Author: Todd R. Mills
Publisher:
ISBN:
Category : Birdsongs
Languages : en
Pages : 392
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Book Description
Birds are indicators of vegetation structure and ecological conditions. The singing activity of birds declines during late-morning periods, which can affect estimates of abundance and conclusions regarding vegetative conditions indexed by birds. Therefore, it is important to quantify periods of bird activity so biologists can plan studies. We determined hourly detections from singing males of 22 nongame bird species in ponderosa pine, quaking aspen, and grassland vegetation types in the Black Hills of South Dakota. Detections of 12 of 22 species differed among 1-hr intervals after sunrise. Detections of yellowrumped warblers, Townsend's solitaires, red-breasted nuthatches, western tanagers, and American robins decreased on count-episodes more than 4 hrs after sunrise. Detections of dusky flycatchers declined on count-episodes more than 3 hrs after sunrise and detections of black-capped chickadees were greatest during the first hour after sunrise and declined afterward. Detections of many other species from songs or calls decreased on count-episodes more than 5 hrs after sunrise. We recommend that bird counts in the Black Hills be completed within 4 hrs after sunrise so estimates of bird abundance are not affected by reduced singing among males.
Author: Todd R. Mills
Publisher:
ISBN:
Category : Forests and forestry
Languages : en
Pages : 12
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Book Description
Author: Carolyn C. Bohn
Publisher:
ISBN:
Category : Forests and forestry
Languages : en
Pages : 36
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Book Description
The effects on channels of small, low-head seasonal water diversions in the Snake River drainage were investigated. Channels below small diversions were compared to the channels immediately above the same diversions to determine if differences in flow conveyance, substrate sediment size distribution, or streamside vegetation density were present. Estimates of flow conveyance were greater above the diversions, as measured by the area between the edges of vegetation on both banks, and by frequent-flow indicators, which generally approximated bankfull stage. No significant difference in substrate particle size or in channel roughness was found between channels above and below diversions. Although use histories of the diversions were not available, limited observations and conversations with users suggest that many of the diversion structures did not substantially divert high springtime flows so that passage of channel-forming flows probably occurred. Some diversion structures apparently divert or trap a portion of the bedload. Stem diameters of vegetation 6 to 48 inches above the ground were significantly larger above the diversions. Tests of stem densities were not significant. Stratification by substrate, season and size of diversion, community type, and source of summer water may be necessary to properly evaluate the effects of small diversions on vegetation stem density and vigor. The elevation of the edge of vegetation appears to be a viable alternative to frequent flow or bankfull indicators for estimating flow conveyance. It also addresses the question of vegetative encroachment into the channel. Use of the edge of vegetation as a channel feature for flow estimates merits further testing. It appears that the operation of the small forest stream diversions studied has not substantially altered most of the parameters studied. Past hydrographs and historical hydrologic data, however, are needed to fully evaluate the channel and vegetation responses.
Author:
Publisher:
ISBN:
Category : Forests and forestry
Languages : en
Pages : 288
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Book Description
Author:
Publisher:
ISBN:
Category : Government publications
Languages : en
Pages : 948
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Book Description
Author:
Publisher:
ISBN:
Category : Forests and forestry
Languages : en
Pages : 142
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Author:
Publisher:
ISBN:
Category : Agriculture
Languages : en
Pages : 1010
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Book Description
Author:
Publisher:
ISBN:
Category : Animals
Languages : en
Pages : 1438
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Book Description
Author: Shane P. Mahoney
Publisher: JHU Press
ISBN: 1421432811
Category : Science
Languages : en
Pages : 177
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Book Description
The foremost experts on the North American Model of Wildlife Conservation come together to discuss its role in the rescue, recovery, and future of our wildlife resources. At the end of the nineteenth century, North America suffered a catastrophic loss of wildlife driven by unbridled resource extraction, market hunting, and unrelenting subsistence killing. This crisis led powerful political forces in the United States and Canada to collaborate in the hopes of reversing the process, not merely halting the extinctions but returning wildlife to abundance. While there was great understanding of how to manage wildlife in Europe, where wildlife management was an old, mature profession, Continental methods depended on social values often unacceptable to North Americans. Even Canada, a loyal colony of England, abandoned wildlife management as practiced in the mother country and joined forces with like-minded Americans to develop a revolutionary system of wildlife conservation. In time, and surviving the close scrutiny and hard ongoing debate of open, democratic societies, this series of conservation practices became known as the North American Model of Wildlife Conservation. In this book, editors Shane P. Mahoney and Valerius Geist, both leading authorities on the North American Model, bring together their expert colleagues to provide a comprehensive overview of the origins, achievements, and shortcomings of this highly successful conservation approach. This volume • reviews the emergence of conservation in late nineteenth–early twentieth century North America • provides detailed explorations of the Model's institutions, principles, laws, and policies • places the Model within ecological, cultural, and socioeconomic contexts • describes the many economic, social, and cultural benefits of wildlife restoration and management • addresses the Model's challenges and limitations while pointing to emerging opportunities for increasing inclusivity and optimizing implementation Studying the North American experience offers insight into how institutionalizing policies and laws while incentivizing citizen engagement can result in a resilient framework for conservation. Written for wildlife professionals, researchers, and students, this book explores the factors that helped fashion an enduring conservation system, one that has not only rescued, recovered, and sustainably utilized wildlife for over a century, but that has also advanced a significant economic driver and a greater scientific understanding of wildlife ecology. Contributors: Leonard A. Brennan, Rosie Cooney, James L. Cummins, Kathryn Frens, Valerius Geist, James R. Heffelfinger, David G. Hewitt, Paul R. Krausman, Shane P. Mahoney, John F. Organ, James Peek, William Porter, John Sandlos, James A. Schaefer
Author: David Hackett Fischer
Publisher: Oxford University Press
ISBN: 019974369X
Category : History
Languages : en
Pages : 981
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Book Description
This fascinating book is the first volume in a projected cultural history of the United States, from the earliest English settlements to our own time. It is a history of American folkways as they have changed through time, and it argues a thesis about the importance for the United States of having been British in its cultural origins. While most people in the United States today have no British ancestors, they have assimilated regional cultures which were created by British colonists, even while preserving ethnic identities at the same time. In this sense, nearly all Americans are "Albion's Seed," no matter what their ethnicity may be. The concluding section of this remarkable book explores the ways that regional cultures have continued to dominate national politics from 1789 to 1988, and still help to shape attitudes toward education, government, gender, and violence, on which differences between American regions are greater than between European nations.
