The Mr. Mom Advantage for Quail
One major difference between pheasants and quail is the role males may play in the reproductive cycle. In some years, perhaps particularly when the density of quail is low, a hen may lay a clutch of eggs, and then leave her male bobwhite mate in charge of incubation duties for the next 24 days. Hens may then take up with one or more additional males.
The male also assumes brood rearing responsibility once the eggs hatch (he has to—Mom is down the road with another boyfriend). Think about that; a hen quail could theoretically produce two or three broods during one nesting season with the assistance of different males.
Consequently, quail have an increased ability to rebound populations quickly given quality habitat and optimum weather conditions during nesting season. In contrast, rooster pheasants play no role in their reproductive cycle other than hen fertilization, so each hen can, at maximum, produce one brood.