Optimum Timeframes for Detecting Songbird Vocalizations in the Black Hills
Optimum Timeframes for Detecting Songbird Vocalizations in the Black Hills

Author: Todd R. Mills

Publisher:

Published: 2000

Total Pages: 0

ISBN-13:

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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.

Optimum Timeframes for Detecting Songbird Vocalizations in the Black Hills
Optimum Timeframes for Detecting Songbird Vocalizations in the Black Hills

Author: Todd R. Mills

Publisher:

Published: 2000

Total Pages: 392

ISBN-13:

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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.

Stream Channel Responses to Streamflow Diversion on Small Streams of the Snake River Drainage, Idaho
Stream Channel Responses to Streamflow Diversion on Small Streams of the Snake River Drainage, Idaho

Author: Carolyn C. Bohn

Publisher:

Published: 2000

Total Pages: 36

ISBN-13:

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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.

Nature's Music
Nature's Music

Author: Peter R. Marler

Publisher: Elsevier

Published: 2004-10-05

Total Pages: 556

ISBN-13: 0080473555

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The voices of birds have always been a source of fascination. Nature’s Music brings together some of the world’s experts on birdsong, to review the advances that have taken place in our understanding of how and why birds sing, what their songs and calls mean, and how they have evolved. All contributors have strived to speak, not only to fellow experts, but also to the general reader. The result is a book of readable science, richly illustrated with recordings and pictures of the sounds of birds. Bird song is much more than just one behaviour of a single, particular group of organisms. It is a model for the study of a wide variety of animal behaviour systems, ecological, evolutionary and neurobiological. Bird song sits at the intersection of breeding, social and cognitive behaviour and ecology. As such interest in this book will extend far beyond the purely ornithological - to behavioural ecologists psychologists and neurobiologists of all kinds. * The scoop on local dialects in birdsong* How birdsongs are used for fighting and flirting* The writers are all international authorities on their subject

Albion's Seed
Albion's Seed

Author: David Hackett Fischer

Publisher: Oxford University Press

Published: 1991-03-14

Total Pages: 981

ISBN-13: 019974369X

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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.