Assessing White-tailed Deer Impacts at the Town Level

David Stainbrook Deer and Moose Biologist Karro Frost Conservation Planning Botanist Assessing White-tailed Deer Impacts at the Town Level

Blue Hills Deer Management Mission Statement The Massachusetts Division of Fisheries and Wildlife (MassWildlife) is responsible for the conservation - including restoration, protection, and management - of the state s natural heritage of wildlife and habitat diversity for the benefit and enjoyment of the public now and into the future.

Workshop Overview Brief summary of deer management in MA Methods to evaluate deer levels at a town-scale Assessing habitat impacts by deer Snapshot Browse Survey Next steps for town managers

Herbivores Spring/Summer White-tailed Deer Buds, leaves, forbs, etc. Fall/Winter Hard/soft mast Woody vegetation

White-tailed Deer Home range is 1 to 3 square miles Breeding season (rut) peaks in mid-november Females give birth to 1-3 fawns per year (late May to early July) Research studies in PA and CT estimate 40-60% survival on fawns

How Do We Manage Deer Numbers Licensed Hunters Regulated Hunting Seasons (2 antlered deer + purchased antlerless permits) Youth (Sept. 30, 2017) Archery (Oct 16 - Nov 25, 2017) Shotgun (Nov 27 - Dec 9, 2017) Primitive (Dec 11 - Dec 30, 2017) MassWildlife Allocates Antlerless Deer Permits Regulate Female Harvest by Zone Track Harvest (Mandatory Reporting) Collect Biological Data Monitor population health, population model

We use a statewide management range of 6-18 deer/mi 2 of forest as a benchmark to meet our goal of keeping deer numbers below the point of major impacts to forest, but in balance with public desire and tolerance for deer.

Why doesn t nature keep deer in balance? Humans removed the major predators that could keep their numbers in balance with habitat (except humans, which were historically a major year-round predator) Even with current predators and vehicle collisions, it is not enough to keep deer numbers from increasing unless additional deer are taken (hunting) We see signs of rising deer numbers in communities with little to no hunting access

Suburban Deer Issues Suburban landscape is great for deer Plenty of food and protection from hunting Allows uncontrolled growth of population Hunting Access is Limited in Suburban Areas Discharge Setbacks (MGL Ch. 131 58) No discharge of firearm or release of arrow within 150 of roads No possession of a loaded firearm or hunting within 500 of an occupied dwelling, unless authorized by owner or occupant Town Ordinances and Bylaws Further discharge restrictions, written permission, etc.

Town by-law: Ashland No discharge of firearms within town limits AND written permission is required to discharge a bow

Towns with more forest in setback tend to have high deer numbers

41 prohibit discharge of firearms 85 require written landowner permission 35 have special restrictions Town By-Laws Restrict Hunting

Evaluating Levels of Deer at a Town Scale

Common Question: How Many Deer? How many deer are in my town? Impossible to count the deer (no such thing as a census) Can conduct surveys to estimate deer numbers, but can be timeintensive, expensive, and typically have wide confidence intervals MassWildlife manages deer at a larger scale than a town 15 zones: large enough to have adequate sample sizes of data, but small enough to pick up variation across the state Estimates of density come from harvest data so can only inform us about density on hunted lands, not areas with little to no hunting Better question: Are deer levels in your town high enough to be causing major impacts to the forest?

Deer and Landscape Ecology When Deer are Over-populated Impact the ecosystem over ~20 deer/sq. mile Reduced plant diversity Increase in most invasive plants Decreased forest regeneration Reduced understory Reduced biodiversity Plants, forest birds, insects, etc.

Evaluating Forest Impacts by Deer Assessing the degree of forest impacts can give you a sense of how high deer numbers are on a specific property (can be much easier than a deer survey) Various Methods of Evaluating Forest Impacts by Deer Very complex surveys (need to be a botanist or forester) Exclosures (can be for monitoring or as a visual for public) Monitor a few specific plant species over time on a plot Great for looking at trends over time (Rawinski s ten-tallest method) Snapshot Survey to identify level of browse on indicator species across a property Easy to conduct and provides a level of current browse impacts

How does this relate to Conservation Commissioners? Loss of potential habitat (cover/food) for other species Impacts to Commission owned property Alteration of Vegetation in Wetland Areas Impacts to rare plants

Rare Plants Of 256 MESA Listed Rare Plants: 3/5 (156) are found in areas regulated under the Wetlands Protection Act Plants in Land Under Water and Open Water not threatened by deer, but Bank pond, stream and river shores Bordering Vegetated Wetlands Land Subject to Flooding And, given the variability of Riverfront Area, many of the other rare plants occur there.

Forested Wetlands Rare Plants Rubs and browse on sprouts Sweet Bay Magnolia, Magnolia virginiana (Endangered)

Forested Wetlands Rare Plants Great Laurel, Rhododendron maximum (Threatened)

Calcareous Wetland Rare Flora Showy Lady-slipper, Cypripedium reginae (Endangered) Great Blue Lobelia, Lobelia siphilitica (E) Andrew s Bottle-gentian, Gentiana andrewsii (E)

Rare Oaks Bur Oak, Quercus macrocarpa (Special Concern) Yellow Oak, Q. Muehlenbergii (Threatened) Note chewed seedling

Assessing Habitat Impacts by Deer

Forest with little to no impact by deer Diversity of shrub and tree species Young trees to replace old trees Herbaceous layer is diverse and intact

Forest negatively impacted by deer Lack of diversity of plant and tree species in understory (mostly plants that deer don t eat are present)

Things to Know Before You Survey What does deer browse look like? Rabbit, Groundhog, etc. 45 degree sharp cut Deer Browse Ragged edge; lack upper incisors

What Do Deer Browse On? Evidence of browsing on preferred plants doesn t tell us much about deer numbers White Oak: Preferred Red Maple: Preferred

What Do Deer Browse On? Herbaceous plants can be added to the survey if done in the spring and summer. Spotted touch-me-not (Jewelweed): Preferred False Nettle: Preferred

What Do Deer Browse On? Selective browsing or evidence of browsing on moderately preferred plants can provide some clues to how high deer numbers may be in that area. As deer numbers rise, more palatable or preferred plants become less available, so deer move on to less preferred plants American Chestnut: Moderate Preference Oriental Bittersweet: Moderate Preference

What Do Deer Browse On? American beech is one of the easiest indicator plants to identify. It is also very browse tolerant, so becomes hedged rather than dying. American Beech: Moderate Preference (great indicator plant)

What Do Deer Browse On? White pine is another easy to identify indicator, which is only typically browsed on in heavily deer impacted areas White Pine: Low Preference (great indicator plant)

Things to Know Before You Survey What plants do deer select for and avoid? These surveys are meant to be quick, easy, and can be done while out in the forest doing other tasks. The surveyor can be a novice and only be able to identify a few indicator plants and it can still be valuable.

Things to Know Before You Survey What plants do deer select for and avoid? Easier to look at plants they don t typically eat and see if they are browsed indicator species

Things to Know Before You Survey What plants do deer select for and avoid?

Score the level of browsing for saplings less than 6ft tall

Performing a Browse Survey Walk through a representative area of the forest while filling out a survey form May-July is the easiest time of year for surveys Walk off-trail through various cover types Avoid areas near trails/roads (unrepresentative) Survey near houses and far from houses Forest, shrub, wetland, etc. Strive to cover at least 10-20% of the property Note browsed plant species and plants expected but not present Take pictures with scale and GPS location Carry GPS to record track where you surveyed or mark it on a map

At the end of the survey, check impact level

Run Through an Example Survey Ashland Town Forest and Cowassock Woods

American Beech (a low/moderate preference food for deer) was heavily browsed, over years, resulting in a hedged appearance. A White Pine (very low preference food for deer) showing years of browsing

Overall there was a clear visual browse line in forest in most areas. Little to no herbaceous layer (e.g., Wild Sarsaparilla) present and ferns are beginning to dominate areas. On the left, you can see one Ash tree that was browsed, but did make it over 4 ft tall.

White Pine (low preference food for deer) showing the lollipop appearance where lower branches were browsed by deer. Keep in mind, lower branches of hemlock and pine can lack foliage related to shading, so look for signs of physical browsing and other examples to make sure it all adds up.

Additional Area to survey later Surveyed Additional Area to survey later Surveyed The goal is to get a representative sample of forest impacts in the area, but it is ok if time constraints limit you to only a few locations, just denote it on the map and survey form.

Complexities of Forests Forest soils and moisture can affect what is growing Ferns can take over (often exacerbated by over-browsing), choke out regeneration, and even reduce the ph of the soil, which can inhibit germination of other plants such as oak. Also some research on acid rain, effects of earthworms, etc. but those impacts should be large scale. A dense, closed canopy forest Limited sunlight to forest floor limits regeneration, so look for any openings from fallen trees where the sunlight hits the forest floor Here is a good test for the germination question: If you see plenty of mature oaks, but few to no young oak saplings. Look closer to the forest floor for oak seedlings in the spring/summer. Often, you will find seedlings germinating, but deer eventually find them before they can survive to become a 2 or 3 year old sapling. There will always be variability, just make sure to document it all and make sure everything adds up.

Vegetation Surveys MassWildlife staff surveyed over 100 properties during the spring/summer of 2016 Additional surveys by town officials, land trusts, and volunteers can add to this data set statewide and we can share it all on our website.

Next Steps for Town Managers

Next Steps: What Can be Done? Be Proactive Do not wait until there is a deer overabundance problem (reach a tipping point) to begin the conversation Establish goals that can be monitored over time Evaluate forest health, record reports of deer damage, ask town police to record all deer-vehicle accidents, etc. Public Education and Communication Public meetings, signage at properties, etc. Work at a regional scale Coordinate with nearby towns and multiple landowners

Are there any non-lethal options? Contraception Surgical Sterilization Near 100% effective at preventing pregnancy Chemical contraception Near 80% effective at preventing pregnancy with boosters Research conclusions Can be effective at preventing pregnancy May not be feasible (difficult and expensive to treat all females) Does not reduce deer numbers because deer have to die Adult females can live over 10-20 yrs Research in MA found adult female survival rates above 90% Not shown to significantly reduce high deer numbers Can potentially stabilize deer numbers if you can keep out new deer

Next Steps: Hunt Models Statewide Model Open access to all licensed hunters during the regulated hunting seasons (simply open the property) Controlled Hunt Any restriction to the statewide model Limited number of permitted hunters Limited days (4-day hunt) Limited methods (archery only) Plenty of models out there: https://deeradvisor.dnr.cornell.edu/ The more restrictions, the more oversight is needed, and the less of an impact it will have at reducing deer numbers

Next Steps: Hunting Access Some major roadblocks to deer management ability can be removed by the town and public Property Access: Work to open state and town lands to hunting and encourage private landowners to allow hunting Landowner liability law: MGL Ch. 21 17c: Protects landowners who allow access without charging a fee Homeowners can allow hunters within 500 feet of their home Work to remove restrictive by-laws Towns can change by-laws to remove discharge restrictions for firearm use while hunting and remove written permission requirements

70 Projected Deer Density Over Time 60 Density (deer / mi 2 forest) 50 40 30 20 Limited Access and Archery Only 10 Statewide Management Range (6-18 deer per SQMI Forest) Maintenance 0 2015 1 2016 2 2017 3 2018 4 2019 5 2020 6 2021 7 2022 8 2023 9 Year

½ mi. If red highlighted areas were open to hunting, it could reduce deer numbers within ¼ mile to perhaps ½ mile

½ mi. If more areas were open to hunting, it would have a much greater impact across the town Still have deer issues in areas far from hunted areas

Contact Info: David Stainbrook : Deer Biologist david.stainbrook@state.ma.us Thank You Karro Frost: Botanist karro.frost@state.ma.us