Table 2 — Spearman correlation coefficients {f) for bird numbers compared with habitat variables; study areas separate and 

 combined 



Average Ponderosa Other Number 



Crown height pine tree Woody snags Food 



canopy taiiest foliage foliage understory >10.2 availability 



cover trees volume volume cover cm/ha index 





Percent 



m 



mP/ha ■ 





Percent 













Study area 1 (Kaibab) 









White— breasted nuthatch 



U.Uo 



ci r\'7 



-0.21 



0.35 



U.4o 



V.iiH 



— O.lo 



Mountain chicl<adee 



-.37 



-.18 



-.56 



.53 



.56 



-.29 



-.48 



House wren 



.51 



.64 



.48 



-.46 



-.08 



^74 



.53 



Pygmy nuthatch 



.37 



.59 



.49 



-.46 



-.31 



.47 



.28 



Total birds 



-.23 



.11 



-.23 



.23 



.32 



-.06 



-.32 









Study area 2 (Trumbull) 









White— breasted nuthatch 





.Ob 



\7Q 



.46 



—.1 U 



.O 1 



1 70 



Mniintain rhirkadee 



.17 



-.1 1 



.38 



.22 



.05 



-.21 



.56 



House wren 



.48 



.44 



.13 



-.13 



-.44 



.13 



-.20 



Pygmy nuthatch 



.06 



.42 



^82 



.30 



-.04 



.32 



.55 



Total birds 



.15 



.31 



\^^ 



.32 



-.01 



.26 



\72 









All locations 











White-breasted nuthatch 



.47 



.15 



.37 



^53 



.07 



.08 



\5^ 



Mountain chickadee 



.11 



-.23 



.00 



\58 



.27 



-.40 



.16 



House wren 



.37 



\58 



.34 



-.36 



-.18 



.48 



.20 



Pygmy nuthatch 



.44 



.32 



\60 



.16 



-.18 



-.01 



\50 



Total birds 



.31 



.08 



.34 



.45 



.07 



-.18 



.38 



'P <0.01. 



variables produced some significant positive rela- 

 tionships. Pygmy nuthatch exhibited significant 

 positive correlations (r = 0.82 and 0.60) (P < 0.01) 

 with ponderosa pine foliage volume at Trumbull and 

 both study areas combined. House wren exhibited 

 significant positive correlation with the average 

 height of the tallest trees on both study areas com- 

 bined (r = 0.58). White-breasted nuthatch exhibited 

 a significant positive correlation with ponderosa 

 pine volume at Trumbull (r = 0.70), as did the four 

 species combined (r = 0.71). At all locations com- 

 bined, white-breasted nuthatch and mountain 

 chickadee had significant positive correlations 

 (r = 0.53 and r = 0.58) with other tree volume, which 

 included pinyon, juniper, and tree-form Gambel oak. 

 Significant positive correlations were exhibited with 

 the index of food availability by white-breasted nut- 

 hatch at Trumbull and the combined study areas 

 (r = 0.73 and r = 0.51), by pygmy nuthatch on the 

 combined study areas (r = 0.50), and by the four 

 species total at Trumbull (r = 0.72). These patterns, 

 similar to what Diem and Zeveloflf (1980) and 

 Cunningham and others (1980) reported, were more 



evident at Trumbull or at all locations combined 

 than at Kaibab. 



There was little correlation between bird numbers 

 and snag densities, woody understory vegetation 

 cover, or time since logging on either study area, 

 except at Kaibab, where house wren had a signifi- 

 cant positive correlation with snag density. Regres- 

 sion analyses performed combining the habitat vari- 

 ables yielded little improvement. 



DISCUSSION 



Results of this study illustrate the potential asso- 

 ciated with using Forest Survey data for the assess- 

 ment of wildlife habitat. Results of the analyses 

 showed some correlation of bird numbers with the 

 interrelated tree ^anopy variables: total foliage vol- 

 ume, ponderosa pine volume, other tree volume, and 

 the index of food availability. These findings indi- 

 cate that general foliage volume estimates or indices 

 can be used to indicate relative habitat suitability. 



The food availability index is a good ordered vari- 

 able (Spearman correlation test) and is sensitive to 



5 



