Deer and Forests, and the People Who Love Them It is common knowledge that if we allow deer to become too abundant, their health will be threatened (malnutrition, winter die-off, disease). But if our goal is to conserve biodiversity, particularly our rare plants, allowing deer to become overabundant presents concerns that extend far beyond the health of just the deer... by Thomas J. Rawinski Finding a shed deer antler is a rare delight. I have found them in Winchen­ don,West Tisbury,Uxbridge, Sturbridge, Holden, Dudley, and almost Bedford (my companion spotted one there a split-sec­ ond before I did). I don’t go out of my way to look for them – they just appear while I scan the understory looking at the plant life. On average, I find one every other year in Massachusetts, which equates to about 100 days afield walking an average of 3 miles a day, or one shed found for every 300 miles walked. I have had bet­ ter success finding them in Connecticut, New York, and Virginia.

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Ph A serious shed hunter would visit suburban conservation lands in eastern Massachusetts (excluding Cape Cod), where deer densities are well above the management goals set by the Massa­ chusetts Division of Fisheries & Wildlife (DFW).Sheffield,Hampden,andQuabbin Park in Ware would also provide good shed hunting opportunities: It’s easier to spot a shed when the undergrowth has been heavily browsed... The beautiful Yellow Lady’s Slipper (Cypripedium parviflorum) is one of many plant species that may be

Photo © Chris Buelow threatened by overabundant deer. 16 My work has taken me to the most glori­ wisdomofLeopold. Dr. Greeleyhad been Deer and Forests, ousenvironsoftheeasternUnitedStates. a student of Leopold’s in the 1940s and I can remember what forestsused to look I once asked him the brilliant question: like before deer arrived en masse, and “What was Aldo like?” and the I have taken a special interest in docu­ Fred paused, sat back in his chair with mentingdeerimpactsonvegetation. Iam his lit pipe, took a puff, and said, “He was certainly not alone – the subject is under a very nice man.” And in his next breath People Who Love Them intense scientific scrutiny all across the he said, “It was so sad to witness the vi­ nation. My purpose in writing this ar­ cious attacks he endured as a result of ticle is to share some observations and his views on deer management.” concerns on the subject of White-tailed At Leopold’s urging and in response to Deer overabundance in the context of widespread starvation mortality in the the forest resource. wintering areas, the state of Wisconsin liberalized the harvest of deer in 1943, Whyaredeerpopulationsrising?There opening an antlerless season. A record aremyriadreasons.Whitetailsareaston­ harvest was followed by public outcry. ishingly adaptable,as evidenced bytheir Shooting so many does was abhorrent ability to inhabit much of the Western to many people, but Leopold continued Hemisphere, and to thrive even in well- to assert the necessity of such. To make urbanized towns such as Needham or mattersworse,guessinwhatyearDisney Dedham. Whitetails are prolific. Seven released the movie, Bambi? It was 1943, deer introduced to Block Island, Rhode and it created the perfect storm of con­ Island, in 1967 grew to a herd of 700 ani­ troversy to destroy Leopold’s hope for malsby1994.Whitetailshaveremarkably ecologically-sound deer management in acute senses and keensurvival instincts, the state. In the aftermath of his defeat, evolved over millions of years, to detect Leopold articulated a compelling philo­ and evade predators (which makes hunt­ sophical vision of conservation: ing them the ultimate challenge). And finally, consider the impact of Conservation is a state of health in the humans in radically altering habitats land.Thelandconsistsofsoil,water,plants, and predator-prey relationships. In the and animals, but health is more than a report, Managing White-tailed Deer in sufficiency of these components. It is a Forest Habitat Froman Ecosystem Perspec­ state of vigorous self-renewal in each of tive: Pennsylvania Case Study (available them, and in all collectively. Such collective fromthe AudubonPennsylvaniawebsite, functioning of interdependent parts for the http://pa.audubon.org/deer_report.htm), maintenance of the whole is characteristic theauthors state: “Thereisawidespread of an organism. In this sense, land is an impulse to blame recent policies and organism, and conservation deals with its management actions, or inaction, for the functional integrity, or health. current deer situation, but the ultimate Had Leopold prevailed, I wonder if causes run much deeper and have been we’d be in the pickle we find ourselves around for a very long time. Profound in today. changes to the landscape and to inter­ actions among wildlife species brought Last summer I helped DFW biologist about by humans are responsible for the Chris Buelow locate Lion’s Foot (Nabalus current high densities of white-tailed serpentarius), a state endangered plant, deer and their pervasive effects on the at the PalmerWildlife Management Area. rest of the ecosystem.” Our concern was that the population For a historical perspective, we can there was being browsed by deer, and, look to the writings of Aldo Leopold, who as a result, was not reproducing. We had deep concerns about the ecological found one remaining patch of the rare devastation being wrought by too many plants, and, as we suspected, the stems deer, as well as concern for the health of had all been chomped. Using dead cedar the deer themselves. As an undergradu­ trees, we constructed a make-shift bar­ ate in the University of Massachusetts’ rier around the plants, which was later Wildlife Biology Program, I was advised replaced by fencing. By autumn, the by the late Dr. Frederick Greeley, who in plants had successfully flowered and his own gentlemanly way, imparted the all was well. 17 Photo © Bruce Sorrie 18 The Small Whorled Pogonia (Isotria medeoloides) shown right, is a state- endangered and federally-threatened species that is eaten by deer. Thanks to its upland habitat preferences, its small populations are typically easy to protect with fencing. The same is not true of the rare Showy Lady’s Slipper (Cypripedium reginae), left, judged by many to be the most beautiful orchid in New England, because it typically inhabits mucky tamarack swamps where effective perimeter fencing is difficult or impossible toinstall.

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impactscanbeexpectedonrich-soilsites Ph wheredeercongregatetofeed.Whenrare grasp. The decline of this iconic wild­ species such as Lion’s Foot, American flower is a sad consequence of the bur­ Ginseng (Panax quinquefolius), Sweetbay geoningdeerpopulationinthedeveloped Magnolia (Magnolia virginiana), or Small landscapes of eastern Massachusetts. If Whorled Pogonia (Isotria medeoloides) you live inside of Interstate 495 and are arethreatened,fencingcanbearelatively fortunate enough to have lady’s slippers simple remedy. on your property, you might think about But fencing isn’t as viable an option in purchasing some fencing before the deer themuckytamarackswampsofBerkshire eat every last one of them. County where Showy Lady’s Slipper The extent to which deer are negatively (Cypripedium reginae), the resplendent impacting biodiversity in Massachusetts queen, presides. Her populations have has not yet been rigorously documented, dwindled in recent years, and botanists but observational evidence is mounting. are in agreement that deer herbivory is Inadditiontotheimpactstotheaforemen­ themainreason.TheNaturalHeritageand tioned species, I am very worried about Endangered Species Program recently New England Blazing Star (Liatris scari­ proposedelevatingtherankofthespecies osa var. novae-angliae), Northern Wild from Special Concern to Endangered to Comfrey (Cynoglossum virginianum var. reflect the heightened threat from deer. boreale), Yellow Lady’s Slipper (Cypripe­ Many of us have fond childhood memo­ diumparviflorum ), TrumpetHoneysuckle ries of Pink Lady’s Slipper (Cypripedium (Lonicera sempervirens), American Bit­ acaule). Itwas the universally adhered-to tersweet (Celastrus scandens), and Great ethic–basedonsomeobscurelawwritten Laurel (Rhododendron maximum). These longago – thatpeople mustnotpick these rarities need to be closely monitored, flowers. But some of us couldn’t resist the and remedial measures implemented temptation to bring a few home to Mother to protect them when necessary. As an where they were always received with aside, deer do not pose a threat to rare gratitude and a mild reprimand: “Thank woodland grasses and sedges, of which you very much, but you really shouldn’t there are many in the state. be picking these.” Today, children returning from their Herbivory impacts will vary spatially, adventures in the woods are more likely temporally, and among plant species in to arrive home with deer ticks on their relation to the population density of the pants instead of lady’s slippers in their herd. As deer densities steadily increase, 19 Photos © Thomas Rawinski When deer are allowed to achieve high population densities their browsing can reduce healthy woodlands rich in species diversity to impoverished habitats where most understory vegetation and tree seedlings are eliminated (left) or only certain ferns and other highly unpalatable understory plants can survive (right). so do the detrimental impacts on vegeta­ higher than my knee. And these were the tion. Much of the early scientific research saplingsthathadmanagedtosurvive;how examined impacts on tree regeneration. many others had been browsed to death Saplings of preferred Sugar Maple, Red during their early years of growth? Deer Maple, Northern White Cedar, White Ash, nowrepresentastressorinthepopulation and oaks are suppressed, while the less- dynamics of Atlantic White Cedar, and it palatable White Pine, Red Spruce, Ameri­ is unlikely that this cedar swamp will be can Beech, Sassafras, Black Cherry, and able to return to its former glory. Black Birchareleftto grow.Overtime,this Toobserveisnotnecessarilytoperceive. selectivebrowsingcanchangethespecies Evaluating deer impacts requires careful compositionofwoodlands.Fromaforestry study,experienceinknowingwhat tolook perspective,thedeclineinvaluabletimber for, and some detective work. Consider species is cause for concern. American chestnut, which only survived About15yearsago,aportionoftheGreat the introduced blight of the 1930s thanks CedarSwampinWestboroughwasflooded to its relentless propensity to sprout by beavers, killing a stand of Atlantic new stems from old root collars. But for White Cedar trees. Periodic disturbances its sprouting ability, American chestnut of this nature are to be expected, and would already be extinct in the wild. even welcomed. Plants and wildlife that I visited many deer-impacted forests depend on early successional conditions before I finally realized what was missing. flourish for a time, while a new generation Old chestnut boles lay on the ground and of young cedar trees arises. stumpswererecognizable.Butwherewere But when I visited the area just a few all the sprouts? Overabundant deer had years ago I was dismayed to find the preventedthemfromgrowinghigherthan young cedars heavily impacted by deer a foot or two, which eventually led to the browsing. They resembled bonsai, no death of the entire plant. It was the final 20 nail in the coffin for American Chestnut at fruiting stems. In contrast, the impact is thesesites.Thebestplacetoseethisquiet detrimental if all of the stems are small drama unfolding in Massachusetts is on and vegetative, or in extreme cases, all thesouthslopeofQuabbinHillinQuabbin but gone from suitable habitats. In the Park, where hunting is not allowed. grasslands of Martha’s Vineyard and In another instance, I recall a visit to Nantucket, monitor populations of Wood Shawangunk Ridge StateForest in eastern Lily( Liliumphiladelphicum ).Thisstunning New York, where I commented on the wildflower is being damaged by deer on sorry condition of the forest vegetation. both islands. A younger botanist in our group was a bit One representative of the lilyfamily that puzzled by my comment. I explained that deer avoid is the poisonous American the forest seemed to be missing plants False Hellebore (Veratrum viride). It often that ought to be there, such as White grows with Skunk Cabbage, which is also Wood Aster (Aster divaricatus), Calico avoided, for reasons that are rather obvi­ Aster (Aster lateriflorus), Bluestem Gold­ ous. Another plant that deer recognize as enrod( Solidagocaesia ),ForestGoldenrod poisonous is White Snakeroot(Ageratina (Solidago arguta), and Perfoliate Bellwort altissima), which often thrives with Hay- (Uvularia perfoliata). We walked a bit fur­ scented Fern (Dennstaedtia punctilobula) ther and I gravitated toward an old fallen in deer-impacted forests on hilly terrain. tree. Among its branches, which formed Prominent outdoor writer and conser­ a barrier to the deer, was a single stem of vationist Ted Williams used the phrase Perfoliate Bellwort. “ecological blight” to characterize the Whenevaluatingdeerimpactstohabitat, condition of such forests. payspecialattentiontoPerfoliateBellwort Much can be learned by examining and other members of the lily family, as places inaccessible to deer, such as steep thesearerelishedbydeer.FalseSolomon’s ledges, bouldery terrain, or fenced land. Seal (Maianthemum racemosum) isagreat If the forbs are more robust or abundant indicator. The browsing impact is toler­ in these areas, a deer impact can be able if you find at least a few flowering or inferred.

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Ph The Wood Lily (Lilium philadelphicum), like most members of the lily family, is relished by deer. The author reports this wildflower is being damaged by deer on Martha’s Vineyard and Nantucket, and suggests that its populations in the grasslands on these islands can be monitored as indicators of browsing impact. 21 The best way to evaluate deer impacts is to construct deer exclosures and then compare the development of the vegetation on the inside versus the outside. Results, as in this case, can be dramatic. The very best way to evalu­ ate deer impacts is to con­ struct exclosures, using fencing at least 7.5 feet tall,

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be apparent in only a year Ph or two, even if large-mesh woven wire while repulsive Garlic Mustard (Alliaria fencing is used that allows for the entry petiolata) a non-native, invasive species, of rabbits and other small herbivores. dominated theadjacentareaswheredeer On Nantucket, exclosures might begin had access. The authors concluded that to show us what the natural vegetation deer create and sustain conditions for in­ lookedlikebeforedeerwereintroducedto vasiveplantstodominatetheunderstory, the island in 1926. (Local residents took it while deer exclusion reverses the trend. upon themselves to bring the animals in What a marvelous revelation: to perceive from Michigan, an operation that would invasive plants as symptoms, and not the be illegal today.) On the mainland, where direct cause, of vegetation degradation deer, and now moose, are part of natural in deer-impacted forests! Reducing the forest systems, exclosures are providing size of overabundant herds, or excluding insights into the feeding habits and her­ deer from sensitive habitats by fencing, bivory impacts of these animals. should shift the balance back toward Nothing, I believe, would help more in native plants. The emerging mantra has conveying the seriousness of the deer become “Nativeplantscanbeatinvasives overabundance problem than having ex- if given a level playing field.” closures set up at high-visibility, publicly accessible sites in Millis, Medfield, Nor­ Pay close attention to Orange Jewel­ folk, Sharon, Milton, Boxborough, North weed( Impatiens capensis),belovedforits Andover, Topsfield, Ipswich, and just beautifulnectar-ladenflowers,entertain­ abouteveryothereasternMassachusetts ingly explosive fruit capsules, and tasty town. Exclosures established on school little seeds. Jewelweed is an annual that propertieswouldprovideoutstandingop­ germinates early in the spring and grows portunities for student science projects. rapidly to form dense stands on moist Likepolitics,allconservationislocal,and soils. Deer love this plant and browse it people will care most about the places preferentially. As deer suppress or pre­ they know and love. vent seedproduction, jewelweedpopula­ tions dwindle or disappear altogether. Revealingamoresubtlebutequallygrim In parts of Connecticut and New York, impact of overabundant deer browsing, where deer densities are extraordinary, research in Pennsylvania has demon­ I have walked for hours without finding strated a strong link between deer and any jewelweed. The habitats that should invasiveplants(Knight,etal.2009. Natural support it, and no doubt once supported Areas Journal 29:110-116). In that study, it, are now dominated by a different an­ native White Trillium (Trillium grandiflo­ nual, Japanese Stiltgrass (Microstegium rum) was the dominant herb within the viminium), which the deer totally avoid. protective confines of a deer exclosure, Sopleasemonitorthestandsofjewelweed inyourcommunityandsoundthe alarmif 22 New England Blazing Star (Liatris scariosa var. novae - angliae) is one of several rare plants deer consume that warrants concern.

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Ph 23 existent. There are no young hemlock saplingsinthehemlockgroves. American beechsproutsarescarcelyafoottall,and thedeerhaveresortedtofeedingonwhite pine, a non-preferred species. I’ve seen this level of impact many times before in my travels – in Virginia, West Virginia, Maryland, Pennsylvania, New Jersey, NewYork,Connecticut,andRhodeIsland. I don’t know, nor do I need to know, the deer density in these forests. What I do

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Ph for birds that prefer to occupy the low or theybegintodecline.JapaneseStiltgrass intermediatelayersofwoodlandhabitats. is presently found along road edges, On the forest floor the otherwise ubiq- railroad tracks and utility rights-of-way uitousCanadaMayflower( Maianthemum in Massachusetts. It is poised to invade canadense) is now uncommon. What you the niche occupied by jewelweed if deer see mostly is Indian Pipe (Monotropa are allowed to provide the opportunity. uniflora), Beech-drops (Epifagus virgin­ Glossy Buckthorn (Frangula alnus), iana), Spotted Wintergreen (Chimaphila Japanese Barberry (Berberis thunbergii), maculata), Rough Goldenrod (Solidago and Black Swallow-wort (Cynanchum rugosa),BlackHuckleberry,SheepLaurel, louiseae) are three of our most trouble­ sedges,woodlandgrasses,and ferns – all some invasives. All three are avoided by plants that are unpalatable due to their deer and are filling niches left vacant by chemical defenses or low-digestible con­ decimated native plants. These species tent. Lowbush Blueberry, Maple-leaved don’t necessarily require deer for es­ Viburnum, and Blackberry, which under tablishment, but they certainly flourish normalcircumstanceswouldprovidesoft when deer are overly abundant. One of mast (i.e., berries and the like) for many the most deer-resistant invasives is the species of wildlife, are now toostuntedto spiny-stemmed Japanese Angelica Tree bear fruit. Thus, there are ripple effects, (Aralia elata), which is showing up in or, as researchers say, “cascading eco­ moreandmoreplaces.Findingitrecently logical effects,” of deer overabundance in Quabbin Park, where deer have dam­ throughout the ecosystem. An extreme aged the native vegetation, came as no examplewouldbetheextirpationofBlack surprise. Bears from Anticosti Island in Quebec, On the subject of Quabbin, I should attributed to the loss of soft mast caused point out that much of the Reservation bydecadesofover-browsingofblueberry is now open to deer hunting within the and raspberry bushes by introduced framework of a controlled public hunt. whitetails. Where the deer have been hunted, the As high quality forage becomes scarce forest vegetation has rebounded beauti­ in deer-ravaged forests, it’s no surprise fully. No single management action has that these animals venture into neigh­ done more to improve the health and borhoods at night to raid gardens and sustainability of Quabbin’s forests. ornamental plantings. I think we all would tolerate some level of damage to Many Essex County forests are getting our shrubbery in exchange for the occa­ absolutely hammered by overabundant sional opportunity to view these grace­ deer, and yet, most people don’t see it. ful beauties at close range outside the The trees look fine, and tall saplings can picture window. But when an annoyance be plentiful. But the perception changes becomes a chronic nuisance, it may be once a browse impact survey has been timetodeploythefencing,invitethebow­ conducted. Saplingsofbrowse-preferred hunters, or select deer-resistant species oak, maple and ash are practically non­ for all future ornamental plantings. 24 e

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Ph We all have empathy toward wildlife, cooperatively with communities and and it’s heartbreaking to think that other stakeholders in crafting solutions the doe we so admired out the picture to problem situations. The book, Wild­ window has entered a very dangerous life and Society: The Science of Human environment. She has placed herself at Dimensions (Island Press, 2009), is an risk of a vehicle strike as she wanders outstanding resource. On page 315 one through our neighborhoods in search of finds the following definition: food. Nothing good comes from a deer- vehicle collision. On that, hunters and Wildlife management is the guidance of non-hunters can certainly agree. decision-making processes and implemen­ tationofpracticestopurposefullyinfluence Some would say that finding solutions interactions among and between people, to the dilemmaof White-tailed Deer over­ wildlife and habitats to achieve impacts abundance has emerged as the nation’s valued by stakeholders. single greatest wildlife-management – and ecosystem-management – chal­ In Oakham, where I live, deer hunting lenge of the 21st century. No argument remains a vibrant aspect of local culture. here. A useful guidance document for Forests are healthy, and deer are hardly communities struggling with this issue ever struck by cars. I’ll probably never is Community-based Deer Management: find a deer antler in Oakham, which suits A Practitioners’ Guide, available on the me just fine. web at http://wildlife control.info/pubs/ Documents/Deer/Guide.pdf. Let’s hope that people with diverse viewpoints can Tom Rawinski is a U.S. Forest Service reach consensus on a course of action botanistbasedinDurham,NewHampshire. that benefits deer, forests, and people Heholdstwodegreesinwildlifebiologyand over the long term. And let’s hope that has worked as a plant ecologist/scientist the issue is addressed with a sense of for The Nature Conservancy, the Virginia urgency in Massachusetts, before the Department of Conservation and Recre­ deer herds become so much larger than ation, and the Massachusetts Audubon they already are. Society. He serves on the Massachusetts Natural Heritage and Endangered Species Wildlife management professionals Advisory Committee. His email address is must continue to work closely and [email protected]. 25