Vegetative Characteristics of Swift Fox Denning and Foraging Sites in Southwestern South Dakota

Vegetative Characteristics of Swift Fox Denning and Foraging Sites in Southwestern South Dakota PDF

Author: Daniel W. Uresk

Publisher:

Published: 2003

Total Pages: 8

ISBN-13:

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Vegetative characteristics of swift fox (Vulpes velox) denning and foraging habitats were studied in southwestern South Dakota. We followed 14 radio-collared foxes over a two-year period and identified 17 den sites and 82 foraging sites. Height-density of vegetation (visual obstruction reading, VOR) was determined on each den and foraging site and on 81 randomly selected sites. Total vegetation VOR was higher (p=0.08) at den sites than on randomly selected sites (11.7±1.4 and 9.5±0.6cm (SE), respectively). Swift foxes used foraging areas with vegetation greater VOR (p=0.01) than that found on randomly selected sites (11.9±0.7 and 9.5±0.6 cm, respectively). Canopy cover for seven major plant species on foraging sites was different than on den sites (p=0.055) but random sites were not different from either foraging or den sites. While previous studies have described swift fox macrohabitats with little vegetative cover (e.g., plowed fields or heavily grazed areas), our study showed that height-density of vegetation is important to these foxes.

Optimum Timeframes for Detecting Songbird Vocalizations in the Black Hills

Optimum Timeframes for Detecting Songbird Vocalizations in the Black Hills PDF

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.

Mammals of Colorado, Second Edition

Mammals of Colorado, Second Edition PDF

Author: David M. Armstrong

Publisher: University Press of Colorado

Published: 2011-05-18

Total Pages: 637

ISBN-13: 145710976X

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Co-published with the Denver Museum of Nature & Science. Thoroughly revised and updated, Mammals of Colorado, Second Edition is a comprehensive reference on the nine orders and 128 species of Colorado's recent native fauna, detailing each species' description, habitat, distribution, population ecology, diet and foraging, predators and parasites, behavior, reproduction and development, and population status. An introductory chapter on Colorado's environments, a discussion of the development of the fauna over geologic time, and a brief history of human knowledge of Coloradan mammals provide ecological and evolutionary context. The most recent records of the state's diverse species, rich illustrations (including detailed maps, skull drawings, and photographs), and an extensive bibliography make this book a must-have reference. Amateur and professional naturalists, students, vertebrate biologists, and ecologists as well as those involved in conservation and wildlife management in Colorado will find value in this comprehensive volume.

Assessing Soil Compaction on Forest Inventory & Analysis Phase 3 Field Plots Using a Pocket Penetrometer

Assessing Soil Compaction on Forest Inventory & Analysis Phase 3 Field Plots Using a Pocket Penetrometer PDF

Author: Michael C. Amacher

Publisher:

Published: 2004

Total Pages: 18

ISBN-13:

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Soil compaction is an important indicator of soil quality, yet few practical methods are available to quantitatively measure this variable. Although an assessment of the areal extent of soil compaction is included as part of the soil indicator portion of the Forest Inventory & Analysis (FIA) program, no quantitative measurement of the degree of soil compaction is made. We tested a small, lightweight pocket penetrometer that measures soil compression strength as a simple, quantitative measure of the degree of compaction of mineral soils under forested conditions. Soil compression strengths were significantly higher in compacted trails and areas than in adjacent undisturbed locations. In contrast, no significant difference in soil compression strength was found between rutted trails and adjacent undisturbed areas. A protocol is suggested for further pilot testing of this device as part of the soil indicator assessment. The main disadvantage of this device is that many of the compacted soils had compression strengths higher than the maximum measurable value of 4.5 tons/ft2. Despite this limitation, this device can rapidly and easily distinguish between compacted and uncompacted areas in the field. Time previously spent by field crews trying to identify qualitative evidences of compaction can instead be used to provide a quantitative measure of the degree of compaction, which would strengthen the analysis and interpretation of the soil quality indicator.