SPECIAL TECHNIQUES 701 



Note-taking was also designed in such a way as to eliminate, to the greatest possible extent, 

 personal judgment on the part of the compartment leaders. When a personal interpretation, 

 such as the determination of a nest predator, was necessary, the leader referred the matter to 

 the director of the survey. Thus the handling of such decisions rested with a relatively few 

 persons. The coippartment crews were used mainly to collect the data and not to interpret 

 them. 



Records were taken in such a manner that a daily numerical summary of the basic material 

 could be kept. The information used in reducing data to a common basis, such as weather 

 and man hours, was carefully recorded on each set of notes. Daily notes were then com- 

 bined into seasonal totals, reduced to a comparable basis with other seasons or years and 

 then analyzed. 



The amount and character of the information gathered was so closely determined by the 

 organization of the data sheets that they are included here. It should be noted that code spaces 

 are provided on each sheet to facilitate the mechanical tabulation of the data (.figures 

 73 to 76). 



SPECIAL TECHNIQUES 



Gathering evidence pertinent to the specific problems involved, often required special tech- 

 niques. Those used in collecting data to evaluate rclatinnships of shelter, food, weather, 

 disease or predator and buffer species to grouse, all differed from each other in many respects. 



Determining Shelter Relationships 



A man usually sees a forest in terms of firewood or lumber whereas it is im|)()rtant to a 

 grouse in terms of its food and shelter value. The first step, therefore, was to subdivide grouse 

 habitats into types according to their food and shelter value to the grouse. Since many 

 individuals were to record shelter data, the subdivisions formulated were reduced to letter 

 symbols*, described in brief form and mimeographed for use on a reference sheet. 



A grouse uses a wide variety of cover types, perhaps more of one than another. When a 

 survey crew flushed a bird, a record was made of the cover it was in. However, there was 

 no indication of the relationship of any one such flush location to the cover requirements of 

 the particular bird involved or the species as a whole. In other words, data regarding the 

 preference of various cover types was extremely variable in nature and immense numbers of 

 records were necessary before any real understanding of the relative degree of use or of the 

 underlying reasons therefor could be obtained. 



A satisfactory number of records was built up by filling out a data sheet each time an adult 

 or a brood of grouse was flushed during the entire period of survey. Over 19,000 adult and 

 1,500 brood flushes were thus recorded by 1937 when their tabulation was undertaken. In 

 order to handle this data efficiently, provisions were made for mechanical coding and sorting. 

 Each individual item on the data sheets was given a descriptive code number and these were 

 punched on code cards. After a specific problem was set up. it was possible to run the cards 

 through a mechanical "sorter" and thus obtain the totals of the items desired. 



Shelter relationships were analyzed around the statistical principle of deviation from the 

 random or "no choice"^ distribution of the bird. Thus an establishment of the pattern in 



.» Sei- ChapUT HI. 



A If a {;rinise exercises no choice of the type of cover it uses, flushes should be evenly distribuleil tliroughuut the area and flushes 

 within a single type would occur in proportion to the extent of that type. 



