By: Travis Runia
In part 3 of this 6 part series, we examined pheasant ecology during September and October.
These were lazy times as long days, comfortable temperatures, and abundant food made life easy for South Dakota ring-necks. As a result, pheasants gained weight during this time period which is necessary to prepare for a cold South Dakota winter.
As fall transitions to winter, the “vacation” pheasants took in September and October will inevitably come to an end. In South Dakota, it’s not if winter will return, it’s when and how severe! The length of daylight is 3 hours shorter in December than in September and the average low temperature is 35 degrees cooler than in October. These dramatic changes in weather mean pheasants will need to change their behavior if they expect to survive a South Dakota winter. Fortunately, although not native, pheasants are quite adapted to the changing conditions and survival can be high especially where prime habitat exists.
In South Dakota, we are fortunate to have good winter habitat well distributed across the landscape. As the first signs of winter arrive, pheasants begin seeking out heavy winter habitat which will provide insulating cover during cold winter days and nights. Pheasants may have to travel great distances if heavy winter cover is not located in close proximity. Movements to winter habitat of up to 10 miles have been documented for pheasants, but most pheasants in South Dakota likely only need to travel several miles or less to find high-quality winter habitat such as cattail sloughs, shelterbelts or thick warm-season grass stands.
Even though pheasants seek out insulating winter habitat, they must still increase their energy intake if they hope to stay warm and store energy. This is because temperatures are now dropping below a pheasant’s thermoneutral zone or the temperature at which a pheasant does not need to use additional energy to stay warm. Unlike September and October when pheasants could simply fluff up their feathers to stay warm, additional energy is now needed to stay warm. In fact, pheasants require 1/3 more energy in December than in October just to stay warm. Pheasants need to consume enough food to continue to store energy as fat and gain weight before the coldest winter months of January and February while also using more energy to stay warm.
In addition to needing 1/3 more energy just to stay warm, pheasants have 3 fewer hours to forage in December than they did in September. This means pheasants are now consuming 20% more food in 25% less time and enduring colder nights that are 25% longer! Even though these struggles, pheasants still manage to gain weight by storing energy in the form of fat during both November and December. Of course, this would not be possible without a change in feeding behavior.
During fall, pheasants feed leisurely throughout the day as there was plenty of time to consume the required amount of food. By November and December, most pheasants are feeding before sunrise and many will even feed after sunset. This shift in behavior enables pheasants to eat more food during fewer hours of day light. Pheasants actually consume twice as much food now as they did during summer. This can be challenging especially when snow blankets the waste grain, primarily corn, which pheasants rely on during winter. It is not uncommon for pheasants to forage for most of the day when snow makes finding food difficult. Food plots such as standing corn or sorghum can ease these winter woes by providing abundant food above the blanket of snow. Pheasants utilizing food plots typically exhibit increased winter survival because exposure to predators is lower than birds feeding for longer periods of time in open fields.
By November and December, a pheasant’s diet has shifted primarily to corn in areas where it is available. Weed seeds are now less abundant, and much of the once available wheat seeds have been plowed under or sprouted during fall. Corn is packed with energy, which is what pheasants need to metabolize to stay warm during the winter months. When pheasants are fortunate enough to gather more corn than they need to use to stay warm, the rest is quickly stored as fat reserves. In fact, hen pheasants increase their body weight by 25% during the two months of November and December with most of the weight increase in the form of fat. Fat represents the densest form in which energy can be stored by birds.
These fat reserves are necessary as severe winter storms can prevent pheasants from foraging for days at a time. During harsh South Dakota blizzards, pheasants hunker down in thick cover and simply wait for the storm to pass. Pheasants rely on their fat reserves to generate body heat during days when they cannot forage. When pheasants emerge after a severe early winter storm, they are bit hungry, but they were in no danger of starving to death. Pheasants could easily endure 3 days without food during early winter.
Although food becomes more difficult to find after the first blanket of snow covers the once exposed waster grains, pheasants are rarely in danger of starving to death. Even during the most brutal winters, most pheasant mortality is due to predation and exposure to the elements. Predation increases sharply when pheasants must forage for long periods of time in open snow covered fields. We have all seen how visible pheasants are against a back drop of snow, and this increased visibility likely leaves pheasants more vulnerable to predators.
In this issue we learned how pheasants easily adapt to the changing seasons in November and December. Pheasants were in excellent body condition and body fat provided stored energy they use to keep warm during early winter blizzards. But how will pheasants handle the extreme winter weather of January and February? With the threat of heavy snow and brutally cold temperatures, be sure to check out the next issue to learn how pheasants handle the most challenging weather conditions of the year.