COVER REQUIREMENTS OF THE GROUSE 135 



or into them. To this conception, table 129* lends considerable weight. 



When this table was analyzed, it was a distinct surprise to find more than a third (41.6 

 per cent) of all nests, that were not actually in an opening, located within 100 feet of a road 

 or trail. 



This figure seems high unless one remembers that two of the three regions of the State 

 are, to a considerable degree, farmed. Most woodlands adjacent to farms have several more 

 or less used woods' roads or trails within their borders. The 100 per cent coverage given 

 each study area by the survey crew, however, precluded any chance that the cover along woods' 

 roads might receive more than its share of attention in looking for nests. 



Of the other types of openings, grouse are most likely to place their nests not far from open 

 land. In total numbers of nests, this situation outranks both slashings and overgrown lands. 

 Young slashings seem to furnish more attractive conditions alongside which to locate nests 

 than do overgrown lands. 



As previously mentioned, the attraction of a road, trail or young slashing apparently di- 

 minishes rapidly as the distance therefrom increases. This tendency is much less marked 

 with open lands. The nests are almost as likely to be placed at any distance up to 100 feet 

 from an open field as within the first ten feet. 



Effect of Crown Cover on Nest Survival 



Having seen the effect cover may exert on nest location, let us examine the difference it 

 may make on the success of nests |il;i<ed therein. \> will be seen in table 130^ 43.5 per 

 cent^ of all the nests located were broken up. Any relationshi|) between cover and the like- 

 lihood of nest destruction may, therefore, prove im|)ortant. 



As indicated in the table, cover seems to bear little relation to the fate of the nest except 

 in a few cases. Nests placed in stands largely composed of conifers (type H) are most 

 likely to be broken up. Conversely, those located in selectively logged woodlands (G), with 

 its scattering of lush herbs and undergrowth where, here and there, a tree has been cut, are 

 least likely to be found by predators. 



It is probable that this difference holds in all regions of the State though this cannot be 

 inferred from the table, for the numbers, thus divided, are too few to show significant dif- 

 ferences except for the Rest of State region. Here the trends follow those already described 

 although there is possibly a greater likelihood of nests in a mixture of mature hardwoods and 

 conifers also being left alone. 



Effect of Undergrowth Density on Nest Survival 



As with crown cover, it is remarkable how little real difference the density of the under- 

 growth seems to make on the fate of the nest (table 131)^. Of 268 nests found in sparse un- 

 dergrovrth 60.4 per cent hatched; in medium density, of 300 nests, 59.0 per cent hatched, 

 whereas of 95 nests found in dense undergrowth 55.8 per cent were successful. 



When the fate of grouse nests is correlated with undergrowth density in the various types of 

 crown cover, no significant tendencies are likewise to be found. There is a slight indication 



• See Appendix, p. 792. 

 A See Appendix, p. 794. 

 t This figure differs slightlv from ihe averages indicated in Chapters VII and XII since it is based on records prior to 1937 while 



the latter include the period through 1942. and also because shelter data were included for certain broken-up nests found while 



collecting eggs for propagation. 

 X See Appendix, p. 796. 



