A. Do turkeys die during harsh winters? Not typically in Pennsylvania - The Pennsylvania Game Commission has not documented any severe turkey winter mortaility since the three consecutive severe winters of 1976-78. Possible disease transmission from concentrated feeding sites.
B. Should I feed turkeys during the winter? Will winter-feeding increase turkey winter survival? No (Winter Feeding Policy and Hixon 1997 paper)
The Pennsylvania Game Commission has a policy of no winter feeding of wildlife. The Game Commission used to have a winter feeding program, but abandoned it because it is ineffective and impractical, and scientific studies of winter feeding programs are almost universal in pointing out the large numbers of disadvantages as opposed to a very few advantages.
(In 1997, a Game Commission intern, Raymond Hixson, developed a report on winter feeding of deer and turkeys, and I will provide the highlights on turkeys.) Turkeys, like deer and other wildlife that are active during winter, have adaptations that help their survival. Fat tissues comprise 25 percent of winter body weights in adult turkeys and 15 percent in juveniles. The increased winter fat serves as an energy reserve and as added insulation, thereby improving survival. Body weight losses of 35 percent in adult wild turkeys and 25 percent in juveniles can result in death, although some wild turkeys may lose a third of their body weight without any devastating effects. Adults have a survival edge over juvenile birds due to greater adipose and muscle tissue reserves. Turkey hens survive longer than males when exposed to severe cold in fasting conditions. Although males may have greater fat reserves, females need relatively less food.
Effects of snow on food availability and turkey mobility are more important to survival than temperature alone. Natural winter turkey food is primarily hard mast that is found on the ground. They also eat ferns, bulbs, and tubers, as well as grass and it's seeds, corn and grains, and what they can pick out of manure that is spread in fields. Vegetation and insects in and along spring seeps also are important. Turkeys often will frequent and roost in conifer stands on sunny slopes where snow melts quickly and bottom areas where terrain moderates the prevailing westerly winds.
Beside other factors, disease transmission is a threat with winter-feeding. Aflatoxicosis, a condition where toxins produced by fungi on spoiled feed, particularly grains, cause wildlife mortality, and may affect turkeys.
The Pennsylvania Game Commission has conducted extensive field research regarding winter-feeding of wild turkeys. In a 19-year study in the Potato Creek drainage of McKean County to determine the effect of supplemental winter-feeding on wild turkey populations, winter turkey losses of up to 30 percent were found during severe winters with fluffy snow conditions, despite supplemental feeding in portions of the study area. Losses of up to 60 percent were documented in higher elevations. Populations usually recovered in one or two years, except during the period of three consecutive severe winters (1976-78), which resulted in depressed populations for three years before showing signs of recovery.
Two hunting preserves with controlled hunting in Elk County were evaluated. Expensive, intensive feeding programs were conducted. Food was distributed regularly along plowed roads. In one preserve, 150-200 turkeys consistently fed along roads. Following the three successive severe winters, the entire preserve was searched on foot and snowmobile. Only 16 turkeys were found in 1978 despite continual feeding programs. Turkey losses were attributed to winter mortality and poor recruitment. A similar decline occurred on the other preserve. Intensive feeding programs did not prove effective.
In one Pennsylvania study, turkey populations were more dependent on the previous summer's reproductive success than upon the mildness of the preceding winter or the number of breeders available. Other research has confirmed these results.
It is not necessarily winter survival that impacts populations, but rather, the success of summer reproduction. Cold, wet springs have the most detrimental effect on survival of turkey poults. Young birds are not only susceptible to hypothermia, but also, cold, wet springs delay insect emergence. Insects comprise the majority of a young poult's diet. Hens that come into the spring in good condition have a greater probability of renesting if their initial nest attempt fails. Therefore, good winter habitat as well as good brood habitat are the most important factors for turkey populations.
The Pennsylvania Game Commission stresses the necessity for habitat management and is extensively engaged in habitat improvement projects designed to provide more natural winter foods for wildlife. The Game Commission does plow State Game Lands roads primarily to open travel lanes and uncover planted food plots for wildlife. The Game Commission suggests that people and clubs develop habitat improvement projects that provide long-term habitat improvement and increase the carrying capacity of the habitat. Examples are planting mast and fruit producing trees and shrubs and protecting the plantings until large enough to survive deer browsing. Planting evergreen cover to provide winter thermal cover also is beneficial. Browse cutting along roadsides as well as timbering to provide regeneration also are beneficial, as well as maintaining spring seeps, which are very important feeding areas for wildlife during severe winters.