

16 
Table 4. Composition of two guilds containing Steller’s jay 
in a community of mature ponderosa pine. All species 
feed in the tree canopy. 

Strata> where 
Vertebrate species* feeding occurs 

Primary Consumer 
Pinyon jay Ton te 
Cedar waxwing Ts, So, TG 
Cassin’s finch LS, ae, LG 
Clark’s nutcracker LS 
Gray jay Ts, TC 
Steller’s jay LS, Tks 
Western tanager peo rae ts 
Pine siskin TS, 58, Te 
Secondary Consumer 
Pinyon jay ES 
Clark’s nutcracker TS, EB, Le 
Cedar waxwing ES, Te 
Gray jay tS; EG 
Steller’s jay TS, TC 
Cassin’s finch LS, Sa. eG 
Pine siskin TS, 85.4 
Evening grosbeak 55, re 
Red crossbill $5, TC 

aSee Appendix III for scientific names. 
bTS = terrestrial surface, SS = shrub strata, TB = tree bole, 
TC = tree canopy. 
as strata are added to vegetative cover types. Numbers of 
guilds also seem to increase at a geometric rate, whereas 
the number of wildlife species increases in a linear manner 
as strata are added to vegetative cover types (Table 3). 
The increase in the number of guilds is a function of both 
the increased opportunities provided by the addition of 
guild blocks and the increased opportunity for “generalists” 
that can utilize unique combinations of guild blocks as 
wildlife habitat. These “generalists” are depicted as “single 
member guilds” in Figs. 10 and 11. These “generalists” are 
fairly common in the upland coniferous woodland com- 
munity (Fig. 11). 
Six wildlife guilds were identified for upland grassland 
(Fig. 9), 11 for the sagebrush steppe (Fig. 10), and 44 as 
possibly occurring in the ponderosa pine community. Ob- 
viously, the number of groups of species that utilize habi- 
tat resources in about the same manner increases as the re- 
source opportunities increase with the addition of strata 
and guild blocks in a habitat. Some of the wildlife guilds 
identified in Figs. 9-11 and Appendix III may seem to be 
unlikely guild partners. This guilding technique, however, 
is intended to link wildlife species with the structure of 
vegetation and to group species that share dependencies on 
vegetation of similar structure. These wildlife guilds may 
include animals from different taxonomic classes and of 
different biomasses. The animals form a guild if they 
utilize similar food sources and breeding strategies even 
though one animal may require grams of a particular 
plant food, whereas another may require a kilogram of 
that food. Changes that impact that food will obviously 
affect both species. 
Several techniques have been used to disaggregate 
groups or guilds of wildlife species to describe particular 
ecological niches or to describe in detail the unique forag- 
ing or reproductive strategies used by a species. Principal 
Component Analysis (PCA), for example, has been used to 
determine how guild members actually partition the re- 
sources within a guild block. For example, PCA has been 
used by Anderson and Shugart (1974) to describe the selec- 
tion of habitat by birds in a deciduous forest in Tennessee, 
by Rotenberry and Wiens (1980) to determine the effects 
of vegetation structure on breeding bird populations in 
steppe habitats of North America, and by Niemi and 
Pfannmuller (1979) to describe the niche structure for 21 
bird species in northeastern Minnesota. 
Discussion 
The guilding technique is a way to organize and analyze 
information about wildlife species to provide insight about 
the structure of wildlife communities under both present 
and proposed habitat conditions. The development of 
wildlife guilds provides an excellent model from which to 
select wildlife species to accomplish a variety of wildlife 
studies. In addition, wildlife guilds are useful for inter- 
preting the results of inventories and assessments, in per- 
forming integrated assessments and management of natu- 
ral resources, and in forecasting the impact of habitat 
change on wildlife. Some of these potential applications 
are described here in detail. The applications are built on 
two assumptions which are in addition to those six de- 
scribed in the introduction to this paper. 
Assumption 7 
Guilds of vertebrate.animals are, because of the nature 
of the species-habitat matrix, closely associated with guild 
blocks. Consequently, it is possible to predict impacts on 
the wildlife community resulting from changes that will 
modify the quantity and quality of guild blocks in the 
vegetative community, 
Integrated Management of Renewable 
Natural Resources 
The association of wildlife species with vegetative struc- 
ture when using the species-habitat matrix provides a com- 
mon denominator with which other natural resources can 
be considered in the integrated analyses of natural re- 
sources. Fish and wildlife species are associated with 
various strata in the guilding process and many other 
natural resource products can also be considered as strata 
products. For example, strip-mining affects surface and 
subsurface layers, most agriculture uses the surface strata, 

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