals in 1875.

Ice-Draft Profiling from Bottom-Mounted ADCP Data

The feasibility of ice-draft profiling using an upward-looking bottom-mounted acoustic Doppler current profiler (ADCP) is demonstrated. Ice draft is determined as the difference between the instrument depth, derived from high-accuracy pressure data, and the distance to the lower ice surface, determined by the ADCP echo travel time. Algorithms for the surface range estimate from the water-track echo intensity profiles, data quality control, and correction procedures have been developed. Sources of error in using an ADCP as an ice profiler were investigated using the models of sound signal propagation and reflection. The effects of atmospheric pressure changes, sound speed variation, finite instrument beamwidth, hardware signal processing, instrument tilt, beam misalignment, and vertical sensor offset are quantified. The developed algorithms are tested using the data from the winter-long ADCP deployment on the northwestern shelf of the Okhotsk Sea.