Because of their dependence on variable mast production for food in areas where large tracts provide typical turkey habitat, good populations normally average about 10 turkeys per square mile of forest over much of eastern turkey range. In agricultural states like Iowa, the presence of abundant food contributes to densities at least twice this great, and may reach 20-30 turkeys per square mile in the best habitats.
Turkeys breed only in the spring. Hens join harems attached to a dominant gobbler, but may breed with any available male. Nests are poorly formed bowls completely on the ground and contain 6-18 eggs (average 11 per clutch). Hens of all ages attempt to nest , but yearling hens are seldom successful and 80% of the poults will be produced by 2 year old or older hens. Nests have been found in most habitat types from dense forest, brush, grown up pastures, fence lines, to alfalfa fields.
Hens incubate 28 days before the eggs hatch. Typically 30-60% of hens will attempt renesting after losing a clutch to cold, wet weather or predators, with about 40-60% of the adult hens will eventually hatch a clutch. Hens do all the brood rearing, and life is precarious for newly hatched poults with over half dying in the first 4 weeks. Of the poults surviving to fall, 35% of the young hens will be lost to predators, primarily coyotes.
Few young or adult turkeys are lost during the winter in most of Iowa, but starvation may occur where deep snows for a prolonged period keep flocks from moving to food sources. Spring is a major mortality period for both sexes, many hens are lost to predators after winter flocks break up and breeding activities begin, and toms fall prey primarily to hunters. Annual survival rates average 57% for females and 35% for males.