

Birds 



A variety of techniques were employed in order to quantitatively describe bird 

 populations of the area. The primary study area (Figure 8) was censused in winter 

 (January 20 - March 2, 1978) and during the breeding season (May 7 - June 30, 1978) 

 using standard methods (Hall 1964; Van Velzen 1972; Kolb 1965). The schedule of 

 the breeding bird census is given in Appendix A. Monthly occurrence, location and 

 habitat type were noted for each bird species. In order to document the importance 

 of riparian habitats, a bird survey transect was established along the railroad 

 right-of-way which parallels the river from the retaining wall along Highway 2 to 

 the mouth of China Creek. The route was walked eight times from January 20 to 

 March 2, 1978, and seven times from April 29 to May 9, 1978, following the technique 

 described by Emlen (1977). The route was extended to cover the area from the falls 

 to 2 km (1.6 miles) upstream and was conducted nine times from May 11 to July 8. 

 Information obtained during these 16 walks was used to compare the relative use by 

 birds in the upland coniferous forest habitat and the riparian deciduous vegetation 

 habitat. Limited mist-net sampling was conducted early in the breeding season but 

 was discontinued, as it was time-consuming and yielded little additional useful data. 

 Species not previously recorded on the study area or the occurrence of a species not 

 previously observed in a particular habitat were noted during general reconnaissance 

 and incidental to other activities. 



Waterfowl were regularly censused from 2 km (1.2 miles) above the falls to the 

 falls during these transects, and the area from the falls to 1 km {H mile) down- 

 stream was regularly monitored. Because much of the river from Libby to near the 

 junction of U.S. Highway 2 and State Highway 202 is not navigable, observations 

 along the river, other than in those areas already mentioned, were made incidental 

 to other activities, usually while enroute between Libby and Troy on Highway 2. 

 Locations of waterfowl observed on the river were recorded on standard data sheets 

 using letter codes from the mouth of O'Brien Creek (A) to Pipe Creek (W), Figure 9. 



Large Mairmals 



Data were recorded on standard data sheets for each ungulate observation, and 

 included the following information: date, time of day, observer, mode of trans- 

 portation, cloud cover, precipitation, percent snow cover, temperature, wind speed, 

 number of animals, group composition, activity, slope, aspect, elevation, forest 

 habitat type, general cover type and terrain type. Eight aerial surveys were made 

 oyer the study area including three helicopter and five fixed-wing flights. Loca- 

 tions of each animal or group observed were plotted on field maps and were also 

 recorded on data sheets using the location codes shown in Figure 9. As shown in 

 this figure, the land area was coded using numerals from Surprise Gulch (1) to east 

 of Pipe Creek (15) on the north side of the river, and from west of Cedar Creek (16) 

 to the junction of Highway 2 and Highway 202 (26) south of the river. 



Monthly bighorn sheep surveys were conducted from Lynx Flats to Quartz Creek 

 from January through July, 1978, and incidental observations collected durina June, 

 November and December, 1977. The surveys were conducted from Highway 2 during 

 early morning or late afternoon and evening. i 



