Ruffed Grouse - Bonasa umbellus
Pennsylvania State Bird
Season and Limit:
Species Status Update
This presentation describes data and rationale leading to the recommendation of a 2017-18 statewide closure of the Grouse Late Season – presented to Board of Game Commissioners on Jan. 30, 2017.
2017-18 Grouse Season Recommendations
The post-Christmas grouse season (hereafter “late season”) is well-loved by many grouse hunters. It is a time to be in the woods with few other people. Ticks are inactive and temperatures are just right for running the dogs. And a quiet covert makes a grouse flush all the more dramatic.
Unfortunately, due to recent declines in hunter flush rates and brood observations, the 2017-18 grouse season recommendation calls for a statewide closure of the late season for at least one year, with future actions to be determined as we better understand changes in grouse population dynamics.
All measures used to track grouse populations have undergone dramatic declines since the statewide late season was established in the 1980s. Of more immediate concern, population data reveals dramatic negative changes that began in the early 2000s and continue to present:
- depressed hunter flush rates (grouse flushes per hour)
- declining July and August brood observations (an index of brood survival)
- dramatically decreased recruitment of juveniles into the adult population between the 1980s to present day (i.e. juvenile per hen ratios in hunter-harvested birds)
- decreased proportion of juveniles in the winter harvest (Dec and Jan)
The goal of the 2017-18 late season closure is to support the weak population recovery that began in 2015 following the historic low point in abundance that occurred in 2014. Record-low brood observations in July and August 2016 suggest action is needed to foster this weak population recovery. The goal is to limit late season harvest to support this unique period of recovery. By limiting late winter harvest in 2018, we are attempting to move more grouse into the spring breeding season of 2018.
View a recording of the season recommendation and rationale as presented to the Board of Game Commissioners.
View the 2016 report on Grouse Population Status and Management Plan Implementation.
Frequently Asked Questions:
How You Can Help
Send Us Your Grouse Feathers
The Game Bird Section has initiated a statewide study of grouse recruitment. In wildlife management terms, 'recruitment' refers to the recruitment of young animals into a population and is an important driver of population trends.
Grouse population declines have been documented throughout Pennsylvania and appear to be especially pronounced in the state's southern regions. By replicating a recruitment study conducted in Pennsylvania during the 1970s and 1980s, we can determine if grouse recruitment has changed over time in northern and/or southern Pennsylvania.
For this study, hunters are asked to submit the 3 outer primary wing feathers ("flight feathers") or the entire wing, a central tail feather, and 2 to 3 rump feathers, along with harvest location information. The goal is to collect a representative sample of harvested birds from throughout the state, with at least 1,000 samples in total. This is an ambitious goal and we need your help!
Grouse Feather Collection Survey – If
any member of your party harvests a grouse, please submit the following feather samples: one entire wing (or 3 outer flight feathers), 1 central tail feather, 2 to 3 rump feathers (
see instructions and diagram (PDF)). Enclose feathers in an envelope. Provide your NAME/PHONE, COUNTY OF KILL, TOWNSHIP and WMU OF KILL, AND DATE OF KILL on the backside of the envelope. DO NOT mix different birds in one envelope. Submit feathers from one grouse in one envelope. If you do not wish to send a tail feather, please send rump and wing feathers anyway. Those feathers still provide important information.
Plan Your Hunt
October 2014 - Just in time for upland bird hunting season, DCNR Bureau of Forestry released an online mapping tool that shows locations of recent timber harvests (since 2005), young aspen, thermal cover, herbaceous openings and other features of interest to hunters. The map includes GPS and measurement tools to enable hunters to find the best routes to sites on state forest lands. The site can be viewed here http://maps.dcnr.pa.gov/bof/huntmap/index.html
The Game Commission also has an online tool for planning trips on Game Lands: Game Commission Mapping Center
Frequently Asked Questions & Answers
What will happen to the grouse season after 2017-18?
Recommendations for season and bag limits are made to the Board of Game Commissioners (hereafter Board) each year, followed by a public comment period and Board vote. This allows season changes to be made in response to new research and population monitoring information obtained each year. The duration of the late season closure is unknown. Re-opening of late season opportunities will depend upon changes and trends in grouse population measures. The effects of changes to hunting seasons are difficult to evaluate in less than three years, so the current 1-yr recommendation of closure could be extended if population data warrants.
The goal of the grouse management program is to develop a responsive harvest management framework that adjusts over time based on changes in the grouse population.
What is Responsive Harvest Management?
A responsive or ‘prescriptive’ management approach is used for some migratory game birds (doves and woodcock) as a safeguard to prevent over-harvest. A responsive management framework incorporates abundance and productivity measures into season-setting decisions so that seasons and bag limits respond to changes in populations. Thresholds and triggers are identified that direct population managers to set liberal, moderate, or conservative seasons. When the population exceeds certain thresholds, the season is lengthened. If the population drops below certain thresholds, the season is restricted.
During the 2017-18 license year, the Game Commission will identify an appropriate responsive management framework for grouse. To accomplish this, relevant population measures will be chosen. Population measures that may be used in the responsive management framework could include measures of production (brood surveys) and abundance (hunter flush rates, statewide harvest and/or harvest per day ratios). Since West Nile virus has been shown to influence populations in every region, an indicator of virus prevalence may also be incorporated.
Once appropriate population measures are chosen, models will be developed to help predict the impact of season changes. Thresholds that trigger season changes will then be identified. The benefit of a responsive harvest framework is that season-setting is consistent from year to year, responsive to the population, and transparent to the public.
What are future research and management priorities?
Primary grouse management priorities through 2018 include the development of a responsive management framework to guide season setting. The primary research priority is to identify factors that influence West Nile virus prevalence in grouse habitat (such as mosquito species involved, elevation, slope, distance from standing water, vegetation characteristics). The habitat management priority is to increase the extent and quality of grouse habitat.
Longer term priorities include assessing the impacts of hunting (if funding and personnel are available) and focusing habitat management in sites where grouse populations can best take advantage of the opportunity. Since private lands are the key to large-scale population recovery, enhancing collaboration with traditional and non-traditional partners to communicate the dramatic need for grouse habitat management is high priority.
What does the Game Commission hope to gain by closing the late season for grouse?
The Game Commission’s priority is to increase the number of birds entering the breeding population in mid-March to mid-April in order to increase baseline breeding populations. Some of these birds will die of natural causes prior to the breeding season, but current research indicates that monthly survival of grouse from January to March is 80 to 90 percent (with adult survival significantly higher than juvenile survival).
If we apply those survival rates to the number of grouse harvested in the late season from 2012 to 2015, we estimate that approximately 24,000 birds would have been carried over into the breeding population over those four years if they had not been harvested in the late season.
Whether this increased survival is enough to make a noticeable difference in grouse populations is not yet known. However, there are several arguments for trying this approach:
- Population connectivity. Both males and females are required to produce the next generation. Males in January through March are occupying a territory established in the previous fall to early winter. If males are removed from their established territories in late winter, these sites are not likely to be re-occupied in time for breeding. Grouse make only one major dispersal in their lives: juvenile dispersal in their first autumn (September). Therefore, the loss of both males and females degrades the connectivity and success of breeding populations
- Experienced breeders. More than half of birds harvested in the late season are adults. Males are occupying an established breeding territory and hens have already had experience in raising a clutch.
- WNV immunity. Nearly a quarter (22%) of all late season birds tested had antibodies to West Nile virus in 2015 (2016 data pending). These birds were exposed to the virus and survived. Based on research with similar species, survivors likely have lifetime immunity. They do not need to fight off the virus again, and their energy can be directed into breeding and raising a clutch. These are high-value birds to recruit into the breeding population.
What is known about the impacts of hunting on grouse populations?
Research on the impact of grouse hunting has returned mixed results depending on amount of available habitat, severity of winter conditions, level of natural (non-hunting mortality), immigration into the hunted population from nearby population sources, level of hunting pressure, and harvest rate. The following background information was prepared by Game Commission grouse biologist Bill Palmer, 2003, and provides a nice overview of the relevant research:
[To find papers cited in this section, go to Google Scholar and enter the authors’ name(s), year and ‘ruffed grouse hunting’ or a similar search phrase].
Early Studies: Research on the effects of hunting on ruffed grouse populations began in the 1930’s in New York by Edminster and others (1937, 1947). After that period, most early research was conducted in aspen habitats at northern latitudes (i.e. Michigan, Palmer 1956, Dorney and Kabat 1960, Palmer and Bennet 1963). The Michigan publications included data from the period when MN closed grouse seasons (1944-47), and WI closed theirs (1945-47). While MI restricted their season, they kept it open during those years and the outcome showed that closing seasons did not do much to help grouse populations. They recovered in all 3 states. Fischer and Keith published their work from Alberta in 1974. All of these studies from the 1930’s into the early 70’s found no impact of fall hunting. Their recommendations for acceptable kill ranged from 25 to 50 % allowable harvest rate and most recommended longer fall seasons because they felt it would not increase the kill by much.
Research in the 1980s: As hunting seasons were being liberalized, there were still concerns for grouse populations. Several studies done in the 80’s showed that grouse hunting mortality was additive (e.g. suppressed populations beyond the level of natural mortality) (see Bergerud 1985, Small et al. 1991). DeStephano and Rusch reported (1986) that hunting mortality during fall was additive but had little impact on grouse populations.
Other studies in the 1980s suggested that hunting mortality impaired subsequent breeding population size on heavily-hunted public hunting areas and in fragmented habitat (Kubisiak 1984, Rusch et al. 1984, Small et al. 1991). In 1988, Gordon Gullion in MN concluded that these consequences were greater from hunting mortality in the late season (Dec through Jan) compared to earlier in season. Small and his associates (Small et al. 1991) suggested that on heavily-hunted public areas, ruffed grouse numbers lost to harvest are replaced by immigration from adjacent areas where hunting mortality is lower. They also suggested that where immigration is reduced due to widespread hunting pressure, or due to habitat loss and fragmentation, grouse numbers would be reduced. This interaction of public lands, hunting pressure, and fragmented habitat resulting in lowered populations (due to reduced immigration) was supported by Robertson and Rosenberg (1988) and Linden and Raijas (1986).
Research in the 1990s: The Appalachian Grouse Project, a multi-state study, investigated population dynamics and ecology of ruffed grouse in the southern and central Appalachian Mountains. Grouse were monitored at sites in KY, MD, OH, NC, PA, VA and WV (not all states in all years). Hunting mortality ranged from 0 to 34% (average 16%). Results showed decreased annual survival of grouse with increased hunting harvest rates (Reynolds et al. 2000). They also found this relationship to be weak in fall (Oct.-Dec.) and strong for late seasons (Jan.-Feb.). They suggested that fall hunting may have no effect on populations, while winter hunting may have a negative effect.
A more-focused look at hunting in VA, WV and KY (at sites with relatively low harvest rates) led the Appalachian study researchers to conclude that “a harvest rate of less than 20% in the southern and central Appalachians is compensatory (i.e. does not suppress populations). We believe current harvest rates can be maintained, but regional state agencies should not amend hunting seasons to facilitate higher harvest rates, particularly in light of the loss of habitat that is occurring throughout the region” (Ecology and Management of Appalachian Ruffed Grouse, 2011).
Additionally, the Appalachian study found evidence that hunting had an indirect effect on grouse survival: “Although we believe regulated sport harvest did not have a direct impact on ruffed grouse survival, there is evidence that disturbance from hunting (and other activities) influenced habitat selection and home range size of ruffed grouse (Whitaker 2003). Ruffed grouse (regardless of sex and age classes) made greater use of clearcuts and mesic bottomlands and had smaller home ranges in the absence of hunting. We believe this type of disturbance deserves consideration in the development of ruffed grouse hunting regulations and land management” (Ecology and Management of Appalachian Ruffed Grouse, 2011).
In short, information on the impact of hunting is mixed. Whether past studies found significant impacts of hunting or not, it is difficult to apply their findings to Pennsylvania grouse as our population now stands: at low abundance; during a period of low brood productivity and survival; with disease impacts occurring statewide, and; during a time when harvest shows low juvenile recruitment.
It is important to note that all large-scale studies of hunting impact were conducted prior to the arrival of West Nile virus in North America. West Nile virus shows strong indications as a significant mortality factor for Pennsylvania grouse. When natural mortality increases substantially, the ‘population math’ changes and the impact of hunting that population may also change. In short, we have little to no clarity on the current impact of hunting on Pennsylvania grouse. A study of the effect of late season harvest on grouse is a priority of the Game Commission grouse management program.
Why not reduce daily bag limit from 2 to 1?
Ninety-eight percent of grouse hunters do not achieve the daily bag limit at any time during the hunting season, and 99 percent of grouse hunters harvest five or fewer birds in an entire license year. In 2015-16 license year, avid grouse hunters (Game Commission Grouse Cooperators) hunting a cumulative 2,292 days, achieved bag limit on just 4 percent of hunt days. Thus, all evidence suggests that reducing bag limit would not increase the number of birds surviving into the breeding population. Additionally, more hunters prefer to see season length reduced rather than bag limit, according to the results of the 2015 Grouse and Woodcock Hunter Survey.
Why not shorten the late season rather than closing it entirely in 2017-18?
Forty percent of late season hunting and harvest occurs in the first week, December 26 – January 1. If the late season were shortened to one week, some hunters who normally hunt later in January would shift their hunting to the open week. Estimating conservatively, we would still be harvesting 50 percent (or more) of the birds normally harvested. To support recovering populations in all regions, the goal of the 2017-18 grouse season is to minimize late season harvest in order to increase the likelihood that these birds are carried into the 2018 breeding population. By shortening the late season to one week, we would be inconveniencing hunters while not retaining the number of breeding birds we need. Likewise, shortening the late season by two weeks (and leaving two weeks open) would not measurably increase grouse abundance, as shown by Game Commission research conducted in the1980s.
Why not create a split zone season, where areas north of I-80 remain open for late season hunting?
The primary concern with this option is that this will increase hunting pressure on these areas as hunters will travel to open units. Already, 45 to 55 percent of the regular season statewide harvest comes from just four Wildlife Management Units (2F, 2G, 2H, 3A). The proportion of late season birds harvested in these four core Wildlife Management Units varies annually based on travel conditions and hunter movement. From 2012 to 2015, the proportion of late season harvest that came from these areas varied from 15 to 62 percent of statewide harvest. The most likely reason for this wide variation is that hunting pressure rises and falls in these core grouse areas based on travel conditions. Further increasing hunting pressure in these areas is not conducive to increasing the number of birds surviving until the breeding season, particularly if roads remain passable in winter.
A secondary concern with this option is that it would increase regulation complexity. When possible, the Game Commission attempts to keep regulations simple and easy to follow, and a statewide season structure is in keeping with this goal.
Why not shorten the season by reducing days in October, November, or mid-December?
The late season is the season which most impacts the breeding population. In the late season, we are harvesting survivors. They have survived earlier hunting seasons and they have survived the rigors of winter to date. Also, late season harvest disproportionately removes adult birds (i.e. experienced breeders) (October adults = 34 percent of harvest; November adults = 51 percent of harvest; December adults = 57 percent of harvest; late season adults = 56 percent of harvest). In 2015-16, the late season also disproportionately remove West Nile virus survivors. In year 1 of sampling, late season birds accounted for twice the proportion of West Nile virus survivors compared to the regular season (22 percent West Nile virus + in late season samples; 11 percent West Nile virus + in regular season samples). Late season birds are just 8 to 12 weeks from the reproductive season. The goal for closing the winter 2017-18 season is to maximize the chances these birds are carried over into the breeding population to support the weak statewide population recovery that is occurring in 2015-16 (and hopefully continuing in 2016-17). Finally, historic research across multiple states has indicated that population-level impacts from winter hunting are stronger than those of fall hunting.
Hunter Concern: People will not have time to hunt grouse with a shortened season.
In our 2015 Grouse and Woodcock Hunter Survey, the Game Commission asked about factors that limited participation in grouse hunting: 71 percent of hunters stated that low grouse populations limit their participation while just 34 percent stated that lack of time limits participation. Based on hunter input, lack of grouse is a much more significant barrier to grouse hunting than lack of time. The Game Commission remains sensitive to the difficulty for hunters of allocating and prioritizing free time across a variety of hunting seasons and personal responsibilities. However, hunter survey data suggests that we can best serve grouse hunters by managing for higher grouse populations. To assess impact on grouse hunting participation, we will monitor any changes that occur in statewide number of hunters and days afield relative to available days.
Hunter Concern: If you shorten the season, it will be difficult to re-open.
The decision to open or close seasons is made annually by the Board of Game Commissioners. By implementing a responsive management framework, the grouse season would change in response to changes in grouse populations. If and when grouse abundance and/or productivity rebounds, the Game Commission will have a mechanism in place to adjust the grouse season.
How will the Game Commission measure success?
We do not know if closing the late season will significantly benefit grouse populations. To detect a response, we will continue monitoring the data that we used to identify population declines: brood surveys, Cooperator flush rates, total statewide harvest, statewide harvest per day ratios, and age/sex ratios of the harvest.
What is current status of Grouse Plan implementation? How does the season recommendation fit into the Game Commission’s Ruffed Grouse Management Plan?
Although the Grouse Plan was ambitious, and resources for grouse management are quite limited, the Game Commission has made (and continues to make) significant progress on plan deliverables. Implementation of the Game Commission’s Ruffed Grouse Management Plan is well underway, with progress made on 19 of 23 management objectives (83 percent) to date
The possibility of changing the grouse season was identified under the Population Objective of the Grouse Management Plan, which stated that season structure would not be changed unless warranted by research results:
Grouse Management Plan Strategies:
1.4 Except for any experimental manipulations needed to meet research objectives, annually recommend a grouse season maintaining current length, timing, and statewide structure until research results are available.
1.5 If warranted based on research results, recommend adjustments to season length and/or bag limits at appropriate scale (statewide, grouped Wildlife Management Units, or individual Wildlife Management Units) to avoid additive mortality from harvest.
Recent analysis of brood surveys, hunter flush rates, impacts of West Nile virus, and low juvenile recruitment into the fall harvest are all research results that triggered the recommendation for a season modification. These research results clearly show that a significant change has occurred in grouse population demographics since the 1980s (when the current season structure was enacted) – and more importantly since the early 2000s (when West Nile virus entered the state). Targeted research on hunting impacts on grouse remains a priority of the grouse management program going forward, if resources permit.
Additionally, progress on the Habitat Objectives of the Grouse Plan is an annual priority of the Game Commission. A Grouse Status report that includes issues affecting habitat management, and figures showing acreage created per year.
If West Nile Virus is a problem, why don’t we find dead grouse in the woods?
When West Nile virus first moved though the US, people found dead crows and blue jays because these species were abundant and live near human settlements. They also lack the incredible camouflage of a grouse. This makes the likelihood of finding a carcass greater for jays and crows. To make matters worse, grouse likely die from West Nile virus in summer, when few hunters and bird dogs are moving through grouse coverts. Finally, a dying grouse is an easy target for predators, so the window for finding a sick grouse or carcass is very brief.
Is West Nile virus from grouse a risk to humans and other species?
Grouse do not infect other species, the virus is spread by the bite of an infected mosquito. Our lab study showed that the virus did not pass from grouse to grouse kept in direct contact with one another (i.e. no spread to ‘control’ chicks). This indicates that a sick grouse is not likely to pass the virus to another animal.
Birds harvested in October thru January were most likely exposed to West Nile virus during summer. Even those who sickened in summer should not have active virus in their blood at the time of harvest. For the same reason, hunting dogs should not be at risk from harvested birds. Hunters should follow the same advice given for any game: use precautions during field dressing and cooking.
Is there a West Nile virus risk to other game birds?
Pheasants and wild turkeys have been shown to be largely unaffected by West Nile virus and these populations have not shown declines tied to the timing of West Nile virus arrival in Pennsylvania. Woodcock have not been directly studied, but their populations have not shown the dramatic declines that correspond to West Nile virus peaks in Pennsylvania.
What about weather impacts on grouse production?
Cold, wet springs may reduce brood survival due to decreased insect availability and outright exposure. Warm wet springs may increase invertebrate (i.e. grouse brood food) populations, but also benefit some mosquito species. Hot dry summers benefit mosquitos that carry West Nile virus because they breed in stagnant water. While managers can indirectly monitor the effects of weather on grouse production using existing surveys, this is a factor we can only react to – not control.
What about predator impacts on grouse?
While the Game Commission directly controls hunting, it is not in direct control of other mortality factors. Managing terrestrial predators is directly in the control of hunters and furtakers. Pennsylvania is fortunate in this regard: In contrast to many other states, Pennsylvania has seen stable to increasing furtaker numbers and furbearer harvests over the past 20 years. Avian predators are migratory and under the jurisdiction of the federal government. Controlling avian predators has been shown to be neither scientifically justified nor publicly acceptable.
What is the Game Commission doing about habitat?
The Game Commission and DCNR actively manage tens of thousands of acres per year to improve forest conditions and create the thick young forest required by grouse. See the Habitat Management section (pages 3 thru 5 and related figures) of this report for more information.
Unfortunately, large-scale management of Pennsylvania forests is beyond the control of public agencies. Roughly 70 percent of Pennsylvania forest land is privately owned and most of those owners are NOT making grouse habitat. Many private landowners are loving their forests to death by neglecting them through hands-off management. Others are slowly degrading the habitat quality of their forests by active mismanagement: high-grading, diameter limit cutting and ‘select cuts’ severely diminish forest health, productivity, and habitat quality.
Finally, the need for more grouse habitat is a long term solution to a long term problem. Forest acreage managed today takes a number of years before it becomes prime grouse habitat. The record low grouse abundance seen in the 2014-15 and 2015-16 license years, coupled with the record low brood survival observed in July and August of 2016, indicates that short term intervention is warranted to stem immediate declines and support recovering populations.
What can I do to assist the recovery of grouse?
If you are passionate about grouse and want to assist, please educate your neighbors, your hunt clubs and fellow hunters about the value of active and responsible forest management. Even well-intentioned landowners can be overwhelmed with choices when it comes to managing their forests. Penn State’s Forestry Extension offers many tools and workshops to assist private landowners:
For landowners with a particular interest in grouse and other wildlife of the young forest, this site is a clearinghouse of online resources to help you with your education efforts: http://youngforest.org.
For assistance with forest management and wildlife habitat planning, consult with a:
Game Commission Private Lands biologist.
and/or DCNR Service Forester.