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Study Methods <br />The following is a discussion of the study methods used by Ecology Consultants, Inc. The study was conducted in <br />1972 for the Craig Power Station. <br />Bird species in each community type were identified and populations were estimated by observation along length and <br />widths traversing the component habitats. Routes were chosen so as to cover a large proportion of each site. A <br />standard 20-stop road census was repeated on nine (9) occasions through habitats of the Craig station region. These <br />studies were supplemented by chance observations of birds throughout the field program and by consulting Colorado <br />Division of Wildlife files for additional census data for ducks, geese, and grouse. <br />Strip census and aerial reconnaissance studied utilization of the areas around the then proposed power plant site by big <br />game during all four season over the study period. Survey transects used for the Survey transects used for the census <br />strips are shown on Figure 44, Big Game Survey Transects. The survey transects were located so that the maximum <br />area of suitable big game habitat would be included. Sightings, tracks, pellet groups, and beds were recorded for both <br />deer and elk. Colorado Division of Wildlife personnel was interviewed and records were examined as auxiliary data. <br />The small mammal populations in the Craig area were studied at various times of the year, in order to determine the <br />seasonal patterns of population density and composition. Weather conditions and seasonal changes appear to have a <br />marked influence on the presence and activity of many of the animals studied. Other contributing factors may be <br />breeding patterns and availability of food. These considerations make it very difficult to estimate and interpret <br />population densities based on single-season observations. <br />Small mammal trapping studies utilized a trapping grid consisting of 288 traps. Trapping stations with two (2) traps <br />per station were positioned 50 feet apart on a square grid with 12 stations on a site. Four (4) such grids were utilized. <br />In addition, two linear transects with a total of 100 traps were located in a mixture of grassland and cattail habitat in <br />Big Bottom. All traps were checked daily. Direct observation and indirect evidence of small mammals supplemented <br />the data collected by trapping. <br />Cottonwood and Sagebrush Stands in Big Bottom Area <br />Study areas were established in both the Cottonwood and Sagebrush stands in Big Bottom. About 111 species of <br />birds have been found to utilize the diverse and complex habitat provided by the Big Bottom area at various times of <br />the year. The primary use of the area is for feeding and resting during migration and breeding. The Big Bottom area <br />provides an important breeding and wintering ground for Canada geese and Mallards. The Big Bottom area comprises <br />about one-fourth of the total habitat in the region. Other important species found in the Big Bottom area include <br />morning doves and sage grouse, both of which use Big Bottom extensively for nesting and feeding. Its been observed <br />that about fourteen great blue heron nests are actively used in the Big Bottom area. In addition, the areas first records <br />of the white-faced ibis have been reported. The bird species observed in the Big Bottom area are listed in Table 45, <br />Summary of Birds Recorded Within Big Bottom and Williams Fork Mountain Habitats. The probable status <br />designations of these birds are summarized on Table 46, Summary of Probable Status Designations for Bird Species <br />Located in Habitats of Big Bottom and Williams Fork Mountains. <br />Although some of the birds range widely over all habitat types, many others depend upon special or limited habitats. <br />The majority of birds observed utilize the riparian woodland habitats provided by the cottonwood stand and similar <br />brushy and forested areas of Big Bottom. The sparse and relatively simplified sagebrush habitats provide more <br />restricted opportunities for nesting and feeding. The sage grouse is entirely dependent upon the sagebrush type of <br />habitat. Other birds, such as the sparrows, kingbirds, shrikes, horned lark, and lark bunting are primarily associated <br />~ with the sagebrush habitat, utilizing the more shrubby habitats as a secondary choice. <br />~. <br />~lPPR.OVED FAR 141001 <br />Permit Renewal No. 4 2.04-42 Revised 3/5/03 <br />