Relative growth of fins in the fourhorn sculpin, Myoxocephalus quadricornis, from the upper Great Lakes
Livers of 445 wild bobwhites taken in Iowa, Wisconsin, and Illinois in late fall and winter of 1947-48 were assayed for vitamin A. All contained vitamin A; but the amount in many was so low that it is estimated that 4% of the birds would have died directly from lack of vitamin A within 3 weeks or that as much as 42% might have been affected enough to make them die from predation and severe weather.
Copeia↗