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Research report recreational trail development impact on wildlife

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Research report recreational trail development impact on wildlife

  1. 1. DRAFT Report: The Impact of Recreational Trail Development for Human and Domestic Dog Use on Urban Wildlife Habitat J. Young June 2012NOTE: This research was not commissioned by South Fork Conservancy or Park Pride. The authorresides on Robin Lane on a lot extending to the center of the South Fork of the Peachtree Creek. He doesnot assert neutrality on the issue of trail construction in all segments of the proposed corridor, andencourages readers to review the articles cited below and form their own conclusions.
  2. 2. TABLE OF CONTENTS1. Introduction............................................................................................................. 32. Abstracts of Papers ................................................................................................. 5 a. General........................................................................................................ 5 b. Mammals..................................................................................................... 7 c. Birds............................................................................................................ 93. Conclusions with Discussion ................................................................................ 13 a. Value of wildlife habitat ........................................................................... 13 b. Trails: Impact on wildlife.......................................................................... 13 c. Dogs: Impact on wildlife .......................................................................... 13 d. Vulnerability of stream corridor ............................................................... 14 e. Need for studies of impact on wildlilfe..................................................... 14 f. Selected rather than connected development............................................ 144. Recommendations................................................................................................. 15 a. Slow down the process now being pushed forward by South Fork Conservancy. Before proceeding, provide wildlife impact studies suitable for EPA/EPD review. .................................................................. 15 b. Give weight to neighbor knowledge of wildlife populations and the negative impacts they have witnessed when access has been increased. .................................................................................................. 15 c. Consider that some segments may be inappropriate for trail development leading to a need to abandon the concept of a connected alternative transportation system of trails................................ 15 d. Set aside sensitive South Fork segments as “no trail wildlife preservation zones,” including the segment between Zonolite and MNP (this segment has beach zones flanked by narrow areas containing animal nests and burrows that are sensitive to dog activity). .................................................................................................... 155. Closing Comments................................................................................................ 156. References:............................................................................................................ 17DRAFT 2
  3. 3. 1. INTRODUCTION South Fork Conservancy is promoting the development of an alternativetransportation corridor consisting of 30+ miles of connected trails along the South Forkof Peachtree Creek in Atlanta and DeKalb County Georgia. The trails would extend fromnear the beginning of the Georgia 400 expressway at I-85 to Decatur, Georgia. The trailswould pass through a number of widely varying urban environments, including woodlandwildlife habitats. See http://www.parkpride.org/get-involved/community-programs/park-visioning#southfork. The South Fork is part of The City of Atlanta’s FINAL APPROVEDGREENWAY ACQUISITION PLAN (GAP), approved by EPA and EPD on March 29,2001. Wildlife habitat preservation is a repeated goal of the GAP. For example: The term “greenway”, as used in this Greenway Acquisition Plan, means a network of natural areas in corridors immediately adjacent to rivers or lakes and managed for conservation, non-point source pollution abatement, and protection of aquatic and stream corridor habitats, which are compatible with low impact uses by the public. In other words, the term “greenway” may be interpreted to mean a “natural stream buffer”. The Greenway System to be implemented under this project allows the implementation of public access facilities such as hiking trails, bicycle trails, and canoe launches. However, only 10 percent of the area acquired under this project may be used for public access or use facilities. Due to the potential for human activities to adversely affect water quality and habitats, public access or use facilities must be designed, constructed, and managed with non-point source pollution prevention as the primary consideration. ... The recreational benefits associated with greenways have been known for several years and are well documented; however, the benefits associated with the protection of water quality and aquatic and stream corridor habitats are still unfolding and the full extent of the capacity of greenways to protect water quality and aquatic and stream corridor habitats may not be clear for several years. ... Other benefits associated with greenways include the following: they protect plant and animal life within the greenway, they distance relatively impervious surfaces from rivers and lakes, they provide space for best management practices (BMPs), they provide effective flood control, and they control erosion. Greenways provide a sanctuary within which living tissue live and multiply in space and time. Some of the species living within greenways are endangered or threatened. Greenways protect riparian corridors from human activities such as development, recreation, and resource extraction. This in return protects species that may be in danger of becoming extinct. Since greenways are natural buffers, the living and non-living tissue function together as an ecosystem which is healthy for humans and the environment. South Fork, despite being a narrow riparian zone, does provide habitat for a rangeof wildlife. Neighbors report seeing deer, opossum, coyotes, barred owls, ducks, pileatedwoodpeckers, downy and redheaded woodpeckers, red tailed hawks, chipmunks,DRAFT 3
  4. 4. snapping turtles, box turtles, blue birds, goldfinch, great blue heron, beaver, foxes,raccoons, and fish. The research reported below was conducted because of concerns (as referenced inthe GAP quoted above) about the impact trail development could have on some relativelyundisturbed segments of the proposed corridor, such as the South Fork between Zonoliteand the Morningside Nature Preserve (MNP). Do the recreational benefits outweigh theenvironmental impact on existing wildlife? Simply assuming this is true may be asignificant error. Furthermore, there is a concern that the serious off-leash dog problem nowexisting at the Johnson/Taylor Preserve in Morningside will be duplicated at otherlocations along South Fork, such as the beaches in the segment mentioned above betweenZonolite and the MNP. Neighbors living near the Johnson Taylor Nature Preserve assertthat increased human and dog recreation there has driven away nesting turtles as well asfoxes, and decreased the frequency of sightings of bird species. Serious efforts to enlistthe police and city agencies to enforce the leash law have failed. We must face the ironic possibility that building out and using the trail plan,instead of putting urban dwellers in more contact with nature may, like otherdevelopments, reduce that contact by decreasing urban wildlife populations.DRAFT 4
  5. 5. 2. ABSTRACTS OF PAPERSAbstracts or excerpts from several research papers listed at the end of this paper areorganized by the species on which they focus in this section: a) General, b) Mammals,and c) Birds. A Reference table of citations for seventeen research papers and articlescan be found in numbered sequence on pages 17-18. a. General[6] Wildlife responses to pedestrians and dogsMiller, SG | Knight, RL | Miller, CKWildlife Society Bulletin [Wildl. Soc. Bull.]. Vol. 29, no. 1, pp. 124-132. 2001.Abstract:As participation in outdoor recreational activities escalates, land managers struggle todevelop management policies that ensure coexistence of wildlife and recreation.However, this requires an understanding of how wildlife responds to various forms ofrecreational activities and the spatial context in which the activities occur. Therefore, wemeasured responses of 2 species of grassland songbirds, one species of forest songbird,and mule deer (Odocoileus hemionus) exposed to a pedestrian, a pedestrian accompaniedby a dog on leash, and a dog alone (only for grassland birds), on and away fromrecreational trails. We assessed the "area of influence" for each treatment by determiningthe probability that an animal would flush or become alert (for mule deer only) given itsperpendicular distance to a trail or a line of movement in areas without trails. Whenanimals were disturbed, we measured flush distance (the distance between thedisturbance and the animal when flushed), distance moved, and, for mule deer, alertdistance (the distance between the disturbance and the deer when it became alert). For allspecies, area of influence, flush distance, distance moved, and alert distance (for muledeer) was greater when activities occurred off-trail versus on-trail. Generally, among on-trail and off-trail treatments in grasslands for vesper sparrows (Pooecetes gramineus) andwestern meadowlarks (Sturnella neglecta), the smallest area of influence and shortestflush distance and distance moved resulted from the dog-alone treatment, and theseresponses were greater for the pedestrian-alone and dog-on-leash treatments. In forests,for American robins (Turdus migratorius), the area of influence, flush distance, anddistance moved did not generally differ between the pedestrian-alone and dog on- leashtreatments. For mule deer, presence of a dog resulted in a greater area of influence, alertand flush distance, and distance moved than when a pedestrian was alone. Natural landsmanagers can implement spatial and behavioral restrictions in visitor management toreduce disturbance by recreational activities on wildlife. Restrictions on types ofactivities allowed in some areas such as prohibiting dogs or restricting use to trails willaid in minimizing disturbance. Additionally, managers can restrict the number and spatialarrangement of trails so that sensitive areas or habitats are avoided.[6] WILDLIFE RESPONSES TO PEDESTRIANS AND DOGSFinal Report Submitted to City of Boulder Open Space DepartmentRichard L. Knight and Scott G. Miller 1996Department of Fishery and Wildlife Biology Colorado State UniversityAbstract:DRAFT 5
  6. 6. We measured the responses of two grassland passerines, one forest passerine, and onelarge mammal exposed to recreational treatments both on- and off-trail, including a pedestrianalone, a pedestrian accompanied by a dog-on-leash, and a dog alone. Responses measuredincluded flush response (whether the animal flushed or not), flush distance (distance betweendisturbance and animal when flushed), distance of flush (distance the animal moved afterflushing). All wildlife species in our study exhibited greater responses when the treatmentoccurred off-trail than when on-trail. In the grasslands, the dog-alone treatment elicited theleast response by vesper sparrows (Pooecetes gramineus) and western meadowlarks (Sturnellaneglects), whereas pedestrian-alone and pedestrian accompanied by a dog-on-leash elicitedgreater responses. In the forest, American robins (Turdus migratorius) responded similarly to@ a pedestrian-alone and a pedestrian accompanied by a dog-on-leash. Mule deer (Odocoileushemionus) exhibited the greatest response when a pedestrian was accompanied by a dog. Ourresults have important implications for the design and implementation of management policies,such as using spatial and behavioral restrictions, to ensure the coexistence of wildlife andrecreationists .[17] WILDLIFE RESPONSES TO RECREATION AND ASSOCIATEDVISITOR PERCEPTIONSAUDREY R. TAYLOR1 AND RICHARD L. KNIGHT21Department of Fishery and Wildlife Biology, Colorado State University, Fort Collins, Colorado 80523 USAAbstract. Outdoor recreation has the potential to disturb wildlife, resulting in energeticcosts, impacts to animals’ behavior and fitness, and avoidance of otherwise suitable habitat.Mountain biking is emerging as a popular form of outdoor recreation, yet virtually nothingis known about whether wildlife responds differently to mountain biking vs. more traditionalforms of recreation, such as hiking. In addition, there is a lack of information on the ‘‘areaof influence’’ (within which wildlife may be displaced from otherwise suitable habitat dueto human activities) of different forms of recreation. We examined the responses of bison(Bison bison), mule deer (Odocoileus hemionus), and pronghorn antelope (Antilocapraamericana) to hikers and mountain bikers at Antelope Island State Park, Utah, by comparingalert distance, flight distance, and distance moved.Within a species, wildlife did not responddifferently to mountain biking vs. hiking, but there was a negative relationship betweenwildlife body size and response. We determined the area of influence along trails and offtrailtransects by examining each species’ probability of flushing as perpendicular distanceaway from a trail increased. All three species exhibited a 70% probability of flushing fromon-trail recreationists within 100 m from trails. Mule deer showed a 96% probability offlushing within 100 m of recreationists located off trails; their probability of flushing didnot drop to 70% until perpendicular distance reached 390 m. We calculated the area aroundexisting trails on Antelope Island that may be impacted by recreationists on those trails.Based on a 200-m ‘‘area of influence,’’ 8.0 km (7%) of the island was potentially unsuitablefor wildlife due to disturbance from recreation.Few studies have examined how recreationists perceive their effects on wildlife, althoughthis has implications for their behavior on public lands. We surveyed 640 backcountry trailusers on Antelope Island to investigate their perceptions of the effects of recreation onwildlife. Approximately 50% of recreationists felt that recreation was not having a negativeeffect on wildlife. In general, survey respondents perceived that it was acceptable to approachwildlife more closely than our empirical data indicated wildlife would allow. Recreationistsalso tended to blame other user groups for stress to wildlife rather than holdingthemselves responsible.The results of both the biological and human-dimensions aspects of our research haveimplications for the management of public lands where the continued coexistence of wildlifeand recreation is a primary goal. Understanding wildlife responses to recreation and the‘‘area of influence’’ of human activities may help managers judge whether wildlife populationsare experiencing stress due to interactions with humans, and may aid in tailoringrecreation plans to minimize long-term effects to wildlife from disturbance. Knowledge ofrecreationists’ perceptions and beliefs regarding their effects on wildlife may also assistpublic lands managers in encouraging positive visitor behaviors around wildlife.[11] Paul M. Cavanagh, PhD, RECREATION IMPACTS:What Science Tells UsAboutDRAFT 6
  7. 7. Managing Conservation Lands (Presentation)Excerpt:• 78 Land Trusts (69.6%) identify protection of wildlifehabitat and natural resources as part of their mission• Many have trails on their lands• Recreation and Public Access may not be compatible with this mission[8] Impacts to the threatened desert tortoise from dogs: a growing threat at theurban interface in the Mojave Desert, California. Desert tortoise (Gopherus agassizii)populations have declined for numerous reasons in recent decades to the point wherepopulations north and west of the Colorado River were federally listed as threatened in1990. One important issue identified in the tortoise recovery plan is attack by domestic orferal dogs. USGS research reveals that attacks from dogs are likely to be a growing threatto recovery of the species. USGS scientists developed a method of grading trauma to livetortoises using 35-mm slides and data sheets, and then retrospectively created a databasethat includes more than 6,000 tortoises from more than 30 long-term and specializedresearch plots in California. The data set, collected between 1977 and 2005, includespotential source and severity of trauma. The objectives of this research were tocharacterize types of trauma affecting live tortoises by size, sex, and location; determineif signs of attacks by domestic or feral dogs could be separated from those of wild canids;determine if types and amounts of trauma differ in tortoise populations living near townsand settlements versus remote areas; and prepare a risk model. The scientists found that,in general, attacks by dogs differed from attacks by wild canids in the amount and type ofscute (scale covering of the tortoise shell) removed and bone exposed, especially to thegular horn (on the underside of the tortoise shell), which is critical for courtship,aggression and protection. Tortoise populations most likely to be affected by dogs occurwithin 2-6 kilometers of settlements and towns. The percent of tortoises with moderate tosevere trauma from predators was significantly higher at sites near settlements than inremote areas. One tortoise population, under study since 1980 and near a settlement, alsoshowed significantly increased frequency in moderate to severe trauma over time Since1994, when the Desert Tortoise Recovery Plan was published by the U.S. Fish andWildlife Service, urban pressures have increased on critical habitat boundaries in severalareas. Kristin Berry, Session 19, Monday, Sept. 24, 4:30 pm.Contact: kristin_berry@usgs.gov; 951-697-6361) b. Mammals[14] Reed, S. E. & Merenlender, A. M. Effects of Management of Domestic Dogs andRecreation on Carnivores in Protected Areas in Northern California. ConservationBiology, 25, 504-513.Abstract: In developed countries dogs (Canis lupus familiaris) are permitted toaccompany human visitors to many protected areas (e.g., >96% of protected lands inDRAFT 7
  8. 8. California, U.S.A.), and protected-area management often focuses on regulating dogs dueto concerns about predation, competition, or transmission of disease and conflicts withhuman visitors. In 2004 and 2005, we investigated whether carnivore species richnessand abundance were associated with management of domestic dogs and recreationalvisitation in protected areas in northern California. We surveyed for mammaliancarnivores and human visitors in 21 recreation areas in which dogs were allowed offleashor onleash or were excluded, and we compared our observations in the recreation areaswith observations in seven reference sites that were not open to the public. Carnivoreabundance and species richness did not differ among the three types of recreation areas,but native carnivore species richness was 1.7 times greater (p < 0.01) and the relativeabundances of native coyotes (Canis latrans) and bobcats (Lynx rufus) were over fourtimes greater (p < 0.01) in the reference sites. Abundances of bobcats and all carnivoresdeclined as the number of visitors increased. The policy on domestic dogs did not appearto affect species richness and abundance of mammalian carnivores. But the number ofdogs we observed was strongly associated with human visitation (R2= 0.54), so the keyfactors associated with recreational effects on carnivores appear to be the presence andnumber of human visitors to protected areas.[15] Reed, S. E. & Merenlender, A. M. 2008. Quiet, Nonconsumptive RecreationReduces Protected Area Effectiveness. Conservation Letters, 1, 146-154.Abstract: Protected areas around the world were created with the goals of preservingbiodiversity and providing nature-based recreation opportunities for millions of people.This dual mandate guides the management of the majority of the worlds protected areas,but there is growing evidence that quiet, nonconsumptive recreation may not becompatible with biodiversity protection. We combined noninvasive survey techniquesand DNA verification of species identifications to survey for mammalian carnivores in 28parks and preserves in northern California. Paired comparisons of neighboring protectedareas with and without recreation revealed that the presence of dispersed, nonmotorizedrecreation led to a five-fold decline in the density of native carnivores and a substantialshift in community composition from native to nonnative species. Demand for recreationand nature-based tourism is forecasted to grow dramatically around the world, and ourfindings suggest a pressing need for new approaches to the designation and managementof protected areas.[3] The Effects of Dogs on Wildlife Communities 1* 2 3Benjamin Lenth , Mark Brennan , and Richard L. KnightFebruary, 2006Final research report submitted to:Boulder County Open Space and Mountain Parks AbstractDomestic dogs (Canis familiaris) are frequent visitors to open space areas, though little isknown about their ecological impacts. We studied the effects of dogs on wildlife bycomparing the activity levels of wildlife in areas that prohibit dogs, with areas that allowdogs off-leash under “voice and sight” control. To measure wildlife activity both on trail andup to 200 m off-trail, we used four methods: pellet surveys, scented tracking plates, remoteDRAFT 8
  9. 9. triggered cameras, and on-trail scat surveys. Additionally, in prairie dog (Cyonomysludocivianus) colonies we measured the distances of prairie dog burrows to the nearest trail,and compared the density of prairie dog burrows between areas with and without dogs. Thepresence of dogs along recreational trails correlated with altered patterns of habitat utilizationby several wildlife species. Mule deer (Odocoileus hemionus) activity was significantlylower in proximity to trails in areas that allow dogs, and this effect extended at least 100 moff-trail. Small mammals, including squirrels (Sciurus spp.), rabbits (Sylviagus spp.),chipmunks (Eutamias spp.), and mice (Peromyscus spp., Reithrodontomys spp., Onychomysspp., Zapus spp.), also exhibited reduced levels of activity in proximity to trails in areas withdogs, and this effect extended at least 50 m off-trail. Furthermore, the density of prairie dogburrows was lower within 25 m of trails in areas that allow dogs. The presence of dogs alsoaffected carnivore activity, although in varying ways. Red fox (Vulpes vulpes) detectionswere higher in areas that allowed dogs, and bobcat (Felis rufus) detections were lower. Thesefindings have implications for the management of natural areas regarding dog policies,particularly those that allow dogs off-leash. c. Birds[4] J. Miller et al., “Recreational trails, human activity, and nest predationin lowland riparian areas.”AbstractIn areas of human settlement, greenways and open-space land are often intended to serverecreational purposes as well as provide wildlife habitat, but the compatibility of thesegoals is uncertain. We examined the effect of recreational trails on the risk of nestpredation and nest predator activity at four lowland riparian sites along the Front Rangeof Colorado. At one site on each of two streams, we placed a transect of artifcial nestsnear a recreational trail and another transect on the opposite side of the stream. We alsoplaced another transect of nests at a second site on each stream that was not associatedwith a recreational trail. In 1995, nests were baited with quail eggs; in 1996 a clay eggwas also added to nests to aid us in nest predator identifcation. Artifcial nests are notperfect surrogates for natural nests, but are useful in generating hypotheses about causesof nest failure and for detecting changes in predator assemblages. Overall, predation rateswere high (94%). There were signifcant differences in vulnerability to predation on thedifferent transect types, with a tendency for predation rates to increase with distance fromtrails. There was a signifcant effect of time with a greater risk of predation in 1996. In1996, 83% of the clay eggs that were recovered showed signs of predation. House Wrensdestroyed 11% of the clay eggs; impressions from Black-billed Magpies, Blue Jays, andCommon Grackles were found on 69%; mice preyed on 25%; and squirrels on 12% of theeggs. Birds attacked more nests near trails than away from trails, whereas mammalsappeared to avoid nests near trails to some extent. These results support the contentionthat recreational trails and human activity may affect nesting success for some species,and suggest that patterns of nest predation reflect the unique, and sometimes, counter-intuitive responses of individual predator species. Rather than relying on simplisticDRAFT 9
  10. 10. assumptions about the compatibility of recreation and wildlife, it is important to considerhow individual species respond to the habitat alteration and human activity associatedwith trails when deciding where trails should be located and in developing overallconservation strategies in human-dominated areas.[5] INFLUENCE OF RECREATIONAL TRAILS ONBREEDING BIRD COMMUNITIESSCOTT G. MILLER,1,3 RICHARD L. KNIGHT,1 AND CLINTON K. MILLER2,41Department of Fishery and Wildlife Biology, Colorado State University, Fort Collins, Colorado 80523 USA2Department of Open Space, 66 S. Cherryvale Road, Boulder, Colorado 80303 USAAbstract. We investigated the influence of recreational trails on breeding birdcommunities in forest and mixed-grass prairie ecosystems in Boulder County, Colorado,United States, during 1994 and 1995. Species composition, nest predation, and broodparasitism by Brown-headed Cowbirds (Molothrus ater) were examined near and awayfrom existing recreational trails. Bird species composition was altered adjacent to trails inboth ecosystems. Generalist species were more abundant near trails, whereas specialistspecies were less common. Within the grassland ecosystem, birds were less likely to nestnear trails. Within both ecosystems, nest predation was greater near trails. In forests, therate of brood parasitism was not influenced by trails. No brood parasitism was found inthe grassland ecosystem. Our results may be useful to natural-lands managers who mustimplement management policies regarding the spatial arrangement of trails and trail-userestrictions.[12] Un-happy Trails?By Mary HobbsBiodiversitynotes -- Newsletter of the Biodiversity Project(http://www.biodiversityproject.org/newsletters/newssp01.htm#trails)spring 2001Editors Note: People are an integral part of many landscapes, and as ourfeature article shows, we can affect the land and the life it supports forgood as well as for ill. Yet sometimes even our most subtle activities canhave an impact on our neighboring wildlife. As more and more of us visitlocal reserves, parks, forests and wilderness areas every year, it becomesincreasingly important to measure the effects, so we can design trails andother recreational activities to minimize human impact on sensitivespecies.Were all familiar with the negative impact of roads and motorized off-roadvehicles on wildlife, but few of us stop to consider whether a walk in thewoods has consequences for resident species.Researchers from Colorado State University (CSU) and the City of BoulderOpen Space Department investigated the effects of recreational trails,hikers, and dogs on local bird and deer populations. Scott Miller and Dr.Richard Knight of CSU, and Clinton Miller of the City of Boulder conductedtwo separate studies to assess impacts of recreational trails and pedestrianDRAFT 10
  11. 11. traffic on resident species.A 1994-95 study sought to determine whether bird species diversity,composition and abundance differed based on proximity to hiking trails. Theresearchers found a greater abundance of some specialized species fartherfrom established human trails. In the grassland ecosystem three bird specieswere found in greater abundance on the control sites (where no trails existed): westernmeadowlark, vesper sparrow, and grasshopper sparrow. Similarly, five forest specieswere more abundant where no trails existed, including the chipping sparrow and thepygmy nuthatch. Not only were a greater number of species found where no trailsexisted, but, the number of individual birds increased relative to distance from the trails.Additionally, nest survival-the successful fledgling of young birds-also increased fartherfrom hiking trails.Not all species suffered from proximity to trails. Generalists, including American robinsand black-billed magpies (a nest predator), did better the closer they were to humanpaths.A 1996 study concentrated on four particular species: three songbird species and muledeer. The researchers measured the response of these species to three different"treatments"-solitary pedestrians, a pedestrian accompanied by a dog on a leash, and adog alone - both on and off trails. In this study, the researchers found that there was asignificant difference in wildlife response near trails. Moreover, off-trail intrudersnegatively affected all four target species.This doesnt mean that people cant experience or enjoy parks and natural places. But itdoes mean that we should stay on trails and be sensitive to the effects we (and our pets)have on local wildlife. In addition, both studies call on natural resource managers toreduce the effect trails have on wildlife through public education and to concentrate trailsin particular areas to minimize habitat fragmentation.[13] Lafferty, K. D., Goodman, D. & Sandoval, C. P. 2006. Restoration ofbreeding by snowy plovers following protection from disturbance.Biodiversity and Conservation 15, 2217-2230. http://www.werc.usgs.gov/laffertyAbstract: Promoting recreation and preserving wildlife are often dual missions for landmanagers, yet recreation may impact wildlife. Because individual disturbances areseemingly inconsequential, it is difficult to convince the public that there is aconservation value to restricting recreation to reduce disturbance. We studied threatenedwestern snowy plovers (Charadrius alexandrinus nivosus) at a public beach (SandsBeach, Coal Oil Point Reserve) in Santa Barbara, California (USA) before and during aperiod when a barrier directed foot traffic away from a section of upper beach wheresnowy plovers roost. The barrier reduced disturbance rates by more than half. Snowyplovers increased in abundance (throughout the season) and their distribution contractedto within the protected area. Snowy plovers that were outside the protected area in themorning moved inside as people began using the beach. Experiments with quail eggsDRAFT 11
  12. 12. indicated an 8% daily risk of nest trampling outside the protected area. Before protection,plovers did not breed at Coal Oil Point. During protection, snowy plovers bred inincreasing numbers each year and had high success at fledging young. These resultsdemonstrate how recreational disturbance can degrade habitat for shorebirds and thatprotecting quality habitat may have large benefits for wildlife and small impacts torecreation.Lafferty, K. D. 2001. Disturbance to wintering western snowy plovers.Biological Conservation 101:315-325.Abstract: Use of a Santa Barbara beach by people and birds varied in both time andspace. There were 100 birds, 18 people and 2 dogs per kilometer. Bird density variedprimarily with the season and tide while human activity varied most between weekendand weekday. Bird distributions along the beach were determined mainly by habitat type(particularly a lagoon and exposed rocky intertidal areas) For crows and western gulls,there was some evidence that access to urban refuse increased abundance. Interactionsbetween birds and people often caused birds to move or fly away, particularly whenpeople were within 20 m. During a short observation period, 10% of humans and 39% ofdogs disturbed birds. More than 70% of birds flew when disturbed. Bird species varied inthe frequency that they were disturbed, partially because a few bird species foraged onthe upper beach where contact with people was less frequent. Most disturbances occurredlow on the beach. Although disturbances caused birds to move away from humans, mostdisplacement was short enough that variation in human activity did not alter large-scalepatterns of beach use by the birds. Birds were less reactive to humans (but not dogs)when beach activity was low.Off-Leash Dog Enforcement – Raleigh, NC(Anecdotal email from Chris Moorman, used by permission)Jeff,Dont know what responses youve received so far, but please see attached a couple ofrelevant documents. We had an "unleashed dog problem" at our university research anddemo forest in the Raleigh, NC city limits. We tried everything but dogs remainedunleashed despite a clearly advertised leash law. During this time, we saw a decline inAmerican Woodcock, a ground-nesting bird. Eventually, dogs were banned from theforest and woodcock returned. Unfortunately, we have no defendable data to support ourobservations.Good luck,Chris M.DRAFT 12
  13. 13. 3. CONCLUSIONS WITH DISCUSSION a. Value of wildlife habitat Preservation of wildlife and its habitat along South Fork is a worthwhile andimportant goal as expressed by neighbors and adopted in the CITY OF ATLANTAFINAL APPROVED GREENWAY ACQUISITION PLAN. [1] Urban wildlife habitat isa scarce resource that should be carefully protected. No type of development that couldimpact it should proceed without benefits that heavily outweigh preservation. b. Trails: Impact on wildlife Even quiet recreational development such as a trail generally results in decreasedabundance of wildlife. [2, 5, 7, 10, 11, 12, 14, 15] i. “Our results indicate that trails affect the distribution and abundance, as well as the reproductive success, of bird species . . .” [5] c. Dogs: Impact on wildlife The presence of dogs on leash or off leash significantly increases the negativeimpact on wildlife habitat. [2, 3, 5, 6, 8, 11, 14] i. “Areas with dogs had: – 35% reduction in bird diversity – 41% reduction in abundance • “results…support the long-term prohibition of dog walking from sensitive conservation areas” [11] ii. “The presence of domestic dogs may introduce diseases or parasites to small mammals, and the burrows of fossorial mammals can be physically damaged as a result of domestic dogs (Stuht and Youatt 1972, Thorne et al. 1982, Durden and Wilson 1990). In addition, dogs walking across burrows caused alarm reactions (Mainini et al. 1993). In the case of birds, the presence of dogs may flush incubating birds from nests (Yalden and Yalden 1990), disrupt breeding displays (Baydack 1986), disrupt foraging activity in shorebirds (Hoopes 1993), and disturb roosting activity in ducks (Keller 1991). Many of these authors indicated that dogs with people, dogs on-leash, or loose dogs provoked the most pronounced disturbance reactions from their study animals.” [2] iii. “Keller (1991) found that ducklings were disturbed while roosting on the shoreline and while feeding in water. The shore-based activities (fishing, people walking, dogs) caused more disturbance than water-based activities (windsurfing, boating). Disturbance affected the activity of young eiders for up to 35 minutes. Keller (1991) reported that small ducklings experienced a numerical increase in predator encounters during the first 5 minutes post-disturbance.” [2]DRAFT 13
  14. 14. iv. Local experience has shown that posting leash law notices at trailheads simply does not deter people from breaking the law in preservation areas. d. Vulnerability of stream corridor South Fork is a narrow riparian zone in which the stream and wetland ecosystemare vulnerable because of the small scale. [2, 4, 5] i. Fragmentation of the habitat [5, 12] seems likely. ii. Unpredictable flooding resulting from upstream human developments already stresses wildlife habitats along the creek [4]. iii. Many of the areas analyzed in the studies mentioned below are much larger than the woodland borders of the South Fork wetland corridor. It is possible that the South Fork wetland corridor, being quite narrow in some segments, is more sensitive than the areas studied to the recreational impacts found by the authors of these studies. e. Need for studies of impact on wildlilfe Developers like South Fork Conservancy and managers who propose to open upsensitive wildlife habitats should proceed only after thorough and adequate studies of thedevelopment’s impact on wildlife preservation, especially in light of required approval byEPA and EPD pursuant to the GAP. [1, 3, 4, 15, 17] i. “there is growing evidence that quiet, nonconsumptive recreation may not be compatible with biodiversity protection.” [15] ii. Locating trails and seeking neighborhood commentary therefore is premature without providing adequate information concerning the impact on wildlife habitats. [1, 3, 4, 15, 17] f. Selected rather than connected development Trail development in South Fork should omit sensitive wildlife habitats thatpresently experience little human or dog visitation. [4, 5, 6, 11, 12, 16] i. “Rather than relying on simplistic assumptions about the compatibility of recreation and wildlife, it is important to consider how individual species respond to the habitat alteration and human activity associated with trails when deciding where trails should be located and in developing overall conservation strategies in human- dominated areas.” [4]DRAFT 14
  15. 15. ii. “managers can restrict the number and spatial arrangement of trails so that sensitive areas or habitats are avoided” [6] iii. “[referenced] studies call on natural resource managers to reduce the effect trails have on wildlife through public education and to concentrate trails in particular areas to minimize habitat fragmentation” [12] iv. “Consolidation of trails to certain areas (e.g., edges of forests and grasslands) will reduce the fragmentation of large blocks of habitat, maintaining less-disturbed areas for species sensitive to fragmentation.” [5] 4. RECOMMENDATIONS a. Slow down the process now being pushed forward by South Fork Conservancy. Before proceeding, provide wildlife impact studies suitable for EPA/EPD review. b. Give weight to neighbor knowledge of wildlife populations and the negative impacts they have witnessed when access has been increased. c. Consider that some segments may be inappropriate for trail development leading to a need to abandon the concept of a connected alternative transportation system of trails. d. Set aside sensitive South Fork segments as “no trail wildlife preservation zones,” including the segment between Zonolite and MNP (this segment has beach zones flanked by narrow areas containing animal nests and burrows that are sensitive to dog activity). 5. CLOSING COMMENTS Looking for appropriate locations for new parklands in Atlanta is a worthwhileproject. However, benefits to human recreation should not automatically be assumed totrump potential negative impacts on quality of life and wildlife habitats. The authorbelieves that the projected “transportation” use of a hiking trail has been exaggerated andshould have a low priority when it would have to disrupt scarce urban wildlife habitat.Providing an experience of the natural world does not require a connected 30 mile trailand can be done selectively so as not to disturb habitats. It appears the area covered by the South Fork Conservancy proposal does containsegments that are less sensitive to habitat disruption and might be used, subject to closeneighbor approval, for parks, including offleash dog parks.DRAFT 15
  16. 16. But if the entire 30 mile corridor is developed, would the red-tailed hawks andowls not have enough prey? Would the ducks be frightened away from their mating andnesting grounds? Would dogs dig up small animal burrows and destroy nests along thetrail? Would the trail become a coyote highway leading to an abnormal lessening ofanimal and bird populations along the trail? None of these potential results should beignored. The author does not believe that a potential for property value increases atlocations near but not along trails should outweigh wildlife preservation concerns.Studies may assert a correlation between parks and economic development in the contextof property values, but these studies can be inapposite when they relate to areas trying tobring in developers of subdivisions, apartment complexes and shopping centers. Ofcourse people want to be within walking distance of a park. The South Fork proposal,however, covers considerable territory in which residents are already within walkingdistance of parks. There are park-deficient areas of southwest and northwest Atlantawhere public and donated money for parks could be focused to improve the city’s ratingfor walking access to parks that probably could be located outside of sensitive riparianhabitats. Finally, the present proposal is not a restoration of existing parks like theOlmstead Linear Park project in Druid Hills. In contrast, a continuous 30+ mile trailwould add significant disruption to wildlife habitats in some segments of the proposedroute along South Fork.DRAFT 16
  17. 17. 6. REFERENCES: 1. CITY OF ATLANTA FINAL APPROVED GREENWAY ACQUISITION PLAN (GAP), approved by EPA and EPD on March 29, 2001 http://www.cleanwateratlanta.org/greenway/GreenwayPlan/default.htm. 2. C. Sime, “DOMESTIC DOGS IN WILDLIFE HABITATS EFFECTS OF RECREATION ON ROCKY MOUNTAIN WILDLIFE” (Chapter 6) http://joomla.wildlife.org/Montana/images/Documents/8dogs.pdf. 3. B. Lenth, et al., “ The Effects of Dogs on Wildlife Communities,” Feb. 2006, Final research report submitted to Boulder County Open Space and Mountain Parks, 4. James R. Miller, N. Thompson Hobbs, Department of Biology and Graduate Degree Program in Ecology, Colorado State University, “Recreational trails, human activity, and nest predation in lowland riparian areas,” Landscape and Urban Planning 50 (2000) 227-236. 5. S. Miller, et al., “INFLUENCE OF RECREATIONAL TRAILS ON BREEDING BIRD COMMUNITY,” Ecological Applications, 8(1), 1998, pp. 162–169. 6. S. Miller, et al., “Wildlife responses to pedestrians and dogs,” Wildlife Society Bulletin Vol. 29, no. 1, pp. 124-132. 2001. http://www.friendsofboulderopenspace.org/documents/dogs_wildlife_responses.p df 7. K. Lafferty, USGS, “Adaptive management of Western Snowy Plovers at Coal Oil Point Reserve (Presentation) http://www.southbayrestoration.org/science/PAW/docs/Lafferty%20Talk%20on% 20Snowy%20Plovers.pdf. See also, coaloilpoint.ucnrs.org/Docs/COPRReport2001-04.doc. 8. K. Berry, “Impacts to the threatened desert tortoise from dogs: a growing threat at the urban interface in the Mojave Desert, California.” http://www.usgs.gov/newsroom/article.asp?ID=1785#.T8Ja7-3Da20 9. S. Anderson, “Recreational Disturbance and Wildlife Populations.” (Chapter 9). http://www.cof.orst.edu/cof/teach/fs453/Anderson_Recreational%20Disturbance %20and%20Wildlife%20Populations.pdf. 10. Boyle, S. A., and F. B. Samson. 1985. Effects of nonconsumptive recreation on wildlife: a review. Wildlife Society Bulletin 13:110–116. [First page]. 11. Paul M. Cavanagh, PhD, RECREATION IMPACTS:What Science Tells Us About Managing Conservation Lands (Presentation) [search: recreation impacts Cavanagh] 12. M. Hobbs, “Un-happy Trails?” Biodiversitynotes -- Newsletter of the Biodiversity Project, spring 2001 13. Lafferty et al., “Restoration of breeding by snowy plovers following protection from disturbance,” Biodiversity and Conservation 15, 2217-2230. 14. Reed, S. E. & Merenlender, A. M. “Effects of Management of Domestic Dogs and Recreation on Carnivores in Protected Areas in Northern California,” Conservation Biology, 25, 504-513. [Abstract only reviewed]DRAFT 17
  18. 18. 15. Reed, S. E. & Merenlender, A. M. 2008. “Quiet, Nonconsumptive Recreation Reduces Protected Area Effectiveness,” Conservation Letters, 1, 146-154. [Abstract only reviewed] 16. Knight, et al., “WILDLIFE RESPONSES TO PEDESTRIANS AND DOGS,” Final Report Submitted to City of Boulder Open Space Department 1996 17. Taylor, et al., WILDLIFE RESPONSES TO RECREATION AND ASSOCIATED VISITOR PERCEPTIONSAcknowledgement: The author appreciates the assistance of members of The WildlifeSociety’s Urban Wildlife Working Group in locating many of these references.DRAFT 18