The biggest detrimental problems to poults are damp springs and wet summers. The problem is twofold: 1) increased susceptability to disease right after hatching, and 2) decreased food supply early in development.

The biggest food supply for the turkey (at least Easterns) are, interestingly enough, grasshoppers (for the proteins). Grasshopper populations plummet during wet summers, hence smaller poults.

Reduced size entering winter increases the odds for 1) famine, 2) disease, and 3) predation.

And in contrast to what was mentioned previously, heavy winters in the Northern climates can have a dramatic effect on populations. If the snow is too deep, not only will the turkeys struggle to find foods, but will also be easier targets for coyotes and cats.

In the Southern states I'm sure Winter has little effect on the birds, being the major precipitate is rain/ice. Howevef, that's one reason why a good % of Southern mature gobblers have "short" beards--the ice storms freeze the beards in the roost, resulting in "ice rot".

Strut