Shelter 83 



They are predominantly food-producing types in the winter and, 

 except in the portions close to conifer shelter, are not used inten- 

 sively at this season. 



In the spring the choice of cover types is substantially the same 

 as in winter except for the hardwoods type as we see from the 

 following comparison of records. In addition to the predominant 

 use of hardwoods, the great preference for coniferous woods, in 

 proportion to mixed woods, is much reduced. The differences be- 

 tween the intensities of use of overgrown land and slashings is not 

 significant. 



Hardwoods 1.00 Use intensity ratio 



Coniferous woods .73 when reduced to 



Mixed woods .69 parts of major type 



Overgrown land .55 taken as 1.0 



Slashings .45 



Open land .03 



In comparison with the use made of the same type groups in 

 winter, we see that both the mixed woodlands and the several hard- 

 wood types have greatly increased in use in proportion to conifers. 

 The coniferous woods is now second to hardwoods as the most in- 

 tensively used type and is used much less than during the winter. 

 The use made of overgrown land and slashings is increased con- 

 siderably as compared with the winter period and during the last 

 half of the spring period assumes great importance. For the spring 

 period we may summarize by saying that an approximately equal 

 requirement exists for coniferous types and for hardwood types, and 

 that mixed woods is extensively used as a compromise containing 

 both of the required elements well balanced. As has been shown 

 elsewhere in the discussion of nesting cover, the female definitely 

 makes use of the hardwood types for the most part after the middle 

 of April. 



By the arrival of summer, the intensity of use of the various cover 

 types has changed immensely. No longer is the coniferous element 

 of great importance. In its place shrubby, brushy, sunny cover- 

 the open types of overgrown land and slashings— is preferred. Coni- 

 fers, while used less extensively than any other type group, except 

 open land, are still used some, mainly to escape excessive sun heat 

 and summer storms. The intensity of summer use of the type groups 

 is as follows: 



