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At least 73 records · Page 4Linked to original sources
USGS2001

The behaviour of 39 pesticides in surface waters as a function of scale

A portion of applied pesticides runs off agricultural fields and is transported through surface waters. In this study, the behaviour of 39 pesticides is examined as a function of scale across 14 orders of magnitude from the field to the ocean. Data on pesticide loads in streams from two US Geological Survey programs were combined with literature data from field and watershed studies. The annual load as percent of use (LAPU) was quantified for each of the fields and watersheds and was used as the normalization factor across watersheds and compounds. The in-stream losses of each pesticide were estimated for a model stream with a 15 day travel time (similar in characteristics to the upper Mississippi River). These estimated in-stream losses agreed well with the observed changes in apparent LAPU values as a function of watershed area. In general, herbicides applied to the soil surface had the greatest LAPU values and minimal in-stream losses. Soil-incorporated herbicides had smaller LAPU values and substantial in-stream losses. Insecticides generally had LAPU values similar to the incorporated herbicides, but had more variation in their in-stream losses. On the basis of the LAPU values of the 39 pesticides as a function of watershed area, a generalized conceptual model of the movement of pesticides from the field to the ocean is suggested. The importance of considering both field runoff and in-stream losses is discussed in relation to interpreting monitoring data and making regulatory decisions.

Hydrological Processes↗
USGS1999

Use of female nest characteristics in the sexual behaviour of male sockeye salmon

On three island beaches in Iliamna Lake, Alaska, large numbers of male sockeye salmon gathered and spawned in artificial excavations that mimicked a female's nest immediately prior to spawning, while apparently ignoring the control site. The number of males attracted was correlated positively with changes in the operational sex ratio. In contrast, on the mainland beach examined, no reaction to the artificial nests was apparent. The results are discussed in terms of mate searching behaviour by males, the duration of the spawning period, and associated selection pressures on males to use characteristics of their environment that provide information on availability of females.

Journal of Fish Biology↗
USGS1989

Behaviour of abandoned room and pillar mines in Illinois

Little comprehensive information has been reported on the behaviour of room-and-pillar mines. The objective of this paper is to present case data on mine failures in the Illinois basin for use in practice. Presented are results of an ongoing study and details on the site characteristics of cases where sags have developed on the surface. Site data are reported to show the geologic, mining, and sag conditions that existed. Sags mainly develop from pillar, floor, or pillar-floor failure. The character of the sags depends upon the type of mine failure as well as the overburden response. Preliminary results show that the statistical no-risk tributary pressure decreases over 300% as the mine age increases from about 2 to 100 years at a long-term value of approximately 300 psi (2070 kPa). As more information is collected and more analysis is done, the allowable tributary pressure can be determined for different site conditions. A plot is also reported that depicts the relationship of the maximum subsidence to site conditions. It was found that the modified subsidence factor was heavily dependent upon the overburden rock thickness. ?? 1989 Chapman & Hall Ltd.

International Journal of Mining and Geological Eng↗
USGS2015

Behavioural response of adult sea lamprey (Petromyzon marinus) to predator and conspecific alarm cues: evidence of additive effects

Sea lampreys Petromyzon marinus, an invasive pest in the Upper Great Lakes, avoid odours that represent danger in their habitat. These odours include conspecific alarm cues and predator cues, like 2-phenylethylamine hydrochloride (PEA HCl), which is found in the urine of mammalian predators. Whether conspecific alarm cues and predator cues function additively or synergistically when mixed together is unknown. The objectives of this experimental study were to determine if the avoidance response of sea lamprey to PEA HCl is proportional to the concentration delivered, and if the avoidance response to the combination of a predator cue (PEA HCl) and sea lamprey alarm cue is additive. To accomplish the first objective, groups of ten sea lampreys were placed in an artificial stream channel and presented with stepwise concentrations of PEA HCl ranging from 5 × 10−8 to 5 × 10−10 M and a deionized water control. Sea lampreys exhibited an increase in their avoidance behaviour in response to increasing concentrations of PEA HCl. To accomplish the second objective, sea lampreys were exposed to PEA HCl, conspecific alarm cue and a combination of the two. Sea lampreys responded to the combination of predator cue and conspecific alarm cue in an additive manner.

St.Mary's River↗
USGS1987

Use of stable sulphur isotopes to monitor directly the behaviour of sulphur in coal during thermal desulphurization

A method has been developed using stable sulphur isotope analyses to monitor the behaviour of sulphur forms in a coal during thermal desulphurization. In this method, the natural stable isotopic composition of the pyritic and organic sulphur in coal is used as a tracer to follow their mobility during the desulphurization process. This tracer method is based on the fact that the isotopic compositions of pyritic and organic sulphur are significantly different in some coals. Isotopic results of pyrolysis experiments at temperatures ranging from 350 to 750 °C indicate that the sulphur released with the volatiles is predominantly organic sulphur. The pyritic sulphur is evolved in significant quantities only when pyrolysis temperatures exceed 500 °C. The presence of pyrite seems to have no effect on the amount of organic sulphur evolved during pyrolysis. The chemical and isotopic mass balances achieved from three different samples of the Herrin (No. 6) coal of the Illinois Basin demonstrate that this stable isotope tracer method is quantitative. The main disadvantage of this tracing technique is that not all coals contain isotopically distinct organic and pyritic sulphur.

Illinois, Indiana, Kentucky↗
USGS1962

Behaviour of calcium carbonate in sea water

Anomalies in the behaviour of calcium carbonate in natural solutions diminish when considered in context. Best values found by traditional oceanographie methods for the apparent solubility product constant K ' CaCO 3 in sea water at atmospheric pressure are consistent mineralogically—at 36 parts per thousand salinity and T-25°C, K ' aragonlte is estimated as 1.12 × 10 −6 and K ' calcite as 0.61 × 10 −6 . At 30°C the corresponding values are 0.98 × 10 −6 for aragonite and 0.53 × 10 −6 for calcite. Because the K ' computations do not compensate for ionic activity, however, they cannot give thermodynamically satisfactory results. It is of interest, therefore, that approximate methods and information now available permit the estimation from the same basic data of an activity product constant K CaCO 3 close to that found in solutions to which Debye-Hückel theory applies. Such methods indicate approximate K aragonite 7.8 × 10 −9 for surface sea water at 29°C; K calcite would be proportionately lower. Field data and experimental results indicate that the mineralogy of precipitated CaCO 3 depends primarily on degree of supersaturation, thus also on kinetic or biologic factors that facilitate or inhibit a high degree of supersaturation. The shallow, generally hypersaline bank waters west of Andros Island yield aragonitic sediments with O 18 O 16 "> O18O16 ratios that imply precipitation mainly during the warmer months, when the combination of a high rate of evaporation, increasing salinity (and ionic strength), maximal temperatures and photosynthetic removal of CO 2 result in high apparent supersaturation. The usual precipitate from solutions of low ionic strength is calcite, except where the aragonite level of supersaturation is reached as a result of diffusion phenomena ( e.g. dripstones), gradual and marked evaporation, or biologic intervention. Published data also suggest the possibility of distinct chemical milieus for crystallographic variations in skeletal calcium carbonate. It appears that in nature aragonite precipitates from solutions that are supersaturated with respect to both calcite and aragonite and calcite between saturation levels for the two species. Such a relation is consistent with Ostwald's rule of successive reactions. Aragonitc of marine origin persists in contact with supersaturated interstitial solutions at ordinary temperature and pressure. Conversion to calcite follows transfer to solutions undersaturated with respect to aragonite or upon exposure to the moist atmosphere.

Geochimica et Cosmochimica Acta↗
USGS1996

Comparison of the partitioning behaviours of yttrium, rare earth elements, and titanium between hydrogenetic marine ferromanganese crusts and seawater

In order to evaluate details of the partitioning behaviours of Y, rare earth elements (REEs), and Ti between inorganic metal oxide surfaces and seawater, we studied the distribution of these elements in hydrogenetic marine ferromanganese (Fe-Mn) crusts from the Central Pacific Ocean. Nonphosphatized Fe-Mn crusts display shale-normalized rare earths and yttrium (REY SN ) patterns (Y inserted between Dy and Ho) that are depleted in light REEs (LREEs) and which show negative anomalies for Y sn , and positive anomalies for La SN , Eu SN , Gd SN , and in most cases, Ce sn . They show considerably smaller Y/ Ho ratios than seawater or common igneous and clastic rocks, indicating that Y and Ho are fractionated in the marine environment. Compared to P-poor crusts, REY SN patterns of phosphatized Fe-Mn crusts are similar, but yield pronounced positive Y sn anomalies, stronger positive La SN anomalies, and enrichment of the HREEs relative to the MREEs. The data suggest modification of REY during phosphatization and indicate that studies requiring primary REY distributions or isotopic ratios should be restricted to non-phosphatized (layers of) Fe-Mn crusts. Apparent bulk coefficients, K d m , describing trace metal partitioning between nonphosphatized hydrogenetic Fe-Mn crusts and seawater, are similar for Pr to Eu and decrease for Eu to Yb. Exceptionally high values of K D Ce , which are similar to those of Ti, result from oxidative scavenging of Ce and support previous suggestions that Ce (IV) is a hydroxide-dominated element in seawater. Yttrium and Gd show lower K D values than their respective neighbours in the REY series. Results of modelling the exchange equilibrium between REY dissolved in seawater and REY sorbed on hydrous Fe-Mn oxides corroborate previous studies that suggested the surface complexation of REY can be approximated by their first hydroxide binding constant. Negative “anomalies” occur for stabilities of bulk surface complexes of Gd, La, and particularly Y. The differences in inorganic surface complex stability between Y and Ho and between Gd and its REE neighbours are similar to those shown by the stabilities of complexes with aminocarboxylic acids and are significantly larger than those shown by stabilities of complexes with carboxylic acids. Hence, sorption of Y and REEs onto hydrous Fe-Mn oxides may contribute significantly to the positive Y SN and Gd SN anomalies in seawater.

Geochimica et Cosmochimica Acta↗
USGS2006

Influence of layer charge and charge distribution of smectites on the flow behaviour and swelling of bentonites

The influence of layer charge and charge distribution of dioctahedral smectites on the rheological and swelling properties of bentonites is examined. Layer charge and charge distribution were determined by XRD using the LayerCharge program [Christidis, G.E., Eberl, D.D., 2003. Determination of layer charge characteristics of smectites. Clays Clay Miner. 51, 644-655.]. The rheological properties were determined, after sodium exchange using the optimum amount of Na2CO3, from free swelling tests. Rheological properties were determined using 6.42% suspensions according to industrial practice. In smectites with layer charges of - 0.425 to - 0.470 per half formula unit (phfu), layer charge is inversely correlated with free swelling, viscosity, gel strength, yield strength and thixotropic behaviour. In these smectites, the rheological properties are directly associated with the proportion of low charge layers. By contrast, in low charge and high charge smectites there is no systematic relation between layer charge or the proportion of low charge layers and rheological properties. However, low charge smectites yield more viscous suspensions and swell more than high charge smectites. The rheological properties of bentonites also are affected by the proportion of tetrahedral charge (i.e. beidellitic charge), by the existence of fine-grained minerals having clay size, such as opal-CT and to a lesser degree by the ionic strength and the pH of the suspension. A new method for classification of smectites according to the layer charge based on the XRD characteristics of smecites is proposed, that also is consistent with variations in rheological properties. In this classification scheme the term smectites with intermediate layer charge is proposed. ?? 2006 Elsevier B.V. All rights reserved.

Applied Clay Science↗
USGS2011

Silver nanoparticles: Behaviour and effects in the aquatic environment

This review summarises and evaluates the present knowledge on the behaviour, the biological effects and the routes of uptake of silver nanoparticles (Ag NPs) to organisms, with considerations on the nanoparticle physicochemistry in the ecotoxicity testing systems used. Different types of Ag NP syntheses, characterisation techniques and predicted current and future concentrations in the environment are also outlined. Rapid progress in this area has been made over the last few years, but there is still a critical lack of understanding of the need for characterisation and synthesis in environmental and ecotoxicological studies. Concentration and form of nanomaterials in the environment are difficult to quantify and methodological progress is needed, although sophisticated exposure models show that predicted environmental concentrations (PECs) for Ag NPs in different environmental compartments are at the range of ng L − 1 to mg kg − 1 . The ecotoxicological literature shows that concentrations of Ag NPs below the current and future PECs, as low as just a few ng L − 1 , can affect prokaryotes, invertebrates and fish indicating a significant potential, though poorly characterised, risk to the environment. Mechanisms of toxicity are still poorly understood although it seems clear that in some cases nanoscale specific properties may cause biouptake and toxicity over and above that caused by the dissolved Ag ion. This review concludes with a set of recommendations for the advancement of understanding of the role of nanoscale silver in environmental and ecotoxicological research.

Environment International↗
USGS2003

Comparative behaviour and dietary effects in early life phases of American sturgeons

Experiments were conducted with the larvae and early juveniles of three species of sturgeon to determine effects of diet and development on swimming and foraging behaviour as well as depth distribution in 100-L aquaria. About 500 hatchlings were placed in each tank with two or three replicates of three or six diet treatments, including live and dry feeds. Eight types of swimming or foraging activity were recorded with a lap-top event recorder and with fish counts in three depths of water. Analysis of variance showed live diets resulted in greater foraging activity in upper water horizons than most dry diets for Atlantic sturgeon, Acipenser oxyrhynchus Mitchill. Scouring, a foraging activity, differed among diet types in early juvenile lake sturgeon, A . fulvescens Rafinesque. Developmental effects included early peaks in the performance of swim-up for all species and swim near surface for two of three species. Postlarvae (post-yolk-sac larvae) of shovelnose, Scaphirhynchus platorhynchus (Rafinesque), and Atlantic sturgeon swam inverted, an apparent foraging tactic associated with elevated or air-water surfaces. Postlarvae maintained (lake sturgeon) or shifted to (other species) bottom swimming with increased scouring activity. Shovelnose early postlarvae occupied higher average water-column heights than lake or Atlantic sturgeon. Shovelnose (only species tested) postlarvae showed greater activity in upper water horizons at night. These results suggest a fundamental shift to benthic foraging during the postlarval phase, with shovelnose sturgeon continuing to forage in suprabenthic zones to a greater degree than the other two species.

Fisheries Management and Ecology↗
USGS2024

Season of death, pathogen persistence and wildlife behaviour alter number of anthrax secondary infections from environmental reservoirs

An important part of infectious disease management is predicting factors that influence disease outbreaks, such as R , the number of secondary infections arising from an infected individual. Estimating R is particularly challenging for environmentally transmitted pathogens given time lags between cases and subsequent infections. Here, we calculated R for Bacillus anthracis infections arising from anthrax carcass sites in Etosha National Park, Namibia. Combining host behavioural data, pathogen concentrations and simulation models, we show that R is spatially and temporally variable, driven by spore concentrations at death, host visitation rates and early preference for foraging at infectious sites. While spores were detected up to a decade after death, most secondary infections occurred within 2 years. Transmission simulations under scenarios combining site infectiousness and host exposure risk under different environmental conditions led to dramatically different outbreak dynamics, from pathogen extinction ( R < 1) to explosive outbreaks ( R > 10). These transmission heterogeneities may explain variation in anthrax outbreak dynamics observed globally, and more generally, the critical importance of environmental variation underlying host–pathogen interactions. Notably, our approach allowed us to estimate the lethal dose of a highly virulent pathogen non-invasively from observational studies and epidemiological data, useful when experiments on wildlife are undesirable or impractical.

Etosha National Park↗
USGS2010

Global positioning system and associated technologies in animal behaviour and ecological research

Biologists can equip animals with global positioning system (GPS) technology to obtain accurate (less than or equal to 30 m) locations that can be combined with sensor data to study animal behaviour and ecology. We provide the background of GPS techniques that have been used to gather data for wildlife studies. We review how GPS has been integrated into functional systems with data storage, data transfer, power supplies, packaging and sensor technologies to collect temperature, activity, proximity and mortality data from terrestrial species and birds. GPS 'rapid fixing' technologies combined with sensors provide location, dive frequency and duration profiles, and underwater acoustic information for the study of marine species. We examine how these rapid fixing technologies may be applied to terrestrial and avian applications. We discuss positional data quality and the capability for high-frequency sampling associated with GPS locations. We present alternatives for storing and retrieving data by using dataloggers (biologging), radio-frequency download systems (e.g. very high frequency, spread spectrum), integration of GPS with other satellite systems (e.g. Argos, Globalstar) and potential new data recovery technologies (e.g. network nodes). GPS is one component among many rapidly evolving technologies. Therefore, we recommend that users and suppliers interact to ensure the availability of appropriate equipment to meet animal research objectives.

Philosophical Transactions of the Royal Society B:↗
USGS2026

Roost switching and behavioural shifts following human disturbance of vampire bats in complex landscapes

In Latin America, management of vampire bats has had inconsistent effects on the spread of lethal rabies infections from bats to humans and livestock. Positive and negative effects on rabies are hypothesised to reflect changes in bat roost fidelity and behaviour following human disturbance, but high landscape complexity has precluded monitoring bat movement in the areas where rabies transmission and bat management activity are most intense. We used animal-borne GPS tags to track 93 vampire bats in a rabies hotspot in the Peruvian Andes, where limited satellite visibility led to partial observation of animal locations. Immediately after capture, handling and tag application, 43% of bats, particularly males and bats with longer forearms, disappeared from the study area, suggesting a rapid roost switching response. Among the remaining 55 bats, a Bayesian state-space model revealed high individual heterogeneity on the disturbance night but on average increased flight distances. Over the remaining 8-night study period, bats gradually remained closer to the roost. These disturbance-driven shifts provide mechanisms to explain how bat disturbance can both accelerate and decelerate rabies spatial spread. More broadly, we present a modelling framework to infer key movement metrics in landscapes where GPS data limitations challenge conventional movement models.

BioRxiv↗
USGS2022

Behavioural adjustments in the social associations of a precocial shorebird mediate the costs and benefits of grouping decisions

Animals weigh multiple costs and benefits when making grouping decisions. The cost-avoidance grouping framework proposes that group density, information quality and risk affect an individual’s preference for con or heterospecific groups. However, this assumes the cost–benefit balance of a particular grouping is constant spatiotemporally, which may not always be true. Investigating how spatiotemporal context influences grouping choices is therefore key to understanding how animals contend with changing conditions. Changes in body size during development lead to variable conditions for individuals over short time-scales that can influence their ecological interactions. Hudsonian godwits Limosa haemastica , for instance, form a protective nesting association with a major predator of young godwit chicks, colonial short-billed gulls Larus brachyrhynchus . Godwit broods may avoid areas of higher gull densities when chicks are susceptible to gull predation but likely experience higher risk from alternative predators as a result. Associating with conspecifics could allow godwits to buffer these costs but requires enough other broods with whom to group. To determine how age-dependent predation risk and conspecific density influence godwit grouping behaviours, we first quantified the time-dependent effects of con- and heterospecific interactions on the mortality risk for godwit chicks throughout development. We then determined how godwit density and chick age affected their associations with con- and heterospecific. We found that younger godwit chicks' survival improved with closer association with conspecifics, earlier hatch dates and lower gull densities, whereas older chicks survived better with earlier hatch dates, though this effect was less clear. Concomitantly, godwit broods avoided gulls early in development and when godwit densities were high but maintained loose associations with conspecifics throughout development. We identified how individuals can optimally shift with whom they group according to risks that vary spatially and temporally. Investigating the effects of a species' ecological interactions across spatiotemporal contexts in this way can shed light on how animals adjust their associations according to the costs and benefits of each association.

Journal of Animal Ecology↗
USGS2014

Diverse juvenile life-history behaviours contribute to the spawning stock of an anadromous fish population

Habitat quality often varies substantially across space and time, producing a shifting mosaic of growth and mortality trade-offs across watersheds. Traditional studies of juvenile habitat use have emphasised the evolution of single optimal strategies that maximise recruitment to adulthood and eventual fitness. However, linking the distribution of individual behaviours that contribute to recruitment at the population level has been elusive, particularly for highly fecund aquatic organisms. We examined juvenile habitat use within a population of sockeye salmon (Oncorhynchus nerka) that spawn in a watershed consisting of two interconnected lakes and a marine lagoon. Otolith microchemical analysis revealed that the productive headwater lake accounted for about half of juvenile growth for those individuals surviving to spawn in a single river in the upper watershed. However, 47% of adults had achieved more than half of their juvenile growth in the downstream less productive lake, and 3% of individuals migrated to the estuarine environment during their first summer and returned to freshwater to overwinter before migrating back to sea. These results describe a diversity of viable habitat-use strategies by juvenile sockeye salmon that may buffer the population against poor conditions in any single rearing environment, reduce density-dependent mortality and have implications for the designation of critical habitat for conservation purposes. A network of accessible alternative habitats providing trade-offs in growth and survival may be important for long-term viability of populations.

Alaska↗
USGS2025

Consistent individual differences and plasticity in migration behaviour of three North American ungulates

Migratory herbivores often time spring migration to coincide with the green-up of plants. When the timing of green-up changes across years, herbivores can respond directly and be plastic to changing conditions or populations may adapt via inherent differences among individuals that may allow for an evolutionary response. We quantified plasticity and individual variation in the timing of spring migration and selection for high-quality forage as a function of the timing of spring green-up using behavioural reaction norms for three North American ungulate species. The timing of arrival to summer range (but not departure from winter range) was plastic to the timing of green-up, and both arrival and departure timing were repeatable. Our results suggest that herbivores synchronise migration with the timing of green-up by adjusting the pace of migration and may be buffered against change via individual differences. Quantifying plasticity and differences in responses represents a crucial step to elucidating the fate of species in a changing world.

Wyoming↗
USGS2014

Mortality, movement and behaviour of native mussels during a planned water-level drawdown in the Upper Mississippi River

Managers in the Upper Mississippi River (UMR) are using reductions in the River's water levels during summer to mimic historical water regimes and rehabilitate habitats for vegetation and other species. Concerns for the unintended effects of these actions on mussel populations threatened to halt these projects. Our objective was to characterise the survival and movement of two mussel species in the UMR associated with a water level drawdown. During 2009 (no drawdown) and 2010 (0.3 m summer drawdown), we glued passive integrated transponder tags to 10 Amblema plicata and 10 Lampsilis cardium at each of 11 sites. Five sites were in shallow areas expected to be minimally affected by the drawdown (reference sites), and six sites were in shallow areas expected to be directly affected by the drawdown (treatment sites). About equal numbers of sites within both the reference and treatment areas had low and high slopes. Tagged mussels were randomly allocated across sites (within years). Recovery of tagged mussels was >88% in 2009 and 2010. Mortality was similar and low (mean, c . 5% in both species) among reference sites but was variable and relatively high (means, c . 27% in L. cardium and c . 52% in A. plicata ) among treatment sites; variation in mortality among treatment sites appeared related to slope. The study found evidence of drawdown associations with net horizontal movements in A. plicata but not L. cardium . Weekly horizontal movements in both species were significantly correlated with changes in water elevation. We observed significant slope associations related to the drawdown for mortality and net horizontal movement in A. plicata . There were strong species-specific differences in the effects of the drawdown on mortality, vertical movement and horizontal movement. These results suggest that A. plicata responded to the drawdown by vertical movement into the substratum, whereas L. cardium responded by horizontal movement to deeper water. No directionality of movement was observed in either species. Collectively, these data suggest that drawdowns can influence the mortality, movement and behaviour of mussels in the UMR. However, more information on spatial and temporal distributions of mussels is needed to better understand the magnitude of these effects. Results from this study are being used by resource managers to better evaluate the effects of this management tool on native mussel assemblages.

Minnesota, Wisconsin↗
USGS2017

Meteorological and environmental variables affect flight behaviour and decision-making of an obligate soaring bird, the California Condor Gymnogyps californianus

The movements of animals are limited by evolutionary constraints and ecological processes and are strongly influenced by the medium through which they travel. For flying animals, variation in atmospheric conditions is critically influential in movement. Obligate soaring birds depend on external sources of updraft more than do other flying species, as without that updraft they are unable to sustain flight for extended periods. These species are therefore good models for understanding how the environment can influence decisions about movement. We used meteorological and topographic variables to understand the environmental influences on the decision to engage in flight by obligate soaring and critically endangered California Condors Gymnogyps californianus . Condors were more likely to fly, soared at higher altitudes and flew over smoother terrain when weather conditions promoted either thermal or orographic updrafts, for example when turbulence and solar radiation were higher and when winds from the east and north were stronger. However, increased atmospheric stability, which is inconsistent with thermal development but may be associated with orographic updrafts, was correlated with a somewhat higher probability of being in flight at lower altitudes and over rougher terrain. The close and previously undescribed linkages between Condor flight and conditions that support development of thermal and orographic updrafts provide important insight into the behaviour of obligate soaring birds and into the environmental parameters that may define the currently expanding distribution of Condors within and outside the state of California.

California↗