Bird Populations in Logged 

 and Unlogged Western Larch/ 

 Douglas-fir Forest in 

 Northwestern Montana 



Bret W. Tobalske 

 Raymond C. Shearer 

 Richard L. Hutto 



INTRODUCTION 



The influence of logging on breeding-season bird 

 populations has been documented for a variety of 

 forest types in the Western United States: mixed 

 conifer (Franzreb and Ohmart 1978; Mannan and 

 Meslow 1984; Verner and Larson 1989), coastal 

 Douglas-fir {Pseudotsuga menziesii) (Hagar 1960; 

 Meslow 1978), interior Douglas-fir (Medin 1985; 

 Medin and Booth 1989), giant sequoia {Sequoia- 

 dendron giganteum) (Kilgore 1971), lodgepole pine 

 (Pinus contorta) (Austin and Perry 1979), and 

 ponderosa pine {Pinus ponderosa) (Szaro and Balda 

 1979). 



Medin (1985) provided a summary of bird species' 

 responses to various logging methods based on 

 several of the cited studies. Although general 

 patterns of response were evident for many species, 

 certain species, including yellow-rumped warbler 

 (scientific names of bird species censused in the 

 study area are in the appendix) and hairy wood- 

 pecker were reported to increase, decrease, or show 

 no response following clearcutting. This suggests 

 that studies of bird responses to logging may be 

 spatially or temporally specific. Thus, a need exists 

 for other investigations of the effects of logging on 

 birds, especially in unstudied forest types. 



Recently we studied the influence of logging on 

 a wide range of birds in the Coram Experimental 

 Forest, located within the western larch (Larix 

 occidentalis) forest cover type (Eyre 1980). This 

 report describes 2 years of observed differences in 

 the avian assemblage following logging and site- 

 preparation treatments. 



STUDY AREA 



This study was located within the southern 

 quarter of the Coram Experimental Forest (CEF), 



about 28 miles (45 km) east of Kalispell, MT, on the 

 Flathead National Forest (fig. 1). It includes both 

 the Terrace Hill sale area (THSA) and the adjacent 

 Coram Research Natural Area (CRNA) (fig. 2). 



Description 



The site occupies a portion of the watershed 

 drained by the South Fork of Abbot Creek. The 

 THSA ranges in elevation from 3,360 to 4,500 R 

 (1,021 to 1,372 m), lies mostly southwest of Abbot 

 Creek, and is on northeast-facing slopes. The 

 CRNA ranges in elevation from 3,500 to 4,458 ft 

 (1,067 to 1,359 m), lies northeast of Abbot Creek, 

 and is mostly on southwest-facing slopes. Slopes 

 of both areas range from 5 to 35 percent. Annual 

 precipitation averages 34 inches (86 cm). Tempera- 

 ture averages 60 °F (16 °C) from May through 

 August (Hungerford and Schlieter 1984). 



The study area represents a serai stage of the 

 subalpine fir/queencup beadlily {Abies lasiocarpal 

 Clintonia uniflora) habitat type classified by Pfister 

 and others (1977). Western larch and Douglas-fir 

 {Pseudotsuga menziesii var. glauca) are the domi- 

 nant trees on the CEF. The old-growth larch is 

 composed mostly of 300-year-old trees and occasion- 

 ally of 500-year-old veterans. Other trees include 

 Engelmann spruce {Picea engelmannii), subalpine 

 fir, lodgepole pine {Pinus contorta), western white 

 pine {Pinus monticola), paper birch {Betula 

 papyrifera), quaking aspen {Populus tremuloides), 

 and black cottonwood {Populus trichocarpa). Domi- 

 nant shrubs include Rocky Mountain maple {Acer 

 glabrum) and fool's huckleberry {Menziesia 

 ferruginea). Queencup beadlily and pinegrass 

 {Calamagrostis rubescens) are the primary herbs. 



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