Pelleted formulated feeds are the best ration that can be provided for ruminants. Elk can survive on high quality second or third cutting alfalfa but deer have greater difficulty in obtaining adequate energy from roughages like this that are high in fiber. If baled hay is all that is provided for deer, it must be high quality alfalfa fed at a level where the deer do not have to consume anything but the leaves and small stems. Supplemental feeding of birds is usually only cone for songbirds but does occur with waterfowl species and turkeys under certain circumstances. The feeding of waterfowl during the winter may encourage alterations of normal migration patterns and possibly be of disease importance.
Avian species respond faster to the providing of food once physical condition has been affected.
Consequently, if the necessity arises, supplemental feeding can be started at anytime and probably be successful. Deaths attributable to starvation may have a great and persistent effect on a population, not only due to the loss of individuals, but also due to the disruption of fertility and reproductive success. Pregnant females catabolize their own fat and protein reserves during periods of food deprivation. The fetus is protected by these actions and continues its development. If a pregnant female is forced to withstand prolonged malnutrition, however, the fetus may die and be resorbed or aborted.