Factors affecting the availability of thick epiphyte mats and other potential nest platforms for Marbled Murrelets in British Columbia

2010 ◽  
Vol 40 (4) ◽  
pp. 727-746 ◽  
Author(s):  
Alan E. Burger ◽  
Robert A. Ronconi ◽  
Michael P. Silvergieter ◽  
Catherine Conroy ◽  
Volker Bahn ◽  
...  
Keyword(s):  
British Columbia ◽  
Forest Canopy ◽  
Tree Height ◽  
Suitable Habitat ◽  
Factors Affecting ◽  
Marbled Murrelet ◽  
Pooled Data ◽  
Model Predictions ◽  
Using Data ◽  
Marbled Murrelets

Nest platforms (mossy pads, limbs, and deformities >15 cm in diameter) are key requirements in the forest nesting habitat of the threatened Marbled Murrelet ( Brachyramphus marmoratus (J.F. Gmelin, 1789)). Little is known about factors that affect the availability of platforms or the growth of canopy epiphytes that provide platforms. We examined variables affecting these parameters in coastal trees in British Columbia using data from 29 763 trees at 1412 sites in 170 watersheds. Tree diameter (diameter at breast height (DBH)) was the most important predictor of platform availability in the pooled data and within each of six regions. In most regions, platforms become available at DBH > 60 cm, but on East Vancouver Island, DBH needs to be >96 cm and possibly on the Central Coast >82 cm. Other regional predictors of platforms included tree height, tree species, and to a lesser extent elevation, slope, and latitude. Most (72%) trees providing platforms had epiphytes (mainly moss) covering one third or more of branch surfaces and 81% had intermediate or thick epiphyte mats. Mistletoe deformities provided <7% of platforms. Our model predictions help to define and manage suitable habitat for nesting Marbled Murrelets and also contribute to understanding forest canopy ecosystems.

scholarly journals Techniques for Investigating Breeding Chronology in Marbled Murrelets, Desolation Sound, British Columbia

The Condor ◽  
2002 ◽  
Vol 104 (2) ◽  
pp. 319-330 ◽  
Author(s):  
Cecilia Lougheed ◽  
Brett A. Vanderkist ◽  
Lynn W. Lougheed ◽  
Fred Cooke
Keyword(s):  
British Columbia ◽  
Breeding Season ◽  
Radio Telemetry ◽  
Feeding Habits ◽  
Brachyramphus Marmoratus ◽  
Marbled Murrelet ◽  
Breeding Synchrony ◽  
Physiological Analysis ◽  
Using Data ◽  
Marbled Murrelets

AbstractWe used several methods to study the chronology and synchrony of breeding events of the Marbled Murrelet (Brachyramphus marmoratus) population at Desolation Sound, British Columbia, from 1996 to 1998. The timing of breeding events varied among years; on average the breeding season lasted from 21 April to 5 September. We assessed the biases of each method used by comparing the results to the estimate of the integrated breeding chronology. Counts of hatch-year birds at sea were biased toward earlier breeders, missing an estimated 24% of the fledglings. Two other methods, physiological analysis of the yolk precursor vitellogenin from blood samples and monitoring by radio-telemetry could produce a complete distribution of breeding events if sampling were done throughout laying. Observations in the forest, date of first observation of a fledgling at sea during the breeding season, and fish-holding behavior produced insufficient data to be used as sole indicators of breeding chronology of this species. In general, breeding synchrony in alcids, assessed using data from a literature review, was unrelated to feeding habits but increased with latitude (41% of the variation was explained by latitude). Marbled Murrelets, however, bred less synchronously than predicted for an alcid at this latitude (50°N).Técnicas para Investigar la Cronología Reproductiva de Brachyramphus marmoratus en Caleta Desolación, Columbia BritánicaResumen. Utilizamos varios métodos para investigar la cronología reproductiva de la población de Brachyramphus marmoratus en la Caleta Desolación de la Columbia Británica desde 1996 a 1998. Encontramos variaciones temporales en la época reproductiva entre años. En promedio, la estación reproductiva se extendió del 21 de abril al 5 de septiembre. Evaluamos el sesgo de los métodos utilizados comparando los resultados individuales con los resultados de la cronología obtenida al integrar todos los métodos. Los conteos de juveniles en el mar estuvieron sesgados hacia aquellas aves que anidan temprano, no detectando aproximadamente 24% de los juveniles producidos en la estación reproductiva. Los otros dos métodos, análisis fisiológico de muestras de sangre para detectar el precursor de vitelogenina en la yema y monitoreo por telemetría, podrían producir una distribución completa de las etapas reproductivas siempre que el muestreo se lleve a cabo a lo largo de todo el período de puesta. Las observaciones directas en los sitios de anidación, la fecha de la primera observación de juveniles en el mar y las observaciones de aves con pescado en el pico produjeron datos insuficientes para ser considerados indicadores únicos de la cronología reproductiva para esta especie. Con base en una revisión bibliográfica se investigó la sincronía reproductiva en álcidos, encontrándose que ésta no está relacionada con hábitos alimenticios pero que aumenta con la latitud (41% de la variación fue explicada por cambios latitudinales). Sin embargo, B. marmoratus se reprodujo menos sincrónico que lo predicho para un álcido a esta latitud (50°N).

scholarly journals Comparison of Coastal Fringe and Interior Forests as Reserves for Marbled Murrelets on Vancouver Island

The Condor ◽  
2000 ◽  
Vol 102 (4) ◽  
pp. 915-920
Author(s):  
Alan E. Burger ◽  
Volker Bahn ◽  
Angeline R. M. Tillmanns
Keyword(s):  
Pacific Northwest ◽  
Structural Diversity ◽  
Vancouver Island ◽  
Old Growth ◽  
Brachyramphus Marmoratus ◽  
Marbled Murrelet ◽  
The Pacific ◽  
Using Data ◽  
Associated Species ◽  
Marbled Murrelets

Abstract Much of the protected habitat available to the threatened Marbled Murrelet Brachyramphus marmoratus and other old-growth associated species in the Pacific Northwest is in narrow strips along the coast (e.g., parks and scenic fringes). Using data over two years from three watersheds on southwest Vancouver Island, we show that such shoreline strip forests represent suboptimal habitat for murrelets. Murrelet detections, including circling and subcanopy behaviors, were significantly lower at 30 coastal stations (20–250 m from the shoreline edge) than at 30 interior stations (1.5–21.0 km inland). Densities of predators were significantly higher at the coastal stations. The coastal trees were of similar mean height and diameter, but they had lower structural diversity and provided fewer and less suitable (thinner epiphyte cover on large boughs) nesting platforms than trees in the interior. When possible, reserves for Marbled Murrelets should be placed in interior and not shoreline forests.

Feeding ecology of the ancient and marbled murrelets near Langara Island, British Columbia

1975 ◽  
Vol 53 (4) ◽  
pp. 418-433 ◽  
Author(s):  
Spencer G. Sealy
Keyword(s):  
British Columbia ◽  
Feeding Ecology ◽  
Prey Availability ◽  
Breeding Cycle ◽  
Marbled Murrelet ◽  
Ammodytes Hexapterus ◽  
Queen Charlotte Islands ◽  
Early Portion ◽  
Marbled Murrelets

Two field seasons (1970 and 1971) were spent studying the feeding ecology of the ancient murrelet (Synthliboramphus antiquus) and the marbled murrelet (Brachyramphus marmoratus) near Langara Island, Queen Charlotte Islands, British Columbia. The relatively offshore-feeding ancient murrelet nests in colonies, lays two-egg clutches, and has truly precocial young. The inshore-feeding marbled murrelet is apparently a solitary nester, has one-egg clutches, and semiprecocial young. The ancient murrelet feeds predominantly on two species of euphausiid crustaceans, Euphausia pacifica and Thysanöessa spinifera, during the early portion of the terrestrial phase of its breeding cycle (early April to late May), but takes a fish, Ammodytes hexapterus, toward the end of the cycle. It is believed that this change in diet as the season progresses reflects a change in prey availability. The apparent patchy distribution of the prey of the ancient murrelet, which requires more time to locate the food source, has probably promoted the evolution of the 72-h incubation shifts found in this species.During the terrestrial phase of the marbled murrelet's breeding cycle (early May to late August), the fish Ammodytes hexapterus and Cymatogaster aggregata are predominantly taken. During the very early part of its breeding season, Thysanöessa spinifera constitutes a considerable part of its diet.

Activity levels of Marbled Murrelets in different inland habitats in the Queen Charlotte Islands, British Columbia

1993 ◽  
Vol 71 (5) ◽  
pp. 977-984 ◽  
Author(s):  
Michael S. Rodway ◽  
Heidi M. Regehr ◽  
Jean-Pierre L. Savard
Keyword(s):  
British Columbia ◽  
High Elevation ◽  
Activity Levels ◽  
Old Growth ◽  
Marbled Murrelet ◽  
Queen Charlotte Islands ◽  
Old Growth Forest ◽  
Second Growth ◽  
Old Growth Forests ◽  
Marbled Murrelets

We compared Marbled Murrelet (Brachyramphus marmoratus) activity levels in May, June, and July 1990 in four habitats in the Queen Charlotte Islands, British Columbia: alpine, old-growth forest at high elevation, old-growth forest at low elevation, and second-growth forest. The number of Marbled Murrelet detections was highest in old-growth forests. In alpine areas, small numbers of murrelet detections were mostly of distant birds flying over low-elevation forest. Numbers of detections were higher in low-elevation than in high-elevation old-growth forests in May and July, but not in June. Proportions of detections within smaller radii of survey stations were higher in low elevation forest in all months. The highest activity levels were associated with old-growth forest stands of large Sitka spruce (Picea sitchensis) and western hemlock (Tsuga heterophylla). The few detections that occurred in second-growth forests were mostly of distant birds. Stations in second-growth forest close to stands of old-growth forest had more frequent detections than stations with no old-growth forest nearby. Our results support the association of Marbled Murrelets with old-growth forests. Limitations of the survey methodology are discussed.

Marbled Murrelets (Brachyramphus marmoratus) foraging with gray whales (Eschrichtius robustus) off Vancouver Island, British Columbia

2013 ◽  
Vol 91 (12) ◽  
pp. 847-852
Author(s):  
K.A. Muirhead ◽  
C.D. Malcolm ◽  
D.A. Duffus
Keyword(s):  
British Columbia ◽  
Marine Mammals ◽  
Prey Capture ◽  
Vancouver Island ◽  
Eschrichtius Robustus ◽  
Brachyramphus Marmoratus ◽  
Seabird Species ◽  
Gray Whales ◽  
Marbled Murrelet ◽  
Marbled Murrelets

Seabirds are known to associate with marine mammals to facilitate prey capture. These occur when mammals either force prey near the surface or provide small scraps of larger prey victims. Gray whales (Eschrichtius robustus (Lilljeborg, 1861)) have been observed to provide invertebrate prey to a variety of seabird species; however, there are no published reports of Marbled Murrelets (Brachyramphus marmoratus (Gmelin, 1789)) feeding in association with gray whales. We observed Marbled Murrelets foraging within several metres of gray whales off Vancouver Island, British Columbia, feeding on epibenthic zooplankton in 2006 and 2008. Join-count statistics identified significant clustering (p = 0.1) of 258 Marbled Murrelets within 300 m of 39 feeding gray whales in June of 2006, and no association between 3 gray whales and 34 Marbled Murrelets in June and July of 2008, marking a foraging association conditional on the abundance of both gray whales and their prey, but potentially significant to Marbled Murrelet survival and fecundity.

Status review of the Marbled Murrelet (Brachyramphus marmoratus) in Alaska and British Columbia

2007 ◽  
Author(s):  
John F. Piatt ◽  
K.J. Kuletz ◽  
A.E. Burger ◽  
Scott A. Hatch ◽  
Vicki L. Friesen ◽  
...  
Keyword(s):  
British Columbia ◽  
Brachyramphus Marmoratus ◽  
Marbled Murrelet

scholarly journals Measuring the Efficiency of Football Clubs Using Data Envelopment Analysis: Empirical Evidence From Spanish Professional Football

SAGE Open ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 215824402198925
Author(s):  
Isidoro Guzmán-Raja ◽  
Manuela Guzmán-Raja
Keyword(s):  
Data Envelopment Analysis ◽  
High Efficiency ◽  
Sport Performance ◽  
Data Envelopment ◽  
Professional Football ◽  
Efficiency Measure ◽  
Factors Affecting ◽  
Football Clubs ◽  
Main Factors ◽  
Using Data

Professional football clubs have a special characteristic not shared by other types of companies: their sport performance (on the field) is important, in addition to their financial performance (off the field). The aim of this paper is to calculate an efficiency measure using a model that combines performance (sport and economic) based on data envelopment analysis (DEA). The main factors affecting teams’ efficiency levels are investigated using cluster analysis. For a sample of Spanish football clubs, the findings indicate that clubs achieved a relatively high efficiency level for the period studied, and that the oldest teams with the most assets had the highest efficiency scores. These results could help club managers to improve the performance of their teams.

scholarly journals Association between Dyslipidemia and Mercury Exposure in Adults

2021 ◽  
Vol 18 (2) ◽  
pp. 775
Author(s):  
Purum Kang ◽  
Hye Young Shin ◽  
Ka Young Kim
Keyword(s):  
Behavioral Interventions ◽  
Dietary Habits ◽  
Subjective Health ◽  
Targeted Prevention ◽  
Adult Males ◽  
Subjective Health Status ◽  
Factors Affecting ◽  
Health And Nutrition ◽  
Metal Levels ◽  
Using Data

Background—Dyslipidemia is one of the prominent risk factors for cardiovascular disease, which is the leading cause of death worldwide. Dyslipidemia has various causes, including metabolic capacity, genetic problems, physical inactivity, and dietary habits. This study aimed to determine the association between dyslipidemia and exposure to heavy metals in adults. Methods—Using data from the seventh Korean National Health and Nutrition Examination Survey (2016–2017), 5345 participants aged ≥20 years who were tested for heavy metal levels were analyzed in this study. Multiple logistic regression was conducted to assess the factors affecting the prevalence of dyslipidemia. Results—The risks of dyslipidemia among all and male participants with mercury (Hg) levels of ≥2.75 μg/L (corresponding to the Korean average level) were 1.273 and 1.699 times higher than in those with levels of <2.75 μg/L, respectively. The factors that significantly affected the dyslipidemia risk were age, household income, body mass index, and subjective health status in both males and females. Conclusions—In adult males, exposure to Hg at higher-than-average levels was positively associated with dyslipidemia. These results provide a basis for targeted prevention strategies for dyslipidemia using lifestyle guidelines for reducing Hg exposure and healthy behavioral interventions.

scholarly journals Psychological Factors Affecting Risk Perception of COVID-19: Evidence from Peru and China

2021 ◽  
Vol 18 (12) ◽  
pp. 6513
Author(s):  
Fredy S. Monge-Rodríguez ◽  
He Jiang ◽  
Liwei Zhang ◽  
Andy Alvarado-Yepez ◽  
Anahí Cardona-Rivero ◽  
...  
Keyword(s):  
Risk Perception ◽  
Risk Communication ◽  
Online Survey ◽  
Factors Affecting ◽  
Self Confidence ◽  
Global Pandemic ◽  
Negative Effect ◽  
The Government ◽  
Using Data ◽  
Health Field

COVID-19 has spread around the world, causing a global pandemic, and to date is impacting in various ways in both developed and developing countries. We know that the spread of this virus is through people’s behavior despite the perceived risks. Risk perception plays an important role in decision-making to prevent infection. Using data from the online survey of participants in Peru and China (N = 1594), data were collected between 8 July 31 and August 2020. We found that levels of risk perception are relatively moderate, but higher in Peru compared to China. In both countries, anxiety, threat perception, self-confidence, and sex were found to be significant predictors of risk perception; however, trust in the information received by government and experts was significant only in Peru, whereas self-confidence had a significant negative effect only for China. Risk communication should be implemented through information programs aimed at reducing anxiety and improving self-confidence, taking into consideration gender differences. In addition, the information generated by the government should be based on empirical sources. Finally, the implications for effective risk communication and its impacts on the health field are discussed.

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