A Four-year Summary of Breeding Bird Surveys in TFL 48 ... - BIOD

most part, stand structure was generalized, following the system proposed by Campbell(1997). However, for all transects established in the Fort St. John TSA in 2005, werecorded more specific stand structure information.Bird species were recorded using standardized four-letter species codes forBritish Columbia (Preston et al. 2005, Appendix 1). Noise levels were expected tohamper the detection of some species or some individuals at a particular distance fromthe observer. Therefore, a measure of noise (i.e., a passing vehicle, chainsaw, flowingwater, etc.) was recorded as either temporary, permanent or absent for each count (seeAppendix 2 for noise categories). Weather variables included temperature, wind speed,cloud cover, and precipitation. Temperature was recorded using an aluminiumarmouredpocket thermometer held in the shade and away from the vehicle for theduration of the count. Wind speed, cloud cover and precipitation were assigned to predefinedcategories, although no surveys were done in moderate to heavy rain or wind(see Appendix 2 for climate categories).Calculations of mean species richness, abundance, and diversity were primarilyused for demonstrating general patterns within TFL 48 and the Fort St. John TSA.Generally, greater than eight years of data are needed for the purpose of assessingpopulation trends of various species and determining reasonable estimates of density(Robbins et al. 1986). Fewer years are needed to develop species-habitat modelsalthough additional years could improve their robustness (Vernier 2005).Several maps were used to facilitate the establishment of transects, includingCanadian Forest Products Ltd. maps, government maps, and Forest Service maps. In4