species within each stand condition and year. The 

 mean of each of these 10 averages was used to test 

 for differences in relative abundance of bird species 

 among stand conditions and years. Samphng veg- 

 etation components at the census points once per 

 year generated 10 sample values for the selected 

 variables within each stand condition. The mean 

 of each set of 10 samples was compared to the 

 means for the other stands during each year. 



All bird species seen less than eight times during 

 both years' censusing over all points were arbitrar- 

 ily excluded from species-level statistical analysis 

 (table 2). These species were included in the guild 



analysis (table 3). Statistical significance in all 

 tests was P < 0.05, employing the Bonferroni 

 adjustment to control for experimentwise error rate 

 (SPSS Inc. 1983). We used two-way analysis of 

 variance to test for significant interaction and main 

 effects for a given species' abundance by stand 

 condition and year (SPSS Inc. 1983). Parametric 

 analysis was justified on the basis of normal prob- 

 ability plots for the common species within the 

 sample. Although count data is heavily right- 

 skewed, the analysis of variance procedure is robust 

 for comparison of samples with similar distributions 

 (Sokal and Rohlf 1981). 



Table 2 — Mean number of birds counted per census point within the four stand conditions at the Terrace Hill study area and 

 adjacent Coram Research Natural Area, Coram Experimental Forest, in 1989 and 1990 



Stand condition 





Foraging 



Nesting 



Clear- 



Partial- 



Unlogged 



Natural 



Proba- 



Species^ 



guild^ 



guild^ 



cut* 



cut* 



forest 



Area 



bility' 



Killdppr 



GF 



GR 



0.15 

















V/?iiiy'q Q\A/ift 



V dUA O OWIII 



FC 



SC 





07 







n 



1 nnn 





TD 



1 L/ 



PC 







97 







H^iirv wnnHnprkpr 



TD 



PC 



.17 



13 



.19 



.33 



1 nnn 





GF 



PC 





. 1 o 





. 1 



1 nnn 



Olix/fi-^iripH fl\/r;?trhAr 



FC 



CB 



.17 



07 



.02 







224 



\A/0^tprn wonH-nPWPP 



FC 



CB 



07 



03 



.05 







1 nnn 



Trpo QW^IInuu 



FC 



SC 



62* 



07^ 





0^ 

 yj 





Steller's jay 



FF 



CB 



.03 



.05 



.13 



.05 



1.000 



Common raven 



GF 



CB 



.11 



.03 



.10 



.22 



1.000 



Black-capped chickadee 



TG 



SC 



.30 



.27 



.40 



.57 



1.000 



l^ountain chickadee 



TG 



SC 



.08 



.17 



.28 



.28 



1.000 



Red-breasted nuthatch 



TG 



SC 



.30 



.42 



.58 



.53 



1.000 



Brown creeper 



TG 



SC 







.03 



.02 



.12 



1.000 



Winter wren 



GF 



GR 







.13 



.08 



.17 



1.000 



Golden-crowned kinglet 



FF 



CT 



0* 



45AB 



47AB 



.73B 



.016 



Ruby-crowned kinglet 



FF 



CT 



.13* 



.52^ 



_40*B 



.17* 



.016 



Mountain bluebird 



GF 



SC 



.13 











.03 



1.000 



Townsend's solitaire 



FF 



GR 



.13 



.25 







.02 



.192 



Swainson's thrush 



FF 



CB 



.15* 



1.05^ 



1.05B 



I.23B 



.002 



American robin 



GF 



BT 



.58 



.30 



.22 



.05 



.096 



Varied thrush 



GF 



BT 



.03* 



.05* 



.10* 



.38^ 



.016 



Solitary vireo 



FF 



CB 



.05 



.10 



.07 



.18 



1.000 



Warbling vireo 



FF 



BT 



,13 



.20 



.18 



.18 



1.000 



Yellow-rumped warbler 



FF 



CT 



.28 



.35 



.28 



.25 



1.000 



Townsend's warbler 



FF 



CT 



.43* 



1.00^ 



1.22^ 



1.50^ 



.002 



MacGillivray's warbler 



FF 



BT 



.02 



.12 



.13 



.22 



.864 



Western tanager 



FF 



CT 



.10 



.20 



.10 







.896 



Chipping sparrow 



GF 



BT 



.68* 



.72* 



.52*B 



.I7B 



.016 



Fox sparrow 



GF 



GR 



.18* 



32AB 



.40*8 



0* 



.016 



Dark-eyed junco 



GF 



GR 



1.27* 



.80* 



.25^ 



.13^ 



.002 



Pine siskin 



FF 



CB 



.78* 



.57*B 



.17^ 



.08^ 



.032 



Total No. species 



32 



32 



29 



30 



28 



25 





'Scientific names of bird species are listed in appendix. 



^Foraging guild: FF = foliage forager; FC = flycatcher; TD = tree driller; TG = tree gleaner; GF = ground forager (Diem and Zeveloff 1980). 

 ^Nesting guild: CT = conifer tree; CB = conifer or broadleaf tree; BT = bush or small tree; PC = primary cavity; SC = secondary cavity; GR = 

 ground (Diem and Zeveloff 1980). 

 ^Tree snags of all species and living paper birch trees were left standing where possible. 



^Low probability values indicate significantly different means among stand conditions, Bonferroni adjusted to control for experimentwise error; 

 superscript letters group similar means for each species (SPSS Inc. 1983). 



5 



