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311.
Importance of Accounting for Detection Heterogeneity When Estimating Abundance: the Case of French Wolves 总被引:1,自引:0,他引:1
SARAH CUBAYNES ROGER PRADEL RÉMI CHOQUET CHRISTOPHE DUCHAMP JEAN‐MICHEL GAILLARD JEAN‐DOMINIQUE LEBRETON ERIC MARBOUTIN CHRISTIAN MIQUEL ANNE‐MARIE REBOULET CAROLE POILLOT PIERRE TABERLET OLIVIER GIMENEZ 《Conservation biology》2010,24(2):621-626
Abstract: Assessing conservation strategies requires reliable estimates of abundance. Because detecting all individuals is most often impossible in free‐ranging populations, estimation procedures have to account for a <1 detection probability. Capture–recapture methods allow biologists to cope with this issue of detectability. Nevertheless, capture–recapture models for open populations are built on the assumption that all individuals share the same detection probability, although detection heterogeneity among individuals has led to underestimating abundance of closed populations. We developed multievent capture–recapture models for an open population and proposed an associated estimator of population size that both account for individual detection heterogeneity (IDH). We considered a two‐class mixture model with weakly and highly detectable individuals to account for IDH. In a noninvasive capture–recapture study of wolves we based on genotypes identified in feces and hairs, we found a large underestimation of population size (27% on average) occurred when IDH was ignored. 相似文献
312.
Timothée Romuald Cook Frédéric Bailleul Amélie Lescroël Yann Tremblay Charles-André Bost 《Marine Biology》2008,154(2):383-391
Knowing the depth zone of neutral buoyancy of divers is important because buoyancy can determine how animals manage their
energy budget. In this study, we estimate the depth zone of neutral buoyancy of free-ranging cormorants for the first time,
using time-depth recorders. We discovered that vertical ascent rates of 12 Crozet and 15 Kerguelen diving blue-eyed shags
(respectively Phalacrocorax
melanogenis and P.
verrucosus) slowed down considerably at the 50–60 m depth zone. We suggest this was due to birds trying to reach the surface from that
point upwards using reduced locomotor activity because the force of buoyancy becomes greater than the force of gravity at
that depth. The results show a shift of this depth zone in relation to maximum targeted dive depth, suggesting cormorants
may control buoyancy through respiratory air volume adjustment. Interestingly, 60 m is close to the maximum depth zone reached
by these two species during dives lasting 4 min, their estimated behavioural aerobic dive limit. This suggests that the decision
to swim deeper has a direct consequence on the energy budget, with time spent recovering at the surface (time thus lost to
foraging) strongly increasing relative to the preceding time of submergence. Resources found in deeper waters must be of sufficient
quantity or quality to justify crossing the frontier of physical neutral buoyancy. 相似文献
313.
The impact of 2 × CO2 driven climate change on radial growth of boreal tree species Pinus banksiana Lamb., Populus tremuloides Michx. and Picea mariana (Mill.) BSP growing in the Duck Mountain Provincial Forest of Manitoba (DMPF), Canada, is simulated using empirical and process-based model approaches. First, empirical relationships between growth and climate are developed. Stepwise multiple-regression models are conducted between tree-ring growth increments (TRGI) and monthly drought, precipitation and temperature series. Predictive skills are tested using a calibration–verification scheme. The established relationships are then transferred to climates driven by 1× and 2 × CO2 scenarios using outputs from the Canadian second-generation coupled global climate model. Second, empirical results are contrasted with process-based projections of net primary productivity allocated to stem development (NPPs). At the finest scale, a leaf-level model of photosynthesis is used to simulate canopy properties per species and their interaction with the variability in radiation, temperature and vapour pressure deficit. Then, a top-down plot-level model of forest productivity is used to simulate landscape-level productivity by capturing the between-stand variability in forest cover. Results show that the predicted TRGI from the empirical models account for up to 56.3% of the variance in the observed TRGI over the period 1912–1999. Under a 2 × CO2 scenario, the predicted impact of climate change is a radial growth decline for all three species under study. However, projections obtained from the process-based model suggest that an increasing growing season length in a changing climate could counteract and potentially overwhelm the negative influence of increased drought stress. The divergence between TRGI and NPPs simulations likely resulted, among others, from assumptions about soil water holding capacity and from calibration of variables affecting gross primary productivity. An attempt was therefore made to bridge the gap between the two modelling approaches by using physiological variables as TRGI predictors. Results obtained in this manner are similar to those obtained using climate variables, and suggest that the positive effect of increasing growing season length would be counteracted by increasing summer temperatures. Notwithstanding uncertainties in these simulations (CO2 fertilization effect, feedback from disturbance regimes, phenology of species, and uncertainties in future CO2 emissions), a decrease in forest productivity with climate change should be considered as a plausible scenario in sustainable forest management planning of the DMPF. 相似文献
314.
Residential Water Consumption,Motivation for Conserving Water and the Continuing Tragedy of the Commons 总被引:1,自引:0,他引:1
Corral-Verdugo V Frías-Armenta M Pérez-Urias F Orduña-Cabrera V Espinoza-Gallego N 《Environmental management》2002,30(4):527-535
This paper explores the effect of the perception of externalities (PE) on residential water consumption. Externalities occur
when individuals make decisions that harm others, without concern for the impact or feeling a need to compensate for the harm.
The aim of this study was to investigate whether PE affects people's motivation to conserve water, and, consequently, the
practice of residential water consumption. Two hundred eighty Mexican citizens responded to a questionnaire investigating
how they perceived that other individuals in their community wasted water. Respondents were also asked about their motives
to conserve water, and direct observations of individual water consumption were recorded. Results were processed within a
structural equations model, which revealed that motives to conserve water significantly inhibit water consumption. Since the
perception of externalities also inhibits conservation motives, the resulting effect of PE on water consumption is positive.
This result means that the more people perceive that others waste water, the less their conservation motives, and, therefore,
the more their own water consumption. 相似文献
315.
316.
Jean-Marie Jouannic Marc Dommergues Frédéric Auber Roger Bessis Claire Nihoul-Fekete Yves Dumez 《黑龙江环境通报》2001,21(10):824-826
We report a case of a sacrococcygeal teratoma (SCT) diagnosed at 22 weeks with a substantial intrapelvic cystic extension leading to bladder outlet obstruction and hydronephrosis at 27 weeks. Prenatal percutaneous shunting of the cystic teratoma was performed at 28 weeks to avoid prolonged fetal pelvic compression by the tumour that could have adverse effects by stretching the pelvic plexus and sacral nerves. Urinary dilatation resolved completely after shunting and a 3880 g baby girl was delivered at 39 weeks. The potential benefits of in utero shunting to avoid urological complications of SCTs with intrapelvic extension are discussed. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
317.
Mélanie Brun Christophe Abraham Marc Jarry Jacques Dumas Frédéric Lange Etienne Prévost 《Ecological modelling》2011,222(5):1069-1079
Abundance indicators are required both to assess and to manage wild populations. As new techniques are developed and teams in charge of gathering the data change, data collection procedures (DCPs) can evolve in space and time. How to estimate an homogeneous series of abundance indicator despite changes in DCP? To tackle this question a hierarchical Bayesian modelling (HBM) approach is proposed. It integrates multiple DCPs in order to derive a single abundance indicator that can be compared over space and time irrespective of the DCP used. Compared to single DCP models, it takes further advantage for abundance estimation of the joint treatment of a larger set of spatio-temporal units. After presenting the general formulation of our HBM approach, it is applied to the juvenile Atlantic salmon (Salmo salar L.) population of the River Nivelle (France). Posterior model checking, using χ2 discrepancy measure, do not reveal any inadequacy between the model and the data. Despite a change in the DCP used (successive removals to catch-per-unit of effort), a unique abundance indicator for the 425 spatio-temporal units (site × year) sampled over twenty-four years (1985-2008) is estimated. The HBM approach allows the assessment of precision of the abundance estimates and shows variation between DCPs: a reduction in precision is observed during the most recent years (2005-2008) when only the catch-per-unit of effort DCP was used. The merits and generality of our HBM approach are discussed. We contend it extends previous single DCP models or inter-calibration of two DCPs, and it could be applied to a wide range of specific situations (taxon and DCPs). 相似文献
318.
McCune Frédéric Samson-Robert Olivier Rondeau Sabrina Chagnon Madeleine Fournier Valérie 《Environmental science and pollution research international》2021,28(14):17573-17586
Environmental Science and Pollution Research - Water is essential for honey bees (Apis mellifera L.), but contaminated sources of water in agricultural environments represent a risk of exposure to... 相似文献
319.
Environmental Chemistry Letters - Air pollution, measured by the concentration of airborne particulate matter with diameter below 2.5 μm (PM2.5), is known to cause globally adverse... 相似文献