Resource Management & Research Report Indiana State Parks & Reservoirs No. 08-1 Title: 2008 State Park Deer Reduction Results: 15 Years in Review Author: Mike Mycroft, Chief of Natural Resources Date: 12/5/2008 Abstract: Indiana State Parks began deer reductions in 1993 with a one day reduction hunt at Brown County State Park in an effort to mitigate damage to vegetation by an overpopulation of white-tailed deer (Odocoileus virginianus). Deer reductions have continued annually since 1995 and have included up to 19 parks per year. The decision to initiate reductions at individual parks has been based on a method of vegetation monitoring developed by Purdue University’s Department of Forestry and Natural Resources. Decisions to continue reductions at individual parks are made annually using harvest data such as harvest per effort and harvest per square mile after each reduction. Additional consideration has recently been given to elemental occurrences and status of state rare, threatened, and endangered flora that could be affected by excessive browsing by deer. Though the program has been largely successful helping vegetation recover, challenges persist as we attempt to get most parks onto an every-other-year maintenance rotation of reductions. High percentages of hunters’ drawn that fail to show-up and over selective hunting have been and continue to prevent higher program success.
Introduction White-tailed deer (Odocoileus virginianus) have thrived in Indiana State Parks since they were reintroduced to Indiana in the middle 20th century. Mild winters and the lack of once present natural predators such as wolves and mountain lions coupled with a decades-long lack of human hunting within protected state park boundaries resulted in excessive browsing by deer that compromised the overall composition, structure and function of most natural communities throughout the state park system. Browse lines and small, malnourished deer were a common sight at most state park properties by the late 1980’s. The first deer reduction hunt was hosted at Brown County State Park on December 4, 1993, with 466 hunters harvesting 392 deer. After a one year hiatus, four parks were hunted in 1995 and 20 state parks have had deer reductions since 1995. Recently, as many as 18 parks have held reduction hunts in the same year (Table 1). The decision to initiate reductions at any one park was made after monitoring the height of three herbaceous species, sweet cicely (Osmorhiza claytoniia), jack-in-the-pulpit (Arisaema triphyllum), and white baneberry (Actaea pachypoda) at individual parks (Webster et al. 2001). Vegetation monitoring continued after reductions began. Starting in 2002, determination to hunt each year hinged on each park’s annual harvest data. Webster and Parker indicated that vegetation begins to recover once a firearm harvest per effort (H/E) nears 0.22-0.20 and/or a harvest per square mile (H/Sq. mi.) is between 12 & 16 deer. Hunter density has ranged between 1 hunter per 18-20 acres. Parks where
2008 State Park Deer Reduction Results: 15 Years in Review archery is regularly used (Clifty Falls and Fort Harrison) due to urban interface have an H/E target of 0.10-0.08 and 1 hunter per 7-10 acres. Reduction Methods Participant hunters in deer reductions are selected from a random drawing for which applications become available in the summer. Both online and paper applications have been available in recent years. One application is required for each two day reduction. Generally, there have been two, two-day reductions two weeks apart, an early and late hunt. Eligible applicants must be 18 years of age by the date of the first reduction hunt, be Indiana residents (or possess a valid Indiana lifetime license), and have any valid deer license. Application deadlines have traditionally been at the end of August. Primary applicants have been able (but not required) to include up to two partners or “buddies� as secondary applicants. No individual name can appear on more than one application, regardless of primary or secondary status.
Table 1. Number of State Parks and Deer Harvested 1993-2008
Year 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008
Number of Parks 1 0 4 7 9 10 9 14 13 13 19 15 16 16 18 17 Total Deer
Total Deer 392 0 1,048 2,027 2,174 1,735 1,510 1,655 1,483 1,522 1,961 1,253 1,336 2,017 1,300 1,468 22,881
Park managers determine the number of participants to be drawn at each property by determining the acres of huntable deer habitat available on each property. These areas exclude parking areas and safety zones such as areas surrounding offices, residences, boundaries and other facilities. Some areas such as campgrounds, shelter areas and those easily accessible via service roads or fire lanes are used for hunters with disabilities. Though a Hunter Education Card (HEC) is not required to apply, an electronic draw system selects first for each park from those applications that have completed a course in hunter education and have a valid HEC. Hunters that precede Indiana HEC requirements (individuals born on or before December 31, 1986 and not required to have an HEC to purchase a hunting license) must still have one to be counted in initial drawing. Remaining open slots are then electronically filled by applications that have not completed hunter education. All individuals on an application must have a HEC for the application to be counted in the HEC draw. In 2008, 4,847 hunters across 2,955 parties were successful in the draw. This number was approximately 57% of all individuals submitting applications. These percentages vary widely from year to year. Approximately 40% of applicants were successful in 2007, yet a few years prior, quota was barely met. Though speculation is present, the reasons for such fluctuation are not
This resource management and research report is issued to provide a quick source of information on issues related to wildlife or natural areas management in Indiana State Parks & Reservoirs. Any information provided is subject to further analysis, and therefore is not for publication without permission.
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2008 State Park Deer Reduction Results: 15 Years in Review firmly understood. Notifications of draw status have traditionally been mailed to both successful and non-successful participants via U.S. Postal Service from respective parks. Successful primary applicants are mailed packets with official credentials, area assignments, maps, and other special instructions. Parks are closed to the general public starting the night before each two-day reduction and reopen the morning after each last day. Safety zones, park boundaries and hunt areas are marked by park staff. Optional open houses are available at many parks the night before each two-day reduction. Participants are required to check-in and out each day of the reductions. Shooting hours have been changed recently from shortly after daylight to 4:00 pm to one half-hour before sunrise to 4:00 pm. Participants have been able and encouraged to harvest up to three deer (additional to state bag limits), one of which can be antlered (at least one antler ≼3 inches long). There is no sequence required of harvest of deer (Earn-A-Buck regulations). Hunters check deer in the park at designated check stations, where staff capture biological and harvest data and provide permanent tags. Measuring Success and Determining Annual Reduction Parks The objective of reduction hunts in the state parks is solely to facilitate the recovery of habitat by lessening the potential of excessive browsing by white-tailed deer. The primary measurement used in determining success has been the harvest per effort (H/E) achieved at each property after annual reduction hunts. Once a property nears 0.22-0.20 mean harvest per effort for that year and/or harvest per square mile (H/Sq. mi.) below 16, consideration begins for not having a reduction the following year. This target H/E indicates that a maintenance phase can possibly be entered into where reductions are suspended on alternate years or every two-three years (Figure 1). However, other variables such as elemental occurrence and status of rare, threatened, or endangered flora may factor into decisions. 0.80 0.70
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Figure 1. 1998-2008 H/E Indiana Dunes State Park (first reduction held 1998). The red (hashed) line highlights the 0.20 target H/E level.
This resource management and research report is issued to provide a quick source of information on issues related to wildlife or natural areas management in Indiana State Parks & Reservoirs. Any information provided is subject to further analysis, and therefore is not for publication without permission.
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2008 State Park Deer Reduction Results: 15 Years in Review H/E has varied widely from park to park each year since 1995. Initially, much of this variation can likely be attributed to such factors as park size, geographic location of different parks and surrounding land use (urban, agricultural, hunted/not hunted) and weapon used (archery vs. firearm). However, the range of variation shrinks as reductions continue along the spectrum of time (Figure 2). This indicates a moderating effect on populations resulting from repeated reductions. Another, more specific example of program success can be found at Harmonie State Park (with two state endangered plants) where H/E has gone from 1.39 in 1995 to 0.32 in 2008. The mean H/E for all parks has gone from 0.98 in 1995 to 0.33 in 2008.
Figure 2. 1993-2008 Harvest Per Effort. The center black bar indicates the mean H/E for each year. The white box indicates the first quartile (bottom of box) and third quartile (top of box). The whiskers represent the minimum (bottom) and maximum (top) H/E for each year. The red (hashed) line highlights the 0.20 target H/E level. Only one property (Brown County) was harvested in 1993, and no properties were harvested in 1994.
H/Sq. mi. provides a secondary means of evaluation. If a park is near the target H/E and in the 12-16 H/Sq. mi. range, vegetation is reasonably expected to recover at a particular park, though it can be contingent upon previous trending and weather. Similar variation and lowered H/Sq. mi. exists along the spectrum as that of H/E (Figure 3). Similar to the example of Harmonie State Park for H/E, a specific example of program success is greatly demonstrated at Tippecanoe River State Park (with three state rare plants) where H/Sq. mi. has dropped from 118 when first hunted in 1997 to 25 in 2008. The mean H/Sq. mi. for all parks has gone from 46 in 1995 to 22 in 2008. Additionally, one park reported checking fawns in 2008 that field dressed in excess of 74 lbs and mature does in excess of 150lbs. This resource management and research report is issued to provide a quick source of information on issues related to wildlife or natural areas management in Indiana State Parks & Reservoirs. Any information provided is subject to further analysis, and therefore is not for publication without permission.
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2008 State Park Deer Reduction Results: 15 Years in Review
Figure 3. 1993-2008 Harvest Per Square Mile. The center black bar indicates the mean harvest per square mile for each year. The white box indicates the first quartile (bottom of box) and third quartile (top of box). The whiskers represent the minimum (bottom) and maximum (top) harvest per square mile for each year. The red (hashed) line highlights the target of 15 harvest per square mile level. Only one property (Brown County) was harvested in 1993, and no properties were harvested in 1994.
Current Outlook Cumulative H/E and H/Sq. mi. trends clearly illustrate success as state parks attempt to facilitate the recovery of vegetation by lessening the potential of excessive browsing by white-tailed deer using reduction hunts. However, with fewer, yet healthier deer present than in years past, many hunters appear to lose interest. Though the reduction program has been an overall success, some parks have leveled out just above the target H/E, and are having a difficult time achieving maintenance status. Based on the mean H/E from 2006-2008 (Figure 4), 7 parks continue experiencing elevated H/E levels and are unlikely to achieve maintenance status in the near future, if ever given the short duration of annual reductions (four days) and surrounding landscape. An additional 6 are bordering maintenance status (two of which are the archery parks) and 6 are currently considered maintenance properties. Parks near harvest goals are experiencing high percentages of drawn participants not showing up or leaving early after harvesting adult bucks. Six parks had a mean noshow percentage above 50% in 2008. Weather can often play into the willingness of a hunter to fully participate in a reduction hunt, but it is suspected that this is not the only factor leaving hunting areas partially filled or empty. It’s no secret that some hunters
This resource management and research report is issued to provide a quick source of information on issues related to wildlife or natural areas management in Indiana State Parks & Reservoirs. Any information provided is subject to further analysis, and therefore is not for publication without permission.
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2008 State Park Deer Reduction Results: 15 Years in Review
Mean Harvest per Effort
see the reduction hunts as little more than a “trophy hunt”. In many cases hunters will pass on antlerless deer waiting on a large adult buck. With more appropriate deer densities than the past and consistent hunting pressure, these “trophy” adult bucks may never show or may not even exist, effectively eliminating that hunter’s effort in the reduction. 2008 found seven parks harvesting near or more than 40% adult bucks (Figure 5). Some of these properties have been consistent with this for three to five years. Figure 6 shows the upward trend of this phenomenon from 1993-2008. 0.55 0.50 0.45 0.40 0.35 0.30 0.25 0.20 0.15 0.10 0.05 0.00
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Figure 4. 2006-2008 mean Harvest Per Effort by park. Elevated parks range from 0.35-0.50. Border parks range from 0.23-0.34. Maintenance parks range 0.12-0.22. Two archery properties that use a different H/E target represent the dip at p11 and p12.
Figure 5. 2008 Percent Adult Bucks Harvested. The red (hashed) line highlights a cautionary level of 40% of adult bucks.
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2008 State Park Deer Reduction Results: 15 Years in Review
Figure 6. 1993-2008 Percent Adult Bucks. The center black bar indicates the mean percent of adult bucks harvested for each year. The white box indicates the first quartile (bottom of box) and third quartile (top of box). The whiskers represent the minimum (bottom) and maximum (top) percent of adult bucks harvested for each year. The red (hashed) line highlights a cautionary level of 40% of adult bucks. Only one property (Brown County) was harvested in 1993, and no properties were harvested in 1994.
If more individual hunter efforts were put into taking deer in general (regardless of sex or size), it is believed that many of the parks could reach maintenance status benefiting the natural communities and operational capacity of individual properties. Options of increasing antlerless harvest might include hunters having to first harvest an antlerless deer before taking an antlered (Earn-A-Buck) or limiting the taking of antlered deer to the second day of each two-day hunt and only to those who participated the first day. Despite these and other challenges, 2008 was successful in harvesting 1,468 deer across 17 parks (Table 2). Parks to have deer reductions in 2009 will be announced after January.
Table 2. 2008 State Park Reduction Stats Harvest H/E H/Sqmi Brown County 198 0.19 9 Chain O'Lakes 152 0.47 38 Charlestown 159 0.36 21 Clifty Falls 32 0.14 15 Ft. Harrison 42 0.15 16 Harmonie 166 0.32 31 Indiana Dunes 42 0.19 12 Lincoln 70 0.33 26 McCormick's Crk 41 0.18 13 Ouabache 62 0.41 39 Pokagon 44 0.27 22 Shades 130 0.33 27 Spring Mill 32 0.31 16 Summit Lake 36 0.20 12 Tippecanoe 107 0.33 25 Turkey Run 73 0.29 20 Whitewater 82 0.39 35
This resource management and research report is issued to provide a quick source of information on issues related to wildlife or natural areas management in Indiana State Parks & Reservoirs. Any information provided is subject to further analysis, and therefore is not for publication without permission.
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2008 State Park Deer Reduction Results: 15 Years in Review Sources Referenced Webster, C.R., M.A. Jenkins, and G.R. Parker. 2001. A Field Test of Herbaceous Plant Indicators of Deer Browsing Intensity in Mesic Hardwood Forests of Indiana USA. Natural Areas Journal 21(2):149158. Webster, C.R., and G.R. Parker. 1997. The Effects of White-tailed Deer on Plant Communities within Indiana State Parks. Proceedings of the Indiana Academy of Science 106:213-231.
This resource management and research report is issued to provide a quick source of information on issues related to wildlife or natural areas management in Indiana State Parks & Reservoirs. Any information provided is subject to further analysis, and therefore is not for publication without permission.
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