Deer Hunting and Forest Health

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The Hudson Valley is a treasured landscape that has undergone tremendous change over the past century. This forum explores how science-based stewardship on private land can help protect and promote healthy forests and open spaces, now and for future generations.

Presentations explore threats our forests and natural areas face – from invasive species and climate change to deer overabundance – and actions that can be taken on a site-by-site basis to optimize conditions. A special focus will be given to the overlap between sport hunting and conservation communities, with a roundtable discussion on advancing common ground. Hosted April 12, 2014 at Cary Institute of Ecosystem Studies

Presentation Part IV by: Raymond Winchcombe, Wildlife Ecologist, Cary Institute of Ecosystem Studies

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Deer Hunting and Forest Health

  1. 1. Impacts to Forests by Deer and the Use of Annual Controlled Hunts to Mitigate those Impacts www.pa.audubon.org/search/node/PA Deer Ecosystem Forum Report
  2. 2. Take Home Message • Deer overabundance leads to serious negative impacts on forested ecosystems. • These impacts affect the abundance, distribution and diversity of plant & animal species. • Over-browsing by deer threatens the survival & perpetuation of our oak dominated forests. • Loss of oaks & the mast they produce would be devastating for a host of animal species & an economic loss of timber resources. • A hunting program focused on consistent female removal can address the impacts of over-browsing by deer.
  3. 3. Valley Forge, PA - 2006
  4. 4. Robust Forest Under story
  5. 5. Discussion Outline • Life History of White-tailed Deer •Impacts to Forest Ecosystems by Deer •Cary Institute’s Deer Management Program •Role of Hunters & Landowners in Managing Deer
  6. 6. Deer Facts You Should Know
  7. 7. • Most abundant large herbivore in the United States • Can live a long time; 10+ years in the wild • Exhibit a polygamous breeding system • Potential for rapid population growth in the absence of predators • Humans are the most significant contemporary predator in most areas
  8. 8. • Adult females usually have twins, triplets possible • Yearlings usually have singles, twins possible • Well nourished fawns can breed & produce a fawn their first year • Single male will breed with several females Reproduction
  9. 9. Population growth experiment results:* 1928-34 6 deer grew to 222 in seven years 1975-80 10 deer grew to 212 in six years * - George Reserve in southern Michigan inside a 1,146 acre fenced site controlling for all sources of mortality.
  10. 10. Polygamous breeding system requires control efforts be focused on females if population control is desired. Contrary to early deer management efforts where females were protected & herds allowed to expand. Early Goals: restock ranges where deer were extirpated due to market & subsistence hunting & habitat destruction.
  11. 11. Deer Impacts to Forested Ecosystems
  12. 12. Ecological Impacts of Too Many Deer • Over browsed habitats • Reduced species diversity (Flora) • Reduced species diversity (Fauna) • Loss of forest structural diversity • Loss of forested systems functionality • Overall decline in deer health/disease transmission
  13. 13. Valley Forge, PA - 2006Valley Forge, PA - 2006
  14. 14. Deer are Selective Browsers • Select foods that are nutritious and highly palatable • Selections based on food availability (feeding progresses from most desirable to least desirable species) • Food abundance & species diversity are dependent on contemporary deer #’s & historical deer densities 0 500 1000 1500 2000 2500 3000 3500 #Budsavailable Mean Available Buds/Species - 1998-2013 0 2 4 6 8 10 12 14 16 %BudsBrowsed Mean % Browsing on Index Species Cary Institute - 1998-2013
  15. 15. Overbrowsing: Direct Effects • Reduced species richness & abundance • Altered species composition (loss of desired species) • Reduced advanced regeneration of desirable species (important timber & mast producing species)
  16. 16. Hunting focused on recreation Regeneration progressing nicely Regeneration stalled Hunting focused on habitat protection Not all hunting is equally effective
  17. 17. Overbrowsing: Indirect Effects • Proliferation of undesirable & browse resistant species (Hay scented & NY fern, beech, striped maple) • Can lead to a shift in balance between native & introduced species (introduced species less palatable) • Can change the direction of forest development (competitive exclusion of desirable by undesirable species) • Reduced abundance of forest dwelling animals (direct competition for food [acorns], altered habitats)
  18. 18. Gun Club Fern Understory
  19. 19. Impacts of Structural Component Loss Loss of shrub & mid-canopy layers & spatial distribution of these layers: • Songbirds: reduced species richness & abundance (loss of feeding, nesting & escape cover). • Reduced abundance & higher predation on small mammal community; eventual decline in predators. • Insect diversity is dependent on vegetation diversity (feeding, egg deposition, larval development).
  20. 20. Valley Forge, PA - 2006Valley Forge, PA - 2006
  21. 21. Structural/Habitat Loss • Microclimate shift: increased light, wind, temperature and lower humidity at the forest floor (impacts germination & survival of some tree species, snails, salamanders, frogs etc.) • Higher survival of less desirable shade intolerant species due to increased ambient light conditions (Hay Scented Fern). • Degraded or loss of habitat for deer (loss of wintering areas, escape cover, food resources).
  22. 22. Deer Population Management at the Cary Institute of Ecosystem Studies
  23. 23. Deer Population Management Options 1. Allow nature to take its course 2. Trap & transfer excess deer 3. Use fertility control agents to regulate herd size 4. Reintroduce predators to control deer numbers 5. Control deer numbers with sharpshooters 6. Use regulated hunting
  24. 24. Program Goals Protect the structure & function of forested ecosystems. Minimize conflicts with planned uses of the property. Cary Deer Management Program
  25. 25. Program Elements • Vegetation monitoring - via surveys • Population index - hunter observations • Population control - annual hunts Cary Deer Management Program
  26. 26. Vegetation Monitoring • 45 Deer browse survey areas (spring) • 4 deer exclosures with paired unfenced plots Cary Deer Management Program
  27. 27. 0 2 4 6 8 10 12 14 16 18 97 98 99 00 01 02 03 04 05 06 07 08 09 10 11 12 13 AVG %Browsed Year Percent Buds Browsed for All Species Cary Institute 1997 - 2013 Mean Cary Browse Survey Results – 1997 - 2013
  28. 28. 0 2 4 6 8 10 12 14 16 %BudsBrowsed Mean % Browsing on Index Species Cary Institute - 1998-2013 Cary Browse Survey Results 1998 - 2013
  29. 29. IES Site 1 0 10 20 30 40 50 60 70 80 50-99 100-149 150-199 200+ Height Class (cm) #ofSaplings Fenced Unfenced IES Site 2 0 20 40 60 80 100 120 140 50-99 100-149 150-199 200+ Height Class (cm) #ofSaplings Fenced Unfenced IES Site 3 0 5 10 15 20 25 30 50-99 100-149 150-199 200+ Height Class (cm) #ofSaplings Fenced Unfenced IES Site 4 0 20 40 60 80 100 120 50-99 100-149 150-199 200+ Height Class (cm) #ofSaplings Fenced Unfenced Cary Institute’s Deer Exclosure Sites
  30. 30. Gun Club Site 1 0 20 40 60 80 100 120 140 160 50-99 100-149 150-199 200+ Height Class (cm) #ofSaplings Fenced Unfenced Gun Club Site 2 0 10 20 30 40 50 60 70 80 50-99 100-149 150-199 200+ Height Class (cm) #ofSaplings Fenced Unfenced Gun Club Site 3 0 10 20 30 40 50 60 50-99 100-149 150-199 200+ Height Class (cm) #ofSaplings Fenced Unfenced Gun Club Site 4 0 20 40 60 80 100 120 50-99 100-149 150-199 200+ Height Class (cm) #ofSaplings Fenced Unfenced Gun Club Location
  31. 31. Hunter Observation Method
  32. 32. Bowhunter Data Collection Bucks Does Fawns Unknowns Days Hunted Hrs. Hunted Area Hunted
  33. 33. Summary Deer Observation Data
  34. 34. Population Control
  35. 35. Population Control - Annual Reductions Specific Goals • Stabilize or reduce local deer numbers • Achieve younger female age distribution • Efficient and safe control effort Cary Deer Management Program
  36. 36. Population Control via Controlled Access Hunt • Participation by invitation • Firearms proficiency requirement • Orientation meeting requirement • Antlerless permit requirement • Effort requirement Cary Deer Management Program
  37. 37. Shooting Proficiency Test 3 shots on a 12” X 12” target Maximum of 5 shots allowed
  38. 38. Cary Deer Management Program Population Control - Hunt Specifics Daily sign in/out at check station Required deer check Blaze orange requirement Designated parking areas Avoid research & restricted areas
  39. 39. Cary Institute Hunter Check Station
  40. 40. 0 5 10 15 20 25 30 35 40 45 50 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 #ofhunters&trips Hunt Sectors Avg. # Different Hunters and Avg. # of Trips by Sector - 2005-12 Mean # different hunters Mean # trips
  41. 41. 0 5 10 15 20 25 30 35 40 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 Total#Deer Hunt Sector # Deer Harvest by Hunt Sector 2005-13 2005 2006 2007 2008 2009 2010 2011 2012 2013
  42. 42. Cary Deer Management Program Population Control - Hunt Specifics Daily sign in/out at check station Required deer check Blaze orange requirement Designated parking areas Avoid research & restricted areas
  43. 43. Cary Institute Deer Check Facility
  44. 44. Tick Collections from Harvested Deer
  45. 45. Hunter Evaluation • Compliance with rules and policies • Hunter effort • Hunter success (adult females) • Cooperation and attitude Cary Deer Management Program
  46. 46. Population Control – Summary Averages – 1976-2013 (#)= range • 53 hunters (30-89) • 2,124 hrs. of effort (1128-2799) • 55 deer removed per year (22-89) • Hunter success rate - 66% (range 38 – 82%) Cary Deer Management Program
  47. 47. Males 51% Females 49% Proportion of Deer in the 1976-2013 Deer Harvests at the Cary Institute
  48. 48. Landowner’s Role in Deer Population Management
  49. 49. Landowner’s Role in Deer Management 1. Control access to the resource 2. Should take a pro-active stance in deer mgmt. 3. Can customize programs/access as needed 4. Require doe harvest for access privileges 5. Require sincere hunter effort for access privileges 6. Don’t tolerate irresponsible behavior
  50. 50. The Role of Hunters in Deer Population Management
  51. 51. Role of Hunters in Deer Management The primary role of hunters in deer population management is the removal of deer. Hunters are the tool deer managers use to control deer numbers. To maximize their effectiveness, hunters must focus their efforts on adult females. Hunters provide important ecosystem level services to the community when adequate female harvests are achieved.
  52. 52. Hunter Responsibilities 1. Safety, safety, safety 2. Respect- for property & all persons 3. Exhibit the highest of ethical standards 4. Zero tolerance for unsafe & unethical behavior 5. Never forget, access is a privilege 6. Embrace their role as deer managers when making decisions regarding which deer to harvest.
  53. 53. Challenges for Deer Managers
  54. 54. Challenges for Deer Managers 1. Adequate access at the landscape scale? 2. Sufficient numbers of antlerless permits? 3. Sufficient hunter effort ( #’s of hunters) 4. Focused hunter harvest (adult females) 5. Providing a quality hunting experience ?
  55. 55. Is There a Recreational Threshold? Is there a deer density at which many hunters do not see enough deer to justify continuing to hunt? (Moyer and Shissler). Basis for a Recreational Threshold – expectations based on past experience Problem: Oscillations in deer #’s based on hunter interest would not be good when the management objective is forest ecosystem /habitat protection . Challenges for Deer Managers
  56. 56. Result When the Need to See more Deer Trumps Habitat Protection
  57. 57. Questions ?
  58. 58. Primary Question Are these oak dominated forests positioned to perpetuate themselves under these different deer management scenarios?
  59. 59. 1976 – 2013 Summary Stats, Firearms 284 Different Hunters Participated 15,746 Hunter Visits 67,030 Hours of Hunting Effort 2,078 Deer Harvested (171 additional deer with archery) 2,249 Total Hunter Harvest (mean 58/yr.)
  60. 60. Linking hunters and landowners P.G.C. must attempt to match the general population, who are the owners of public and private land, with those who hunt in a way that is beneficial to both and mutually agreeable. This is likely to depend on the willingness of P.G.C. to: • enforce trespass laws on private land • surrender the traditional value of equitable distribution (the concept that all hunters should harvest an equal number of animals) • adopt more liberal season and bag limits that would allow hunters to be effective in resolving landowners’ problems with deer overbrowsing Cited from the PA Audubon Deer Ecosystem Forum Report
  61. 61. IES Deer Exclosure Study Ray Winchcombe & Charles Canham • Central Dutchess County • 3 Locations • 4 sites/location • 2 plots/site (fenced & unfenced 10x10 M plots) • 1992 - present
  62. 62. Deer Management Scenario's • Unhunted property – 1,000 acres; primarily forested habitat (borders 900 acres of hunted forest lands). • Gun club property – 1,500 acres; mix of forest, cultivated field & old field habitat. Several decades of deer hunting; inconsistent doe harvest policy. Focus is on recreation and hunter satisfaction • Cary Institute – 2,000 acres; mix of forest, old field & open field habitats. Over three decades of deer population management via controlled access hunting; consistent doe harvests. Focus is on protecting the structure & function of the forested ecosystem.
  63. 63. High tensile, woven wire mesh fence 6.5’ tall (10x10 m)
  64. 64. Unhunted Site 1 0 5 10 15 20 25 30 50-99 100-149 150-199 200+ Height Class (cm) #ofSaplings Fenced Unfenced Unhunted Site 2 0 20 40 60 80 100 120 50-99 100-149 150-199 200+ Height Class (cm) #ofSaplings Fenced Unfenced Unhunted Site 3 0 20 40 60 80 100 50-99 100-149 150-199 200+ Height Class (cm) #ofSaplings Fenced Unfenced Unhunted Site 4 0 5 10 15 20 25 30 35 50-99 100-149 150-199 200+ Height Class (cm) #ofSaplings Fenced Unfenced Unhunted Location
  65. 65. Response to Primary Question Unhunted site: data suggests this oak forest will not be able to perpetuate itself. Complete lack of any advanced regeneration.
  66. 66. Response to Primary Question Cary Inst.: data suggests this oak forest will perpetuate itself. Presence of seedlings in the various height classes bodes well for this forest. Focused deer management must continue.
  67. 67. Consequences of Deer Over Abundance • Severe overbrowsing of forested habitats •Altered plant species composition, distribution & abundance • Reduction of understory structural diversity • Reduced habitat quality (deer & other fauna)
  68. 68. When overly abundant, deer can have serious negative effects on forest communities • Mechanism – consumption of vegetation • These effects can be either direct (species loss) or indirect (shifts in species composition). • Overbrowsing alters the physical structure of forests thus having a negative impact on a host of other animal species (vertebrate & invertebrate). • High deer densities & overbrowsing combine to threaten the future existence of our forests as we know them today.
  69. 69. Consequences of Deer Overabundance • Long-term reduction in BCC (deteriorated winter habitat) • Decline in herd health (disease transmission, losses) • Conflicts with CCC (acceptable limits that people will endure) • Increased frequency of deer/vehicle encounters • Excessive damage to agricultural, nursery & landscape plantings & timber production.
  70. 70. IES Archery Hunting Areas Map
  71. 71. Day of the Month - Nov./Dec. 18 19 20 21 22 23 24 25 26 27 28 29 30 1 2 3 4 5 6 7 8 9 10 Day of Season M T W TH F Sa Su M T W Th F Sa Su M T W Th F Sa Su M T Name 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 T. Hrs. T. Days # 5+ Hrs. Succ. Deer Harv.** Acuti 8 7 7 7 2.5 6 37.5 6 5 Y D Alexander 9 7 6.5 5 2 8 3.5 5.5 3 4 3 2 3.5 3.5 3 5 2.5 3.5 5 2 2.5 89 21 8 Y B Beasley 1.5 1.5 6 1.5 6 7 2 3.5 1.7 2.5 3.5 4.5 2.5 4 47.7 14 3 Y B*,D*,D Beck 3 5 5.5 3 4 3 23.5 6 2 N Cahill 6 6 5 6 23 4 4 Y B Clarke S. 5.5 3.5 3.5 4.5 4 3 3 27 7 1 N Clarke B. 9 5.5 3.5 3.5 4.5 4 3 33 7 2 Y B Corona 9 7.5 7 7.5 2.5 8 2 5.5 49 8 6 Y B,F Crandall 5 8 6.5 7.5 27 4 4 Y D Crooker J. 9 4 8.5 4 8.5 8.5 6.5 8.5 8 3 5 73.5 11 8 Y B Crooker Jy. 9 4 8.5 4 9.5 8.5 8 8.5 8 68 9 7 Y D,F DeBonis 3.5 3.5 2.5 9.5 3 0 N Diggelmann 3.5 3.5 7 2 0 N Dodaro S. 5 4.5 5.5 6 2.5 6 2.5 2 4 5 2.5 5 1.5 52 13 6 Y B,D,D Record of Hunter Effort & Success

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