scholarly journals Nocturnal Foraging Behavior of Wintering Surf Scoters and White-Winged Scoters

The Condor ◽  
2005 ◽  
Vol 107 (3) ◽  
pp. 637-647 ◽  
Author(s):  
Tyler L. Lewis ◽  
Daniel Esler ◽  
W. Sean Boyd ◽  
Ramūnas Žydelis
Keyword(s):  
British Columbia ◽  
Foraging Behavior ◽  
Human Activities ◽  
Radio Telemetry ◽  
Day Length ◽  
Melanitta Perspicillata ◽  
Nocturnal Foraging ◽  
Melanitta Fusca ◽  
Coastal British Columbia ◽  
Foraging Time

Abstract We studied the nocturnal foraging behavior of Surf Scoters (Melanitta perspicillata) and White-winged Scoters (Melanitta fusca) during winter in coastal British Columbia, Canada. Using radio telemetry, we collected nocturnal and diurnal data documenting the frequency of foraging dives and the location of scoters in relation to their intertidal foraging grounds. We found that dive foraging rarely occurred during nocturnal periods for either species. Only 2% of nocturnal observation blocks for both scoter species contained diving, compared with 98% of diurnal observation blocks. This corresponded to an average of only 0.1 min spent underwater per half-hour observation block during the night and over 7 min during the day. Both species of scoters were located farther offshore and in deeper waters during nocturnal hours, indicating that they were not using intertidal foraging areas at night. Our results suggest that Surf Scoters and White-winged Scoters face daylight-imposed limits on the amount of available foraging time. These potential day-length restrictions should be considered when reviewing human activities that potentially alter the amount of available foraging time or food supplies in winter habitats. Comportamiento de Forrajeo Nocturno de Melanitta perspicillata y M. fusca Resumen. Se estudió el comportamiento de forrajeo nocturno de Melanitta perspicillata y M. fusca durante el invierno en la costa de British Columbia. Utilizando radio-telemetría, se colectaron datos nocturnos y diurnos sobre la frecuencia de buceos para alimentarse y la ubicación de las aves con relación a la zona intermareal. Se encontró que los buceos nocturnos son infrecuentes para ambas especies. Sólo en el 2% de las observaciones nocturnas de ambas especies se presentaron instancias de buceo, en comparación con el 98% de las observaciones diurnas. Esto corresponde a un promedio de 0.11 minutos bajo el agua por cada 30 minutos de observación durante la noche y más de 7 minutos durante el día. Ambas especies se ubicaron más alejadas de la costa y en aguas más profundas durante la noche, indicando que los individuos no utilizaron zonas intermareales durante este periodo. Estos resultados sugieren que M. perspicillata y M. fusca enfrentan restricciones en el número de horas disponibles para alimentarse en función de la cantidad de luz. El efecto de la duración del día debe ser considerado cuando se estudia el impacto de actividades humanas que pueden alterar el tiempo disponible para forrajeo o la cantidad de alimento durante el invierno.

Nocturnal and diurnal foraging behaviour of brown bears (Ursus arctos) on a salmon stream in coastal British Columbia

2002 ◽  
Vol 80 (8) ◽  
pp. 1317-1322 ◽  
Author(s):  
D R Klinka ◽  
T E Reimchen
Keyword(s):  
British Columbia ◽  
Ursus Arctos ◽  
Night Vision ◽  
Black Bears ◽  
Spawning Migration ◽  
Brown Bears ◽  
Light Levels ◽  
Nocturnal Foraging ◽  
Consumption Rates ◽  
Coastal British Columbia

Brown bears (Ursus arctos) have been reported to be primarily diurnal throughout their range in North America. Recent studies of black bears during salmon migration indicate high levels of nocturnal foraging with high capture efficiencies during darkness. We investigated the extent of nocturnal foraging by brown bears during a salmon spawning migration at Knight Inlet in coastal British Columbia, using night-vision goggles. Adult brown bears were observed foraging equally during daylight and darkness, while adult females with cubs, as well as subadults, were most prevalent during daylight and twilight but uncommon during darkness. We observed a marginal trend of increased capture efficiency with reduced light levels (day, 20%; night, 36%) that was probably due to the reduced evasive behaviour of the salmon. Capture rates averaged 3.9 fish/h and differed among photic regimes (daylight, 2.1 fish/h; twilight, 4.3 fish/h; darkness, 8.3 fish/h). These results indicate that brown bears are highly successful during nocturnal foraging and exploit this period during spawning migration to maximize their consumption rates of an ephemeral resource.

Clear diel patterns in breeding calls of harbor seals (Phoca vitulina) at Hornby Island, British Columbia, Canada

2018 ◽  
Vol 96 (11) ◽  
pp. 1236-1243
Author(s):  
Katrina Nikolich ◽  
Héloïse Frouin-Mouy ◽  
Alejandro Acevedo-Gutiérrez
Keyword(s):  
British Columbia ◽  
Foraging Behavior ◽  
Breeding Season ◽  
Light Level ◽  
Harbor Seal ◽  
Phoca Vitulina ◽  
Harbor Seals ◽  
Female Behavior ◽  
Nocturnal Foraging ◽  
Male Calling

During the breeding season, male harbor seals (Phoca vitulina Linnaeus, 1758) produce underwater calls for sexual advertisement. The daily and seasonal timing of these calls is influenced by female availability (i.e., tidal haul-out patterns, foraging behavior, and oestrus cycle). Therefore, temporal patterns of male calling can provide clues about patterns of female behavior. We collected underwater recordings during the 2014 breeding season at Hornby Island, British Columbia, Canada, and examined the relationships of light level, progression of breeding season, and tide relative to call presence or absence and calling rate. Calls were 15 times more likely to occur at night than during the day. Nocturnal peaks in calling rate have been observed in other harbor seal populations and have been attributed to tidal haul-out patterns and nocturnal foraging of females. In this study, tide level did not have a significant effect on calling rate, and female foraging behavior was not monitored. One acoustic observation of mammal-eating killer whale (Orcinus orca (Linnaeus, 1758)) calls was followed by 48 h of decreased calling rate. We infer that predation risk influences the temporal pattern of male calling at this location and suggest further study to support this hypothesis.

Influence of the time and rate of liquid-manure application on yield and nitrogen utilization of silage corn in south coastal British Columbia

1996 ◽  
Vol 76 (2) ◽  
pp. 153-164 ◽  
Author(s):  
B. J. Zebarth ◽  
J. W. Paul ◽  
O. Schmidt ◽  
R. McDougall
Keyword(s):  
British Columbia ◽  
Dairy Manure ◽  
Inorganic Fertilizer ◽  
N Recovery ◽  
Corn Yield ◽  
Residual Soil ◽  
Soil Nitrate ◽  
Liquid Manure ◽  
Manure Application ◽  
Coastal British Columbia

Manure-N availability must be known in order to design application practices that maximize the nutrient value of the manure while minimizing adverse environmental impacts. This study determined the effect of time and rate of liquid manure application on silage corn yield and N utilization, and residual soil nitrate at harvest, in south coastal British Columbia. Liquid dairy or liquid hog manure was applied at target rates of 0, 175, 350 or 525 kg N ha−1, with or without addition of 100 kg N ha−1 as inorganic fertilizer, at two sites in each of 2 yr. Time of liquid-dairy-manure application was also tested at two sites in each of 2 yr with N-application treatments of: 600 kg N ha−1 as manure applied in spring; 600 kg N ha−1 as manure applied in fall; 300 kg N ha−1 as manure applied in each of spring and fall; 200 kg N ha−1 applied as inorganic fertilizer in spring; 300 kg N ha−1 as manure plus 100 kg N ha−1 as inorganic fertilizer applied in spring; and a control that received no applied N. Fall-applied manure did not increase corn yield or N uptake in the following growing season. At all sites, maximum yield was attained using manure only. Selection of proper spring application rates for manure and inorganic fertilizer were found to be equally important in minimizing residual soil nitrate at harvest. Apparent recovery of applied N in the crop ranged from 0 to 33% for manure and from 18 to 93% for inorganic fertilizer. Key words: N recovery, manure management

STRUCTURE, STRATIGRAPHY, AND PALEONTOLOGY OF AN UPPER TRIASSIC SECTION ON THE WEST COAST OF BRITISH COLUMBIA

1965 ◽  
Vol 2 (5) ◽  
pp. 442-484 ◽  
Author(s):  
Donald Carlisle ◽  
Takeo Susuki
Keyword(s):  
British Columbia ◽  
Structural Information ◽  
Pillow Lava ◽  
Middle Part ◽  
Upper Triassic ◽  
Coast Range ◽  
Thermal Alteration ◽  
The West ◽  
Coastal British Columbia ◽  
Sedimentary Unit

The highly deformed section at Open Bay is one of the few good exposures of a thick sedimentary unit within the prebatholithic rocks along coastal British Columbia. It provides new structural information relating to emplacement of a part of the Coast Range batholith and it contains an important Upper Triassic fauna unusually well represented. Structural and paleontological analyses are mutually supporting and are purposely combined in one paper.Thirteen ammonite genera from 14 localities clearly substantiate McLearn's tentative assignment to the Tropites subbullatus zone (Upper Karnian) and suggest a restriction to the T. dilleri subzone as defined in northern California.Contrary to an earlier view, the beds are lithologically similar across the whole bay except for variations in the intensity of deformation and thermal alteration. Their contact with slightly older relatively undeformed flows is apparently a zone of dislocation. Stratigraphic thicknesses cannot be measured with confidence, and subdivision into "Marble Bay Formation" and "Open Bay Group" cannot be accepted. Open Bay Formation is redefined to include all the folded marble and interbedded pillow lava at Open Bay. Lithologic and biostratigraphic correlation is suggested with the lower middle part of the Quatsino Formation on Iron River, 24 miles to the southwest. Basalt flows and pillowed volcanics west of Open Bay are correlated with the Texada Formation within the Karmutsen Group.The predominant folding is shown to precede, accompany, and follow intrusion of numerous andesitic pods and to precede emplacement of quartz diorite of the batholith. Structural asymmetry is shown to have originated through gentle cross-folding and emplacement of minor intrusives during deformation.

“Boil them Hearts”

2016 ◽  
Vol 46 (1) ◽  
pp. 50-74
Author(s):  
Jason Redden
Keyword(s):  
Nineteenth Century ◽  
British Columbia ◽  
Indigenous Peoples ◽  
Scholarly Literature ◽  
Material Resources ◽  
Theoretical Inquiry ◽  
Critical Exploration ◽  
Coastal British Columbia ◽  
Academic Study

This paper addresses the academic conversation on Protestant missions to the Indigenous peoples of coastal British Columbia during the second half of the nineteenth century through a consideration of the role of revivalist piety in the conversion of some of the better known Indigenous Methodist evangelists identified in the scholarly literature. The paper introduces the work of existing scholars critically illuminating the reasons (religious convergence and/or the want of symbolic and material resources) typically given for Indigenous, namely, Ts’msyen, conversion. It also introduces Methodist revivalist piety and its instantiation in British Columbia. And, finally, it offers a critical exploration of revivalist piety and its role in conversion as set within a broader theoretical inquiry into the academic study of ritual and religion.

Some Morphological Differences Between the Subspecies of Cutthroat Trout, Salmo clarkii clarkii and Salmo clarkii lewisi, in British Columbia

1959 ◽  
Vol 16 (6) ◽  
pp. 903-922 ◽  
Author(s):  
S. U. Qadri
Keyword(s):  
British Columbia ◽  
Lateral Line ◽  
Cutthroat Trout ◽  
Complete Separation ◽  
The Body ◽  
Natural Distribution ◽  
Spot Number ◽  
Coastal Cutthroat Trout ◽  
Morphological Differences ◽  
Coastal British Columbia

Coastal cutthroat trout, S. c. clarkii Richardson, occupy most lakes and streams of coastal British Columbia, including the adjacent islands. Yellowstone cutthroat, S. c. lewisi (Girard), occupy southeastern British Columbia; their range is separated from that of the coastal subspecies by a zone lacking cutthroat trout. A map showing all natural distribution records in the province is presented. From 60 to 146 specimens were examined for distinguishing characters. Spots below the lateral line are more numerous towards the anterior end in S. c. clarkii, but more numerous towards the posterior end in S. c. lewisi. A plot of spot number in selected areas of the body provides almost complete separation of individuals of the two subspecies. Significant differences also occur in certain scale counts and in body and peduncle depth, although these characters overlap considerably between the subspecies. No difference was found in vertebral count.

An examination of controls on debris flow mobility: Evidence from coastal British Columbia

Geomorphology ◽  
2010 ◽  
Vol 114 (4) ◽  
pp. 601-613 ◽  
Author(s):  
R.H. Guthrie ◽  
A. Hockin ◽  
L. Colquhoun ◽  
T. Nagy ◽  
S.G. Evans ◽  
...  
Keyword(s):  
British Columbia ◽  
Debris Flow ◽  
Flow Mobility ◽  
Coastal British Columbia

scholarly journals Does the Cascade Wolf Survive?

Oryx ◽  
1979 ◽  
Vol 15 (2) ◽  
pp. 185-190
Author(s):  
Robert Pisano
Keyword(s):  
British Columbia ◽  
Domestic Dogs ◽  
Coastal Forests ◽  
Complete Protection ◽  
Wolf Management ◽  
The Usa ◽  
Coastal British Columbia ◽  
Special Protection

The Cascade wolf Cants lupus fuscus is extinct in the USA. But it may survive in Canada, in the coastal forests of British Columbia, the northernmost part of its original range. But British Columbia gives this highly endangered subspecies no special protection. Over-hunting and hybridisation with neighbouring wolf subspecies and domestic dogs are the chief threats. The author reviews wolf management in coastal British Columbia and suggests changes that would improve the Cascade wolf's prospects, including complete protection of all wolves on wilderness islands where it may survive.

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