1 Cryptic Behavir f Black Bears (Ursus americanus) in Rcky Muntain Natinal Park, Clrad Authr(s): Henry E. McCutchen Surce: Bears: Their Bilgy and Management, Vl. 8, A Selectin f Papers frm the Eighth Internatinal Cnference n Bear Research and Management, Victria, British Clumbia, Canada, February 1989 (199), pp Published by: Internatinal Assciatin f Bear Research and Management Stable URL: Accessed: 2/1/29 16:25 Yur use f the JSTOR archive indicates yur acceptance f JSTOR's Terms and Cnditins f Use, available at JSTOR's Terms and Cnditins f Use prvides, in part, that unless yu have btained prir permissin, yu may nt dwnlad an entire issue f a jurnal r multiple cpies f articles, and yu may use cntent in the JSTOR archive nly fr yur persnal, nn-cmmercial use. Please cntact the publisher regarding any further use f this wrk. Publisher cntact infrmatin may be btained at Each cpy f any part f a JSTOR transmissin must cntain the same cpyright ntice that appears n the screen r printed page f such transmissin. JSTOR is a nt-fr-prfit rganizatin funded in 1995 t build trusted digital archives fr schlarship. We wrk with the schlarly cmmunity t preserve their wrk and the materials they rely upn, and t build a cmmn research platfrm that prmtes the discvery and use f these resurces. Fr mre infrmatin abut JSTOR, please cntact Internatinal Assciatin f Bear Research and Management is cllabrating with JSTOR t digitize, preserve and extend access t Bears: Their Bilgy and Management.
2 CRYPTIC BEHAVIOR OF BLACK BEARS (URSUS AMERICANUS) IN ROCKY MOUNTAINATIONAL PARK, COLORADO HENRY E. MCCUTCHEN, Research Bilgist, Natinal Park Service, Rcky Muntain Natinal Park, Estes Park, Clrad 8517 Abstract: Black bear (Ursus americanus) in many U.S. and Canadian natinal parks becme habituated t humans. They are ften bld, frequent human use areas and are generally a nuisance. At Rcky Muntain Natinal Park, Clrad, the antithesis f this behavir has been bserved in the black bear ppulatin. A 4-year study using radi-telemetry and bservatin indicates that althugh many bears have hme ranges in high human use areas, they are secretive and avid humans and develped areas. The behavir f 2 f the park's radi-cllared bears is dcumented and discussed. Int. Cnf. Bear Res. and Manage. 8:65-72 Mst U.S. and Canadian natinal parks with ppulatins f American black bears (Ursus americanus) have reprted prblems with this species. In part because they are prtected in parks, bears have becme habituated t humans, human activity, and develpment. They have tended t depend n human fds and refuse, and they have caused human injury and prperty damage because f these unwanted habits. Black bears in mst parks are highly visible and are cmmnly bserved by the public alng rads, trails, and in campgrunds. Many parks have histrically experienced high numbers f bear inci- dents and depredatins (Barnes 1967, Bray 1967, Marsh 1972, Peltn et al. 1976, Zardus and Parsns 198, Harms 1979 and 198, Singer and Brattn 198, Graber 1981, Keay and VanWagtendnk 1983, Herrer 1985). Because f bear depredatins and human injury, mst natinal parks have develped prgrams, cstly in funding and manpwer, t mitigate r reduce black bear prblems (Marsh 1972, Peltn 1972, Peltn et al. 1976, Harms 1979 and 198, Zardus and Parsns 198, Singer and Brattn 198, Keay and VanWagtendnk 1983). These include: educatinal prgrams t teach park visitrs and emplyees prper behavir and fd handling techniques in regard t bears; establishment and vigrus enfrcement f rules and regulatins relating t fd handling and dispsal and feeding bears, and capture and transplant r remval f prblem bears frm the ppulatin. Expensive schemes t handle human refuse have been devised, such as installatin f many bear-prf fd cntainers and garbage cans; clsing pen pit dumps; scheduling daily garbage pickups, and hauling refuse lng distances ut f the parks. These measures have significantly reduced the numbers f bear incidents and bear-related human injuries ver the past 15 years. Hwever, many parks still have many bear incidents and depredatins. The black bear situatin at Rcky Muntain Natinal Park, Clrad cntrasts with that f the ther parks. The park has a small black bear ppulatin and althugh the area is predminately frested and receives 2.5 millin visitrs during mst years, depredatins r incidents have been few t nn-existent. There has seldm been a need t destry r transplant a bear. Further, black bears are rarely bserved by park visitrs r emplyees. The park has never had t implement a majr bear management prgram r install bear-prf garbage cans because f bears. In 1984 a research prgram was initiated n the black bears in the park t determine their ppulatin dynamics, status, and behavir. The bears here were generally fund t be shy and secretive. Their behavir is similar t that f Eurpean brwn bears (Ursus arcts) (Rth 1976 and 1977, Rben 198, Huber and Rth 1986, Elgmrk 1976 and 1987) rather than that f black bears in Nrth American natinal parks (Marsh 1972, Peltn 1972, Peltn et al. 1976, Zardus and Parsns 198, Harms 198, Graber 1981, Herrer 1985, Hastings et al. 1986). This paper describes and dcuments the behavir f the bears at Rcky Muntain Natinal Park. STUDY AREA Rcky Muntain Natinal Park, lcated in nrth central Clrad, is 16,7 ha in size. The park, established in 1915, lies alng the Cntinental Divide. Situated abut 65 km nrthwest f Denver, a majr metrplitan area, the park preserves ne f the mst rugged and spectacular reaches f the Clrad Frnt Range. The elevatins are high, ranging frm 2,329 m t 4,345 m. There are ver 1 muntain peaks exceeding an elevatin f 3, m. Mst f the area is muntainus with steep cliffs and rugged U-shaped valleys frmed by glaciers during the Pleistcene epch. The climate is cntinental with a mean annual temperature f 6 C and a mean annual precipitatin f 41 cm at the lwer elevatins. Mean annual temperatures decrease and precipitatin increases with an increase in elevatin (Stevens 198). The highest precipitatin ccurs in the spring in the frm f heavy,
3 66 BEARS-THEIR BIOLOGY AND MANAGEMENT wet snw. In the summer, afternn thunderstrms als bring precipitatin. Abut tw-thirds f the park is frested. At the lwer elevatins, frm 2,3 m t 2,7 m, is a msaic f frests and grasslands with meadws and riparian types alng the fldplains and river bttms. The frests cntain stands f pndersa pine (Pinuspndersa), Duglas-fir (Pseudtsuga menziesii), aspen (Ppulus tremulides), and ldgeple pine (Pinus cntrta). On the mre pen slpes there are stands f big sage (Artemisia tridentata) and bitterbrush (Purshia tridentata) as well as grassland cntaining muntain muhly (Muhlenbergia mntana), needle-and-thread (Stipa cmata) and sedges (Carex spp.). Wet meadws cntain timthy (Phleumpratense), tufted hairgrass (Deschampsia caespitsa) and Kentucky bluegrass (Pa pratensis). Alng the rivers are stands f willw (Salix spp.), narrwleaf cttnwd (Ppulus angustiflia) and birch (Betula glandulsa). At mid-elevatins, frm 2,7 m t 3,5 m, are subalpine assciatins with stands f Engelmann spruce (Picea engelmannii) and subalpine fir (Abies lasicarpa) with an understry f whrtleberry (Vaccinium spp.). Ldgeple pine is present n areas f shallw sil and in ld burs. Limber pine (Pinusflexilis) and aspen stands are als present in sme sites. The upper elevatins, abve 3,5 m, cntain alpine tundra. Tundra is fairly extensive in the park cvering abut ne-third f the area. Vegetatin cnsists f tufted hairgrass, sedges, Mt. Washingtn dryad (Dryas ctpetala), cliff sedge (Carex scpulrum), Parry primrse (Primula parryi), kbresia (Kbresia mysurides) and glden avens (Geum rssii). The area had a lng histry f land use befre its establishment as a natinal park. Settlers began t arrive in the 186's. Many areas in the park were farmed, mined, lgged, and burned. Large ranches were established and there was heavy grazing by dmestic livestck. Because f its scenic beauty, the area was als recgnized fr its recreatinal pprtunities, which led t the early develpment f dude ranches and resrts. In the early days the area was nted fr its gd hunting. Large ungulates, including elk (Cervus elaphus), mule deer (Odcileus heminus) and bighrn sheep (Ovis canadensis) were extremely abundant (Stevens 198). Wlves (Canis lupus), grizzly bears (Ursus arcts), and black bears were present, but nt as cmmn as ungulates (Armstrng 1975). Lss f habitat, lcal hunting, and market hunters frm Denver reduced the ungulate herds s that by the turn f the century the elk had been extirpated (Sprague 1925, Stevens 198). The bighrn ppulatins persisted but declined drastically pssibly frm scabies and lss f winter range in the 193's (Wright et al. 1932). The wlf became extinct in the early 19's and the grizzly by the late 192's (Wright et al. 1932, Armstrng 1975). The black bear survived these human impacts but in lw numbers (Wright et al. 1932). In 1915, after 15 years f effrt by cnservatinists, the area was established as a natinal park. Since then, a majr effrt in managing the park has been aimed at restring the area t natural cnditins frm past land uses. Farms, ranches, hmes, and resrts within the park bundary were purchased and razed. Disturbed areas were revegetated r allwed t revegetate naturally. Critical ungulate winter range was purchased and restred. Elk and bighrn sheep were reintrduced and have shwn impressive increases (Stevens 198, Stevens and Hansn 1986). The presence f the park nw dminates the lcal ecnmy. Turism has becme the majr business. Turism and develpment, particularly alng the eastern bundary, has increased t the pint that it threatens the integrity f the park. The gateway twn f Estes Park t the east has expanded t the park bundary. Dude ranches, cndminiums, cnference centers, and private hmes are increasing in numbers every year. Frtunately the areas adjacent t the nrth, west, and suth park bundaries are primarily public lands where human develpment and use is cntrlled. Hunting fr bears and ther wildlife species ccurs utside the park bundary. Reginally, urbanizatin is ccurring at a rapid pace alng the Frnt Range lwlands nrth f Denver and east f the park. Rcky Muntain is ne f the mst heavily used U.S. natinal parks with 2.6 millin visits in 1987, dwn frm 3 millin in 1978 (Rcky Muntain Natinal Park Fact Sheet, Oct. 1988). The park receives mre visitatin than Yellwstne, yet is nly ne-eighth the size. Day use predminates; hwever, there are ver 3, camper nights annually at the 5 campgrunds (Statement fr Management, 1982, Rcky Muntain Natinal Park). Use is highly seasnal with the bulk ccurring during June, July, and August. Over 75% f the visitr use is cncentrated n the east side f the Cntinental Divide in the park (Master Plan, 1976, Rcky Muntain Natinal Park). There are 25 backcuntry camp sites with an annual use f abut 35, user nights, dwn frm a peak f 62, in 1977 (Statement fr Management, 1982, Rcky Muntain Natinal Park). Day hiker use is als high, estimated at abut 6, per year n the 3 miles f park trails (Statement fr Management, 1982, Rcky
4 BLACK BEAR BEHAVIOR IN ROCKY MOUNTAI NATIONAL PARK * McCutchen 67 Muntain Natinal Park). Cmmercial hrse rides are estimated at 4, t 5, per year riginating frm 2 liveries in the park and 24 utside. Autmbile traffic is heavy n the park's 1 mile$ f rads during peak days f visitr use. Trail Ridge Rad, which traverses frm the east side t the west side f the park, can receive mre than 1, cars per hur use during peak perids (McCutchen unpubl. data). T alleviate traffic cngestin t Bear Lake, anther favred area, a shuttle bus system is in peratin during the summer. Black bears are present in the park but have never been cnsidered cmmn (Armstrng 1975). Current research indicates that the ppulatin in the park is 3 t 35 bears with abut 1 bear per 3 km2 (McCutchen unpubl. data). The bear ppulatin in the park is viewed as a "high elevatin" subppulatin cntiguus with a larger ppulatin f "lw elevatin" bears surrunding the park. Because the bears are secretive, they are seldm bserved by the many visitrs using the rads and trails. Bear scat and feeding sign is seldm seen in r near visitr use areas. Althugh bears have access t garbage cans and dumpsters (which are nt bear-prfed), as well as campgrunds, picnic grunds, and backcuntry campsites, there is seldm an incident f a bear raiding them (McCutchen unpubl. data). A review f the histric recrds suggests that bear incidents are smewhat peridic in the park (McCutchen unpubl. data). Bear incidents were lw in the late 195's and early 196's. During the 196's there were 2 high years, 1963 and 1967, with 45 and 27 incidents, respectively. Frm 1959 t 1967 there were abut 2 cntrl actins per year with bears (14 transplanted and 2 killed) in the park. Frm 1968 t 1983 there were nly 17 bear incidents fr a rate f 1 per year. Three bears were captured and transplanted in cntrl actins. The reasns fr the 2 years f high incident rates in the 196's as cmpared t the 197's and early 198's is nt knwn. Visitatin in 1962 was 1.7 millin increasing t 2.5 millin in 1972, then staying fairly cnstant (Natinal Park Service 1976). Thus, visitatin and bear incidents d nt seem t be crrelated. The reductin f incidents after the 196's may be related t the purchase and razing f a number f private guest ranches within the park, which had pen pit dumps used by bears, and bear cntrl in the park at that time (D. Stevens 1989, Rcky Muntain Natinal Park, pers. cmmun.). In 1984, after a 17-year hiatus, anther exceptinal year ccurred when a bear began t raid backcuntry campsites. That year there were abut 9 incidents. The ffending bear, a subadult male, was captured and remved frm the area. In subsequent years bear incidents were again lw. MATERIALS AND METHODS Between 1984 and 1988, we captured 23 black bears in the park with culvert traps r with Aldrich ft snares. We immbilized them with a cmbinatin f Ketamine and Rmpun. They were marked with numbered aluminum ear tags, weighed, and measured. The first premlar was pulled fr cementum aging. Seventeen f the bears were radi-cllared (Telnics, Mesa, AZ). Radi-telemetry was cnducted n ft, by autmbile, by fixed-wing aircraft, and by helicpter. An attempt was made t btain at least ne accurate lcatin n each bear each week. The usual prcedure was t btain a general lcatin n a bear by vehicle then mve in n ft t btain a mre accurate fix thrugh a series f triangulatins. It was extremely difficult t apprach t within abut 1 m f the bears withut disturbing them and chasing them away. Because f this, researchers wuld ften stay back abut 4 m r mre t btain fixes. We estimated that radi-fixes btained at 1 m r less were accurate t abut?25 m. Radi-fixes 5 m t 1 km were accurate t abut +15 m. Radi-lcatins were nly btained diurnally as nighttime lcatins were t difficult t btain in the rugged terrain. After the bear research began, the park staff develped a bear infrmatin netwrk. All bear sightings reprted by park persnnel (75 permanent and 3 seasnals) and park visitrs were channeled int a central dispatch ffice, recrded, then passed n t the research team. Because bears were rare, park visitrs ften stpped at the entrance statins r visitr centers and reprted their bear sightings. Backcuntry rangers reprted bear sightings r signs. Garbage handlers reprted bear r ther animal raids n garbage cans alng their rute. Fr this reprt the 2-year cmpsite hme ranges and radi-lcatins f 2 female bears fr the years 1985 and 1986 are examined. These are bears N. 2 with 47 radilcatins, and N. 3 with 52 radi-lcatins. Bear N. 2 was estimated t be 14-years-ld in She had n cubs in 1985 and lst her cubs in the spring f Bear N. 3 was estimated t be 4-years-ld in She had n cubs either year. These bears were selected because they had hme ranges in the prtin f the park with the greatest human use. During these time perids, n ther bears were knwn t be permanent residents in these bears' hme ranges; hwever, different bears, believed t have been transients, were sighted in the area. Snare lines were set t determine if ther bears were present. Nne were captured except the knwn females. The relcatin data were lumped fr 1985 and 1986 t increase the sample sizes fr statistical analyses and t
5 68 BEARS-THEIR BIOLOGY AND MANAGEMENT shw the radi-lcatins and hme ranges n a single map. The 2 bears were captured in the summer f 1985, s that year's data were nly fr a part f the summer and fall. The 1986 radi-lcatin data are fr the entire year. The resultant 2-year cmpsite hme ranges and sizes fr the 2 bears are similar t thse btained thrugh mre limited radi-tracking in 1987 and 1988 (McCutchen unpubl. data). T prvide a measurement f each bear's avidance behavir in relatin t human use, radi-lcatin data were pltted n a base map. The distance f each lcatin t the clsest set f human use features was then measured t the nearest.1 km. Human use features I believed t be f imprtance included trails, trailheads, paved rads, dirt rads, human residences, picnic areas, majr campgrunds, backcuntry campgrunds, the park bundary, and miscellaneus develpments (ski area, majr pulluts, parking lts, visitr centers, stables). Hme ranges were delimited by the minimum plygn methd (Mhr 1947). RESULTS AND DISCUSSION Figure 1 depicts the 2-year cmpsite hme ranges f bears N. 2 and 3. The hme ranges verlapped nly slightly. Adult females in the park appeared t have nearly exclusive hme ranges (McCutchen unpubl. data), and may be territrial, similar t the black bears reprted by Yung and Ruff (1982) and Rgers (1987). Bear N. 2 had a hme range (7.8 km2) that was rughly bunded by Trail Ridge Rad t the nrth, the main park rad t the east, the Bear Lake Rad t the suth, and timberline t the west (Fig. 1). Within her hme range were apprximately 17 km f rads, 59 km f trails, 11 backcuntry sites, 9 trailheads, 2 majr picnic grunds, a majr campgrund, a majr verlk, 2 majr parking lts, and 1 small residential area. Alng the rads were abut 1 small pulluts and picnic tables with attendant garbage cans. Bear N. 2 ccasinally crssed the rads t the nrth and suth but was never knwn t crss the rads t the east. The greater prtin f her hme range was in the backcuntry, accessible nly by trails. She frequently used the nrthwestern sectin f her hme range cntaining Frest Canyn, a nearly impassable rugged area, f dense spruce/fir frest and dead fall cntaining n trails. Her hme range was away frm areas f majr human develpment, particularly the area t the east f her. This area includes the Twn f Estes Park utside the park and an intensive zne f develpment in the park cntaining 2 majr campgrunds, a netwrk f majr rads, park headquarters, several residential areas, and a visitr center. Althugh campgrunds are an attractant bears in many natinal parks (Martinka 1974, Peltn et al. 1976, Harms 1979 and 198, Graber 1981, Herrer 1985), bear N. 2 was never knwn t visit the campgrunds. The distance f bear N. 2's radi-lcatins t visitr use areas (Fig. 2a) indicates that althugh she stayed away frm these areas, the average distance was quite variable depending upn the area type. Much f her hme range was dissected by trails; thus, she was lcated clser t trails (.8 km) and trailheads (1.9 km) n the average than ther areas f use. Based n lcatins in her hme range (Fig. 1) she seemed t be electing t be near trails in the suthern part, apparently fr 2 reasns. First, trails in this area are near creeks and wet areas, which, frm my experience, appear t be favred bear habitat. Secnd, there is sme research bias here as her signal was mre easily picked up alng trails than in "dead spts" away frm trails. Bear N. 2 was seldm lcated in r near areas f majr develpment where human use and residence was n a 24-hur basis r was year-rund, e.g., the majr campgrunds, and the park bundary area (Fig. 2a). Bear N. 3 had a smaller hme range f 35.1 km2 (Fig. 1), which was dissected by 2 majr rads, Trail Ridge Rad t the suth and Fall River Rad thrugh the valley in the center. Bth f these rads received heavy human use in the summer. Bear N. 3's hme range cntained 24 km f rads, 9 km f trails, a ski area, a majr verlk, 6 large pulluts, 3 trailheads, and a small residential area. In additin, a majr picnic grund was lcated almst in the gegraphic center f her hme range. At the pulluts and ther use areas were numerus garbage cans fr the visitrs' cnvenience. Bear N. 3's hme range verlapped nly slightly with bear N. 2's. Bear N. 3 tended t utilize the rugged, steep, muntain slpes nrth and suth f Fall River, particularly the nrth-facing slpe with its denser vegetatin. Figure 2b indicates that she als was radi-lcated away frm areas f human use. She was lcated clser t the paved rads than ther features but still maintained an average distance f 1.1 km frm them. She maintained the farthest distance away frm the nearest majr campgrund (6. km) and the park bundary (6.5 km) t the east, n the average (Fig. 2b). She was never knwn t visit the picnic grund in the center f her hme range even thugh it had dumpsters and garbage cans. In additin t the radi-telemetry, indirect evidence f avidance was determined frm the lack f any reprted bear-raiding f the refuse cntainers in this area during that time perid. Figures 2a and 2b prvide a rugh index f the
6 BLACK BEAR BEHAVIOR IN ROCKY MOUNTAIN NATIONAL PARK * McCutchen m L ~/ apprx. timberline, C, 3292 m NORTH meters I Rcky Muntain Natinal Park Bundary paved rad dirt rad bear #2 lcatin bear #2 hme range bundary *- bear #3 lcatin bear #3 hme range bundary areas f high human use park headquarters H backcuntry campsite A trailhead * trail campgrund A picnic area I majr stpping pint X ski area s residence urban develpment Fig. 1. Tw-year cmpsite hme ranges f black bears N. 2 and N. 3 ( ) in relatin t human use areas, Rcky Muntain Natinal Park, Clrad.
7 7 BEARS THEIR BIOLOGY AND MANAGEMENT 13 E LU z H- C/) z O FEMALE #2 CONFIDENCE INTERVAL (95%) MEAN 1 I RANGE I I 1 EE LL z c) z C w _J - C a Q >-"'i -K zsi Cc () v>. cc - ZW O C O YE z --)z < LU -rcis Q 5 cc. a. < O m C) z I : ac I 4:j Q >-Lu cc w ZW < f) >- a c w (! I c I I I - 1C C Z _ 5 a I a. c c HUMAN USE FEATURES HUMAN USE FEATURES Figs. 2aand 2b. Radi-lcatin distances f black bears N. 2 (N= 47) and N. 3 (N= 52) frm human use features ( ), Rcky Muntain Natinal Park, Clrad. tlerance f bth bears t varius park recreatinal develpments. The varius linear transprtatin crridrs (trails and rads) were mre tlerated than structures and facilities. Bear N. 2 was lcated clser t trails than t any ther type f area prbably because there were s many in her hme range. Bear N. 3 was lcated clser t paved rads. Althugh paved rads tended t receive much greater use than dirt rads, bth bears seemed t tlerate paved rads slightly better than the dirt rads. The bears tended t keep abut 1.5 t 4 km n the average frm trailheads, human residences, and picnic grunds. They stayed the farthest, ver 4 km n the average, frm the majr campgrunds. These average distances (Figs. 2a and 2b) illustrate a few general trends. Avidance behavir f the bears is shwn by the minimum distance the bears were lcated frm human use areas (Figs. 2a and 2b). Frm the minimum distance statistics, ther than the instance f bear N. 3 being lcated alng a trail, bth bears were always lcated away frm areas f human use. I hypthesize that similar data develped fr a bear habituated t a campgrund r radside wuld shw a clser mean distance and a minimum distance f zer as cmpared t a nn-habituated bear shwing a farther mean distance and minimum distance greater than zer. Black bears have been knwn t stay away frm human use areas during the day and visit them at night (Ayres et al. 1986) t btain fd. There was n evidence that bears N. 2 and 3 did this. That the bears did nt use visitr use areas at night can be inferred in several ways: they were nt bserved at night alng rads and trails nr in the frntcuntry r backcuntry campsites by the numerus park visitrs r by rangers n patrl; bear scat was rarely bserved n trails by the bear research team r backcuntry rangers; and the numerus garbage cans placed alng the rads and in picnic grunds and campgrunds were nt raided at night. The cryptic behavir f the bears in the park can als be shwn by the small number f sightings and incidents during 1985 and 1986 (Table 1). An incident was recrded when a bear was bserved in a visitr use area fraging fr human fd r when a garbage can was raided by a bear. In 1985 there were 16 bear sightings and 1 incident parkwide. Of these, 7 were sightings in bear N. 2's hme range and 1 was a sighting in bear N. 3's. Mst f these sightings within the hme ranges were f the radi-cllared bears; hwever, a large, different bear was sighted nce in bear N. 2's hme range, during the breeding seasn. It was mst likely a male because bear N. 2 had cubs the fllwing seasn. In 1986 (Table 1), there were 13 sightings and 4
8 BLACK BEAR BEHAVIOR IN ROCKY MOUNTAI NATIONAL PARK * McCutchen 71 incidents parkwide. There were 2 sightings and 1 incident in bear N. 2's hme range and 2 sightings and n incidents in bear N. 3's. Again thrugh radi-tracking fllw-up, the sightings were. mst likely f the radicllared bears. The 1 incident, hwever, was caused by a transient bear. Cnsidering that the bulk f the visitr use in the park is in bear N. 2 and bear N. 3's hme ranges, including the estimated 6, hiker-days f trail use, the number f sightings is small. The mst graphic demnstratin f the level f avidance f these females t human use areas ccurred in In the summer f 1985, bears N. 2 and N. 3 were captured. Bear N. 2 weighed 49 kg and bear N. 3, captured in late summer, weighed 35 kg. In the winter f they were reweighed at the dens. Bear N. 2, wh had 2 cubs, still weighed 49 kg, and bear N. 3 weighed nly 25 kg. In the summer f 1986 bear N. 2 was recaptured and weighed 71 kg. I suspect that these weight lsses during the winter f were attributed t a pr fd year in Bear N. 2 lst her cubs and I suspect that she was in such pr cnditin at a weight f 49 kg that she culd nt prvide adequate nutritin fr them. Als fr that winter, bear N. 3 lst abut 26% f her summer weight. Neither f these bears raided readily available garbage cans alng rads and in picnic areas r human fd in backcuntry campsites befre r after this apparently difficult denning perid. The study team culd nly ask "Why wuld these bears risk starvatin in the den rather than frage n readily available, high energy, human fds in their hme ranges"? The data presented abve suggest that black bears in this park exhibit a "mdel" behavir that many ther parks are striving fr. Yet, this "mdel" behavir exacts a cst frm the bears althugh they are persisting in an area f high human use. In the park there is a netwrk f human use travel crridrs and centers f high human use with readily available high prtein garbage. There are even human use areas in what we perceive as quality bear habitat (riparian areas, aspen stands), yet the bears avid Table 1. Black bear sightings and incidents, 1985 and1986, Rcky Muntain Natinal Park, Clrad. Sightings Incidents Hme ranges bear N bear N Other areas Ttal these areas and utilize the interstices within the human use web. Researchers f black bears and grizzlies in sme parks have nted 2 types f behavir in the same ppulatin, depending upn whether r nt they visited human use areas fr fd. Fr grizzlies in Yellwstne, Mattsn et al. (1987) labeled these types "wary" and "habituated". Ayres et al. (1986) separated the black bears in Sequia Natinal Park int "natural" and "campgrund bears". At Rcky Muntain Natinal Park the black bears, with rare exceptin, wuld be classified as "wary" r "natural". There is n evidence f"habituatin" (McArthur 1983) at the present time. Parks with a histry f artificial feeding f bears, such as Yellwstne, Sequia and Kings Canyn, Ysemite, and the Great Smky Muntains, have persisting prblems with habituated bears, even with intensive bear management prgrams in place ver the past 15 years. At Rcky Muntain bears were never allwed t feed n human fds (Wright et al. 1932). Frm the time the park was established in 1915, bears that develped the habit f feeding n human fds were remved frm the park. Martinka (1972) ntes that this was the case in Glacier Natinal Park. Yet, Glacier regularly has prblems if fd is unsecured. Black bears cmmnly enter campgrunds, picnic areas and ther develped areas, and ccasinally btain unsecured fd. Elgmrk (1976, 1987) suggested that the cryptic behavir f brwn bears in Nrway may have been the result f histric verhunting and "gun selectin". He hypthesized that this trait culd be passed n via heredity and learning t new generatins. Perhaps heredity and learning have influenced Rcky Muntain Natinal Park's black bears because they were heavily hunted prir t the park's establishment. Als, the park is s small that nearly every bear may be expsed t hunting adjacent t the park bundary during its lifetime, even thugh they are prtected in the park. Tw f the bears radi-cllared in the park (subadult males) have been killed by hunters utside the park. An additinal factr may be the selective pressure f the remval f prblem bears that has been maintained n the small ppulatin f Rcky Muntain bears since the park was established in At the present time the reasn r reasns fr the cryptic behavir f the black bears at Rcky Muntain Natinal Park will cntinue t be investigated. Fllwing the bears fr several generatins may prvide sme insight int the behavir; hwever, this phenmenn may never be easily explained. The behavir may be the result f genetics, learning, r a cmbinatin f these. Other interrelated factrs might include a histry f hunting prir t park
9 72 BEARS-THEIR BIOLOGY AND MANAGEMENT establishment; Natinal Park Service cntrl actins; a lack f widespread histrical artificial feeding; lw ppulatin densities with an inability t fill available vacant habitat; lw rates f reprductin; lss f habitat; and pr quality, interspersin, and juxtapsitin f resurces. Whatever the reasns, these bears apparently give up valuable habitat t the mre dminant species, man, within their wn hme ranges. LITERATURE CITED ARMSTRONG, D.M Rcky Muntain mammals. Rcky Muntain Nature Assc. Inc. Estes Park, Clrad. 174pp. AYRES, L.A., L.S. CHOW, AND D.M. GRABER Black bear activity patterns and human induced mdificatin in Sequia Natinal Park. Int. Cnf. Bear Res. and Manage. 6: BARNES, V.G., JR Activities f black bear. M.S. Thesis, Cl. State Univ., Ft. Cllins. 116pp. BRAY, O.E Ppulatin study f black bear. M.S. Thesis, Cl. State Univ., Ft. Cllins. 97pp. ELGMORK, K A remnant brwn bear ppulatin in Nrway and prblems f its cnservatin. Int. Cnf. Bear Res. and Manage. 3: The cryptic brwn bear ppulatin f Nrway. Int. Cnf. Bear Res. and Manage. 7: GRABER, D.M Eclgy and management f black bears in Ysemite Natinal Park. Ph.D. Thesis, Univ. Calif., Berkeley. 26pp. HARMS, D.R Natinal parks Pages in D. Burk, ed. The black bear in mder Nrth America. Bne and Crcket Club. Amwell Press, Clintn, N.J. 3pp. _ Black bear management in Ysemite Natinal Park. Int. Cnf. Bear Res. and Manage. 4: HASTINGS, B.C., B.K. GILBERT, AND D.L. TURNER Black bear aggressin in the backcuntry f Ysemite Natinal Park. Int. Cnf. Bear Res. and Manage. 6: HERRERO, S Bear attacks. Winchester Press, Piscataway, N.J. 287pp. HUBER, D., AND H.U. ROTH Hme ranges and mvements f brwn bear in Plitvice Lakes Natinal Park, Yugslavia. Int. Cnf. Bear Res. and Manage. 6: KEAY, J.A., AND J.W. VANWAGTENDONK Effects f Ysemite backcuntry use levels n incidents with black bears. Int. Cnf. Bear Res. and Manage. 5: MARSH, J.S Bears and man in Glacier Natinal Park, British Clumbia, Int. Cnf. Bear Res. and Manage. 2: MARTINKA, C In Summary f discussin. Int. Cnf. Bear Res. and Manage. 2: _ Preserving the natural status f grizzlies in Glacier Natinal Park. Wildl. Sc. Bull. 2(1) MATTSON, D.J., R.R. KNIGHT, AND B.M. BLANCHARD The effects f develpments and primary rads n grizzly bear habitat use in Yellwstne Natinal Park, Wyming. Int. Cnf. Bear Res. and Manage. 7: NATIONAL PARK SERVICE Final master plan, Rcky Muntain Natinal Park. 4pp. MCARTHUR JOPE, K.L Habituatin f grizzly bears t peple: a hypthesis. Int. Cnf. Bear Res. and Manage. 5: MOHR, C.O Table f equivalent ppulatin n Nrth American mammals. Am. Midi. Nat. 37: PELTON, M.R Use f ft trail travelers in the Great Smky Muntains Natinal Park t estimate black bear (Ursus americanus) activity. Int. Cnf. Bear Res. and Manage. 2:36-42., C.D. Scrr, AND G.M. BURGHARDT Attitudes and pinins f persns experiencing prperty damage and/r injury by black bears in the Great Smky Muntains Natinal Park. Int. Cnf. Bear Res. and Manage. 3: ROBEN, P Status f the brwn bear in the Pyrenees. Int. Cnf. Bear Res. and Manage. 4: ROGERS, L.L Effects f fd supply and kinship n scial behavir, mvements, and ppulatin grwth f black bears in nrtheastern Minnesta. Wildl. Mngr. N pp. ROTH, H.U Status f the last brwn bears f the Alps in the Trentin, Italy. Int. Cnf. Bear Res. and Manage. 3: Defecatin rates f captive brwn bears. Int. Cnf. Bear Res. and Manage. 4: SINGER, F.J., AND S.P. BRATTON Black bear/human cnflicts in the Great Smky Muntains Natinal Park. Int. Cnf. Bear Res. and Manage. 4: SPRAGUE, A.E Game mre plentiful nw than 5 years ag in Estes Park regin. Estes Park Trail. 5 June STEVENS, D.R The deer and elk f Rcky Muntain Natinal Park. Natl. Park Serv. Mime. 163pp. _, and D.D. HANSON The use f transplanting t expand bighrn sheep range. Prc. Bienn. Nrth Am. Wild Sheep Cuncil. 5: WRIGHT, G.M., J.S. DIXON, AND B.H. THOMPSON Fauna series N. 1. Natl. Park Serv., U.S. Dep. Inter. 157pp. YOUNG, B.F., AND R.L. RUFF Ppulatin dynamics and mvements f black bears in east central Alberta. J. Wildl. Manage. 46(4): ZARDUS, M.J., AND D.J. PARSONS Black bear management in Sequia and Kings Canyn Natinal Parks. Int. Cnf. Bear Res. and Manage. 4:195-2.