Deer Overabundance is Impacting Biodiversity in Parks Located in Fairfax County, Virginia. Sean Campbell, Tammy Henry, Megan Scott, Craig Shafer, and Jessica Trice

Overabundance of Deer Animals are Overabundant* when: a)threaten human life or livelihood b)are too numerous for their “own good” c)depress the densities of economically or aesthically important species d)cause ecosystem dysfunction 100 Years of Deer in United States Deer are Reproductive Machines *Caughley (1981)

Impacts of an Overabundance of Deer Automobile Damage >1100 deer collected ~ 20% deer collisions Average collision cost = $ th highest rate of deer collision in the country Change to Forest Structure - Regeneration Patterns Disease: Human & Animal Lyme Disease & Others Hemorrhagic Disease & Chronic Wasting Disease Ornamental Plant Damage Biodiversity: – Animals – Plants

Causal Links:  People  Predators  Hunting  Development  Fragmentation PlantsAnimals Biodiversity Deer Overabundance  Auto Collision  Disease

Carrying Capacity Theory (Caughley) Ecological Carrying Capacity (K) Maximum Sustainable Yield (MSY)  Economic Carrying Capacity (I) Sociological Carrying Capacity (Cultural) Deer Carrying Capacity & Vegetation Factors: 1.Plant biomass  Environment 2.Rate of Plant Intake/Animal  Density of Plants 3.Rate of Population ∆ of deer  Density of Plants

Impacts on Biodiversity - Browse-line shows degree of deer impact - Changes forest structure (impacts on birds and invertebrates) - Reduced habitat for ground-nesting animals, decreased food sources, affects on plant reproduction - Reduced tree regeneration & decreased diversity in regrowth - Increased ability for invasive/exotic species to establish

Criteria 1.Socially and Ethically Acceptable 2.Economically Feasible 3.Sustainable 4.Efficient 5.Quantifiable/Accountable Results 6.Ecologically Sound 7.Proven Methodology

Potential Solutions: Ignore the problem Reduce human population - relocation or birth control Unpalatable plants - naturally or chemically treated Visible or audible deterrents Prevent future land use changes (ie. development) Corridors/underpasses for deer Reintroduce predators (wolf, black bear, puma & bobcat) Immunocontraception Fence deer in/out - physical or shock/alarm collars Relocate deer Change Fairfax County hunting regulations Managed reduction - snipers or recreational hunting

Evaluating the criteria… Managed reduction - snipers or recreational hunting Meets all 7 criteria: socially acceptable, economic, sustainable, efficient, accountable, ecologically sound, & proven Plan : multifaceted hunting approach Police Force Consulting Firm Recreational Hunters Reducing the deer population will lead to an increase in biodiversity - both in plants & animals.

Positive Results of an Appropriately Managed Deer Population Larger healthier deerLarger healthier deer Improving habitatImproving habitat Conserving biodiversityConserving biodiversity Increased Environmental/Educational OpportunitiesIncreased Environmental/Educational Opportunities Economic benefitsEconomic benefits Provides food/sustenanceProvides food/sustenance Decreased human/wildlife conflictDecreased human/wildlife conflict Cultural Traditions/Recreational OpportunitiesCultural Traditions/Recreational Opportunities Funds raised to contribute to other wildlife management effortsFunds raised to contribute to other wildlife management efforts

Fairfax County Parks: Huntley Meadows Pohick Bay

NEXT: Application of Deer Management Strategy in Fairfax County, VA Fairfax County Deer Management Plan Comparison of Huntley Meadows & Pohick Bay Recommendation to Hemlock Overlook Huntley Meadows - sharpshooting, managed hunts (shotgun & archery) Pohick Bay - no planned reductions

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