— By Travis Runia, senior upland biologist for SDGFP
Editor’s Note: This excerpt is from a six-part series on pheasant ecology written by Travis Runia, senior upland biologist for the South Dakota Game, Fish and Parks Department. The series was originally written for the South Dakota Conservation Digest and is reprinted here with permission.
To read the entire pheasant ecology series by Runia, or to read the South Dakota Conservation Digest online, go to gfp.sd.gov.
Earlier in this six-part series, we examined the details of pheasant ecology during July and August.
To summarize, reproductive responsibilities for roosters are nearly complete by early July. By late July, they have replaced all of their feathers and even managed to gain weight for the first time in five months. This trend continues into August, as these are easy times for South Dakota roosters.
Conversely, hens reach their worst body condition of the year in August. Egg laying, incubating and brood-rearing responsibilities are extremely energy demanding and decrease the amount of time that hens could spend foraging. These energy-demanding activities also cause most hens to delay their molt until July when more energy could finally be allocated to growing new feathers.
Chicks have seen their own challenges, as predation and farm equipment have taken their toll. Half of pheasant chicks will not survive until fall due to predation or farm machinery. While adults molt once during summer, chicks actually molt twice, and by early July most have replaced their down with hen-like flight feathers.
Chicks that survive and make it to late August rely on protein-rich insects for food to grow tissue and feathers. By August, most chicks typically begin replacing their juvenile feathers with adult feathers, which carries on their demand during late summer for protein-rich insects. By 17 or 18 weeks of age, most pheasant “chicks” resemble adults in plumage.
September and October
By September and October the heat of summer has faded along with the struggles that went with it for pheasants. Temperatures have moderated and are well within a pheasant’s thermoneutral zone. In other words, pheasants do not need to use more energy to stay warm or keep cool when the air temperature is between 40 and 104 degrees.
Along with the comfortable temperatures and long days of early autumn, abundant food is available through waste grains, weed seeds and insects. This is good news for pheasants, especially hens that typically enter September in their worst body condition of the year and may weigh 25 percent less than they did in April.
Although abundant food resources become available during early fall, diet still varies considerably between cocks, hens and chicks. Before we discuss why this variation in diet occurs, let us consider the differences in nutritional content of the available food resources.
Corn and wheat are the primary waste grains available to pheasants during fall. One could assume these two waste grains would be equally nutritious to pheasants, but that is not the case.
Corn contains 23 percent more metabolizable energy than wheat, but wheat contains 60 percent more protein than corn. Most weed seeds are highly nutritious with protein levels that are similar or higher than wheat and metabolizable energy similar to corn.
Foxtail grass, an abundant annual grass that frequents farm fields and disturbed areas, is highly nutritious, abundant and highly utilized by pheasants in autumn. Sunflowers, millet and milo are also locally important food sources.
Soybeans, although abundant and high in energy and protein, contain digestive inhibitors which render them nearly worthless as food for birds. Research has revealed that birds lose weight and become malnourished when fed soybeans. Protein-rich insects remain available through early fall until the first hard frost.
The completion of wheat harvest in August coincides nicely with the period when hen pheasants need protein and energy to recover from the demanding tasks of motherhood.
Remember, hens are in their worst condition of the year in early September and still have to molt and regrow their feathers. Fortunately, chicks start leaving the hen at 10 weeks of age, so by September most broods are on their own.
After nesting and brood-rearing responsibilities have caused hen pheasant weight to decline by 25 percent, September provides prime conditions to make up these losses before winter. Hens now have time to concentrate solely on feeding for the first time in five months.
Because wheat and weed seeds are abundant and a good source of protein and energy, hen pheasants target these food sources in September and October. Insects provide the highest protein content and are targeted, as well.
By mid-October the amount of wheat available to pheasants has declined due to tillage or germination. Wheat seeds also deteriorate quickly when wet. Fortunately, hens finish their molt in October, so protein demand for hens will decrease at the same time as wheat and insect resources decline.
As corn harvest gets underway in October, hens will consume mostly corn and weed seeds by late October. Corn provides more energy than most hens need in October, so they will gain modest weight for the first time in six months.
Pheasant chicks are experiencing life on their own for the first time in September. Although they still weigh less than their adult counterparts, chicks will consume just as much food as adults. Pheasant chicks still need a diet rich in protein to continue their molt and grow to adult size. Chicks will consume two or three times more insects and weed seeds and less waste grains than adults to meet their protein demand.
By October, most chicks have reached adult size, but they are consuming more food than adults because the final stages of their molt require additional energy and protein. You may notice that hunter-harvested birds in October are in various stages of molting. Late-hatched roosters are even hard to distinguish from hens. The age (in weeks) of hatch-year roosters in the bag can be aged by the length of their outer three flight feathers.
Adult roosters have had it easy since they finished their molt in July, and this continues in September and October. Remember, adult roosters were able to molt earlier because they did not have any energy-draining motherhood responsibilities.
Roosters began bulking up for winter in July, and their weight increase continues into early fall. Insects represent a smaller portion of an adult roosters’ diet than hens or chicks. Roosters only need protein for body maintenance, and this can easily be supplied through weed seeds, wheat and corn. The rooster’s diet mirrors what is available, but corn is preferred when corn and wheat are both available. Roosters continue to store fat reserves as winter is right around the corner.
September and October are relatively lazy times for pheasants, as long days, comfortable temperatures and abundant food made life easy for South Dakota ringnecks. As a result, pheasants gain weight during this time period, which is necessary to prepare for a cold South Dakota winter.
November and December
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 three hours shorter in December than in September, and the average low temperature is 35 degrees cooler than in October. These dramatic changes mean pheasants will need to change their behavior if they expect to survive a South Dakota winter. Although they’re not native to the Dakotas, 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 that 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, shelter belts or thick 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 one-third 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 one-third more energy just to stay warm, pheasants have three fewer hours to forage in December than they did in September. This means pheasants are now consuming 20 percent more food in 25 percent less time and enduring colder nights that are 25 percent longer.
Even through 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.
Earlier in the fall, pheasants typically feed leisurely throughout the day as there is plenty of time to consume the required amount of food. By November and December, however, 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 daylight and beyond.
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, that 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 percent during these two months, with most of the weight increase in the form of fat.
Fat represents the densest form in which energy can be stored by birds, and fat reserves are necessary as severe winter storms can prevent pheasants from foraging for days at a time. During harsh 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 a bit hungry, but they were in no danger of starving to death. Pheasants could easily endure three days without food during early winter. Although food becomes more difficult to find after the first blanket of snow covers the once exposed waste 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 backdrop of snow, and this increased visibility likely leaves pheasants more vulnerable to predators.
About the Author: Travis Runia, from Huron, S.D., is the senior upland biologist for the South Dakota Game, Fish and Parks Department.