BIODIVERSITYAND BEARS - A CONSERVATIONPARADIGM SHIFT

DANIELSIMBERLOFF, Department of Ecologyand EvolutionaryBiology, University of Tennessee, Knoxville,TN 37996, USA,email: [email protected]

Abstract: Burgeoningconservation problems and shrinkingresources to deal with themhave fosteredan ongoing paradigmshift from single- managementto management. Simultaneously,the main conservationgoal has become maximizationof . The fact that both ecosystem managementand biodiversity have variousmeanings is ominousfor conservationof some species, such as charismaticlarge mammals. The focus on processesrather than species, andon species richnessrather than identity, could detractfrom conservation of bears(Ursidae). On the otherhand, managementof large blocks of habitatcan be helpful. Bears are highly symbolic to humansin many contexts and thus are naturalflagship species, capableof attractingattention and resources to largeconservation efforts. Thereis currentlyinsufficient information to qualifythem as keystonespecies- species whose fate directlydetermines those of manyother species in a system. However,because they have largeand often well-defined require- mentsand some specieshave been well-studied,they may be excellentumbrella species: theirmaintenance would require habitat management that would also maintainpopulations of many other species. The facts that ecosystem managementis currentlyheralded as the governing paradigmfor much conservationand that bears may serve as umbrellaspecies to assist ecosystem managementpose an enormouschallenge to researchers.There are few empiricallytested methods in the ecosystemmanagement toolbox, and developing and testing such methods will requiretesting insightful hypotheses and conductingintensive monitoring, some of whichwill haveto be long-term.Without such research and monitoring, "ecosystem management," "biodiversity conservation,"and "" will remaincatchphrases rather than operational terms.

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Key words: bear,biodiversity, conservation, ecosystem management, , keystonespecies, umbrellaspecies

Resource managers are faced with a drastic increase BIODIVERSITYAND ECOSYSTEM in the numberof threatenedpopulations and communi- MANAGEMENT ties and with tremendously increased for The new methodproposed for conservationis thus eco- funds to deal with them. So it is unsurprisingthat they system management, and its goal is to conserve have sought new and more efficient conservation ap- biodiversity. But both the method and the goal are prob- proaches. In an age when, for example, one in every 8 lematic (Simberloff 1998, 1999). With respect to the plant species worldwideand one in every 3 in the United goal, there is confusion about what biodiversity really States is threatenedwith rapidextinction (Stevens 1998), means. It is a buzzword, but a pseudocognate one, in traditional conservation, emphasizing management of that, despite many meanings, most users think that ev- populations and species of particular concern, seems eryone is using the same definition (Gaston 1996). Most hopeless. Many refuges in the U.S. and elsewhere were lay personsconstrue "biodiversity" as the numberof spe- establishedto save dwindling populationsof single spe- cies in a system (), and this is what con- cies-Kirtland's warbler(Dendroica kirtlandii)and the servation biologists usually mean when they speak saguaro cactus (Carnegiea gigantea), among others. informally. Technically, however, it has other compo- Similarly,the EndangeredSpecies Act (16 U.S.C. 1531- nents. Often it is viewed as having 3 levels: genetic, 1544) mandatesthe draftingof a recovery plan to arrest species, and (e.g., Office of Technol- or reverse the decline of any listed species. With about ogy Assessment [U.S. Congress] 1987). More recently, 1,000 listed species already,and, for plants alone in the there is frequentreference to structuraland process di- U.S., about 5,000 species that fulfill the criteriafor list- versity as crucial components of biodiversity (e.g., ing, it is small wonderthat the species-by-speciesmethod Franklin 1988). The processes and structuresmay ini- seems increasinglyhopeless, difficult, and costly. tially be seen as key to maintainingspecies and ecosys- Further,the growing emphasison biodiversityhas fos- tems, but they can come to be the valued elements tered a shift in conservation goals and methods. The themselves (Simberloff 1998). terms "biological diversity"and "biodiversity"first ap- These various definitionsof biodiversitylead to major pearedin the conservationliterature around 1980 (Norse problems. First, of course, differentpeople may be talk- 1993) and by 1992 had virtually exploded in terms of ing aboutdifferent things. If we are primarilyconcerned numbersof publications(Haila and Kouki 1994). They with saving species, we might be surprisedand uneasy now dominatethe popularand scientific literature,high- to see a managementplan aimed specifically at preserv- lighted by the proceedings of the National Forum on ing structuraldiversity of a forest. Second, it is not at all Biodiversity,Biodiversity (Wilson 1986). obvious how to measure diversity other than at the spe- 22 Ursus 11:1999

cies and perhapsgenetic levels (Simberloff 1998, 1999), Bears and Nature yet most people assume that biodiversity is not just an But what does all this have to do with bears? Bears abstract and can be made If concept readily operational. are archetypalflagship species-species so charismatic we cannot measure something unambiguously,disputes that they can become the symbol and leading featureof are bound to arise. For is a forest a example, particular an entire conservation program. Bears captivate our or is it another of a unique type, simply representative imagination-why else would a bear representthe U.S. found in a reserve type already system? ForestService, and a bear-likepanda become the symbol As for the method of as with ecosystem management, of a leading conservation organization? Childrenplay there is no consensus definitionof biodiversity, "ecosys- with teddy bears, not teddy owls. Among 1,247 4-year tem management"(Grumbine 1994, 1997; Simberloff colleges and universities in the U.S., no fewer than 33 In the for various 1999). U.S., example, government chose bearsas theiremblems, second only to eagles (39), define agencies ecosystem managementdifferently (or which have religious connotationsand are used prima- forswear a the definition, as does Departmentof Com- rily by church-supported and religious schools even have merce), though all adoptedit as the governing (Simberloff, unpublisheddata). At least 3 species and managementmethod (Morrisey et al. 1994, Simberloff one subspecies of bears are represented. Some are cute 1999). and cuddly, some are funky, others are fierce. Bears are At least 2 features of many definitions of ecosystem the focus of numerousNative American and other cer- management have potentially grave consequences for emonies and myths (e.g., Hallowell 1971, Snyder 1990, conservation (Simberloff 1999). First, a key aspect of Moret 1994, Black 1998). Bears are a complex, exploded most management agency definitions is that metaphor,as epitomized most forcefully by Faulkner's humans are typically part of . Thus, natural "TheBear," essentially a naturemyth (Lydenberg1952). areasfrom which humanactivity is excluded are de-em- A main interpretationof "The Bear" is that it symbol- phasized as antitheticalto the notion of a normalecosys- izes the relationshipof humansto the land, and the hunt tem. Second, most definitionsof ecosystem management for the bear,Old Ben, representsthe conquestof the South focus on ecological processes ratherthan species (Meffe and the destructionof wilderness (Lydenberg1952). and Carroll 1994). Sometimes the processes are desired It is clear thatbears have come to representnature and to maintain the entire ecosystem and the species in it, wilderess-big wilderness-in the moder conserva- but often the processes themselves seem to be the raison tion movement and among conservation biologists as d'etre of ecosystem management. For example, a con- well, probablyfor the same complex reasons they play sensus definitionof ecosystem managementproduced by such key anthropological,religious, and literary roles. representativesof many government agencies and pri- They are big and fierce, yet sufficiently anthropomor- vate organizations(Keystone Center 1993) listed main- phic to engenderour sympathyand concern. The vision tainingprocesses as the firstgoal. The focus on processes of the Wildlands Project begins thus: "Our vision is and de-emphasisof naturalareas has led to concern that simple: we live for the day when Grizzlies in Chihuahua ecosystem managementcould become a tool for species- have an unbrokenconnection to Grizzlies in Alaska..." bashing (Soule 1994). Procedures,even effective ones, (WildlandsProject 1995/1996:1). The Yellowstone-to- based on single-species managementcould be discarded Yukonproject under the umbrellaof the WildlandsProject on the grounds that they represent an outmoded para- insists on the need for continuityand large areasfor bears digm. Further,many ecosystem processes can be pre- to thrive in the entire region. Conservationbiologists servedeven as the species normallyresponsible for them have similarly focused on bears in many areas of aca- decline or disappear (Tracy and Brussard 1994). For demic and applied research,from theoretical studies of example, low-diversity second-growthforest often has genetic deterioration(e.g., Shaffer 1983, Allendorf 1994) greater primaryproductivity than diverse primaryfor- and metapopulationdynamics (e.g., Doak 1995) through est. Many flagship species might well disappearfrom studiesof wildlife roadkill(e.g., Brody andPelton 1989). an ecosystem without appreciablechanges in some key processes. This is especially true of some charismatic large vertebratesthat typically have low total BEARS,ECOSYSTEM MANAGEMENT, and total . The emphasis on substitutability AND BIODIVERSITY of various and and on species (Ehrlich Mooney 1983) Bears, with 7 species, certainlydo not comprise much functional and in an equivalence redundancy, ecological species-level biodiversity. So if the main goal of ecosys- sense also rendersindividual less (Walker1992), species tem managementis to maximize biodiversity,the loss of important. INVITEDPAPER * BIODIVERSITYAND BEARS * Simberloff 23 bears may be seen as a minor issue. Many people, in- Keystone,Flagship, and Umbrella cluding some who count themselves as conservationists, Species feel this with to bearsin theirback- probably way respect The concept of a "" may rationalize or even I do not believe yards regions (Grumbine1992). concern over an individual species if biodiversity is the that our should be the number goal simply maximizing main goal. A keystone species is one that affects many of but if one does feel this species, my point is, really othersin an ecosystem, far beyond what one would have what is therefor aboutbears? way, justification worrying expected given its biomass or numbers (Paine 1969, One is that the of a bear possibility disappearance spe- 1995). The concept has been assailed on the grounds cies from an a cascade of ecosystem might precipitate that there is no clear demarcationof how much impact a extinctions, and that these would constitutea subsequent species must have to qualify for this status or even an substantialdecrease in I will discuss this biodiversity. operationalway to measure impact (Mills et al. 1993, below. For now, let us assume thatthe elimi- proposition Hurlbert1997). However, there are enough instances in nation of a bear would entail no particular population which a single species clearly affects the fates of many losses in the major subsequentspecies system. others(examples and referencesin Simberloff 1998) that Some Christensenet al. 1996) ecologists (e.g., simply it seems perverse to throw out the entire notion simply assume that loss of a species-any species-somehow because it is difficult to specify a cut-off point. The im- harms the in the absence of much evidence. ecosystem, pacts of some single-species removals (e.g., American 2 traditional for However, arguments saving specific spe- chestnut [Castanea dentata] and beaver [Castor cies even in the absence of evidence that matterto they canadensis]) show that some species affect many others. the rest of the are the system rivet-popper hypothesis And top often play key roles in regulating (Ehrlich and Ehrlich 1981) and the redundancyhypoth- entire ecosystems (Terborghet al. 1999). Might bears esis (Walker 1992). The envi- rivet-popper metaphor qualify as keystone species? sions a maniac randomlyremoving airplanerivets. Loss Many proposed examples of keystone species dispro- of some rivets may not bring the airplanedown, but at portionatelyfeed on species that would otherwise domi- some point, removalof the next rivet causes a crash. The nate space or some otherresource (e.g., Paine 1969). The rivet-popperhypothesis is agnostic aboutexactly why the introductionof carnivores into new systems has some- plane crashes (Simberloff 1999). It could be the cumu- times precipitatedtrophic cascades-impacts propagated lative impact of the absence of many rivets (for example, down throughthe and affecting many species, wing vibrationcould surpasssome threshold),or it could even those not eaten by the (references in Polls be that the last rivet served some unique function, and, and Strong 1996). It is precisely this top-down impact had a differentrivet been removed at this point, the plane of some carnivoresthat suggests to the WildlandsProject would still be airborne. The redundancy hypothesis that establishmentof preserveslarge enough to maintain (Walker 1992) states that many species in species-rich them is crucial to the existence of naturalecosystems. ecosystems belong to groups of functional equivalents, However, terrestrial examples of predator-mediated and so long as at least one representativeof each group trophic cascades are rare and often rest on isolated sys- remains, the system will continue to function more or tems such as the wolves (Canis lupus) and moose (Alces less normally as species are lost. Removal of the last alces) of Isle Royale (Peterson and Page 1983). Polis species in any functional group, however, will destroy and Strong (1996) argueon several groundsthat trophic the entire system. Of course, the second interpretation cascades are generally rare, especially terrestrialones, of the rivet-poppermetaphor is exactly the redundancy butthat omnivory by the top carnivorewill facilitatethem. hypothesis. Two recent widely publicized experiments Except for polar bears (Ursus maritimus), bears are (Hooper and Vitousek 1997, Tilmanet al. 1997), though remarkably omnivorous (Bunnell 1984a,b,c; Lentifer they do not directly test the cer- redundancyhypothesis, 1984). However, thereis a notabledearth of evidence of tainly give resultsconsistent with it and suggest thatplant the populationimpact of bears on the species they eat. is not as crucial to ecosystem function For black bears (U. americanus) and brown bears (U. as the numberof functional groups. arctos), there is much evidence that the availability of So if some people thinkbears are not importantto save certainprey species affectsbear densities rather than vice- in their own right, it seems that a justification for them versa-classic bottom-up control (e.g., Committee on might be that they serve unique functions in their re- Management of Wolf and Bear Populations in Alaska spective ecosystems. What is the function of a bear? [National Research Council] 1997). One might have 24 Ursus 11:1999 expected the , because of its more restricted conservation areas for the Florida black bear (Ursus diet, to have a great impact on seal (Otariidae)popula- americanusfloridanus) would include more threatened tions, but I know of no evidence thatit does. It may well vertebratesand plants than would those for the Florida have influenced seal evolution in many ways that could panther(Felis concolor coryi), a species whose legend- ultimately have ecological effects (Stirling 1988), but ary home range size would seem to qualify it as a perfect currentecological impactson seal populationsare poorly umbrella. studied. Experimentson black and brown bear removal Using umbrellaspecies is hypothesized to be a short- have been inconclusive with respect to their normal in- cut, in that it may lead to effective conservation of fluence on ungulateprey populationsthat might, in turn, biodiversitywithout the enormousinvestment of time and have system-wide impacts (Committeeon Management money requiredto study each species in a of Wolf and Bear Populations in Alaska [National Re- and determineits precise habitatrequirement. A compo- search Council] 1997). A black bear removal experi- nent of the Wildlands Project advocates using as um- ment in east-centralSaskatchewan (Stewart et al. 1985) brella species large carnivores that are also flagship is perhapsthe only one even to suggest a populationim- species, that have some defined habitatassociation, and pact on an ungulate (moose), and this result is not de- that have alreadybeen well-studied, such as black bears finitive. (D. Foreman, The Wildlands Project, Tucson, Arizona, Species can have enormoussystem-wide impacts other USA, personal communication,1997). It is difficult to thanthrough the energytransfer achieved by eatingthem, imagine a more logical choice. of course:beaver dams, rooting by feralhogs (Sus scrofa), and uprooting of trees by elephants (Proboscidea) all ECOSYSTEMMANAGEMENT FOR transformecosystems. The Asian blackbear (Selenarctos BEARSAND BIODIVERSITY thibetanus) can do enormous damage to forests by its Ideas on how to manage ecosystems for biodiversity habit of strippingbark off trees, thus killing as many as are for the most partjust that-ideas that show a com- 40 trees per family per night (Bunnell 1984a, Moret mitment to that goal ratherthan a toolbox of scientifi- 1994), thoughthe full ecosystem consequenceshave not cally tested, on-the-groundmethods (Simberloff 1999). been assessed. Naiman and Rogers (1997) suggest that For example, the "new forestry" (Franklin 1989) con- the grizzly bear (Ursus arctos horribilis) can, in concert sists of suggestions (such as leaving some slash rather with several other species, maintaina mosaic of than clearing or burningit) that sound reasonablein that in riparianforests by tramplingand digging; again, the they provideresources for species sufferingunder previ- crucialmeasurements have yet to be taken. Bears as well ous logging systems, but they are largely untested. It has as other carnivores,such as mink (Mustela vison), have yet to be shown that even conscientious applicationof been implicatedin the massive transferof nutrients,par- all these techniques really would preserve biodiversity, ticularlyphosphorus and nitrogen,from marine systems yet allow substantiallogging. Thereis researchon some to terrestrialones by virtue of heavy feeding on runs of aspects of leaving dead wood (referencesin Simberloff salmon (Oncorhynchusspp.) and subsequentdeposition 1999), but much remainsto be done. Similarly,much is of feces and salmon carcasses on land (Willson et al. known aboutthe impactof various fire regimes on some 1998, Hilderbrandet al. 1999). The consequences of forest types (e.g., Hermann 1993) and there is a well- this fertilizationand the role of bears in it have just be- developed technology of controlledburs, but much re- gun to be assessed. search is needed before it will be possible to say what If bears are not yet known to be keystone species, they fire regimein which system will fosterwhich biodiversity are, as noted above, flagship species par excellence, and andhow the optimalregime can be conducted.For single- thus may merit protectionif only because their presence species management,many techniqueshave a long his- energizes an entire conservationeffort. Would there be tory of study and perfection-captive propagation, as much concernfor habitatdestruction in westernNorth translocation, supplemental feeding, etc. Ecosystem America if the grizzly bear did not live there? Because managementis not as mature,at least as concerns effect of their large sizes, with consequent low densities and of various methods on biodiversity. large home ranges,bears may also be excellent umbrella With respect to bears, a part of the threatfaced by at are species. These are species thatrequire such largeamounts least some populations of all species is that they of a specified naturalhabitat that saving them would al- hunted, for sport, for the gall bladdertrade, or because most certainly incidentally save many other species re- they are seen as pests (Nowak 1991, WorldWildlife Fund quiringthe same habitat(Meffe and Carroll 1997). For 1998). This is not a majormortality factor for most spe- example, Cox et al. (1994) have shown that proposed cies considered as umbrellas, such as the Florida pan- INVITEDPAPER * BIODIVERSITYAND BEARS * Simberloff 25 ther or the northern spotted owl (Strix occidentalis is currentlylittle evidence thatthey are keystone species, caurina). An umbrellaspecies serves as an umbrellaby but several aspects of the biology of some bear species virtue of demanding habitat requirements(see above), suggest that they might serve as excellent umbrellaspe- and its population trajectoryis generally interpretedas cies in ecosystem managementapproaches. To test this reflecting change in habitat quality or amount, rather hypothesis will requireextensive monitoringand, where than rate of harvest. Populationsof all bear species are possible, field experiments. also threatened in this regard (e.g., by deforestation [Nowak 1991]), though the relative importanceof har- vest and habitat change varies from case to case and is ACKNOWLEDGMENTS often controversial. However, there is little doubt that I thankthe conference organizersfor the invitationto habitat change is often crucial, and thus to the extent preparethis paper,B. Gilbertfor discussion of bearecol- that ecosystem managementwill entail managing large ogy, and S. Hermannand M. Tebo for suggestions on the blocks of habitatso that they can sustain viable popula- manuscript. tions of most or all species in region, it can be a useful tool in bear conservation. However, if bears are to be umbrella species for particular communities, specific LITERATURECITED habitat-centeredmanagement procedures that aid both ALLENDORF,F.W. 1994. Genetically effective sizes of grizzly the bear and a substantialcomponent of its community bear populations.Pages 155-156 in G.K. Meffe and C.R. editors. must be tested empirically with enough monitoring to Carroll, Principlesof conservationbiology. Sinauer Associates,Sunderland, Massachusetts, USA. allow a definitive statementabout whether they work. A BLACK, L.T.1998. Bears in human andritual. crucial of current imagination Ursus pervasive, shortcoming ecosystem 10:343-347. is insufficient to test managementplans monitoring hy- BRODY,A.J., ANDM.P. PELTON.1989. Effects of roads on black Withoutsuch data on a substan- potheses (Yoon 1997). bearmovements in westernNorth Carolina. Wildlife Society tial fraction of the community as well as the umbrella Bulletin 17:5-10. species, all we have are clever ideas. BUNNELL,F. 1984a. Small bears.Pages 96-97 in D. Macdonald, For example, the importanceof corridorsin maintain- editor. The encyclopedia of mammals. Facts on File ing viable populationshas rarelybeen tested empirically; Publications,New York, New York, USA. thusthe whole notionremains controversial (Hobbs 1992, . 1984b. Grizzly bear. Pages 88-91 in D. Macdonald, editor. The of mammals. Facts on File Simberloffet al. 1992). The absence of datais one prob- encyclopedia New New USA. lem; another is that corridors need not have the same Publications, York, York, . 1984c. American black bear. Pages 94-95 in D. importancefor all species in all systems, dis- yet many Macdonald, editor. The encyclopedia of mammals. Facts cussions of them are The black with generic. bear, its on File Publications,New York, New York, USA. attachmentto forests and occasional hesitancy to cross CHRISTENSEN,N.L., A.M. BARTUSKA,J.H. BROWN, S. CARPENTER, open spaces (Harting1987, Halioua 1991), as well as its C. D'ANTONIO,R. FRANCIS,J.F. FRANKLIN,J.A. MACMAHON, documented problems with cars (Wooding and Brady R.E Noss, D.J. PARSONS,C.H. PETERSON,M.G. TURNER,AND 1987, Brody and Pelton 1989), may be one animal that R.G. WOODMANSEE.1996. The report of the Ecological actuallybenefits from corridors. Does it? Do other spe- Society of America committee on the scientific basis for cies in its communities? What sorts of corridors? ecosystemmanagement. Ecological Applications 6:665-691. COMMITTEEON MANAGEMENTOF WOLF AND BEAR POPULATIONSIN ALASKA(NATIONAL RESEARCH COUNCIL). 1997. Wolves, bears, CONCLUSIONS and their prey in Alaska. National Academy Press, Washington,D.C., USA. Ecosystem management, ill-defined as it may be, is Cox, J., R. KAUTZ,M. MACLAUGHLIN,AND T. GILBERT.1994. rapidly becoming entrenchedas the dominantmode of Closing the gaps in Florida's wildlife habitatconservation conservationactivity, both because of perceived econo- system. Florida Game and Fresh WaterFish Commission, mies of scale and because it seems adaptedto a goal of Tallahassee,Florida, USA. maintaining biodiversity. Single species, even charis- DOAK,D.F. 1995. Source-sink models and the problem of habitat matic ones like bears, are destined to be de-emphasized degradation:general models and applicationsto the Yellowstone Conservation 9:1370-1379. in much conservationplanning as this shift occurs. How- grizzly. Biology EHRLICH,P.R., AND A.H. EHRLICH.1981. Extinction: The causes ever, the manifold human fascination with bears, and and consequencesof the of Random theirrole as for them to the role of disappearance species. symbols nature,adapt House, New York,New York,USA. in kind of conservation in- flagship species any effort, , AND H.A. MOONEY. 1983. Extinction, substitution, and cluding those with biodiversity as the chief goal. There ecosystem services. BioScience 33:248-254. 26 Ursus 11:1999

FRANKLIN, J.F. 1988. Structural and functional diversity in , AND . 1997. Principlesof conservationbiology, temperateforests. Pages 166-175 in E.O. Wilson, editor. Second edition. Sinauer Associates, Sunderland, Biodiversity. National Academy Press, Washington,D.C., Massachusetts,USA. USA. MILLS, L.S., M.E. SOULE,AND D.F. DOAK. 1993. The keystone- . 1989. Towarda new forestry.American Forests, 1989 species concept in and conservation. BioScience (Nov/Dec):1-8. 43:219-224. GASTON,K.J. 1996. What is biodiversity? Pages 1-9 in K.J. MORET,J. 1994. Un ours-lune au pays du soleil levant. Terre Gaston, editor. Biodiversity. A biology of numbers and Sauvage 81:61-67. (In French.) difference. Blackwell, Oxford, U.K. MORRISSEY,W.A., J.A. ZINN,AND M.L. CORN.1994. Ecosystem GRUMBINE,R.E. 1992. Ghost bears. Exploring the biodiversity management:Federal agency activities.Library of Congress, crisis. Island Press, Washington,D.C., USA. CongressionalResearch Service, Washington,D.C., USA. . 1994. What is ecosystem management?Conservation NAIMAN,R.J., AND K.H. ROGERS.1997. Large animals and Biology 8:27-38. system-level characteristicsin river corridors.BioScience 1997. Reflections on "What is ecosystem 47:521-529. management?" 11:4147. NORSE,E.A., EDITOR.1993. Global marine biological diversity. HAILA, Y., AND J. KouKI.1994. The phenomenonof biodiversity Island Press, Washington,D.C., USA. in conservationbiology. Annales Zoologici Fennici 31:5- NOWAK,R.M. 1991. Walker's mammals of the world, Fifth 18. edition. Johns Hopkins University Press, Baltimore, HALIOUA,J. 1991. Baribal. Une invitation chez les ours. Terre Maryland,USA. Savage 57:64-81. (In French.) OFFICEOF TECHNOLOGYASSESSMENT (U.S. CONGRESS).1987. HALLOWELL, A.I. 1971. Bear ceremonialism in the eastern Technologies to maintain biological diversity. U.S. Woodlandsarea. Pages 141-143 in F.L. Utley, L.Z. Bloom, GovernmentPrinting Office, Washington,D.C., USA. and A.F. Kinney, editors. Bear, man, and God: Eight PAINE,R.T. 1969. A note on trophiccomplexity and community approaches to William Faulkner's "The Bear." Random stability. American Naturalist 103:91-93. House, New York,New York,USA. . 1995. A conversation on refining the concept of HARTING,A.L. 1987. Grizzly bear-black bear relationships. keystone species. ConservationBiology 9:962-964. Pages 77-78 in M.N. LeFranc, Jr., M.B. Moss, K.A. PETERSON,R.O., AND R.E. PAGE. 1983. Wolf-moose fluctuation Patnode, and W.C. Sugg, III, editors. Grizzly bear in Isle Royale National Park, Michigan, USA. Acta compendium. Interagency Grizzly Bear Committee, Zoologica Fennica 174:251-253. Washington,D.C., USA. POLIS, G.A., ANDD.R. STRONG. 1996. Food web complexity and HERMANN,S.M., EDITOR.1993. Proceedings of the Tall Timbers communitydynamics. AmericanNaturalist 147:813-846. fire ecology conferenceNo. 18. The longleafpine ecosystem: SHAFFER,M.L. 1983. Determiningminimum viable , restoration and management. Tall Timbers sizes for the grizzly bear.International Conference on Bear Research Station, Tallahassee,Florida, USA. Research and Management5:133-139. HILDERBRAND, G.V., T.A. HANLEY, C.T. ROBBINS, AND C.C. SIMBERLOFF,D. 1998. Flagships, umbrellas, and keystones: Is SCHWARTZ.1999. Role of brown bears (Ursus arctos) in the single-species management passe in the landscape era? flow of marine nitrogen into a terrestrial ecosystem. Biological Conservation83:247-257. Oecologia 121:546-550. . 1999. The role of science in the preservationof forest HoBBs,R.J. 1992. The role of corridorsin conservation:solution biodiversity.Forest Ecology and Management115:101-111. or bandwagon?Trends in Ecology andEvolution 7:389-392. , J.A. Farr,J. Cox, andD.W. Mehlman.1992. Movement HOOPER,D.U., AND P.M. VITOUSEK. 1997. The effects of plant corridors: conservation bargains or poor investments. composition and diversityon ecosystem processes. Science ConservationBiology 6:493-504. 277:1302-1305. SNYDER, G. 1990. The practice of the wild. North Point Press, HURLBERT,S.H. 1997. Functionalimportance vs. keystoneness: San Francisco, California,USA. Reformulatingsome questions in theoreticalbiocenology. SOULE,M.E. 1994. Normative conflicts and obscurantismin AustralianJournal of Ecology 22:369-382. the definition of ecosystem management.Page 20 in W.W. KEYSTONECENTER. 1993. National ecosystem management Covingtonand L.F. DeBano, editors. Sustainableecological forum meeting summary. Keystone Center, Keystone, systems: Implementing an ecological approach to land Colorado,USA. management. U.S. Department of Agriculture Forest LENTIFER,J.W. 1984. Polarbear. Pages 92-93 in D. Macdonald, Service, Fort Collins, Colorado,USA. editor. The encyclopedia of mammals. Facts on File STEVENS,W.K. 1998. One in every eight plant species is Publications,New York, New York, USA. imperiled, a survey finds. New York Times (9 April):Al, LYDENBERG,J. 1952. Nature myth in Faulkner's "The Bear." A24. American Literature24:62-72. STEWART,R.R., E.H. KOWAL,R. BEAULIEU,AND T.W. ROCK.1985. MEFFE, G.K., AND C.R. CARROLL. 1994. Principles of The impactof black bear removalon moose calf survivalin conservation biology. Sinauer Associates, Sunderland, east-centralSaskatchewan. Alces 21:403-418. Massachusetts,USA. STIRLING,I. 1988. Polar bears. University of Michigan Press, INVITEDPAPER * BIODIVERSITYAND BEARS * Simberloff 27

Ann Arbor,Michigan, USA. WILDLANDSPROJECT. 1995/1996. Wildlands. The Wildlands TERBORGH,J., J.E. ESTES,P. PAQUET,K. RALLS, D. BOYD-HEGER, Project. Wild Earth5(4):1. B.J. MILLER,AND R.F. Noss. 1999. The role of top carnivores WILLSON, M.F., S.M. GENDE, AND B.H. MARSTON. 1998. Fishes in regulating terrestrialecosystems. Pages 39-64 in M.E. and the forest. BioScience 48:455-462. Soule and J. Terborgh,editors. Continentalconservation: WILSON, E.O., EDITOR.1986. Biodiversity. National Academy Scientific foundationsfor regional conservationnetworks. Press, Washington,D.C., USA. Island Press, Washington,D.C., USA. WOODING, J.B., AND J.R. BRADY. 1987. Black bear roadkills in TILMAN, D., J. KNOPS, D. WEDIN, P. REICH, M. RITCHIE,AND E. Florida. Proceedings of the Annual Conference of the SIEMANN.1997. The influence of functional diversity and Southeastern Association of Fish and Wildlife Agencies composition on ecosystem processes. Science 277:1300- 41:438-442. 1302. WORLDWILDLIFE FUND. 1998. Website http://www.wwf.org/new/ TRACY, C.R., AND P.F. BRUSSARD. 1994. Preserving biodiversity: fires/species.htm species in landscapes. Ecological Applications4:205-207. YOON,C.K. 1997. Many habitat conservation plans found to WALKER,B.H. 1992. Biodiversity and ecological redundancy. lack key data. New YorkTimes (23 December):B13. ConservationBiology 6:18-23.