For the last 30 or 40 years the prevailing wildlife literature said that wild pheasants are dependent on cereal grains to strive in the wild, and that the wild pheasants can't survive well in hot or humid warm weather and minerals like calcium are needed for their survival. This theory is also taught in wildlife management courses.
The healthy wild and growing Mexicali pheasant population basically debunks or disprove those theories. This clearly shows that wild pheasants can survive and reproduce in other warn or southern parts of the country.
QH, gave us some great background information on the Mexicali pheasant and why they are successful. The links below give more information on that area:
www.finandfeathersafaris.com/Baja/Program2.htm
huntandgofish.com/?adventures=hunters-only
If the Chinese workers came from southern China near Shanghai which is on the 30th parallel (the 30th parallel is the same as Mexicali or Houston, Texas a warm climate) the ringneck pheasants they brought over to Mexicali may have been genetically conditioned to deal with a warm climate. We need more authentic wild ringneck (P. c.torquatus) wild directly from southern China and directly from the bush.
Now back to cotton, I can't tell you how many times I have shot at pheasants over cotton (both harvested and unharvested) in the Texas panhandle.
Wild pheasants need undisturbed nesting cover (more than cereal grain) for the hens for about 40 days in the spring time or early summer or late summer, a variety of crops can provide that window of nesting opportunity.
In Mexicali, 65 degree ground temps are reached in late Feb. or early March and cotton can be planted by the end of Feb. and by June cotton is growing and providing cover and an abundance of insects. In addition to that, the week to three week old chicks need cover and insects and that is where cotton plays a big part in wild pheasant production, the fat juice worms and insects the cotton produces when chicks need protein for growth.
There are parts of the corn belt with low pheasant numbers and parts of the panhandle with lots of cotton and a surprising number of wild pheasants.
Look carefully at the background of the main photo taken at an outfitter in Tulia, Texas, notice the cotton field in the background:
http://www.tulecreek.com/ins_outs.asp