00 pheasat folder 
sex ratito foltdw ,- 
hktra  tre letter trom A. 1. Cartwrit to Ald    Leopold, My 13, 1944. 
. .. 'Measants spread into southern Kwitoba several years ago from 
North  akota. It was a avancin &r      of ook birds with very few 
femles observed at all. Some observers told me that the sex ratio 
was about 50 to I sales to females. Howevr, the sex ratio speedily 
was redued ad lest year Arohie lakie - a very reliable obserer, 
stated that the sexs appeared to be Olose to parity woreas the 
previous year he oonsiAere. mss ia     s  of f0ls, 3,1.     is 
is rather so4 evideo of a spiralling sx ratio ad the 
oaloulation shows this is to be expeated. I think you will find your 
60:40 feml. to male ratio will remain oonstant only so ln ais the 
popation is holding its own but any  hange In p.lation levels in 
relation to the earrying Oapaoity of the l a will probably reveal 
a change i* t1e sex ratio.