Setting the Spring Season

SPRING TURKEY HUNTERS hear gobbling on scouting trips long before the season opens, because there is some pretty intense gobbling activity from March through the middle of April. Understandably, turkey hunters want to be out in the woods when they believe that the birds are gobbling best, but just when does that happen? When is the most gobbling going to take place each year and how should our hunting seasons be timed?

Wildlife biologists have studied the breeding cycle of wild turkeys and how it relates to the timing of a spring hunting season. There are many factors to consider, and biologists in the Northeast and Mid-Atlantic region have looked at this extensively.

As I would hope every hunter would agree, spring gobbler hunting must provide recreational opportunity with minimal risk to turkey populations. In general, the season should open when hen turkeys are apt to be laying or incubating their eggs. In this part of the country, there is a 6-week window of opportunity for spring seasons during April and May.

Breeding and nest initiation are stimulated by the length of daylight hours (photoperiod), but weather also plays a role. When light conditions are right for breeding, cold or unseasonably warm weather can speed up or delay the process by as much as two weeks.

Biologists use several methods to determine when the spring season should occur. According to the scientific literature, there are three peaks of gobbling activity. The first is associated with the break-up of winter flocks; the second with the beginning of incubation among hens; and the third with re-nesting of hens that lost their first or second nest attempts. Seven to 10 days after many of the hens are incubating, gobbling frequency increases, as toms seek the few remaining available hens. Surveys of gobbling toms in New Jersey, Virginia and West Virginia indicate that the second peak occurs from the last few days of April through mid-May. The timing of peak gobbling may vary based on weather and other factors, but it seldom shifts more than 10 days in either direction.

Capture of turkey poults in late summer allows biologists to age the young birds (in days) with a fair degree of accuracy, which then allows them to count backwards to a hatch date, and, in turn, an incubation date. This provides a cross-reference to check the accuracy of gobbling frequency observations. Perhaps the best way to determine the timing of peak nest initiation, the onset of incubation and hatch dates is through radio-telemetry.

Radio-marked hens can be closely monitored, allowing researchers to accurately obtain nesting data. According to a study in Pennsylvania from 1953-63, the average statewide incubation date for hen turkeys was April 28. More recently, in a Game Commission radio-telemetry study on South Mountain in southcentral Pennsylvania, the average incubation date for adult hens was May 8. Juvenile hens in the same study had an average incubation date of May 13. Both the older data and the recent information suggest that Pennsylvania's spring gobbler season is timed correctly. Check out the accompanying graph to see a representation of gobbling and nesting activity through March, April and May. The graph was developed using data from West Virginia. Peak breeding, egg laying and incubation probably occur 10 days or so later in most areas of Pennsylvania.

Spring turkey season dates are established according to the reproductive cycle of the wild turkey. Setting the season carefully, using the parameters just covered, is the primary reason we can hunt gobblers during the spring and not affect long-term population levels or disrupt the breeding behavior of the birds. That generally means hunting seasons open around the same time hens begin nesting.

In Pennsylvania, hunting occurs when most of the breeding has been completed and many hens are on the nest. Most state wildlife agencies set spring season dates after the first peak in gobbling and breeding. In response to requests for an earlier spring season, Bill Drake, a now-retired PGC biologist, looked at data available from surrounding states. His report recommended that the spring season here open on or near May 1 each year. This recommendation can also be found in the "Wild Turkey Management Plan for Pennsylvania."

Quiet gobblers, "henned-up" toms, warm days and hunting after full leaf-out are often cited as reasons the spring gobbler season should start earlier. Interestingly enough, interference from hens may suggest that the season is as early as it can be. Gobbling activity decreases with increases in hunting pressure, so the woods may be silent, not because the birds are "gobbled out," but because they have been pressured. An earlier opening day might allow hunters to take advantage of cooler weather, fewer insects, fewer leaves and a time period in which some gobblers might be more susceptible to being called, but gobbling activity will always decrease once hunters enter the woods. Also, biologists must consider more than dates and hunter success when setting spring seasons.

A later opening date provides a measure of protection for turkey nests, hens and even jakes. Hens that are in the process of laying eggs are prone to abandon their nests if disturbed. Starting the season close to May 1 may reduce nest abandonment. Hens that are not yet incubating are often found with gobblers early in the season. Lone hens in the process of laying eggs are apt to be moving around the woods during hunting hours if the season occurs too early. The later the season opener, the fewer hens will be available for accidental or illegal shooting. Later opening days may, therefore, enhance the survival of hens. In studies, illegal harvest of hens accounted for 34 percent of all the hen mortality in the spring in Virginia and 13 percent in West Virginia (where the season opened later). Jakes tend to be more vulnerable to harvest earlier in the season. As May progresses, hormone levels and testes size decrease in jakes more quickly than in adults. Therefore a later season may protect some jakes and allow them to mature. An appreciable harvest of males before the bulk of the breeding could affect nesting success and reduce populations in subsequent years. Setting the season to occur after most of the breeding is complete assures that the population will continue to grow.

A later season may make hunting a bit more difficult because full leaf-out limits visibility and hearing. Hot weather may suppress gobbling activity and hunter participation. The managing agency must decide which compromise is in the best interest of the wild turkey resource as a whole and which one is most suitable for hunters.

Pennsylvania has a large turkey population but also a lot of turkey hunters. Tradition and demand for fall hunting opportunity remain high. Given the large number of hunters and the desire to provide good hunting opportunities in both spring and fall, Game Commission biologists have recommended a later season opener than some hunters would like to see. In order to ensure that the turkey flock continues to grow, the later opening day is a wise decision. Commission biologists are examining other options for expanding spring hunting opportunity. Since the first spring season in 1968, the season length has grown from six days to four weeks. Hunting hours have expanded from a 10 a.m. closing to the present noon closing time.

Spring gobbler hunting is excellent right now in the commonwealth. The Game Commission has done an outstanding job restoring and managing wild turkey populations. My advice is to hunt whenever you can. Although there might not be as many birds gobbling at first light as you heard in April, some of the best hunting can be had late in the season, when the old gobblers are seriously looking for hens. I've worked gobblers in the Keystone State right up until quitting time on the last day, and I've often heard gobbling into June.

When you are out this spring, think about the responsibility biologists have to the wild turkey resource. Remember that most turkey biologists are also turkey hunters. Realize that wildlife biologists do their best to provide you with good hunting opportunities, but their decisions involve compromise and concern for the resource. Enjoy the spring season and the chance to experience the thrilling gobble of a tom, and above all, hunt safely.

- Bob Eriksen, NWTF Regional Biologist









Pennsylvania Game Commission, 2001 Elmerton Ave, Harrisburg Pennsylvania 17110-9797