Treesearch

Nest holes drilled by woodpeckers (Picidae) are frequently used by secondary cavity-nesting species, but interspecific use of open and domed nests is less well known. Nests constructed by many southwestern desert birds last longer than one year (pers. obs.) and are consequently reused by the same pair (e.g., Abert's Towhees [Pipilo aberti], pers. obs.) or by other birds as suitable nests. I observed several instances of interspecific nest use in honey mesquite (Prosopis glandulosa) habitat of the lower Colorado River valley, on the Colorado River Indian Reservation about 10 km north of...

A recent "Opinion" in the Wildlife Society Bulletin (Bart and Anderson 1981) made a case against publishing symposia proceedings because (1) papers of non-refereed symposia often lack credibility and, therefore, harm both the authors and the profession, (2) proceedings are not readily retrievable, and (3) some symposium reports are not appropriate for publication. Although some proceedings may be disorganized and include poorly written papers, Bart and Anderson's generalization unnecessarily downgrades what can be an excellent tool for technology transfer. In this rebuttal opinion we give...

Although the "dwarf" race of the Brown-headed Cowbird (Molothrus ater obscurus) is sympatric with the Crissal Thrasher (Toxostoma dorsale) in the lower Colorado River valley, I observed no parasitism in 15 thrasher nests. To determine whether or not the absence of cowbird eggs was caused by egg rejection, I experimentally parasitized nine thrasher nests. Cowbird eggs were ejected by thrashers at all experimental nests. To test the prediction that ejection or absence of cowbird eggs reduces nesting mortality, I compared thrasher nesting success to that of a sympatric accepter, the Abert's...

This paper is a distillation of some of the most important information resulting from a half-century of research on sagebrush-grass rangelands. It has been prepared as a reference for managers and users of rangelands and as a help for planning and decisionmaking.

A calibration model for screen-caged Peltier thermocouple psychrometers was developed that applies to a water potential range of 0 to-80 bars, over a temperature range of 0° to 40° C, and for cooling times of 15 to 60 seconds. In addition, the model corrects for the effects of temperature gradients over zero-offsets from -60 to + 60 microvolts. Complete details of model development are discussed, together with the theory of thermocouple psychrometers, and techniques of calibration and cleaning. Also, information for computer programing and tabular summaries of model characteristics are...

Documentation is given for using a simulation model combining the Stand Prognosis Model and the Douglas-fir Tussock Moth Outbreak Model. Four major areas are addressed: (1) an overview and discussion of the combined model; (2) description of input options; (3) discussion of model output, and (4) numerous examples illustrating model behavior and sensitivity.

Public input has become a necessary part of public land management planning (Bettwy 1978). In recreation resource planning, information on user's preferences can be an important input (Driver and Brown 1978). This paper reports on 1977 and 1978 studies of the preferences of Oak Creek Canyon users. Those studies were requested by USDA Forest Service managers to assist them in developing a management plan for the Canyon. Of particular concern to management, was information on user preferences for recreation experiences and management actions.

Presents photographs of wildland vegetation appropriate for the 13 fuel models used in mathematical models of fire behavior. Fuel model descriptions include fire behavior associated with each fuel and its physical characteristics. A similarity chart cross-references the 13 fire behavior fuel models to the 20 fuel models used in the National Fire Danger Rating System.

Aerial surveys, brood beat outs, road surveys, and brood observations have been used to estimate numbers of waterfowl broods (M. E. Anderson, unpubl. reps., South Dakota Dep. Game, Fish, and Parks Fed. Aid Proj. W-17-R-7 and 8,1953, 1955; Bennett 1967). M. C. Hammond (unpubl. rep., U.S. Bur. Sport Fish and Wildl., 1970) summarized several brood survey techniques and suggested that combining 2 or more techniques might be desirable for increased accuracy in some detailed waterfowl studies. The objective of this study was to compare 2 techniques, flush counts and hidden observation counts,...

Research was designed to assess the establishment and growth potential of 30 perennial forbs by seeding and/or transplanting them on coal mine spoil materials over a 2-year period. Five species showed exceptional emergence and vigorous growth from direct seeding. Six species showed vigorous growth with the use of transplanted plants. Seeding resulted in successful stands of most forbs on coal mine spoil material.