Treesearch

Twenty-two radio-tagged hens hatched 265 chicks, of which all but 4 left the nest. Mortality of chicks was high, especially in the first 24 days, with only 28.4% surviving to the end of summer. Brood ranges varied from 22 to 2248 ha with an average of 488.6 ha for 15 broods that had at least one chick alive on 10 August. Several factors influenced the size of the range, including timing of the nest, age of the hen, and loss or potential loss of young due to predation, mowing or grazing. Small areas within the total range were used more intensively. These areas averaged 40.4 ha. Broods were...

Replacement of lost mates within the same nesting season has been recorded in 26 raptor species (Newton 1979). Only three species (Cooper’s Hawk, Accipiter cooperii; Northern Goshawk, A. gentilis; and Peregrine Falcon, Falco peregrinus) have exhibited full adoption, i.e., incubation of eggs and/or rearing of young by an unrelated, replacement mate (Rohwer 1986). Neither mate replacement within the same season nor adoption has been recorded for Bald Eagles (Haliaeetus leucocephalus). Herrick (1932) describes two Bald Eagle mate replacements of 11 and 14 weeks’ duration, but both occurred...

The English-Spanish/Spanish-English equivalent translations of scientific and management terms (jargon) commonly used in the field of natural resource management are presented. The glossary is useful in improving communications and fostering understanding between Spanish- and English-speaking persons.

Describes use of increment borers for interpreting fire history in coniferous forests. These methods are intended for use in wildernesses, parks, and other natural areas where sawing cross-sections from fire-scarred trees is prohibited.

Weathering rates of orthoclase and plagioclase were computed from mass balances of Na, K, and Ca in three forested watersheds in the Idaho batholith. On the basis of stand conditions, two watersheds were assumed to have no net gains or losses of cations in biomass, and increases in biomass were measured in the third watershed. Balanced feldspar hydrolysis reactions were established based on kaolinite as a weathering product. Free silica (SiO2) release predicted from reaction stoichiometries ranged from 94 to 99% of measured SiO2 flux from the watersheds. These results suggest that the...

A vegetation classification was developed, using the methods and concepts of Daubenmire, on the Ashland, Sioux, and Grand River/Cedar River Districts of the Custer National Forest. Of the 26 habitat types delimited and described, eight were steppe, nine shrub-steppe, four woodland, and five forest. Two community types also were described. A key to the habitat types and some of the changes resulting from disturbances of the vegetation also are included.

Prairie grouse habitat usage was observed for six years. Spring and summer habitat usage was primarily in the upland and midland grassland habitat types. Habitat usage shifted during the fall and winter to cropland and associated tree shelterbelts. The switchgrass plant community was the primary concealment cover for nesting and roosting. Cropland and associated tree shelterbelts was the primary habitat during winter.

The Universal Transverse Mercator (UTM) international, planar, grid system is described and shown to offer greater simplicity, efficiency and accuracy for plotting wildlife locations than the more familiar Latitude-Longitude (Latilong) and Section-Township-Range (Cadastral) systems, and the State planar system. Use of the UTM system is explained with examples.

Deciduous woodlands provide important habitat for wildlife but comprise < 1% of the land area in the northern great plains. we sampled vegetation, birds, and mammals in 1983 and 1984 in 2 stand types of green ash (Fraxinus pennsylvanica) woodlands in northwestern South Dakota. Closed-canopy stands were multilayered communities with dense overstories of several age classes and sizes of trees and a variety of shrubs. Open-canopy stands lacked foliage layers and had sparse overstories of decadent trees. Fifteen birds and mammals occurred in significantly greater numbers (P < .05) in closed-can...

The percentage of arthropods and plants in the diets of seven small rodents captured on prairie dog colonies and adjacent mixed grasslands were estimated by microhistological techniques. Arthropod composition over the two year study averaged 51% and 37% on prairie dog colonies and mixed grasslands, respectively. Composition of arthropods on prairie dog colonies was greater during the summer than in late spring or late summer. Conversely, arthropods made up a considerably smaller percentage of small mammal diets in the summer on mixed grasslands. Nearly twice as many small mammals, excluding...