Post by Woody Williams on May 2, 2017 7:08:10 GMT -5
Turkey season comes in...
TOO LATE
TOO EARLY
JUST RIGHT
From Steve Backs..(letter to another turkey hunter posted on another site)
Thank you for your inquiry regarding spring turkey season dates in Indiana. Yes, we receive and respond to such inquiries which tend to increase in the first couple of years after we make a ‘calendar shift” from the earlier end of the framework to later end of the framework in the standardized season date framework developed in 1983. Since this is a busy time of year, I will give you the generally broad generic response to the issue. A couple things, you should recognize is that our turkey populations/spring harvests in Indiana and throughout the eastern US have dropped off, some places worse than others. How much of this drop remains the “new normal” remains to be seen and in the end, prevailing habitat conditions across the landscape will likely be the main determining factor. I will also attach a number of articles or publications related to this issue that might give you a more informed insight into some of the arguments, issues, and concerns. I have also attached the 2016 spring harvest report for Indiana that has a summary table toward the end of the report that shows the dates and harvests for the previous spring turkey seasons in Indiana since 1970. Also attached, is a section on the status of Indiana wild turkeys in the 2016 Annual Wildlife Science Report that documents some of the declines in turkey populations and harvest indices. Finally, before the responses below, for what it is worth at this point in the spring season, despite the inclement weather of opening weekend, the current harvest as of this morning is 500+ birds ahead of where the harvest was after opening weekend in 2016.
Some of this is part of my “generic’ response to what is an age old question that is the subject of many chatroom forums and debates but in the end, the turkey biology has not changed. I’m assuming you are an avid turkey hunter who is interested in the long term sustainable hunting opportunities and the science behind the decisions. Read what you care to and hopefully my response and the materials attached will give you more insight to what many think is a simple question.
The southern states have undergone a progressive evolution toward earlier spring opening dates primarily because of political pressures rather than turkey biology. Now that progression has come under scrutiny and concern as turkey populations and harvests have undergone significant declines – see announcement from SEAFWA Directors. Much of the concern has grown from the ever increasing body of evidence accumulating from various studies in multiple states (e.g., OH,PA, WV, VA, MO, GA,SC, etc) since the late 1990’s showing increasing higher levels of accidental hen loss associated with progressively earlier spring season dates, higher than expected harvest rates of adult gobblers during the spring turkey seasons (e.g., KY averaged 65-68% gun-related mortality during the 10 years of spring hunting), and shifting demographics of the gobbler age structure that is likely influencing the normal breeding season success. I have attached a couple popular and portions of technical articles that touch on these issues. Consulting Whittaker et al’s the figure you will see that Indiana’s spring turkey season dates actually fall slightly on the early side of the strict theoretical & biologically supported dates for reducing accidental hen loss. The ever increasing information provided by GPS transmitters that 24/7 track turkey movements, incubation dates, and more recently, the acoustic listening devices that can monitor gobbling activity across the landscape the amount and the quality of the information will continue to build.
An early spring green-up and leaf out often causes many anxious wild turkey hunters wondering about the potential influence on the onset of breeding in wild turkeys. The onset of or pre-breeding season behavior of territorial displays & gobbling activity by gobblers that in some years can be observed as early as January, gets turkey hunters thinking about the upcoming season. This year the abnormally mild winter and potentially an early spring green up, has no doubt increased turkey hunter anxiousness for the upcoming turkey season. In decades past, we have observed wild turkey gobblers displaying and gobbling on our winter trap sites as early as mid-January but generally those displays and other pre-breeding season behaviors will start being more consistent beginning in March. Adult males begin coming into breeding condition far ahead of hens and the increased gobbler activity is has more to do with setting up breeding territories. The breeding development & behavior of hens lags behind that of gobblers and is controlled primarily by increasing day length. In years of severe winter stress, both males and females may have a delayed breeding chronology.
Increasing day-length (photo-period), which remains unchanged each year, is the primary factor influencing the breeding chronology of wild turkeys and most other birds. Prevailing climatic conditions (e.g., temperature, rainfall, lack of snow cover, % cloudiness) will influence the development of vegetation. Early spring green-ups are thought to enhance the physical condition of hens prior to breeding but day-length is dominant factor influencing hormone levels and ovulation progression (egg development) even if the hen is in excellent physical condition. Season dates for turkey hunting are set to assure that the majority of hens, on average, have already bred and are beginning to incubate their eggs. This timing reduces accidental hen shootings during the hunting season and generally intercepts the second peak of gobbling activity when gobblers are vulnerable due to their breeding behavior. The proportion of hens lost to accidental shootings can increase significantly if spring hunting commences prior to the general onset of incubation.
Hunters often remark that they heard more gobbling activity in the weeks prior to the season and then gobbling diminishes either in the days prior to the season or soon after the season begins. Several studies of gobbling activity on hunted and non-hunted areas indicates just 3-4 days of hunting related activity is a primary factor in reducing gobbling activity. Human related activity influencing potential gobbling activity would include pre-season scouting, pre-season video-taping of gobbling turkeys, mushroom hunting, and spring flower observations.
Indiana has an “open permit” turkey gobbler season allowing anyone with a permit to hunt, the convenience to choose when and where they hunt during the “all-day” shooting hours (1/2 hr before sunrise to sunset) throughout our 19-day season length. The spring season dates for wild turkey hunting were standardized over decades ago as, “... from the first Wednesday after April 20 and continuing for an additional eighteen (18) consecutive days.” The range of opening dates is from April 21 to 27 and easily determined for any year by consulting a calendar. The standardize season dates were set to best capture the “average” wild turkey hen breeding cycle when most hens have initiated incubation. The standardized dates were developed in the early 1980’s when the majority of the turkey hunting range was in southcentral and southwest Indiana. The standardized dates also provided a convenience to our hunting publics, especially those hunters who need to request their leave time 6-12 months prior to taking it. The straightforward, open permit season is easy to understand and appreciated by our hunters who lead busy lives with ever-changing job and family schedules.
Attached is the 2016 harvest report and the last table is a summary table of Indiana’s Spring Seasons. I have attached a couple more technical articles related to spring breeding and nesting chronology. Indiana like many other Midwestern states has experienced 11 years of consecutive summers of below normal brood production, due to above normal precipitation during the critical early brood period, with the traditionally the best turkey range in south central, southeast, and west central Indiana hit the hardest. The declines are being seen throughout the eastern US but some of the more dramatic declines have occurred in the southeast US where there has been consistently longer integration of turkey hunting in the culture. The abstract by Eriksen touches on this change.
As a natural resource agency, we are responsible for safeguarding the resource and as well as providing sustained hunting opportunities in a changing landscape and the annual oscillations (ups & downs) in the wild turkey production. The reduced production has resulted in smaller winter flocks sizes, reduced gobbling counts conducted prior to spring seasons, and a lower proportion of jakes in the spring harvests in recent years (see annual Wildlife Science Report). Hopefully, the exceptionally advanced spring vegetation and warm temperatures will an increase in this year’s summer brood success. We badly need an up-swing in our summer turkey production.
Thank you for your interest.
Sincerely,
Steven E. Backs
Wildlife Research Biologist
Statewide Project Leader (Wild Turkey & Ruffed Grouse Project; Wild Pig Elimination Effort)
TOO LATE
TOO EARLY
JUST RIGHT
From Steve Backs..(letter to another turkey hunter posted on another site)
Thank you for your inquiry regarding spring turkey season dates in Indiana. Yes, we receive and respond to such inquiries which tend to increase in the first couple of years after we make a ‘calendar shift” from the earlier end of the framework to later end of the framework in the standardized season date framework developed in 1983. Since this is a busy time of year, I will give you the generally broad generic response to the issue. A couple things, you should recognize is that our turkey populations/spring harvests in Indiana and throughout the eastern US have dropped off, some places worse than others. How much of this drop remains the “new normal” remains to be seen and in the end, prevailing habitat conditions across the landscape will likely be the main determining factor. I will also attach a number of articles or publications related to this issue that might give you a more informed insight into some of the arguments, issues, and concerns. I have also attached the 2016 spring harvest report for Indiana that has a summary table toward the end of the report that shows the dates and harvests for the previous spring turkey seasons in Indiana since 1970. Also attached, is a section on the status of Indiana wild turkeys in the 2016 Annual Wildlife Science Report that documents some of the declines in turkey populations and harvest indices. Finally, before the responses below, for what it is worth at this point in the spring season, despite the inclement weather of opening weekend, the current harvest as of this morning is 500+ birds ahead of where the harvest was after opening weekend in 2016.
Some of this is part of my “generic’ response to what is an age old question that is the subject of many chatroom forums and debates but in the end, the turkey biology has not changed. I’m assuming you are an avid turkey hunter who is interested in the long term sustainable hunting opportunities and the science behind the decisions. Read what you care to and hopefully my response and the materials attached will give you more insight to what many think is a simple question.
The southern states have undergone a progressive evolution toward earlier spring opening dates primarily because of political pressures rather than turkey biology. Now that progression has come under scrutiny and concern as turkey populations and harvests have undergone significant declines – see announcement from SEAFWA Directors. Much of the concern has grown from the ever increasing body of evidence accumulating from various studies in multiple states (e.g., OH,PA, WV, VA, MO, GA,SC, etc) since the late 1990’s showing increasing higher levels of accidental hen loss associated with progressively earlier spring season dates, higher than expected harvest rates of adult gobblers during the spring turkey seasons (e.g., KY averaged 65-68% gun-related mortality during the 10 years of spring hunting), and shifting demographics of the gobbler age structure that is likely influencing the normal breeding season success. I have attached a couple popular and portions of technical articles that touch on these issues. Consulting Whittaker et al’s the figure you will see that Indiana’s spring turkey season dates actually fall slightly on the early side of the strict theoretical & biologically supported dates for reducing accidental hen loss. The ever increasing information provided by GPS transmitters that 24/7 track turkey movements, incubation dates, and more recently, the acoustic listening devices that can monitor gobbling activity across the landscape the amount and the quality of the information will continue to build.
An early spring green-up and leaf out often causes many anxious wild turkey hunters wondering about the potential influence on the onset of breeding in wild turkeys. The onset of or pre-breeding season behavior of territorial displays & gobbling activity by gobblers that in some years can be observed as early as January, gets turkey hunters thinking about the upcoming season. This year the abnormally mild winter and potentially an early spring green up, has no doubt increased turkey hunter anxiousness for the upcoming turkey season. In decades past, we have observed wild turkey gobblers displaying and gobbling on our winter trap sites as early as mid-January but generally those displays and other pre-breeding season behaviors will start being more consistent beginning in March. Adult males begin coming into breeding condition far ahead of hens and the increased gobbler activity is has more to do with setting up breeding territories. The breeding development & behavior of hens lags behind that of gobblers and is controlled primarily by increasing day length. In years of severe winter stress, both males and females may have a delayed breeding chronology.
Increasing day-length (photo-period), which remains unchanged each year, is the primary factor influencing the breeding chronology of wild turkeys and most other birds. Prevailing climatic conditions (e.g., temperature, rainfall, lack of snow cover, % cloudiness) will influence the development of vegetation. Early spring green-ups are thought to enhance the physical condition of hens prior to breeding but day-length is dominant factor influencing hormone levels and ovulation progression (egg development) even if the hen is in excellent physical condition. Season dates for turkey hunting are set to assure that the majority of hens, on average, have already bred and are beginning to incubate their eggs. This timing reduces accidental hen shootings during the hunting season and generally intercepts the second peak of gobbling activity when gobblers are vulnerable due to their breeding behavior. The proportion of hens lost to accidental shootings can increase significantly if spring hunting commences prior to the general onset of incubation.
Hunters often remark that they heard more gobbling activity in the weeks prior to the season and then gobbling diminishes either in the days prior to the season or soon after the season begins. Several studies of gobbling activity on hunted and non-hunted areas indicates just 3-4 days of hunting related activity is a primary factor in reducing gobbling activity. Human related activity influencing potential gobbling activity would include pre-season scouting, pre-season video-taping of gobbling turkeys, mushroom hunting, and spring flower observations.
Indiana has an “open permit” turkey gobbler season allowing anyone with a permit to hunt, the convenience to choose when and where they hunt during the “all-day” shooting hours (1/2 hr before sunrise to sunset) throughout our 19-day season length. The spring season dates for wild turkey hunting were standardized over decades ago as, “... from the first Wednesday after April 20 and continuing for an additional eighteen (18) consecutive days.” The range of opening dates is from April 21 to 27 and easily determined for any year by consulting a calendar. The standardize season dates were set to best capture the “average” wild turkey hen breeding cycle when most hens have initiated incubation. The standardized dates were developed in the early 1980’s when the majority of the turkey hunting range was in southcentral and southwest Indiana. The standardized dates also provided a convenience to our hunting publics, especially those hunters who need to request their leave time 6-12 months prior to taking it. The straightforward, open permit season is easy to understand and appreciated by our hunters who lead busy lives with ever-changing job and family schedules.
Attached is the 2016 harvest report and the last table is a summary table of Indiana’s Spring Seasons. I have attached a couple more technical articles related to spring breeding and nesting chronology. Indiana like many other Midwestern states has experienced 11 years of consecutive summers of below normal brood production, due to above normal precipitation during the critical early brood period, with the traditionally the best turkey range in south central, southeast, and west central Indiana hit the hardest. The declines are being seen throughout the eastern US but some of the more dramatic declines have occurred in the southeast US where there has been consistently longer integration of turkey hunting in the culture. The abstract by Eriksen touches on this change.
As a natural resource agency, we are responsible for safeguarding the resource and as well as providing sustained hunting opportunities in a changing landscape and the annual oscillations (ups & downs) in the wild turkey production. The reduced production has resulted in smaller winter flocks sizes, reduced gobbling counts conducted prior to spring seasons, and a lower proportion of jakes in the spring harvests in recent years (see annual Wildlife Science Report). Hopefully, the exceptionally advanced spring vegetation and warm temperatures will an increase in this year’s summer brood success. We badly need an up-swing in our summer turkey production.
Thank you for your interest.
Sincerely,
Steven E. Backs
Wildlife Research Biologist
Statewide Project Leader (Wild Turkey & Ruffed Grouse Project; Wild Pig Elimination Effort)
