Seasonal Movements of an Alaska Peninsula Brown Bear Population

SEASONAL MOVEMENTSOF AN ALASKA PENINSULABROWN BEAR POPULATION

LELAND P. GLENN, Alaska Department of Fish and Game, 333 Raspberry Road, Anchorage 99502 LEO H. MILLER,Alaska Department of Fish and Game, 333 Raspberry Road, Anchorage 99502.

Abstract: On the central Alaska Peninsula, 344 different coastal brown bears (Ursus arctos L.) were immobilized and markedduring 5 spring seasons. Between 1970 and 1976, the observed locations of 123 markedbears were determined354 times, and the locations of 139 markedbears killed by huntersduring spring and fall huntingseasons were recorded.Bears moved greaterdistances per unit of time duringspring than during otherseasons of the year. Summermovements were restrictedas bearsconcentrated along streamsto feed on salmon. Dispersalaway from streams began in late summer. Denning usually began by mid-November, but some bears remained out of hibernationthrough mid-December. The seasonal ranges of 30 adult females averaged 293 km2 and those of 4 adult males averaged 262 km2. Limited movement data for adult males suggested that males spent more time thanfemales in or near escape cover. The mobility and springdistribution of adultfemales were relatedto changes in theirreproductive status. Single adultfemales moved furtherthan females accompaniedby young. Females with 1- to 3-year-oldyoung utilized open lowland areasduring the springand tended to be in mountainousterrain when breedingand when accompaniedby young throughage 6 months. Subadultmales were moretransient than females, tendingto move out of theirmaternal seasonal range after family separation;subadult females tended to remain. The seasonal range of 5 subadultmales and of 6 subadultfemales averaged 740 km2 and 224 km2, respectively.

This paper describes seasonal distribution and resourcemanagers with informationon the general pat- movements of brown bears on a 8,547 km2 study area tern of movements of a coastal brown bear population. located on the central Alaska Peninsula. The Alaska This study was conductedby the Alaska Department Peninsula extends 680 km southwest from mainland of Fish and Game and was funded by Alaska Federal Alaska into the Pacific Ocean. It contains probablythe Aid in Wildlife RestorationProject W- 17-2 through8. largestremaining parcel of primebrown bear habitat yet A. Egbert,J. Faro, A. Franzmann,C. Irvine, E. Klink- unalteredby man. The region supportsa large popula- hart, C. Mcllroy, K. Pitcher, B. Rausch, and K. tion of bears and annuallycontributes about 25 percent Schneider, Alaska Departmentof Fish and Game, as- of the total statewide harvest (average, 200 of 800). sisted in the field and laboratory. Credit for piloting About 50 of the 200 bears are taken on the study area. skills and field assistance is given to J. Farwell, A. Increased hunting pressure has required increasingly Gretchen, G. Jarvella, G. Kitchen, B. Lyons (de- restrictiveand complex hunting regulationsto stabilize ceased), C. Martin,B. Morgan(deceased), J. Osgood, bear populationlevels. In recent years, there has been a R. Shower, and J. Swiss. markedincrease in mineralexploration and otherrelated industrialactivities, all of which may ultimately prove STUDY AREA detrimentalto this bear land owner- population. Also, The study area(Fig. 1) is approximately110 km long are ship patterns changing as provisions of the Alaska and 65 km wide and lies between two semi-active vol- Native Claims Settlement of Act 1971 areimplemented. canoes: Mount Aniakchak (1,021 m) on the northeast bear Administering managementprograms on federal, and Mount Veniaminof (2,226 m) on the southwest. state, Alaska Native, and lands will be private difficult. These mountainsare dominantfeatures of the portionof Information on movements of coastal brown bear the Aleutian Range that extends throughthe study area. is populations limited, especially for populations that A broad, flat coastal plain with many small lakes and receive heavy huntingpressure and for bearsthat depend meanderingstreams lies between the mountainsand the on salmon (Oncorhynchusspp.) for food. Craighead coast of Bristol Bay. Lowlands of the coastal plain are (1976) the reported strong influence of earth-filledgar- poorly drained and remain flooded until streams sub- on bear bage dumps grizzly density and movements side, usually in the thirdweek of June. Mountainsof the within and beyond Yellowstone National Park. Bems AleutianRange graduallyascend from the coastal plain, and Hensel described (1972) summerand fall activities with peaks averaging850-975 m above sea level. On the of 14 brown bears on Kodiak National Wildlife Refuge Pacific side of the mountains,habitat is characterizedby and discussed the size of activity areas in connection steep slopes with alder (Alnus sp.) covered foothills. with and food-gathering denning. Glenn et al. (1976) The broad valley of the Meshik River and Black and noted that bears were strongly attractedto salmon in Chignik lakes bisect the Alaska Peninsula. Dominant Alaska's McNeil River State Game Sanctuaryduring vegetationis sedge (Carex spp.) and willow (Salix spp.) July and August. The purposeof this is to study provide in tundra areas and dense alders, willows, crowberry 308 BEARS THEIR BIOLOGY AND MANAGEMENT

PalmerCap-Chur darts. When a female with young was located, the adult always received the first drug injec- tion. The pilot thenmoved the helicoptera shortdistance away and herdedthe family groupto keep them together and away from thick escape cover and wet areas where they might drown. After the female was immobilized, the same procedurewas used to capturethe young (except cubs-of-the-year).Cubs-of-the-year were captured by hand. Most bears (451 of 502) were capturedin valleys and foothills below the alder zone or on the coastal plain, where the helicopter could be safely maneuvered;the other bears were capturedin the mountains. One upper first premolartooth and one lower first premolartooth were removedfrom each capturedbear older thancubs- of-the-year. The teeth were sectioned to determineage from cemental layers (Mundy and Fuller 1964, Craigheadet al. 1970, Willey 1974). All capturedbears were markedwith ear tags and were tattooedon the groin and on the inside of the upper lip. A numberednylon- and-fiberglassidentification collar designed to permit visual identificationby observersin fixed-wing aircraft was developed, tested and used to mark38 adultbears. Fig. 1. Map of study area and Alaska location map. Fifteen adultbears were collaredwith radiotransmitters (Empetrum nigrum), blueberry (Vaccinium spp.), low- manufacturedby AVM InstrumentCompany, Cham- bush cranberry(V. vitis-idaea), and grasses in moun- paign, Illinois. tainous areas. Weather is characterizedby high winds, The movements of collared bears were monitoredby overcastskies, fog, andrain showers in the summer,and periodic aerial surveys. Each survey aircraftwas equip- by snow showers and cloud cover in the winter. The ped with a portable receiver and a 3-element yagi an- residenthuman population is sparse. Access to the area tennaattached to the wing strut.The position and direc- is by aircraftor boat. tion of movement of marked bears were plotted on 1:250,000 U.S. Geological Survey topographicmaps. METHODS A state regulationrequires that successful bear hun- Bears were captured and marked in spring only, ters presenttheir bear skulls and hides to Departmentof beginning in 1970 and continuing through 1975, Fish andGame personnelfor recordingof kill data. This excluding 1973. Three hundred forty-four different regulation allows departmentpersonnel to interview bearswere marked;about 46 percentof these bearswere successful bear huntersor their guides in orderto estab- recaptured 1 or more times. Sixty-two marked adults lish precise locationsof bearkills. This system was used were relocated by individually identifiable markings to determine kill locations of tagged bears. Marked 188 times, and 61 subadultswere relocated 123 times. bears were detected in the harvest by the presence of The locations of 139 marked bears that were killed fiberglasscollars or radiocollars,ear tags or holes in the during spring and fall hunting seasons were recorded. ears, lip and grointattooes, andmissing upperand lower Bears were located and capturedwith the aid of a Bell first premolars. 206A Turbo helicopter and a fixed-wing Piper PA-18 Because this investigation was concerned with bear aircraft.The fixed-wing aircraftwas used as a spotter movements that may bias population censusing, em- plane. Radio communicationbetween the two aircraft phasis was placed on spring distribution.Mean airline directed the helicopter pilot to the located bear. Bears distances traveled by bears away from their original were located by randomexcursions over the study area. springcapture sites were determinedin orderto show the Bears were immobilized from the helicopter by in- extent of movement. The termsubadult refers to a single jecting Etorphine (M-99) or phencyclidine hy- bear 2-4 years of age. A seasonal range is an area used drochloride (Sernylan) into the rump muscles with duringspring, summer,or fall but excludes the denning SEASONAL MOVEMENTS * Glenn and Miller 309 area (Craighead 1976), and is determinedby marking females with cubs-of-the-yearremained in the vicinity the location sightings on a map and connecting the of their dens until the snow had disappeared. peripheralpoints. Bear movements during June were complex. Except for females with cubs-of-the-year, bears moved greater TIME OF SIGHTING distancesper unit of time thanduring other periods of the I APRIL - MAY * JUNE year. Bears descended from mountainous subalpine I JULY - AUGUST * SEPTEMBER - OCTOBER X NOVEMBER areas onto the coastal plain. Time spent on the plain varied with the individual; most bears were observed only once, but some remainedlonger than 16 days. The rates of capturesuccess in lowland areas provided indi- F * U ..v -S. 1U 1 o4 ces of changes in bear density. Between 28 May and 10 : ..,/,//)/. June, an average of 0.6 bear was capturedper hour of ,-- ( j 9 0 aerial search;between 15 and 30 June, the capturerate

9 U increased to 1.3 bears per hour. Bears were attractedto / / Bristol Bay to feed on dead gray whales (Eschrichtius . / I . i 1 1 1 7 i : I ; I I .p . -- .i , I I i ! g. - I ; r ; , I 1 i I i I I i . . . p i I I I , I i, , 1 i robustus), walruses (Odobenus rosmarus), harbor seals i 1 I i i I I li 1 I I i I \ ii 9 g* * (Phoca vitulina), and other marine mammals that

* * A washed ashore. caribou tarandus) a * v Although (Rangifer calving areas did not appearto attractbears, they were \P >11 I '/ '// 16 -A y observed preying on caribou calves. Bears were ob- (5U *\ 13 .A 9 16 served catching moose (Alces alces) calves and feeding on adult caribouand moose. The coastal plain provided -8 3R 4 a source of proteinfood that was especially attractiveto females with young older than cubs-of-the-year. The observed density of bears on the plain reached a peak in Fig. 2. Dispersal in miles (1.61 km), by season, from spring capture sites for adult male and female brown bears and young (both sexes) captured as subadults mid-June, remainedhigh until about 30 June, and then and relocated in subsequent years at any age. declined rapidly as bears moved to salmon spawning streams,located primarily in the foothills of the Aleutian RESULTS AND DISCUSSION Range. Fig. 2 summarizes the seasonal dispersal of marked bears away from original spring capture sites. The 1:1 Summer Movements ratio of markedto unmarkedbears capturedduring June The arrivalof salmon in streamswas responsible for 1975 and the locations of markedbears killed by hunters the most dramaticseasonal shift in bear distributionand supportthe conclusion thattagged bears were distributed density. By 15 July, the previously dispersed bear throughoutthe population. population had concentrated near salmon spawning streams,remaining there during the peak of spawningin Spring Movements August. Brown bears began feeding on salmon in early Lentferet al. (1972) reportedthat the greatestpropor- July and some bears were observedeating salmon in late tion of Alaska Peninsulabrown beardens was located in November. the Aleutian Range at an elevation of about 396 m. In There are approximately75 streamswithin the study our study, most brown bears had moved away from den area that provide habitatfor spawning salmon. Because sites to lower elevations by 25 May. Emergence from bears are strongly attractedto the salmon food source, dens usually began in early April and continued to the the chronology of salmon migrationinto 2 major fresh- end of May. The high proportionof adult males killed water spawning systems is briefly described here. The during the early part of spring bear hunting seasons Black Lake-Chignik River watershed supported the (average, 89 percentbefore 20 April and72 percentafter largest salmon-rearingarea on the lower Alaska Penin- 10 May) indicates that males emerged from dens earlier sula and attractedthe largest summer bear population. than females. Females with cubs-of-the-yearwere ob- For example, on salmon spawningtributaries near Black served nearden sites as late as 6 June;females with older lake in early August, it was common to count more than young were not observed near den sites after 25 May. 100 different bears during a 3-hour aerial bear survey. Craighead and Craighead (1972) reported that some Bears began feeding on red salmon (Oncorhynchus 310 BEARS - THEIR BIOLOGYAND MANAGEMENT nerka) about 7 July as the fish began moving into 11 this male traveledthe entire width of the Alaska Penin- salmon spawning tributariesthat comprise the Black sula (82.0 km). The second male, 8.5 years old, was Lake-Chignik River system. Red salmon spawning captured7 July 1972 nearthe beachon the Pacific Ocean terminatedin 10 of these tributariesabout 1 September. side of the Aleutian Range and was killed by a hunter Silver salmon (0. kisutch) spawned in the remaining near Chignik Lake on 14 May 1976, having traveled streams into October. The Port Heiden Bay-Meshik 98.0 km within the Aleutian mountains. The capture River watershed supportedthe second largest salmon- locations of 7 males 8-14 years old indicatedthat these rearingarea in the study area. Red, chum (0. keta), and males remainedin the mountainsuntil late June andthen king (0. tschawytscha)salmon entered Port Heiden Bay moved to streamsto feed on salmon. and Meshik River tributarieson 1 July. The peak of There was considerable variation in the seasonal spawningoccurred here between 1 and 15 August when ranges of female bears. Craighead (1976) stated that it was common to count more than 35 different bears home range size was influencedby availabilityand dis- duringbear surveys flown along these tributaries.Silver tributionof food, proximityof mates, den site require- salmon arrivedin late August and spawned in some of ments, habitat preference, foraging habits, age, sex, these streams into December. (Salmon chronology is conditionof the animal, andother factors. Results of this providedby A. Shaul, Area Fisheries Biologist, Alaska study supportconclusions by Craighead(1976) and de- Departmentof Fish and Game, personal communica- monstratethe complexities involved in providing a de- tion.) tailed description of population movements. Three examples illustrate variations in movements of adult Fall Movements females: (1) Female No. 19 (seasonal range, 26 km2) At the end of August, bearsbegan moving away from was never observedon the coastal plain. She apparently streamsand supplementedtheir fish diet by feeding on used the mountains and lowland areas adjacentto the berries. Although berries were availablenear spawning mouth of West Fork River. (2) Females No. 728 and streams, some bears traveled to higher elevations to 731 (combined seasonal ranges, 345 km2) usually feed. The bear population continued their dispersal traveledhalf the width of the Alaska Peninsula as they through September. During October, the numbers of moved from mountains located near the center of the bears using the coastal plain increased noticeably, al- peninsula to salmon spawning tributarieseast of Black though numbersrecorded in spring were much greater. Lake. These females were never observedfar out on the By mid-November,some bearspresumably had denned, coastal plain but were observed within 10 km of the since fewer were observed during aerial reconnais- foothills during spring and fall. Females No. 747 and sance. Some bears remainedout of hibernationthrough 773 (combined seasonal ranges, 614 km2) usually mid-December. Furtherstudy is requiredto determine traveledthree-quarters of the width of the peninsula as conditions that influence predenning movements and they moved fromthe mountainseast of Black Lake to the time of denning. Mostbears observed during fall were in beach on the coastal plain and back. They were never the subalpine alder zone and alpine areas. observed on the coastal plain in fall. Females with 1- to 3-year-old young tended to be Movements of Adults recapturedeach spring in open lowland area; females The seasonal ranges of 30 adultfemales average 293 with cubs-of-the-year were seldom captured because km2 (range, 26-1,098 km2), and those of 4 adult males they were generally observed in mountainousterrain. averaged262 km2 (range, 62-749 km2). The small size Only 1 of 12 females with 6-month-old cubs was cap- of the male sample restrictedcomparison of adult male turedbefore 19 June, andmost (9) were capturedafter 24 and female ranges. Radiocollarsattached to adultmales June. Three of 12 females with cubs-of-the-yearwere in providedlittle movementinformation because they were capturedon the coastal plain, and 9 were captured easily shed; the average neck diameterfor 9 males (30 valleys and foothills of the Aleutian Range. Observa- cm) was similar to their average zygomatic width (27 tions before 15 June indicated the locations of 14 cm). Limitedstraight-line distance data for 2 adultmales females with cubs-of-the-year. Ten of these family and 4 were suggest that range size is larger than that previously groups were located in rugged alpine areas Aerial reported:The first male was captured28 June 1970 near located in dense alder thickets in the foothills. the beach on the south side of Port Heiden Bay and was surveys conducted during August, when bears were recaptured28 June 1972 on the AniakchakRiver, 8 km easily observed along salmon spawning streams, from the Pacific Ocean. Between age 6.5 and 8.5 years, showed that about 50 percent of the young in family SEASONAL MOVEMENTS * Glenn and Miller 311 groups were cubs-of-the-year. Eighty-three percent of 49 adultfemales. During a single annualcycle, females the capturedyoung (N = 153) in family groups were with cubs 6-1 1 months old traveleda mean distance of older than cubs-of-the-year. These data reflect the re- 13.5 km; females with older young traveled a mean luctance of females with 6-month-old cubs to move distance of 17.5 km. Single adult females traveled away from protective cover before 20 June. fartherthan all other females, 20.8 km. These move- The observed distribution of apparently estrous ments support the conclusion that annual mobility of females supports capture findings that most breeding adult females is associated with changes in their repro- females remainedin or near the mountains. Thirtyest- ductive status. rous females over 5 years of age were capturedin open Females normally separatefrom their young within lowland areas duringJune. Of these females, 8 were in their home ranges. One female (No. 433) 19 years old, the company of young males (5-7 years old); 12 were however, traveled64 km southwest of the center of her single and may have already bred, and 10 were single home range before separatingfrom her 2 young, aged and lactating, indicating that family separationhad re- 3.5 years (Nos. 434 and 435). When capturedwith her cently occurred. During the same month, we captured young on 15 June 1974, the adult female's vulva was and frequently observed mated bears in mountainous swollen, indicatingher estrus cycle had begun. Fifteen terrain.The higher density of males over 7 years of age days later, she returnedalone (56 km to the northeast) in the mountainsas opposed to the coastalplain appeared and was capturedwhile breeding with a male 5.5 years to influence the spring distributionof estrous females. old. Female offspring No. 434 was killed 29 km south- Whetherthe distributionof adult males is naturalor is west of her 15 June capturesite duringthe Octoberbear influenced by bear hunting is unknown. Hunting is fo- hunting season. Female No. 433 was located alone on cused on single bears because females with young are 24 October 1974 and 7 October 1975 within 6.4 km of protected. Since young usually remain with adult her original capturesite. females for 2.5-3.5 years, greater hunting pressure is The speed of travel of male No. 714, aged 6.5 years, exerted on adult males. Adult males whose seasonal provides evidence of the potential rate of mobility. ranges include exposed lowland areas run a greaterrisk While on the coastal plain, this male moved 25.8 km of being shot. This hunting pressure may explain why between 19 and 22 June and 72.5 km between 22 and 26 few males over the age of 6 years were capturedon the June. coastal plain and why most breeding females were ob- Homing movements were also recordedand provide served or capturedin the mountains. informationon the speed of movement throughmoun- The mean seasonal distances traveled by adult male tainous terrain. Female No. 89, 3.5 years old, was and female bearsaway from theiroriginal spring capture capturedon 24 June in the village of Chignik Lagoon, sites are shown in Table 1. The cumulative 6-year located on the Pacific side of the Aleutian Range. This movementsof 13 adultmales were greaterthan those of bear was transportedby helicopterto the northwestside of Black Lake and released. After recovering from the effects of the immobilizing drug, she returnedto the Table 1. Distance (km) moved from original capture sites by adult female brown village of Chignik Lagoon, an airline distance of 40.2 bears with different-aged young during a single annual cycle and by adult and km, within 24 hours. Excluding travel in deep snow subadult male and female bears on the central Alaska Peninsula, 1970-76. during periods of warm weather, there appearedto be Distance (km) few geographicalbarriers that restrict bear movements. Sex and age Number Number of of bears observations Mean Range Movements of Subadults Female The seasonal ranges of 5 males bears between mean Subadult singlea of 3.3 and 5.5 749 km2 Adult single 10 20 20.8 2-45 ages years averaged (range, Adult with cubs 7 14 13.5 2-34 111-2,109 km2). The rangesof 6 females between mean Adult with yearlings 18 37 17.5 2-81 ages of 3.3 and 5.9 years averaged 244 km2 (104-420 Adult with young aged 2+ years 14 27 17.4 3-66 km2). Males tended to move out of their maternalsea- All adult females 49 165 16.6 2-81 sonal range;females tended to remain. This characteris- Male tic was emphasized by computing the mean distance Subadult singlea Adult 13 23 31.5 5-98 traveled by male and female bears captured as single subadultsand observed at any age thereafter(Table 1). "Capturedas subadultsand relocatecd in subsequent years at any age. The mean age of 35 subadultmales at first capturewas 312 BEARS THEIR BIOLOGYAND MANAGEMENT

3.3 years and of 26 subadultfemales was 3.5 years. In pared with those of males capturedas single subadults subsequentyears, these bearswere relocated 167 times. and relocated at any age thereafter,the data indicated The mean airline distance traveled by males was 48.5 that males travel long distances during the first few km, or abouttwice thatof females, 21.8 km. Whenthese months after family separation. bearswere last observed, the mean age of males was 5.2 The longest recordeddistances were madeby 5 young years (range, 2.5-9.5); that of females was 5.3 years males (mean distance, 126 km) that were killed outside (range, 2.5-10.5). The distance moved by young the study area: (1) Yearling male No. 80 was captured females was similarto thatof single adultfemales, 20.8 with his mothernear the beach on the south side of Port km. Since distances moved between time of family Heiden Bay. When he was 4.8 years old, he was killed separationand first capturewere unknown, these aver- by a hunter, 166 km southwest of his original capture ages were considered minimum. site. (2) Male No. 799 was 2.5 years old when captured We also computedthe difference in distance traveled alone nearBlack Lake. He was reportedkilled at age 6.8 by 14 subadultmales and 9 subadultfemales before and years, 134 km to the northeast. (3) Male No. 865 and after family separation.Movements by these bearspro- sibling male No. 866 were capturedwith their mother vided furtherevidence that males were more transient nearthe Meshik River when 2.5 years of age. Male No. than females. The average age of males when first cap- 865 was killed at age 4.8 years, 107 km to the southwest. turedwith their motherswas 2.2 years; the average age (4) Male No. 866 was killed when he was 6.8 years old, for females was 1.8 years. When last sighted, these 23 95 km to the southwest of his original capturesite. (5) bears were alone; the average age of males was 5.3 Male No. 142 was captured alone near the mouth of years, thatof females 5.9 years. After family separation, Ocean Creek when he was 3.5 years old. The next males were relocated a mean distance of 83 km and springhe was killed 129 km to the southwest. About 50 females a mean distance of 27 km from their original percent (N = 66) of young males capturedin family capture sites. When these young were with their groups when 1.5-3.5 years of age have not been relo- mothers, the family groups moved a mean distance of cated. On the basis of kill locations of markedmales, it 16.4 km from their capturesites. When the movements appearsthat many of these bearshave moved outside the of these males capturedwith their mothers were com- study area.

LITERATURECITED GLENN, L. P., J. W. LENTFER, J. B. FARO, AND L. H. MILLER.1976. Reproductivebiology of female brown BERNS, V. D., AND R. HENSEL. 1972. Radio-tracking brown bears (Ursus arctos), McNeil River, Alaska. Pages bears on Kodiak Island. Pages 19-25 in S. Herrero, ed. J. W. andG. E. - 381-390in M. R. Pelton, Lentfer, Folk, Bears their biology and management. IUCN Publ. Jr., eds. Bears- theirbiology and management. IUCN New Ser. 23. Publ. New Ser. 40. CRAIGHEAD,F. C., Jr. 1976. Grizzly bear ranges and move- LENTFER,J. W., R. J. HENSEL,L. H. MILLER,L. P. GLENN, ment as determined by radiotracking. Pages 97-109 in M. ANDV. D. BERNS.1972. Remarkson denninghabits of R. Pelton, J. W. Lentfer, and G. E. Folk, Jr., eds. Bears Alaskabrown bears. Pages 125-137in S. Herrero,ed. theirbiology and management.IUCN Publ. New Ser. Bears- theirbiology and management.IUCN Publ. 40. New Ser. 23. , AND J. J. CRAIGHEAD.1972. Grizzly bear prehiberna- MUNDY, K. R., AND W. A. FULLER. 1964. Age determination and denning activities as determined by radiotrack- tion in the grizzlybear. J. Wildl. Manage.28(4):863- ing. Wildl. Monogr. 32. 35pp. 866. bear CRAIGHEAD, J. J., F. C. CRAIGHEAD, Jr., AND H. E. PEARSON, A. M. 1975. The northerninterior grizzly McCUTCHEN. 1970 Age determination of grizzly bears Ursusarctos L. Can. Wildl.Serv. Rep. Ser. 34. 86pp. from fourth premolar tooth sections. J. Wildl. Manage. WILLEY,C. H. 1974. Agingblack bears from first premolar 34(2):353-363. tooth sections. J. Wildl. Manage. 38(1):97-100.