scholarly journals Quantitative Assessment of Current Risks to Harlequin Ducks in Prince William Sound, Alaska, from theExxon ValdezOil Spill

Author(s):  
Mark A. Harwell ◽  
John H. Gentile ◽  
Keith R. Parker ◽  
Stephen M. Murphy ◽  
Robert H. Day ◽  
...  
The Condor ◽  
10.1650/7504 ◽  
2004 ◽  
Vol 106 (3) ◽  
pp. 711 ◽  
Author(s):  
Samuel A. Iverson ◽  
Daniel Esler ◽  
Daniel J. Rizzolo

The Condor ◽  
2004 ◽  
Vol 106 (3) ◽  
pp. 711-715 ◽  
Author(s):  
Samuel A. Iverson ◽  
Daniel Esler ◽  
Daniel J. Rizzolo

Abstract We used capture-mark-recapture data to assess winter philopatry by Harlequin Ducks (Histrionicus histrionicus) in Prince William Sound, Alaska, during winters 1995–1997 and 2000–2001. Philopatry was quantified using homing rates, which were estimated as the proportion of birds recaptured at their original site out of all recaptured birds. Between-year homing rates of 0.95 (95% CI: 0.87–1.00) and 1.00 (0.92–1.00) were estimated for females and males, respectively, at three locations on Montague Island. Similar homing rates were measured in western Prince William Sound, where estimates were 0.92 (0.80–0.98) for females and 0.96 (0.79–1.00) for males, with a scale of detected movements for all recapture birds ranging from 3–52 km. Our results indicate that wintering aggregations may be demographically independent at a much finer spatial scale than genetic data indicate, and that conservation efforts should recognize this degree of demographic separation among population segments. Filopatría Invernal de Histrionicus histrionicus en Prince William Sound, Alaska Resumen. Utilizamos datos de marcaje y recaptura para determinar la filopatría de Histrionicus histrionicus en Prince William Sound, Alaska, durante los inviernos de 1995–1997 y 2000–2001. La filopatría fue cuantificada utilizando la tasa de retorno, estimada a partir de la proporción del total de aves capturadas que se recapturaron en su sitio original. Las tasas de retorno entre años, estimadas en tres localidades en la isla Montague, fueron de 0.95 (95% IC: 0.87–1.00) y 1.00 (0.92–1.00) para hembras y machos, respectivamente. En Prince William Sound se midieron tasas de retorno similares, donde las estimaciones fueron 0.92 (0.80– 0.98) para las hembras y 0.96 (0.79–1.00) para los machos, y para todas las aves recapturadas se detectó una escala de movimiento entre 3 y 52 km. Nuestros resultados indican que las agrupaciones de invierno pueden ser demográficamente independientes a una escala espacial mucho más fina de lo que los datos genéticos indican, y que los esfuerzos de conservación deberían reconocer este grado de separación demográ fica entre segmentos de poblaciones.


The Condor ◽  
2000 ◽  
Vol 102 (4) ◽  
pp. 920-926 ◽  
Author(s):  
Daniel Esler ◽  
Timothy D. Bowman ◽  
Thomas A. Dean ◽  
Charles E. O'Clair ◽  
Stephen C. Jewett ◽  
...  

Abstract We evaluated relationships of Harlequin Duck (Histrionicus histrionicus) densities to habitat attributes, history of habitat contamination by the 1989 Exxon Valdez oil spill, and prey biomass density and abundance during winters 1995–1997 in Prince William Sound, Alaska. Habitat features that explained variation in duck densities included distance to streams and reefs, degree of exposure to wind and wave action, and dominant substrate type. After accounting for these effects, densities were lower in oiled than unoiled areas, suggesting that population recovery from the oil spill was not complete, due either to lack of recovery from initial oil spill effects or continuing deleterious effects. Prey biomass density and abundance were not strongly related to duck densities after accounting for habitat and area effects. Traits of Harlequin Ducks that reflect their affiliation with naturally predictable winter habitats, such as strong site fidelity and intolerance of increased energy costs, may make their populations particularly vulnerable to chronic oil spill effects and slow to recover from population reductions, which may explain lower densities than expected on oiled areas nearly a decade following the oil spill.


2020 ◽  
Author(s):  
José‐Carlos Delgado‐González ◽  
Carlos‐de‐la Rosa Prieto ◽  
Nuria Vallejo‐Calcerrada ◽  
Diana‐Lucía Tarruela‐Hernández ◽  
Sandra Cebada‐Sánchez ◽  
...  

VASA ◽  
2017 ◽  
Vol 46 (5) ◽  
pp. 383-388 ◽  
Author(s):  
Henrik Christian Rieß ◽  
Anna Duprée ◽  
Christian-Alexander Behrendt ◽  
Tilo Kölbel ◽  
Eike Sebastian Debus ◽  
...  

Abstract. Background: Perioperative evaluation in peripheral artery disease (PAD) by common vascular diagnostic tools is limited by open wounds, medial calcinosis or an altered collateral supply of the foot. Indocyanine green fluorescent imaging (ICG-FI) has recently been introduced as an alternative tool, but so far a standardized quantitative assessment of tissue perfusion in vascular surgery has not been performed for this purpose. The aim of this feasibility study was to investigate a new software for quantitative assessment of tissue perfusion in patients with PAD using indocyanine green fluorescent imaging (ICG-FI) before and after peripheral bypass grafting. Patients and methods: Indocyanine green fluorescent imaging was performed in seven patients using the SPY Elite system before and after peripheral bypass grafting for PAD (Rutherford III-VI). Visual and quantitative evaluation of tissue perfusion was assessed in an area of low perfusion (ALP) and high perfusion (AHP), each by three independent investigators. Data assessment was performed offline using a specially customized software package (Institute for Laser Technology, University Ulm, GmbH). Slope of fluorescent intensity (SFI) was measured as time-intensity curves. Values were compared to ankle-brachial index (ABI), slope of oscillation (SOO), and time to peak (TTP) obtained from photoplethysmography (PPG). Results: All measurements before and after surgery were successfully performed, showing that ABI, TTP, and SOO increased significantly compared to preoperative values, all being statistically significant (P < 0.05), except for TTP (p = 0.061). Further, SFI increased significantly in both ALP and AHP (P < 0.05) and correlated considerably with ABI, TTP, and SOO (P < 0.05). Conclusions: In addition to ABI and slope of oscillation (SOO), the ICG-FI technique allows visual assessment in combination with quantitative assessment of tissue perfusion in patients with PAD. Ratios related to different perfusion patterns and SFI seem to be useful tools to reduce factors disturbing ICG-FI measurements.


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