Open Access. Powered by Scholars. Published by Universities.®
- Discipline
- Keyword
Articles 91 - 99 of 99
Full-Text Articles in Entire DC Network
Fall Diet Of Chukars (Alectoris Chukar) In Eastern Oregon And Discovery Of Ingested Lead Pellets, Hanspeter Walter, Kerry P. Reese
Fall Diet Of Chukars (Alectoris Chukar) In Eastern Oregon And Discovery Of Ingested Lead Pellets, Hanspeter Walter, Kerry P. Reese
Western North American Naturalist
No abstract provided.
Horned Lark (Eremophila Alpestris L.) Predation On Alkali Bees, Nomia Melanderi Cockerell, Richard W. Rust
Horned Lark (Eremophila Alpestris L.) Predation On Alkali Bees, Nomia Melanderi Cockerell, Richard W. Rust
Western North American Naturalist
Horned Larks (Eremophila alpestris L.), sampled during the first 2 weeks of alkali bee (Nomia melanderi Cockerell) emergence at bee nesting sites in 2 alfalfa seed-growing regions in central Nevada, ate significantly more male than female alkali bees. Exploitation rates suggest that individual Horned Larks consume 10 to 200 alkali bees per day and feed an additional 300 to 1000 bees per day to nestlings nestlings.
Environmental Characteristics And Benthic Invertebrate Assemblages In Colorado Mountain Lakes, Brenda Moraska Lafrancois, Daren M. Carlisle, Koren R. Nydick, Brett M. Johnson, Jill S. Baron
Environmental Characteristics And Benthic Invertebrate Assemblages In Colorado Mountain Lakes, Brenda Moraska Lafrancois, Daren M. Carlisle, Koren R. Nydick, Brett M. Johnson, Jill S. Baron
Western North American Naturalist
Twenty-two high-elevation lakes (>3000 m) in Rocky Mountain National Park and Indian Peaks Wilderness Area, Colorado, were surveyed during summer 1998 to explore relationships among benthic invertebrates, water chemistry (particularly nitrate concentrations), and other environmental variables. Water samples were collected from the deepest portion of each lake and analyzed for ions and other water chemistry parameters. Benthic invertebrates were collected from the littoral zone using both a sweep net and Hess sampler. Physical and geographical measurements were derived from maps. Relationships among benthic invertebrate assemblages and environmental variables were examined using canonical correspondence analysis, and the importance of sampling …
Effects Of Grass Bug Feeding And Drought Stress On Selected Lines Of Crested Wheatgrass, Robert S. Nowak, James D. Hansen, Cheryl L. Nowak
Effects Of Grass Bug Feeding And Drought Stress On Selected Lines Of Crested Wheatgrass, Robert S. Nowak, James D. Hansen, Cheryl L. Nowak
Western North American Naturalist
The sequential effects of feeding by grass bugs (Irbisia pacifica [Hemiptera: Miridae]) and of drought stress on the growth of 2 crested wheatgrasses (the hybrid Agropyron cristatum × desertorum and A. cristatum cv. 'Fairway') were investigated in a controlled greenhouse experiment. Growth rates of genotypes that were previously selected for resistance to grass bug feeding were not consistently greater than those of unselected genotypes when plants were exposed to bug feeding. Thus, the mechanism of resistance to bug feeding for the selected genotypes does not appear to be "tolerance," i.e., rapid growth rates that allow the resistant genotypes to …
Nesting Phenology And Productivity Of Birds In The White And Inyo Mountains, California, As Assessed With Nest-Boxes, Linnea S. Hall, Michael L. Morrison
Nesting Phenology And Productivity Of Birds In The White And Inyo Mountains, California, As Assessed With Nest-Boxes, Linnea S. Hall, Michael L. Morrison
Western North American Naturalist
Nest-boxes were monitored from 1988 to 1992 on 5 grids in the pinyon-juniper (Pinus-Juniperus) woodlands of the White and Inyo Mountains, California, to determine breeding phenology and productivity of cavity-nesting birds, and characteristics of used and non-used nest-boxes. We found a total of 112 nests of 6 species. Bewicks Wrens (Thryomanes bewickii; 64 nests), Mountain Chickadees (Poecile gambeli; 18), Ash-throated Flycatchers (Myiarchus cinerascens; 12), and Juniper Titmice (Baeolophus ridgwayi; 11) were the most common species utilizing the boxes. Nest phenology and numbers of young were similar to values reported elsewhere …
Improving Seed Germination Of Salicornia Rubra (Chenopodiaceae) Under Saline Conditions Using Germination-Regulating Chemicals, M. Ajmal Khan, Bilquees Gul, Darrell J. Weber
Improving Seed Germination Of Salicornia Rubra (Chenopodiaceae) Under Saline Conditions Using Germination-Regulating Chemicals, M. Ajmal Khan, Bilquees Gul, Darrell J. Weber
Western North American Naturalist
Salicornia rubra Nels. (Chenopodiaceae) is a salt-tolerant annual species occurring in salt playas of the Great Basin desert in western United States. It forms pioneer communities on the most saline location of an inland salt playa at Goshen, Utah. Seeds of Salicornia rubra are capable of germinating at 1000 mM NaCl at 25–35 °C alternating temperature regime. Dormancy-regulating chemicals were evaluated for their ability to alleviate the innate and salinityenforced dormancy in seeds of Salicornia rubra. Betaine, GA3, kinetin, fusicoccin, ethephon, thiourea, proline, and nitrate had no effect in alleviating primary dormancy. Increases in NaCl concentration progressively inhibited germination …
Fishtail Mesa: A Vegetation Resurvey Of Relict Area In Grand Canyon National Park, Arizona, Peter G. Rowlands, Nancy J. Brian
Fishtail Mesa: A Vegetation Resurvey Of Relict Area In Grand Canyon National Park, Arizona, Peter G. Rowlands, Nancy J. Brian
Western North American Naturalist
Relict sites are geographically isolated areas that are undisturbed by direct and indirect human influences. These sites facilitate long-term ecological monitoring by providing a reference for gauging impacts occurring elsewhere. Knowledge gained through comparing vegetation change on matched relict and proximal disturbed areas can help partition the causes of change into natural and human-produced components. Fishtail Mesa in Grand Canyon National Park is a 439-ha relict site that is inaccessible to domestic livestock. Human visitation is infrequent and irregular, and fires have never been suppressed or managed. In 1958, U.S. Forest Service range scientists conducted a survey of Fishtail Mesa …
Establishment, Growth, And Early Survival Of Woody Riparian Apecies At A Colorado Gravel Pit, James E. Roelle, Douglas N. Gladwin, Brian S. Cade
Establishment, Growth, And Early Survival Of Woody Riparian Apecies At A Colorado Gravel Pit, James E. Roelle, Douglas N. Gladwin, Brian S. Cade
Western North American Naturalist
Presence of a wetted edge during the period of seedfall was an effective predictor of suitable establishment (defined as germination and survival to the 1st autumn) locations for Populus deltoides subsp. monilifera, Salix amygdaloides, S. exigua, and Tamarix ramosissima seedlings during 3 successive years of a gravel pit revegetation project in Fort Collins, Colorado. At locations predicted to be suitable for establishment, position within the pit (possibly reflecting additional moisture provided by seepage) was a significant factor in determining whether establishment actually occurred. Cover of herbaceous species, which became established at the same time as, or after, woody seedlings, was …