Northern Prairie Wildlife Research Center
|Of all the strategies proposed for increasing pheasant population, only one really works: increasing the amount of available habitat.|
From the point of view of a wildlife agency such as the North Dakota Game and Fish Department, pheasants are a renewable resource. They can be harvested in large numbers, yet maintain constant population levels. Pheasant populations have a high turnover rate whether hunted or not. Their numbers are unaffected by controlled hunting of roosters, and "surplus" roosters - those not needed for breeding - cannot be stored for future use like grain in a bin.
Pheasants that cannot be supported by the available habitat will die, whether taken by hunters, predators, starvation, disease, exposure, or any other threats that challenge them. Providing birds for hunting might, from one point of view, be considered the goal of a management program, but from another perspective, hunters are actually participating in the efficient management of pheasant populations.
|The annual cycle begins in spring with a hypothetical population of 100 adult birds. By nesting season end, 30 are lost to natural causes and farming operations such as mowing. Half the hens produce broods, totalling 300 young. By autumn, the population of 370 is reduced by predation, road losses, and natural mortality to 239. Hunting and natural mortality takes 115 birds. Winter stress reduces population to the original 100 adults.|
Pheasants are a polygamous species, and the removal of 90 percent or more of the roosters has no effect on reproduction. North Dakota hunters have never approached that level of harvest. On an annual basis, North Dakota pheasant hunters could increase their harvest by 35 percent and still not harm the population.
Hunting mortality is the most visible form of wildlife mortality, and many people expect that it will affect the following year's population. Scientific experiments have conclusively shown that reasonable sport hunting does not cause game populations to decrease. A nine-year study in northern Iowa and southern Minnesota matched pheasant population trends in a 1 9-county area in each state. The pheasant density in the Iowa counties remained higher than that in the adjoining Minnesota counties, and the trend in the pheasant population in the two states remained parallel in spite of the fact that the Iowa pheasant seasons were twice as long as the Minnesota seasons.
The mortality rate of pheasants is similar for both hunted and adjacent non-hunted areas. The yearly mortality rates usually exceed 70 percent, and the high rate for unhunted populations negates the effect of hunting on the following year's population.
In general, the size of an animal correlates with its metabolic rate and thus with its life expectancy and reproductive rate. Small animals have high metabolic and reproductive rates, and short life expectancy. Conversely, larger animals have a longer life expectancy, lower reproductive rate, and hunting mortality has a greater effect on the number alive the following reproductive season.
The effect of hunting on small animals with high mortality rates is well demonstrated by songbirds. We do not hunt songbirds, yet the number does not increase yearly. To close or shorten the pheasant season would substantially reduce hunting recreation with no positive effect on subsequent bird populations.
Many hunters fear that long seasons will result in an overharvest of roosters and too few roosters to assure egg fertility. Such fears are unfounded. North Dakota hunters take only about 60 percent of the available roosters, and egg fertility remains consistently over 90 percent.
Under certain circumstances even hunting hen pheasants would not reduce populations. If the number of hens in a spring population is higher than the number required to produce the maximum number of young that can be raised in an area, the excess hens could have been removed during the preceding hunting season.
The hunting of hen pheasants is a topic guaranteed to stir up heated debate even among pheasant biologists. Some maintain that a huntable surplus exists. They point out that in other game species, such as grouse and partridge, both sexes are taken without apparent damage to the population.
Others contend that shooting hens is like killing the goose that lays the golden egg. They maintain that even though there are surplus hens, future conditions may become more favorable for reproduction and we should have a maximum number of hens to take advantage of any increase in the carrying capacity of the land. The dissenters also doubt the possibility of regulating the season to ensure that only surplus hens and no more are taken.
North Dakota has allowed a hen in the bag in past years. Because hunting surveys indicated that hunting pressure on hens was light and that the regulation was unpopular, the shooting of hens was terminated following the 1945 hunting season.
In many respects, pheasant hunting is self-regulating and governed by the "law" of diminishing returns. Usually, more than 75 percent of the pheasants killed each season are shot during the first nine days of the season, and most of them are taken on the opening weekend. Rooster pheasants learn fast, and the harder they are hunted the more difficult they are to find. As the population declines, more hours of effort are required to bag each bird. Soon a point is reached at which hunters simply will not expend further effort in pursuit of their quarry. Thus, lengthening the season adds few birds to the total number killed, but it does offer more recreational opportunities to hunters.
Any discussion of pheasant management inevitably includes the issues of stocking, winter feeding, and predator control. These have been described as three of the sharpest thorns in the pheasant manager's side. They consume a great deal of money and manpower, but provide few tangible results.
Nevertheless, these programs are often popular with hunters who do not differentiate between introductory stocking and annual maintenance stocking. The purpose of introductory stocking is to establish a new species in an area that provides suitable habitat. Maintenance stocking is a means of trying to maintain populations at levels higher than the habitat will support by releasing game-farm birds. Maintenance stocking ignores natural controls which govern population levels in an established population.
|Sometimes surplus pheasants are trapped and moved from one area of
good habitat to
another area of good habitat. These wild-trapped birds have a better chance of
survival than do pen-reared birds.
Maintenance stocking, or stocking where a population is well established, is virtually useless. A given unit of land has a carrying capacity: a maximum number of pheasants that it will support. This carrying capacity is determined by environmental factors and may change from season to season and year to year. Pheasants produce more young each year than the land will support, and these extra birds are doomed. The addition of game-farm birds simply adds to the surplus.
Maintenance stocking is expensive and produces a very low return. Long-term documentation of annual stocking attempts by the North Dakota Game and Fish Department, wildlife clubs and other organized groups as well as private individuals shows that less than five percent of released cock pheasants are bagged by hunters. Rising costs of raising birds coupled with low survival rates indicate that maintenance stocking would require the entire license fees of several hunters to pay for each of the few additional birds bagged during hunting seasons.
Stocking increases the risk of introducing disease or inferior genetic strains into a population and on this basis alone, is difficult to justify.
|The high cost of raising birds, low survival rates of pen-reared
birds in the wild, and
other factors make stocking programs difficult to justify.
North Dakota is characterized by extremes in climate, and during harsh winters, some people feel the need to feed pheasants. Like stocking, winter feeding is a stopgap measure, expensive in time and money, and provides few benefits for the pheasant population.
Pheasants can survive long fasts, can dig through deep snow drifts for grain, and will move into farmyards for a free meal. Winter feeding programs are based on a human emotional need to do something for the birds, rather than on the birds' physical need for supplemental food.
In spite of the good intentions of their supporters, most winter feeding programs fail. Grain is generally distributed where humans have easiest access: along open roads and highways or near farmsteads. These are not generally the areas of greatest need and feeding there can be detrimental. Many birds drawn to roads by feeding are subsequently killed by passing vehicles.
A statewide feeding program is extremely expensive, costing thousands of dollars per day for grain alone to provide the 3 1/2 ounces of foodstuffs that pheasants consume daily during the winter. Transportation and labor costs to distribute grain to areas where it is needed could easily double the cost.
Predator-control programs are sometimes proposed to decrease the number of birds killed by predators. Unfortunately, predator-prey relationships are not a simple matter of mathematics whereby the subtraction of a predator equals the addition of pheasants for the hunter.
Predators are opportunists, and prey on any species readily available. A fox or coyote will take a pheasant if it can, but opportunity varies with pheasant numbers and habitat quality. Predators tend to pursue the most abundant prey species, and in North Dakota pheasants seldom make up a major portion of any predator's diet. Their primary prey includes mice, ground squirrels and rabbits, species characterized by reproductive rates exceeding those of the pheasant.
Diminishing returns control the actions of four-legged or flying predators much as they do those of human hunters. When prey populations decrease to the level of the carrying capacity of the land, continued efforts result in decreased returns. At that point, a prey species such as the pheasant becomes relatively safe from predation.
Researchers in southern Minnesota annually trapped and removed 15 to 20 predators from each square mile of a study area. The rate of pheasant nest destruction was reduced by at least half, and the reproductive rate doubled. Nevertheless, pheasant numbers continued to decline, and researchers concluded that predator control did not compensate for habitat losses.
In addition, this Minnesota study showed that predator control is prohibitively expensive. It cost approximately $21 per predator removed, or $4.50 for each additional chick hatched. With normal survival rates of about 50 percent, the cost for each additional bird reaching maturity was about $9. Since only half of these birds could be expected to be roosters, the cost reached $ 18 for each bird that might be shot in the fall.
The only certain method of increasing pheasant populations is to improve their living conditions. To do that, the major factor limiting the population must be identified. In most parts of North Dakota, good quality undisturbed nesting habitat is the primary problem, and secure habitat can modify the effects of secondary limiting factors such as weather and predation.
Given these conditions, what kind of management programs will affect enough acres of land to materially increase pheasant populations?
Since some 92 percent of the land in North Dakota is privately owned, most pheasants are also produced and hunted on private land. Thus, any program to significantly increase pheasant numbers on a statewide basis depend on increasing pheasant habitat on private land. Federal farm programs offer the only economically feasible potential for attaining this goal.
[pic]The high cost of raising birds, low survival rates of pen-reared birds in the wild and other factors make stocking programs difficult to justify.
The Soil Bank program of the late 1950s and early 1960s converted some 2.72 million acres of cropland to year-round cover in North Dakota, and the pheasant population increased significantly. Early vegetative stages (weeds) characteristic of crop-land retirement provide a safe haven for nesting as well as a refuge from predators and winter weather. When the Soil Bank program ended, and land went back into crop production, pheasant numbers declined accordingly.
Habitat management is the key to abundance of pheasants, or of any wildlife species, and only through sound programs can populations thrive. The Habitat Stamp Program is one of the Game and Fish Departments responses to the continuing loss of habitat. In its first nine years (1981-1990) the program generated over $2 million for habitat preservation, creation and enhancement.
The Department's Interest Money Program also offers funds to provide habitat. During the five-year period, l983-1988, approximately $600,000 has been furnished by this program. Combined, these two programs are annually helping maintain about 15,000 acres of wildlife habitat.
The immediate future for pheasants in North Dakota looks bright because of the Conservation Reserve Program created by the U.S. Department of Agriculture farm bill of 1985. It is similar to the Soil Bank program, and by September 1991, North Dakota farmers had enrolled more than 2.88 million acres of croplandin 10-year permanent-cover contracts. This is about 10.2 percent of the state's cropland, and is larger than the peak acreage enrolled in the Soil Bank program. In effect, CRP has multiplied by approximately 192 times the acreage in the Game and Fish Department private land management programs.
Based on the pheasant response to the Soil Bank program, it is realistic to expect a notable increase in the state's pheasant population during the life of CRP. Overall loss of habitat during the last 30 years will prevent the population from equaling that of the late 1950s. Cropping of forage from CRP land such as that authorized in response to the droughts of 1988 and 1989 will reduce the contribution of such land to pheasant recovery.
|An ideal ratio of land-use for pheasant production includes a high proportion of grain crops which provide a stable food source. Wheat also provides nesting cover, and alfalfa offers brood cover. Pastures and grasslands make good nesting cover, and idle acres are important areas for nesting, roosting, loafing, and winter cover. Ideally, each cover type would occur in small units and in close proximity to other types.|
The ring-necked pheasant is a relative newcomer to North Dakota, yet has become so much a part of the state's heritage that many people are unaware that it is not a native bird. But, if pheasants are to prosper in the state, and continue to provide pleasure to hunters and others who simply enjoy seeing them, they must have sufficient habitat. While federal programs will do the most to improve statewide populations, Game and Fish Department programs can help improve habitat on both public and private land. The fact that pheasants may live their entire lives on a single quarter section of land means that individual landowners can materially affect the number of pheasants on their property. Interested landowners may contact the Game and Fish Department for further information.