the same each year, the dates of establishment of nests 

 are not. Kabat, Thompson. & Kozlik (1950:4-5, 15) 

 postulated that weather that causes a delay in the an- 

 nual hatch may place prolonged reproductive stress on 

 adult pheasant hens and result in an increase in the mor- 

 tality rate of these hens; stress in these hens, as indicated 

 by loss in body weight, appeared to be related directly 

 to the number of eggs laid. Buss, Swanson, & Woodside 

 (1952:280) concluded that adverse weather in early 

 June, 1950 (weather characterized by unseasonably heavy 

 precipitation and low temperatures), delayed renesting 

 among pheasants in southeastern Washington ; the delay 

 subjected the hens that attempted to renest to the pro- 

 longed physical stress of additional egg-laying and in- 

 creased the rate of mortality among them. Kabat et al. 

 ( 1956:,33-34) pursued further the problems of stress in 

 hen pheasants and showed that adult hens were in their 

 poorest physiological condition in July and August, to- 

 ward the end of the reproductive season and during 



molt. \Vagner (1957:308-310) more fully expounded 

 the e\idence of accelerated late-summer mortality of 

 adult hens, linking it with the physiological stresses 

 caused by ]3rolonged reproductive efforts, particularly 

 egg-laving. 



Although numerous inxestigators have provided con- 

 \incing evidence that many pheasant hens die during 

 the reproductive and molting periods, the relationship 

 between their deaths and the autumn populations of 

 young has not been well defined. A high proportion of 

 young in the fall population does not necessarily indicate 

 a good hatch in the preceding breeding; season. Wasrner 

 (1957:313) pointed out that late-summer hen mortality 

 "appears to bias hen age ratios or total-population age 

 ratios from iinhunted areas sufficiently to cause one to 

 form erroneous conclusions if not taken into account." 



The time of death of adult hens has an important 

 effect on the hatch of chicks and on efforts made to 

 measure the hatch. If a hen dies prior to the completion 



1\ 



^ 



Fig. 6.— Oiii- iif scMial huiulrcil fccdiii!; -iitcs of pliiMsanis in ,in Illinois cornfield in c.uU M;irrh, 1960. .'\bout 400 pheas- 

 ants had scrali hcd thniiit;!) nidn- llian a fncu nf c cini|i:u led snow to lo.uli waste corn in lliis field. 



14 



