Spatial Patterns of Yearling Male Blue Grouse and Their Relation to Recruitment into the Breeding Population

The Auk ◽  
1983 ◽  
Vol 100 (3) ◽  
pp. 653-657 ◽  
Author(s):  
Ian G. Jamieson ◽  
Fred C. Zwickel
Keyword(s):  
British Columbia ◽  
Spatial Patterns ◽  
Radio Telemetry ◽  
Breeding Population ◽  
Adult Males ◽  
Costs And Benefits ◽  
Breeding Range ◽  
Dendragapus Obscurus ◽  
Different Types ◽  
Occupied Territories

Abstract Movements of yearling male Blue Grouse (Dendragapus obscurus) were monitored by radio telemetry during the springs of 1980 and 1981, on Hardwicke Island, British Columbia. The locations of the birds were clumped around territories of adult males. Most birds were associated with a few occupied territories, others settled near vacant sites that had been used as territories in previous years, and a few moved widely over the breeding range. Some territories attracted more yearlings than others. Presumed costs and benefits that may be associated with different types of spatial patterns of yearling males are discussed.

Seasonal changes in spatial patterns and behavior of yearling male blue grouse on the breeding range

1983 ◽  
Vol 61 (12) ◽  
pp. 2777-2780 ◽  
Author(s):  
Ian G. Jamieson
Keyword(s):  
British Columbia ◽  
Home Range ◽  
Spatial Patterns ◽  
Seasonal Changes ◽  
Late Summer ◽  
Home Ranges ◽  
Breeding Range ◽  
Dendragapus Obscurus ◽  
Radio Transmitters ◽  
And Behavior

Changes in spatial patterns and behavior of yearling male blue grouse (Dendragapus obscurus) equipped with radio transmitters were recorded during spring and summer, 1980 and 1981, on Hardwicke Island, British Columbia. Sizes of home ranges decreased and yearlings appeared to become less dispersed as the season progressed. Most birds moved off their initial home range and onto new areas on the breeding range by late summer although the timing of this movement varied among individuals. Interactions involving yearling males with females and territorial males decreased as the season advanced. Changes in spatial patterns and behavior appear to be related to seasonal changes in levels of hormones in yearling males.

A STUDY OF THE BLUE GROUSE (DENDRAGAPUS OBSCURUS (SAY)) ON VANCOUVER ISLAND, BRITISH COLUMBIA

1960 ◽  
Vol 38 (4) ◽  
pp. 701-713 ◽  
Author(s):  
C. David Fowle
Keyword(s):  
British Columbia ◽  
Feeding Habits ◽  
Free Water ◽  
Breeding Cycle ◽  
Adult Males ◽  
Seasonal Movements ◽  
Second Growth ◽  
Dendragapus Obscurus ◽  
In Captivity ◽  
Main Item

A study was made of the summer habitat, seasonal movements, fluctuations in populations, population density, breeding cycle, and summer feeding habits of Dendragapus obscurus fuliginosus (Ridgway). During the summer the grouse were found mainly in the early stages of the developing second-growth forests following fire or logging. The birds descended to the lowlands in late March and early April. Most of the adult males returned to the uplands by the end of July, The females and broods left the lowlands by the end of September. There is evidence of several well-marked fluctuations in the numbers of blue grouse in British Columbia since 1904. A density of about.2 adults per acre was recorded in late June and early July. Nesting took place in May and the first young appeared early in June. After the first of July it was not uncommon to see two females with their intermingled broods feeding together. The summer foods of both adults and young were almost entirely vegetable. Grit was the main item in gizzards from birds collected before the middle of July but later it was largely replaced by hard seeds. The grouse were not observed to drink free water except in captivity. There is a rough parallelism between frequency of occurrence of the main items of food in the environment and the proportion of each occurring in the diet.

scholarly journals Between Market Failures and Justice Failures: Trade-Offs Between Efficiency and Equality in Business Ethics

2021 ◽  
Author(s):  
Charlie Blunden
Keyword(s):  
Business Ethics ◽  
Private Firms ◽  
Market Failures ◽  
Costs And Benefits ◽  
Trade Offs ◽  
Efficiency Losses ◽  
Different Types ◽  
Hybrid Theory ◽  
Market Failures Approach ◽  
Ethical Obligations

AbstractThe Market Failures Approach (MFA) is one of the leading theories in contemporary business ethics. It generates a list of ethical obligations for the managers of private firms that states that they should not create or exploit market failures because doing so reduces the efficiency of the economy. Recently the MFA has been criticised by Abraham Singer on the basis that it unjustifiably does not assign private managers obligations based on egalitarian values. Singer proposes an extension to the MFA, the Justice Failures Approach (JFA), in which managers have duties to alleviate political, social, and distributive inequalities in addition to having obligations to not exploit market failures. In this paper I describe the MFA and JFA and situate them relative to each other. I then highlight a threefold distinction between different types of obligations that can be given to private managers in order to argue that a hybrid theory of business ethics, which I call the MFA + , can be generated by arguing that managers have obligations based on efficiency and duties based on equality to the extent that these latter obligations do not lead to efficiency losses. This argument suggests a novel theoretical option in business ethics, elucidates the issues that are at stake between the MFA and the JFA, and clarifies the costs and benefits of each theory.

scholarly journals Spatially varying constraints of human-caused fire occurrence in British Columbia, Canada

2017 ◽  
Vol 26 (3) ◽  
pp. 219 ◽  
Author(s):  
Philip E. Camp ◽  
Meg A. Krawchuk
Keyword(s):  
British Columbia ◽  
Spatial Patterns ◽  
Fire Management ◽  
Fire Occurrence ◽  
Explanatory Variables ◽  
Human Footprint ◽  
Key Factor ◽  
Key Drivers ◽  
Spatially Varying

Human-caused wildfires are controlled by human and natural influences, and determining their key drivers is critical for understanding spatial patterns of wildfire and implementing effective fire management. We examined an array of explanatory variables that account for spatial controls of human-caused fire occurrence from 1990 to 2013 among six ecosystem zones that vary in human footprint and environmental characteristics in British Columbia, Canada. We found that long-term patterns of human-caused fire in ecosystem zones with a larger human footprint were strongly controlled by biophysical variables explaining conditions conducive to burning, whereas fire occurrence in remote ecosystem zones was controlled by various metrics of human activity. A metric representing the wildland–urban interface was a key factor explaining human-caused fire occurrence regardless of ecosystem zone. Our results contribute to the growing body of research on the varying constraints of spatial patterns of fire occurrence by explicitly examining human-caused fire and the heterogeneity of constraints based on human development.

Key principles for the improved conduct of health technology assessments for resource allocation decisions

2008 ◽  
Vol 24 (03) ◽  
pp. 244-258 ◽  
Author(s):  
Michael F. Drummond ◽  
J. Sanford Schwartz ◽  
Bengt Jönsson ◽  
Bryan R. Luce ◽  
Peter J. Neumann ◽  
...  
Keyword(s):  
Resource Allocation ◽  
Health Technology ◽  
Resource Allocation Decision ◽  
Decision Makers ◽  
Costs And Benefits ◽  
Allocation Decision ◽  
Health Technologies ◽  
System A ◽  
Different Types ◽  
Allocation Decisions

Health technology assessment (HTA) is a dynamic, rapidly evolving process, embracing different types of assessments that inform real-world decisions about the value (i.e., benefits, risks, and costs) of new and existing technologies. Historically, most HTA agencies have focused on producing high quality assessment reports that can be used by a range of decision makers. However, increasingly organizations are undertaking or commissioning HTAs to inform a particular resource allocation decision, such as listing a drug on a national or local formulary, defining the range of coverage under insurance plans, or issuing mandatory guidance on the use of health technologies in a particular healthcare system. A set of fifteen principles that can be used in assessing existing or establishing new HTA activities is proposed, providing examples from existing HTA programs. The principal focus is on those HTA activities that are linked to, or include, a particular resource allocation decision. In these HTAs, the consideration of both costs and benefits, in an economic evaluation, is critical. It is also important to consider the link between the HTA and the decision that will follow. The principles are organized into four sections: (i) “Structure” of HTA programs; (ii) “Methods” of HTA; (iii) “Processes for Conduct” of HTA; and (iv) “Use of HTAs in Decision Making.”

Space fit for a king: spatial ecology of king cobras (Ophiophagus hannah) in Sakaerat Biosphere Reserve, Northeastern Thailand

2019 ◽  
Vol 40 (2) ◽  
pp. 163-178 ◽  
Author(s):  
Benjamin Michael Marshall ◽  
Colin Thomas Strine ◽  
Max Dolton Jones ◽  
Taksin Artchawakom ◽  
Ines Silva ◽  
...  
Keyword(s):  
Habitat Use ◽  
Breeding Season ◽  
Protected Area ◽  
Spatial Ecology ◽  
Radio Telemetry ◽  
Biosphere Reserve ◽  
Adult Males ◽  
Anthropogenic Pressures ◽  
Anthropogenic Landscapes ◽  
Ophiophagus Hannah

Abstract A species’ spatial ecology has direct implications for that species’ conservation. Far-ranging species may be more difficult to conserve because their movements increase their chances of encountering humans. The movements can take them out of protected areas, which is especially risky for species that are routinely persecuted. The king cobra (Ophiophagus hannah), a large venomous elapid, is subject to anthropogenic pressures, such as persecution and habitat loss. Here we present results from a study using radio telemetry to quantify movements and habitat use of nine king cobras in and around a protected area in Northeast Thailand. This study is the first investigation into the movements and habitat use of king cobras outside of the Western Ghats, India. On average, the tracked king cobra’s use areas of 493.42 ± 335.60 ha (95% fixed kernel), moving 183.24 ± 82.63 m per day. King cobras did not remain in intact forested area. Five of the individuals frequently used the human-dominated agricultural areas surrounding the protected area, appearing to make regular use of irrigation canals. Two adult males showed increases in movements during the breeding season. One male’s increased breeding season range caused him to venture beyond the protected area, shifting his habitat use from intact forests to scrub in human-dominated areas. King cobras’ large home range and willingness to use anthropogenic landscapes merits special consideration from conservation planners.

scholarly journals Do Some Northern Goshawk Nest Areas Consistently Fledge More Young Than Others?

The Condor ◽  
2002 ◽  
Vol 104 (2) ◽  
pp. 343-352
Author(s):  
Erica L. McClaren ◽  
Patricia L. Kennedy ◽  
Sarah R. Dewey
Keyword(s):  
British Columbia ◽  
New Mexico ◽  
Spatial Patterns ◽  
Vancouver Island ◽  
Breeding Habitat ◽  
Habitat Characteristics ◽  
Accipiter Gentilis ◽  
Uinta Mountains ◽  
Northern Goshawk ◽  
Jemez Mountains

Abstract In long-lived raptors, research suggests that some nest areas consistently fledge more young than others, with the majority of young in the population being produced by a few females. If this claim were true for Northern Goshawk (Accipiter gentilis) populations, it would benefit land managers to identify high-quality goshawk breeding habitat. We examined whether the number of young fledged varied spatially among Northern Goshawk nest areas within three study areas where long-term reproductive data from goshawks were available: (1) Vancouver Island, British Columbia; (2) Jemez Mountains, New Mexico; and (3) Uinta Mountains, Utah. A mixed-model ANOVA indicated there was minimal spatial variation in nest productivity among nest areas within the three study locations. Rather, nest areas exhibited high temporal variability in nest productivity within each study area. These results suggest that temporal patterns such as local weather and fluctuating prey populations influenced Northern Goshawk reproduction more than spatial patterns such as habitat characteristics. Nest productivity may inadequately reflect spatial patterns in goshawk reproduction and so it would be premature to assume that habitat quality for Northern Goshawks was equal among nest areas within these study areas. Future research should examine spatial variability among nest areas in adult and juvenile survival rates to gain a complete picture of population responses to habitat change. ¿Se Producen Consistentemente Más Volantones de Accipiter gentilis en Algunos Sitios de Anidación que en Otros? Resumen. Investigaciones en aves rapaces longevas sugieren que consistentemente más polluelos empluman en algunos sitios de anidación que en otros y que la mayoría de los juveniles en la población son producidos por unas pocas hembras. Si esto fuera cierto para poblaciones de Accipiter gentilis, ayudaría a las autoridades ambientales a identificar hábitat reproductivo de alta calidad para la especie. Evaluamos si el número de polluelos emplumados varió espacialmente entre sitios de anidación de A. gentilis dentro de tres áreas de estudio para las cuales había datos reproductivos de largo plazo disponibles: (1) Vancouver Island, British Columbia; (2) Jemez Mountains, New Mexico; y (3) Uinta Mountains, Utah. Un modelo mixto de análisis de varianza indicó que la variación espacial en la productividad de los nidos entre sitios de anidación dentro de las tres áreas de estudio fue mínima. En cambio, los sitios de anidación presentaron una alta variabilidad temporal en la productividad de los nidos dentro de cada área de estudio. Estos resultados sugieren que los patrones temporales como el clima y las fluctuaciones de las poblaciones de presas influencian la reproducción de A. gentilis más que los patrones espaciales como las características del hábitat. La productividad de los nidos puede reflejar inadecuadamente los patrones espaciales de la reproducción de A. gentilis, de modo que sería prematuro suponer que la calidad de hábitat fue igual entre los sitios de anidación dentro de las áreas de estudio. Para tener una perspectiva completa de la respuesta de las poblaciones a cambios en el ambiente, investigaciones futuras deberían examinar la variabilidad espacial entre sitios de anidación en las tasas de supervivencia de aves adultas y juveniles.

scholarly journals Male and female bats differ in their use of a large urban park

2019 ◽  
Vol 5 (1) ◽  
Author(s):  
Krista J Patriquin ◽  
Cylita Guy ◽  
Joshua Hinds ◽  
John M Ratcliffe
Keyword(s):  
Urban Areas ◽  
Green Space ◽  
Prey Availability ◽  
Radio Telemetry ◽  
Demographic Data ◽  
Urban Environments ◽  
City Centre ◽  
Adult Males ◽  
Urban Green ◽  
Urban Green Spaces

Abstract Understanding how wildlife respond to ever-encroaching urbanization is of great concern. Bats are the second-most speciose mammalian order and while many appear to be urban adapted, we currently have a limited understanding of their demography and habitat use within urban environments. Using a combination of captures to obtain demographic data, radio-telemetry to examine foraging and roosting behaviour, and data on diet and prey availability, we examined how big brown bats (Eptesicus fuscus), a synurbic species, use an urban green space (High Park) in Canada’s largest city centre, Toronto. We found that adult males outnumbered adult females more than two to one and that males were found throughout the park, while females were concentrated in an area with greater access to water, but lower prey availability. We also found that bats of both sexes were in poorer body condition than reported for other non-urban areas, including a site within southern Ontario. Our data suggest that High Park may not provide adequate resources for reproductive females as they were never found roosting in the park and beetles, their preferred prey, were limited. Although previous studies suggest urban green spaces may offer refuge to bats, most have not considered sex-specific responses to urbanization as they have largely been based on acoustic surveys. Our study therefore highlights the importance of considering demographic differences in response to urbanization to better inform urban management plans and green space development.

Surplus yearlings and the regulation of breeding density in blue grouse

1980 ◽  
Vol 58 (5) ◽  
pp. 896-905 ◽  
Author(s):  
Fred C. Zwickel
Keyword(s):  
Body Weight ◽  
Control Area ◽  
Removal Experiment ◽  
Breeding Density ◽  
Surrounding Area ◽  
Total Removal ◽  
Breeding Range ◽  
Experimental Area ◽  
Large Numbers ◽  
Dendragapus Obscurus

An experiment in which yearlings of both sexes of blue grouse (Dendragapus obscurus fuliginosus) were removed from breeding range showed that about two times, or more, yearlings of each sex were identified here as compared with a nearby control area, though numbers of "surplus" yearlings varied among years. The removal of large numbers of yearlings from the experimental area did not reduce breeding density, except ephemerally in 1 year. Nor did the removal of these birds affect populations in the surrounding area. These data confirm results from earlier studies with blue grouse, that surplus yearlings of both sexes are present on the breeding range. Replacement yearlings of both sexes (those taking the place of birds removed) were able to breed, but those removed sequentially (1974 to 1976) were lighter in body weight than those captured on control areas or those that settled synchronously after a near-total removal experiment in the same area. I infer from these results that some form of behaviour keeps surplus yearlings from settling on the breeding range and that this behaviour is a key mechanism involved in the regulation of breeding density. The important behaviour may involve either yearling–yearling or adult–yearling interactions.

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