Wisconsin Pheasant Reproduction Studies Based on Ovulated Follicle Technique

Abstract
This is the 3d and final report of ovulation studies of the ring-necked pheasant in Wisconsin. The first two reports involved artificially-propagated pheasants, and it was concluded that the remains of ovulated follicles are valid criteria for determining ovulation incidence, ovulation rates and numbers of eggs laid from onset of laying up to 6 months postovulation. It was also concluded that this technic could be applied to the study of productivity in wild pheasant populations. Data obtained from application of the ovulated-follicle technic are presented. Also, new information on reproduction is given including the avg. date of 1st egg, laying rate, total eggs laid and the no. of clutches abandoned before penned birds began incubation. This reproduction information and the ovulated-follicle data are compared with the analyses of ovaries collected from 2 wild populations occupying different types of habitat. It was concluded that the date of 1st egg laid by wild hens can be estimated by examination of ovulated follicles, and that a high percentage of all hens observed began laying by mid-April. Apparently the stimulus which initiated egg-laying was not directly related to the phenomena which cause incubation. Laying eggs at random and deserting one or two nests probably represents typical behavior for a wild hen; this behavior has resulted in gross misinterpretation of the typically high nest mortalities reported in many studies. Comparison of populations on two dissimilar areas in s. Wisconsin showed that high egg production was correlated with relatively low reproduction on one area, with directly opposite conditions occurring on the other area.