Inferring linear feature use in the presence of GPS measurement error

Global Positioning System (GPS) collars are increasingly used to study animal movement and habitat use. Measurement error is defined as the difference between the observed and true value being measured. In GPS data measurement error is referred to as location error and leads to misclassification of observed locations into habitat types. This is particularily true when studying habitats of small spatial extent with large amounts of edge, such as linear features (e.g. roads and seismic lines). However, no consistent framework exists to address the effect of measurement error on habitat classification of observed locations and resulting biological inference. We developed a mechanistic, empirically-based method for buffering linear features that minimizes the underestimation of animal use introduced by GPS measurement error. To do this we quantified the distribution of measurement error and derived an explicit formula for buffer radius which incorporated the error distribution, the width of the linear feature, and a predefined amount of acceptable type I error in location classification. In our empirical study we found the GPS measurement error of the Lotek GPS_3300 collar followed a bivariate Laplace distribution with parameter ρ = 0.1123. When we applied our method to a simulated landscape, type I error was reduced by 57%. This study highlights the need to address the effect of GPS measurement error in animal location classification, particularily for habitats of small spatial extent.     

Reproductive ecology of <Emphasis Type="Italic">Fungiacyathus marenzelleri</Emphasis> from 4100 m depth in the northeast Pacific Ocean

Fungiacyathus marenzelleri (Vaughan, 1906) is a deep-water solitary coral, cosmopolitan in distribution that is found at depths of 300–6,328 m. This study examined gametogenesis, inter-annual variability and reproductive periodicity of F. marenzelleri collected from Station M (34°50′N, 123°00′W) in the northeast Pacific at a depth of 4,100 m. Samples were collected (May, June, October 1996; August 1998; February, June 2001; and June 2002) and histologically processed with spermatogenic stage, oocyte size and fecundity measured. Four stages of spermatogenesis were identified and all males contained multiple stages of sperm development in each seasonal sample. Three stages of oocyte development were identified; previtellogenic (<28–150 μm), vitellogenic (150–300 μm) and late vitellogenic (300–400 μm). Comparison of mean oocyte diameters among sampling dates showed there were no inter-annual variations or seasonal differences. Overall, fecundity was 1,290 (±407) oocytes polyp⁻¹, and with no significant differences between sample months. Fecundity was not polyp-size dependent. This study shows a similar quasi-continuous mode of reproduction to this species examined from the Northeast Atlantic Ocean, but the fecundity is reduced by 50%. The reproductive output may fluctuate in relation to the input of organic material at this site, as shown by non-significant trends in the oocyte size-frequency and fecundity data. A quasi-continuous output of gametes would promote successful fertilisation and wide dispersal of the lecithotrophic larvae.     

Novel system of communication in crickets originated at the same time as bat echolocation and includes male-male multimodal communication

The Science of Nature - The capability of producing sounds and vibrations is well known in insects and is thought to be a form of intra- and interspecific communication. Sounds and vibrations are...     

Chemical and Physical Controls on the Oxygen Regime of Ice‐Covered Arctic Lakes and Reservoirs1

Abstract: We examined the chemical, morphological, and anthropogenic controls on winter‐oxygen biogeochemistry in ice‐covered lakes and reservoirs on the North Slope of Alaska. We measured dissolved oxygen (DO), solute concentrations, water depth, and ice thickness at three natural thaw lakes and four reservoirs (flooded gravel mines) for two winters. In all seven study sites, DO concentration and pH decreased with depth, and temporally through the winter (November to April). DO concentration was four to six times greater in the deeper reservoirs (8‐13 mg/l) compared with shallow natural lakes (ca. 2 mg/l). Lakes and reservoirs with high dissolved organic carbon (DOC) concentration were susceptible to large decreases in oxygen over the winter. DO concentration differed markedly between years, but was not attributed to changes in water‐use or winter water‐chemistry. Alternatively, we suggest that dissolved oxygen concentration was lower during freeze‐up, possibly associated with higher lake‐productivity during the summer. Our results suggest that current water‐use practices on the North Slope of Alaska caused little to no change in DO concentration over the winter. In particular, considering the high pumping activity and shallow depth, lakes with low DOC concentration (≤6 mg/l) showed strong resilience to change in chemistry over the winter. We suggest that both lake and reservoir depth, and DOC concentration are key factors influencing oxygen consumption in ice‐covered arctic lakes and reservoirs.     

The Adaptation for Conservation Targets (ACT) Framework: A Tool for Incorporating Climate Change into Natural Resource Management

As natural resource management agencies and conservation organizations seek guidance on responding to climate change, myriad potential actions and strategies have been proposed for increasing the long-term viability of some attributes of natural systems. Managers need practical tools for selecting among these actions and strategies to develop a tailored management approach for specific targets at a given location. We developed and present one such tool, the participatory Adaptation for Conservation Targets (ACT) framework, which considers the effects of climate change in the development of management actions for particular species, ecosystems and ecological functions. Our framework is based on the premise that effective adaptation of management to climate change can rely on local knowledge of an ecosystem and does not necessarily require detailed projections of climate change or its effects. We illustrate the ACT framework by applying it to an ecological function in the Greater Yellowstone Ecosystem (Montana, Wyoming, and Idaho, USA)-water flows in the upper Yellowstone River. We suggest that the ACT framework is a practical tool for initiating adaptation planning, and for generating and communicating specific management interventions given an increasingly altered, yet uncertain, climate.     

Building Local Community Commitment to Wetlands Restoration: A Case Study of the Cache River Wetlands in Southern Illinois, USA

Natural resource professionals are increasingly faced with the challenges of cultivating community-based support for wetland ecosystem restoration. While extensive research efforts have been directed toward understanding the biophysical dimensions of wetland conservation, the literature provides less guidance on how to successfully integrate community stakeholders into restoration planning. Therefore, this study explores the social construction of wetlands locally, and community members’ perceptions of the wetland restoration project in the Cache River Watershed of southern Illinois, where public and private agencies have partnered together to implement a large-scale wetlands restoration project. Findings illustrate that the wetlands hold diverse and significant meanings to community members and that community members’ criteria for project success may vary from those identified by project managers. The case study provides managers with strategies for building community commitment such as engaging local citizens in project planning, minimizing local burdens, maximizing local benefits, and reducing uncertainty.     

The moral self: A review and integration of the literature

The role of the self in moral functioning has gained considerable theoretical and empirical attention over the last 25 years. A general consensus has emerged that the self plays a vital role in individuals' moral agency. This surge of research produced a proliferation of constructs related to the moral self, each grounded in diverse theoretical perspectives. Although this work has advanced our understanding of moral thought and behavior, there has also been a lack of clarity as to the nature and functioning of the moral self. We review and synthesize empirical research related to the moral self and provide an integrative framework to increase conceptual coherence among the various relevant constructs. We then discuss emerging opportunities and future directions for research on the moral self as well as implications for behavioral ethics in organizational contexts. Copyright © 2014 John Wiley & Sons, Ltd.     

Air-substrate mercury exchange associated with landfill disposal of coal combustion products

Previous laboratory studies have shown that lignite-derived fly ash emitted mercury (Hg) to the atmosphere, whereas bituminous- and subbituminous-derived fly ash samples adsorbed Hg from the air. In addition, wet flue gas desulfurization (FGD) materials were found to have higher Hg emission rates than fly ash. This study investigated in situ Hg emissions at a blended bituminous-subbituminous ash landfill in the Great Lakes area and a lignite-derived ash and FGD solids landfill in the Midwestern United States using a dynamic field chamber. Fly ash and saturated FGD materials emitted Hg to atmosphere at low rates (-0.1 to 1.2 ng/ m2hr), whereas FGD material mixed with fly ash and pyrite exhibited higher emission rates (approximately 10 ng/m2hr) but were still comparable with natural background soils (-0.3 to 13 ng/ m2hr). Air temperature, solar radiation, and relative humidity were important factors correlated with measured Hg fluxes. Field study results were not consistent with corresponding laboratory observations in that fluxes measured in the latter were higher and more variable. This is hypothesized to be partially an artifact of the flux measurement methods.