Pheasant Ecology: Effects of Hunting
Questions continually arise from both hunters and non-hunters alike about the effects of regulated sport hunting on ring-necked pheasants. These questions along with their answers provided by Pheasants Forever's biologists make up this brochure.
Should bag limits and season lengths be adjusted with the ups and down of pheasant numbers?
Remember that optimum management for any gamebird provides the greatest possible harvest while allowing adequate carryover stock for reproduction - something easily done with pheasants. Ring-necked pheasants are promiscuous birds, and one rooster (male) may mate with as many as a dozen hens (females). Hunting just the males removes "surplus" roosters not needed for reproduction in the spring. In addition, since hens and roosters are easily distinguished in wingshooting situations, pheasants are managed much more conservatively than most other upland gamebirds—as the hen segment of the population is protected from hunting. Thus, adjusting season length and bag limits on surplus roosters will have almost no effect on future populations!
How is pheasant harvest measured?
Reliable estimates of annual harvest are obtained by random mail and phone surveys polling 2-5% of the hunters. This data is extrapolated to estimate the season's harvest. The percent of roosters harvested is determined by surveys of the post-season population. A low ratio of hens to roosters (3:1) indicates relatively few males were taken. A high ratio (10:1) indicates a very efficient rooster kill—a level of harvest seldom seen except in localized situations.
During the season, when is the hunting success, harvest and pressure the greatest?
In most cases, hunting pressure, success and harvest are greatest during the early part of the season. For example, Iowa's greatest hunting pressure occurs in the first half of the 70+ day season, with 71% of the trips taking place during the first 30-34 days. It is common for 30-50% of the season's harvest to take place during opening weekend in many states.
The effect of hunting pressure on harvest may be dictated by season length or available cover. Short seasons may have heavy pressure throughout. When cover is sparse, birds are concentrated, allowing the harvest of a larger portion of roosters. In contrast, an abundance of escape cover, such as provided by delays in crop harvest, can make pheasants nearly impossible to bag. These conditions can cause variations in hunting pressure throughout the season.
How great of a problem is loss of crippled birds?
Each year, a segment of the pheasant population is crippled by birdshot and not retrieved by hunters. By using hunter interviews and check station data, biologists estimate an additional mortality of 10-35% of the retrieved kill occurs due to crippling. This additional loss of surplus males is inconsequential to future pheasant production.
How does hunting affect roosters in a pheasant population?
Survival of roosters in hunted populations is normally very low, but that is not a concern. In fact, hunters could harvest 93% of pre-hunt rooster numbers without harming the population. However, such a high rate of harvest is very unusual if not impossible. The normal range is from 45-65%. Adding an average crippling loss of 10% means that 55-75% of roosters are often removed from the fall population. In states where significant harvest occurs (Iowa, Nebraska, Kansas and South Dakota), rooster kill averages around 70%. Elsewhere, particularly in western states, fewer hunters and less interest usually mean a reduced harvest rate.
How is reproduction affected by harvest of roosters and how do we know that the number taken is not detrimental?
A Michigan study in the early 1950's indicated that a single rooster in a game-farm environment was able to mate with and successfully fertilize 49 hens. Other studies also indicate that the number of roosters available to fertilize hens during the spring is not of great concern. Many biologists feel that an ideal male:female spring sex ratio would be about 1:10, indicating both an optimal harvest and adequate males for reproduction. Spring sex ratios in most states with significant pheasant harvests average about one cock for every 2-4 hens.
What are the effects of hunting on hens?
It has often been thought that in areas of low pheasant numbers, frustration in finding roosters might lead to increased illegal hen kill. However, Iowa data suggests that more hens were killed in areas where pheasant populations were most dense, because increased pressure offered greater opportunity for accident. It has been documented that from 6-16% of the fall hen population is harvested illegally, with an average of 10 percent. While ethically troublesome, this loss shouldn't cause biological concern.
Few states currently allow legal shooting of wild hen pheasants and there is little definitive data on how hen hunting affects reproduction. Some biologists have speculated that if more than 25-35% of hens were harvested, recruitment would decrease. The record is ambiguous - controlled hen seasons in Montana, Idaho, California, Iowa and Nebraska apparently did not limit reproduction, but data from Wisconsin, South Dakota and Minnesota indicate the opposite. Because of that fact and past traditions, we don't hunt hens today.
Are there any comparisons between different systems of harvest regulations which support the assertion that liberal seasons don't reduce pheasant populations?
Research completed in Minnesota and Iowa shows that imposing hunting season restrictions has no measurable effect on future recruitment of pheasants. Biologists compared 27-year population trends (1964-1990) in two adjacent areas of similar habitat and weather conditions (upper two tiers of Iowa counties and the lower two in Minnesota). Hunting regulations were not similar. Minnesota daily bag limits were one bird less on average, and season length only about half that of Iowa's. During four consecutive years, Minnesota restricted and even closed its seasons when severe winter weather reduced populations. Iowa, by contrast, maintained its liberal seasons (50+days), although the same magnitude of pheasant declines were evident. (See graph.)
In spite of the differences, Iowa and Minnesota had remarkably similar population trends over the 27-year period. The conservative management approach in Minnesota resulted in season restrictions that had little or no benefit to the population. From 1967-70 Minnesota severely curtailed or closed the pheasant season because of a string of bad winters. During those four years only 50% of normal harvest was achieved, leading to the loss of 2.4 million hunter hours and 400,000 roosters, which could have been harvested without a negative effect on future populations.
Are there any reasons for an earlier season?
Yes! Population loss is continual. Earlier seasons allow birds that otherwise succumb to predation or other mortality to be utilized for hunting recreation. However, the progression of crop harvest and potential for unpleasantly warm weather are important consideration in an early opener.
What is the effect of restricting bags?
Reducing bag limits will have little effect on pheasant populations. In most states, seasonal bag per hunter is only 2-4 birds. The only reason to reduce bags is to more equally distribute harvest among hunters. Considering the majority of hunters are active only during the first two weeks of the season, the effect of restricting daily bag limits would be minimal.
Does changing closing dates affect the population?
The argument has been made that closing hunting seasons earlier will prevent birds from being flushed from good winter cover into marginal areas where they are vulnerable to winter storms and predation. This may occur in some cases. However, because of diminishing returns to hunters as the season progresses, later season closures have a minimal effect on current or future pheasant populations. Simply put, fewer people hunt in late season and affect only scattered pockets of cover.
What's the bottom line?
In a nutshell-liberal, legal, roosters-only seasons do not harm populations. If seasons work as designed, the outcome is a reduced standing population of male ring-necked pheasants. Extensive research has shown this has little or no effect on pheasant reproduction and subsequent populations.
Need more information about enhancing pheasant populations?
Try the Pheasants Forever Essential Habitat Guide — a handy reference on all kinds of pheasant cover, including shelterbelts, food plots and nesting cover. And, be sure to check with your local Pheasants Forever chapter, where you will find cost sharing, planting assistance, or just advice from a friendly chapter volunteer.
