ALASKA DEPARTMENT OF FISH AND GAME. SlJ. 1 ll 5 ;CE OF ALASKA Bill Sheffield, Governor. DEPARTMENT OF FISH AND GAME Don W. Collinsworth, Commis-sioner

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1 c ;Js,_!i ALASKA DEPARTMENT OF FSH AND GAME ''"' PiE;.; Return To JUNEAU, ALASKA - Q(Jt\t\iEN'f CONTROL SJ. 5 ;CE OF ALASKA Bi Sheffied, Governor Q DEPARTMENT OF FSH AND GAME Don W. Coinsworth, Commis-sioner kj DVSON OF GAME... Jiobert Ac Hinman, Acting t}rec:tor Steven R. Peterson, Research Chief r- w i.j f., n u.. ; ' t f w Q ' ' RESPONSES OF CARBOU TO PETROLEUMRELATED DEVELOPMENT ON ALASKA'S ARCTC SLOPE By Raymo nd D. Cameron Kenneth R. Whitten and Water T. Smith,, P! ' u n w Voume V Progress RepQrt Federa id in Widife Restoration Project w-- and w.. -, Job.R D r u ' u f" r- u,. Persons are free to use mateia in these reports for educationa or, informationa purposes. However, since most reports treat pny part of continuing studies, persons intending to use this ateria in scientific_ pubications shoud obtain prior _r>r.mission from the Department of Fish and Game. n a cases, tpative concusions shoud be identified as such in quotation, c:tnd due credit tvoud be appreciated. (Printed Apri 98) ::. : L,v--;t\!; _.,,_ " :: " 4.. " ( '. -

2 r PROGRESS REPORT (RESEARCH) f f r State: Cooperator: Project No. : Job No.: \.aska None W-- W--.8R Project Tite: Big Game nvestigations Job Tite: Responses of Caribou to Petroeum-reated Deve.opment on Aaska' s Arctic Sope. ' ] r Period Covered: January, 98 through December, 98 { ' SUMMARY Resuts of aeria surveys in 98 indicated good overwinter surviva of the 98 cohort of the Centra Arctic Herd (CAH) and high initia production/oversummer surviva of the 98 cohort. Comparison of regiona estimates of caf percentage with those obtained uring surveys aong the Daton High\tay /Trans-Aaska Pipeine indicate continued avoidanc of the corridor by cow/caf pairs. The rationae, objectives, and experimenta design of a new coaring program are outined in detai. Between June and November 98, radio-coared cows were monitored to determine the st-year movements of their offspring; these same caves wi be coared as short yearings and monitored simiary for up to years. t is noteworthy that during this 6-month period ony 4 coared individuas crossed the pipeine corridor. i f,. t Because of mid weather and ack of snow cover in 98, virtuay a caving occurred on the coasta pain; initia caf production was high, 85 caves/ cows. Two distinct high-density caving areas for the CAH were identified, one north of the Kuparuk Deveopment Area (KDA) and another on the Canning River deta. Of,9 cariuou cassified during road surveys aong the West Sak Road (WSR) in summer 98, 8% were caves, substantiay ower than the estimate of '7% caves for the region west of the Kuparuk River. Caribou were most numerous aong the initia and te;nina portions of the WSR; the corresponding caf percentages, however, differed apprecia.by. The oca decine in caf representation and other changes/inconsistencies in caribou distribution within the KDA may be a resut of increasing traffic and construction activity. A provisiona anaysis, using a i L _j

3 . : f... J;!! _i.. :J :;... :, J.. _f _( disturbance index, indicates that cows with caves are underrepresented near areas of heavy oca disturbance; this avoidance response appears to be attenuated by insect harassment. Present and use poicies for the centra Arctic Coasta Pain do not adequatey address probems associated with industria deveopment o' caribou caving grounds, insect reief habitat, and within movement zones. An anaysis of existing and possibe future conficts between petroeum deveopment and caribou is presented, together with some genera recommendations for minimizing those conficts. n the ong term, we beieve that panning of surface uses and seective subsurface easing is the ony rationa approach to protecting caribou habit-at on the Arctic Sope. Key words: caribou, disturbance, pipeines, seasona movements. ti j;. r! ;. r ' )- H f \ '!:!! L!f! tj f; i.'!' ' j ( r' '',i ' '!.:4: :.J j! ' t> ii L

4 ! r J J JJ CONTENTS Summ.ary..... i Pre face.... :..... Effects of the Trans-Aaska Pipeine Corridor on the Distribution and Movements of Caribou. Background. e Objectives.... Procedures.. o Findings and Discussion. 9 o Composition of Caribou Determined by Aeria Survey. Composition of Caribou Aong the TAP Corridor 4. Deveopment and Ateration of Caribou Movement Patterns... 6 Background L 6 Objectives... 7 Procedures 7 Findings and Discussion. 8. Distribution and Movements of Caribou in Reation to the Kuparuk Deveopment Area o 9 Background.. 9 Objectives... e Procedures. Findings and Discusion Distribution of Caving Caribou. Summer Distribution West of the Kuparuk River. 4 Regiona Group Composition. 4 Distribution and Group Composition of Caribou Aong the West Sak Road 4 nsect-induced Movements 7 Disturbance and Loca Group Composition 8 Recommendations..9 Acknowedgments >.. 4 Literature Cited 5 5 Figures... 7 Tabes..!.. Appendix A. Popuation Dynamics of the Centra Arctic Herd, " 4 Appendix B. Responses of Caribou to ndustria Deveopment on Aaska's Arctic Sope 46 Appendix c. Survey-nventory Progress Report on the Centra Arctic Herd, 98-8 e 5 Appendix D. Survey Observations on the Caving Grounds of the Centra Arctic Herd, -4 June Appendix E. (Draft) ssue Paper--Caribou and Petroeum Deveopment, November Appendix F. (Excerpts) North Sope State Lands Guideine Document, 9 January 98 7 ; "'' iii L _j

5 J ' " -' ) ' ' j PREFACE Since the discovery of oi at Prudhoe Bay in 967, much attention has been focused on the effes of oified and industria deveopment on fish and wi).!i.ie resources, and on barren-ground caribou (Rangifer taranaus grnti) in particuar. Widife surveys of the centra Arctic Sope conducted in the ate 96's and eary :9/'s indicated that the Prudhoe Bay region was probaby within the periphera ranges of both the Western Arctic and Porcupine Herds (Hemming 97), and that some,-, caribou might occupy the genera area during summer (Gavin 97). After 97, however, the number of caribou using this area decined rapidy,, to an estimated,5 in 97 (Gavin 97). This apparent withdrawa paraeed a decrease in the size of the Western Arctic Herd, from 4, in 97 (Henuning 97) to 64, in 976 (Davis and Vakenburg 978). Since 975, no arge infuxes from adjacent herds have been observed, and it is now cear that caribou presenty ranging in the vicinity of Prudhoe Bay and aong the North Sope route of the Trans-Aaska Pipeine (TAP) constitute a separate subpopuation of about 9, caribou (Appendix A), the Centra Arctic Herd (CAH) (Cameron and Whitten 979a). Caribou occupancy of the Prudhoe oified and TAP corridor has decined with sustained petroeum deveopmen :. This response is primariy a refection of oca avoidance of the area by cows and caves (Cameron et a. 979, 98; Cameron and Whitten 98a; Appendix B). n spite of dispacement from previousy occupied units of range, the herd is very productive (Appendix B). Nevertheess, existing conficts with industria deveopment and the potentia for progressive disruption raise a ntmber of concerns for the future we-being of the CAH and othe caribou subpopuations on the Arctic Sope. Among the possibe consequences is reduced surviva of neonata caves resuting from disturbanceinduced dispacement of parturient cows from traditiona caving grounds. A nd major concern is the potentia restriction of summer movements in response to insect harassment, specificay, the bioenergetic ramifications of reduced access to coasta insect reief areas. The mitigation of these and other conficts wi require a basic understanding of disturbance mechanisms, incuding the types and intensities of deveopment that constitute negative stimui, the threshod eves of disturbance that trigger range abandonment, the amount of dispacement toerabe before overuse of remaining range occurs, and whether caribou wi accommodate to oca disturbance over time. Despite t:he present dearth of knowedge regarding these fundamenta reationships, practica short-term mitigation of existing or imminent probems wi become possibe as reevant. site-specific data are accumuated. Thus, genera criteria deveoped for pipene design and pacement wi hopefuy maximize physica passage of caribou, and strategic scheduing of construction activity shoud minimize disturbanceinduced dispacement. Continued coordinated study, both basic i ",

6 and appied, wi ikey resut in more specific guideines for petroeum deveopment on the Arctic Sope. This project presenty comprises distinct research jobs that are directed toward the foowing goas: {) 'ro determine the immediate and ong-term effects of petroeum deveopment, pipeine construction/operation, and reated activities on the distribution, movements, and productivity of caribou on Aaska's Arctic Sope; ( ) To characterize the behaviora responses of caribou to physica and sensory disturbance associated with industria deveopment; and () To formuate mitigating standards for faciities design/pacement and for the types, timing, and eves of activity within caribou habitat. Compementary survey and inventory activities in the form of routine popuation monitoring are aso in progress. Data on herd size, caf production, and yearing recruitment are reported as annua updates on the status of the CAH (Appendix C). EFFECTS OF THE TRANS-ALASKA PPELNE CORRDOR ON THE DSTRBUTON AND!-VE-ENTS OF CARBOU. BACKGROUND The Trans-Aaska Pipeine (TAP) traverses the range of the Centra Arctic Caribou. Herd (CAH) (Cameron and Whitten 979a). Comparisons of caribou observations aong the Daton Highway with corresponding data from the surrounding region have reveaed abnormaities in the distribution and group. composition of caribou associated with the pipeine corridor. Caves are ceary underrepresented, indicating avoidance of the corridor area by materna groups (Cameron and Whitten 98a; Cameron et a. 979, 98). - The foowing is a summary of data obtained in 98. As in past interim reports, interpretation of caribou observations aong the TAP corridor/prudhoe compex is somewhat superficia; concusions are tentative, based primariy on unadjusted data. n 98, we wi prepare an in-depth fina rep(.)rt for the entire 8-year study period. We wi fuy expore caribou distribution and group composition aong the TAP corridor in reation to popuation dynamics, habitat seection, and a number of spatia, tempera, and disturbance variabes.,; """ - i

7 OBJECTVES n accordance with stipuations.5.4.* and.5.. of the Grant of Right-of-Way for the TAP and in anticipation of simiar stipuations for the Northwest Aaskan Ga s Pipeine, this project is designed to accompish the foowing principa objectives:, ) To determine seasona./ annua changes in the distribution and group sex/age composition of caribou in the vicinity of the TAP corridor, with specia interest in the identification and assessrnent of oca abnormaities. ) To determine the ocation and direction of corridor crossings by caribou. ) To characterize the behaviora responses of caribou to the Daton Highway, pipeine (s), traffic, and human activity. PROCEDURES Systematic aeria surveys of caribou in the centra Arctic region (Cameron and Whitten 979a) vere conducted on 7- Apri and again on -5 November 98 Summer estimates of regiona sex/age composition were made in conjunction with a census of the CAH (Appendix A). A surveys were conducted by Be 6 heicopter, and car.i.bou were cassified according to standard sex and age criteria (Cameron and Whitten 979). Caribou were surveyed periodicay from the Daton Highway between ate February and eary Deceroberr generay on or about the Oth and 5th of each month. Coverage and observation procedures are described esewhere in detai (Cameron et a. 979) Road survey data were entered in a computer fie (Honeywe Mode, University of Aaska). FNDNGS AND DSCUSSON Compositon of Caribou Determined by Aeria Survey } ' Caves composed % of 998 caribou cassified in Apri (Tabe ). Composition and census data obtained in 98 indicated an adut sex ratio of 8 bus: cows, a decine from the ratio of bus: cows e,stimated in 978 (see Appendix A). Bus were overrepresented in the spring survey (5 bus/ cows}. Adjusting for the estimated actua ratio of 8 bus: cows yieds a spring estimate of 6% caves in the herd. f a simiar adjustment is made on the fa 98 data, an estimated regiona * "Lessees sha costruct and maintain the pipeine, both buried and above-ground sections so as to assure free passage and movement of big game aimas." ti,. () , ! t

8 ., vaue of % caves is obtained. A comparison of fa and spring caf percentages indicates good over\-inter caf surviva and continu.ed high recruitment of short yearings into the CAH. n ate Juy, a summer composition survey was conr.ucted in conjunction with a photocensus. Of 4,67 caribou cassified in postcaving aggregations (Tabe ), 5% were caves, '"ith an estimated rati of 65 caves: cows. Correcting the observed bu: cow ratio (7 bus: cows) to our best estimate of 8 bus:.oo cows yieds 6% caves in summer 98. This equas the highest caf percentage obtained since surveys were begun in 975 and is especiay high considering the arge number of immature cows recruited into the herd in 979 and 98 (Appendix A). G During fa 98, caves composed 6% of the,7 caribou cassified (Tabe ). The estimate of 6 caves/ cows indicates virtuay no mortaity of caves between midsummer and fa. Composition of Caribou Aong the TAP Corridor Between March an.d November 98, 8,8 caribou were seen from the Daton Highway (Tabe ), substantiay more than the corresponding 98 tota (Cameron et a. 98). This increase is primariy attributabe to more frequent road coverage and a modification in our criteria for incusion of groups in the survey records. Previousy, groups too far away to be cassified were not reguary incuded in survey totas. n 98, a aribou visibe from the road were recorded; consequenty, numerous additiona c.aribou were cassified as "unknowns." This procedura change affected ony the spring and fa counts, when snow cover improved aighting conditions for distant groups. A tota of 5,559 caribou (67%) were cassified. Caf percentages during spring, summer, and fa were 6, 5, and 4%, respectivey--a higher than the corresponding 98 estimates but generay consistent with the recent trend in oca caf representation (Cameron et a. 98). Fig. presents a 7-year comparison of ratios of caf percentages observed from the Daton Highway to those determined by corresponding aeria surveys of the centra Arctic regionm Beginning with fa 978 data, regiona caf percentages were adjusted according to bu:cow ratios extrapoated from the 98 CAH census observations (see Appendix A). This reanaysis resuted in sma revisions in the ratios reported previousy (Cameron and Whitten 98a, 98_ ; Cameron et a. 98), but interpretations and concusions remain the same Two separate ratios have been potted to describe caf representation in summer 98 aong the corridor (Fig. ). These represent separate cacuations based on different summer totas. On 9 Juy, a group of 96 caribou incuding 68 caves was observed moving south under insect harassment in the auvia. grave south of the Prudhoe Bay Compex(PBC). This group 4 jt. ' ,-- - '-""'..., "'"''"' " '

9 "' v.!? ;\,... "'...::. ---_.,,_,-...-.<-.., " '' \ :r -! contained 87% of the tota number of caves seen aong the Daton Highway in summer 98. These caribou (incuded in the tota, Tabe ) were ceary transient, having moved into the corridor nd inect stress- Even with this group incuded, the cacuated ratio of. indicates that ony about one-fifth the expected number of caves were present in groups observed from the road in summer 98. Deetion of this group reduces the summer caf percentage to 5%, the owest vaue for any season in which adequate aata were obtained, and resuts in the owest caf raio () for any season to date. The ratios for 98 are consistent with recent trends. Fo.owing a sharp decine during , the respective summer and f ratios stabiized at approximatey. and. 6. Spring ratios for are roughy.intermediate. Nevertheess, it is cear that caf representation in greurc observed from the Daton Highway in 98 remained substantiay owe than the corresponing regiona estimates. j f - -J J. ' - The decreased incidence of caves aong the Daton Highway is a resuit of avoidance of the corridor by entire groups, rather than individua CQW/caf pairs. Overa caf percentages for groups with caves aong the Daton Hihway (Tabe ) are simiar to the respective regiona estimates. Seasona differences in caf percentate indicate that cows with caves are more sensitive to disturbance du.ring summer than in fa. Sighting rates for summer and fa 98 were 49 and 44 caribou/ ; respectivey--sighty above those in 98 but simiar to recent vaus (Cameron et a. 98). Rates were cacuated on the basis of tota goups cassified and are therefore comparabe to those reported previousy. The spring rate of 78 Garibeu/ km is the highest ever recorded for any season and is more thah doube the comparabe 98 vaue of 6 caribou/ km. However, since spring vaues are avaiabe for ony the past years, it is impossibe to determine whether or not this indicates a trend toward increased occupancy of the corridor.,, '.. Rates of crossing the Daton Highway by caribou were highy variabe in '98.5, 7.9' and f.o -observed crossings/ caribou sightings for spring, summer, and fa, respectivey. oth spring and fa rates are simiar to previous vaues (Cameron et a. 98). The summer crossing rate, however, is the highest recorded to date and is primariy attributabe to the sighting of 4 bu (of 4 tota crossings observed during summer 98) that crossed the road during the Ju:x' survey. Loca movements of sma bu bands aong and across the Daton Highway are oonunon du:t::'ing the summer insect period, but crossings by arge, intact groups are rarp Daiy traffic eves on the Daton Highway during 98 were substantiay higher than in 98 (Tabe ). n June 98, the cheek station was moved 58 mies north, from the Yukon River to 5

10 r w ) c.-, Disaster Creek;. therefore, 98 summer traffic eves are not directy comparabe to previous years' data. However, current estimates are more rapresenta.tive of te actua traffic on the Arctic Sope and indicate a net increase over the previous years.. DEVELOPMENT AND ALTERATON OF CARBOU MOVEMENT PATTERNS. BACKGROUND Past studies have estabished that parturient and postpartum caribou tend to avoid areas of intensive petroeum-reated deveopment. Caribou surveys conducted aong the Trans-Aaska Pipeine (TAP) Corridor and within the Pudhoe Bay Compex (BC) between 975 and 98 yieded overa caf percentages that, with eception, were substantiay ower than corresponding regiona estimates (Cameron et a. 98; Appendix B). Seasona differences in this rsponse pattern are apparent. During summer, caf proportions within the TAP Corridor decined sharpy from 975 tc 977 and have remained at -5% of estimated regiona vaues through 98. Fa caf proportions decreased simiary b.=tween 975 and 978 but increas.t;!d to 6-7% of regiona esimates in Thus, despite some indication of a trend reversa during fa, summer caf representation within the corridor continues to be abnormay tow. These 6-year trends in oca caf representation are not consistent with the corresponding changes in consruction-reated disturbance. Given that femae carbou and their caves respond negativey to increasing eves of deveopment and human activity, it seems ogica to expect improved sex/age representation during periods of reduced disturbances. n addition, repeated exposure to oca disturbance might aow some individua femaes to accommodate to what woud otherwise be negative stimui. The above premise is not supported by avaiabe data on annua trends in distur:;)ance, particuary during summer. Various indices of deveopment-reated activity indicate that highest reative eves occurred in 975 and 976, foowed by a distinct net decine thereafter through 978 (Cameron and Whitten 98a); estimated daiy traffic on the Daton Highway suggests a continued decrease in oca activity through 979, foowed by an increase in 98 (Cameron et a. 98). Loca disturbance has since increased over 98 estimates but remains we beow peak eves. Ceary, continued under-representation of materna pairs during summer refects sustained avoidance of the TAP Corridor/PBC despite an appreciabe moderation of disturbance stimui. On the other hand, the recent recovery during fa suggests increased accommodation, possiby in.response to reduced activity foowing competion of the TAP. However, it remains to be seen whether this trend wi continue as coasta oified 6

11 deveopment proceeds and with the possibe initiation of gas pipeine construction. The centra point is that an increase in oca caf representation has not accompanied the net decine in deveopment activity within the TAP Corridor/PBC. Athough this coud refect a response ag foowing diminution of adverse stimui, it is aso conceivabe that atered patterns of seasona distribution arid movements of caribou tend to persist as new traditions. These changes might aso be reinforced by materna group eaders and sustained further by their femae offspring. Hence, components of range and/or specific habitats once abandoned by individua or cohesive bands may not be reoccupied for many years after the withdrawa of industria activity--and perhaps ony then by a chance reinvasion. This study was designed to examine the mechanisms by which caribou movement patterns are estabished and subsequenty sustained or atered An understanding of these mechanisms wi assist in projecting the effects of proposed industria or urban deveopment, in terms of both the duration of habitat oss and the ikey consequences to caribou users. The project is now in the eary stages of impementation, and this report is an update of progess made during the 98 fied season. OBJECTVES To evauate the degree to which the seasona movements of individua adut caribou are infuenced by their st-year movements as caves. To identify and des.cribe any disturbance-reated ateration of seasona distribution and movements of such caribou. To <ietermine sexua differences movement and dispersa patterns, preferences, and range fideity. in the deveopment of caribou socia reationships, habitat PROCEDURES :, ( ) -,! J J < Caribou have been, and wi continue to be, radio-coared as described previousy (Whitten and Cameron 98). As of fa 98, 5 adut femaes were equipped with functiona transmitters. n spring 98, additiona femaes wi be coared to provide a minimum of individuas with transmitters that wi remain operationa for at east year. Offspring of these femaes wi be coared as short yearings in March or Apri _...,...,.,...,..,.._..,_..,.._.. - """" "-"'..._._'"""'- ''-'"'.,"'""' _.,_,..._....., "'" , - - ',_, J.,. 7 ' ( t

12 '.J. ' ; '., : i i '!. '''..,, '..;' Standard methods of tracking by fixed-wing aircraft (Whitten and Cameron 98) wi be used. Radio-coared cows an. their offspring wi be reocated monthy between June and September, and again in November, March, and May of the foowing year. Beginning in June 98, movements of the origina adut femaes wi be tracked for at east year. ndividuas radio-coared as shor yearings wi be reocated for the functiona ife of the transmitters (ca. yrs). For each resighting, ocation, group composition, habitat type, and any oca disturbance wi be recorded; when reocating coared offspring, the presence or absence of their materna cows (visua coars wi remain after transmitters expire) wi be noted. The st-year movements of coared co\vs and their caves wi be compared with the subsequent activities of those same caves as yearings and aduts. Particuar attention wi be focused on sexua differences in distrbution, movement chronoogy, habitat use, and group structure. This program wi aso provide an opportunity to examine patterns of sex- and/or age-reated mortaity and fecundity. FNDNGS AND DSCUSSON. A radio-coared cows were ocated during both June and Juy. However, because of frequent incement weather, we were ony abe to reocate individuas in September and in November. Excuding cows with radio coars that are due to expire, there are caribou on which we have compete 98 data. Tracking of these cows for a nd fu year (i.e., June 98-May 98) wi provide usefu information on between-year variation in the movements of adut femaes, simiar data can be obtained opportunisticay in subsequent years by tracking the - or -year movements of additiona cows to be coared in spring 98. This wi provide a vauabe r :::ference base for interpreting any annua shifts in the movemen t patterns of femaes as caves, yearings, and aduts. We have not yet estabished the format for data anaysis, and the imited resighting information obtained to date is insufficient for any detaied interpretation. However, some generaizations on the seasona movements of CAH cows are noteworthy. During the caving period in eary June, most of the radiocoared cows were found within 4 km of the coast on both sides of the TAP Corridor/PBC, to the east, and to the west; none were observed within the PBC itsef. n addition, a but 4 coared cows were found in areas of concentrated caving activity (see Part, this report); 4 were found in the Mine Point area, 6 were in the upper Kachemach River, were in the ower Canning River/Buen Point area, and was near Frankin Buffs. Of those remaining, were ocated about 8 km inand on '. 8

13 i!! [. {.i,j,;\ ' j.,.... < '"J..! j ;t - ' '., ;::; ' - ') ' ;e, J j 'f - - -,<i:s the Tooik River, was at Mikkesen Bay, and was about 5 km inand near the Kavik River. A but coared femaes had caves at hee. During the remainder of June and throughout Juy, most coared individuas exhibited considerabe east-west movement within the coasta zone. Despite this activity, ony coared cow crossed the TAP Corridor. This individua caved between the Kuparuk and Sagavanirktok Rivers, approximatey km south of Deadhorse airport, and subsequenty moved eastward to the Frankin Buffs area; the TAP is predominanty buried in the genera region where the crossing most ikey o-=curred. Otherwise, radio-coared cows remained either east or -est of the TAP Corridor /PBC.. By mid-september, additiona coared caribou had crossed corridor, both to 'the west and, again, in the vicinity Frankin Buffs; the individua that had crossed to the east Juy remained on the east side. Of the cows reocated November, other had crossed to the west. To summarize, 6 coared caribou were reocated repeatedy over neary a 6-month period, yet ony 4 crossings of the TAP Corridor/PBC by different individuas were detected. This ow crossing' frequency compements simiar data reported previousy (Whitten and Cameron 98) and is consistent with observations of continued ow occupancy of deveoped areas by cows and caves (Part, this report). n contrast to these concusions, Chid (97) and White et a. (975) observed arge mixed groups of summering caribou moving through the PBC during the eary 97's. The recent cessation of such movements suggests a tendency toward reative isoation of eastern and western portions of the cow-caf compo:ner.. t of the CAH. During summer 98, coared cows were aso usefu in describing movements of caribou that occurred in response to changing insect activity.. A summary of those movements in reation to the Kuparuk Deveopment Area (KDA) is deat with in Part of this report.. Data on coared cows indicate exceent oversummer surviva of caves.. Admittedy, some individuas were not found during fa 98 (see above), but a coared femaes observed with caves a t hee in June were sti accompanied by caves in September and/or November. These observations reaffirm demographic evidence for recent high eves of recruitment to the CAH (Appendix A).. DSTRBUTON AND MOVEMENTS OF CARBOU N RELATON TO THE KUPRUK DEVELOPMENT AREA. BACKGROUND The Kuparuk Deveopment Area (KDA) is ocated immediatey west of the main Prudhoe Bay oified, within an active caving area and 9 the of in in,!

14 an important component of summer range.. We beieved that detaied knowedge of regiona caribou distribution and movements woud assist in the formuation of deveopment practices which woud accommodate caribou, hopefuy within estabished geotechnica constraints.. t woud aso provide an opportunity to identify and quantify the sources of oca disturbance and the reactions of caribou to these stimui. Finay, in conjunction with continued moni t9ring of CAH status, the preser..t program provides an opportuni'ty to document any reated effects on herd productivity. This report suwarizes the 98 resuts of continued surveys of the CAH caving grounds* and aong the West Sak Road (WSR). These findings and various between-year comparisons are considered in reation to weather-reated variabes and oca disturbance. OBJECTVES To describe annua variations in the distribution of CAH caribou on their caving grounds, with specia reference to caving activity in the vicinity of the KDA. To determine between-year differences in the distribution, movements, and sex/age composition of caribou within or near the KDA during summer. To determine the ocation of road/pipeine crossings. To characterize the responses of caribou to oca structures and disturbance.., PROCEDURES Caving ground surveys were conducted between and 4 June; virtuay a caves Tfere born during the previous 7- days. Survey observations were made during this same period in 978, 979, and 98 (Cameron and Whitten 979b, 98b; Cameron et a. 98}. Distribution of caving caribou on the coasta pain was de termined by fying a series of north-south transects, each extending 4 km inand from the coast. Primary transects were at 9.7 km (6 mi) intervas between the Nationa Petroeum Reserve-Aaska (NPR-A) 'boundary on the west and Camden Bay on the east (transects E and 9, respectivey; Fig. ). Additiona transects were fown at. km ( mi) intervas in the vicinity of the Kuparuk oified and at 4.8 krn ( mi) intervas through the Prtdhoe Bay Compex (PBC). Transect numbers and ocations correspond to those used previousy, except that new fight ines were added to'both the east and west in * Preiminary report submitted to t.he Office of Coasta Management {Aaska Coasta Management Program) and ARCO Aaska, nc., October 98..:::::: ; '.,.

15 A north-south transects were fown by Be 6-B heicopter with the piot and front-seat observer searching primariy in the direction of fight and rear-seat observers searching to either side of the aircraft. USGS :6,6 maps were used for navigation and for recording ocations of caribou groups; ony groups within approximatey.6 km ( mi) of each transect were used in the transect data anaysis, athough more distant groups were often cassified for additiona information. Airspeeds of - krn/hour and atitudes of -5 m were maintained unti a group of caribou was sighted. Composition was ascertained by making a ower, sower pass or by hovering briefy at a distance of 5- m and using binocuars. ndividuas were cassified on the basis of genitaia, body size, and/or anter deveopment as bus, cows, caves, or yearings. The southern imit of the coasta caving area was estimated by fying east-west or southeast-northwest transects beginning roughy aong the southern edge of the north-south transects (Fig. ). These transects were fown by Cessna 8 with piot and observer. Locations of caribou were noted on :5, USGS maps; ony group size and number of caves were recorded. n addition, when caribou were sti in sight at the southern end of a north-south transect, heicopter surveys continued southward unti caribou were no onger visibe; these extended-transect data were aso hepfu in estabishing the southern imits of caving. Midsummer sex/age composition of caribou in the region surrounding the KDA was determined in conjunction with an aeria photo census of the CAH. A caribou observed aong the coast between the ARCO West Dock and the Kaubik River were assumed to be potentiay associated with the KDA. Post.caving groups were monitored unti maximum aggregation occurred. Numbers of caribou were estimated from photographs of aggregations taken on Juy. These caribou then dispersed, and new aggregations formed on 7 Juy, when composition was determined by anding a heicopter near each group and cassifying as many caribou as possibe. Composition was assumed representative of the tota numbers estimated on Juy. Numbers and composition of the remainder of the CAH were simiary estimated from aggregations found between Deadhorse and the Canning River on 7 Juy. -r The 7SR (Fig. ) was surveyed systematicay by ight truck (Cameron and Whitten 979 ), genera.y twice daiy, between 5 June and 7 August. For each survey, the eve of insect harassment 'tvas estimated by direct observation as none, ight, moderate, or severe, and prevaiing weather was summarized. Houry weather reports for Deadhorse airport were obtained from the Arctic Environmenta nformation C?.nter, University of Aaska, Anchorage. Mean 4-hour insect eves were cacuated {White et a. 975) for each day of the survey program. Rates of vehicuar traffic on the WSR were determined using an automatic infrared trai/traffic counter (Scientific Dimensions, nc.)

16 .. #. -.. (Cameron and Whitten 979b); counter readings were taken at the beginning and end of eac survey as we as during additiona nonsurvey trips through the area. An attempt was made to subjectivey rate the reative disturbance magnitude of various temporary/permanent faciities, storage areas, and construction/maintenance activity occurring within an esti.mated road km of each caribou sighting. Together with the traffic rates determined for each :survey (see above), a numerica disturbance index was cacuated in a manner simiar to that reported for 98 data (Cameron et a. 98). Caribou survey data from the WSR (incuding ocation, observation distance, group composition, direction of movement, road/pipeine crossingsr insect eves, and disturbance indices) were entered in a computer fie (Honey-we Mode, University of Aaskaj. Seected data. on tota numbers and group composition were retrieved and compied on the basis of various pos.i tion, distance, insect harassment, and/or disturbance variabese Distribution of Caving Caribou FNDNGS AND DSCUSSON.' ' \.!' Detaied surveys of the CAH caving grounds began in 978. nitia emphasis was on caving distribution in zeation to the active Prudhoe Bay oified and the deveoping Kuparuk oified, vith ess compete coverage of the reativey undisturbed area extending eastward to Buen Point (Cameron and Whitten 979b, 98b). The area of intensive coverage was expanded sighty in 98- but sti did not encompass the entire caving grounds (Cameron et a. 98). However, with even more extensive surveys during 98, observations indicated that virtuay a CAH caving occurred within t:he area of coverage. Caribou numbers decined sharpy at both the eastern and western imits of the north-south transcts (Fig. 4) this ow density apparenty extened a't: east 4 km beyond the survey area to the edges of the Porcupine Herd and Teshekpuk Hed caving grounds on the east and west, respectivey (D. Ross and P.. Reynods, pers. commun.). A tota of, 446 caribou (, 6 on-tran:::;ect) were cassified. nitia productivity was 85 caves/ cows. Two distinct centers of caving were evident (Fig. 4). One, in the vicinity of the KDA, has been described in previous studies; the other, in the Canning River deta area; was observed during 978 and 979 surveys and was tenta tivey quantified in 98 (Cameron and Whitten 979b, 98b; Cameron et a. 98). Based on observations fx:--m primary transects, the area in the ower Canning River appears to support at east as many caving caribou as the Kuparuk area. Tis iz consistent with counts of postcaving aggregations which have sho.;:n more caribou east of the PBC/TAPS Corridor t.han to the west. (Cameron and Whitten unpub. data)..,?..-

17 _i r j.. " '!! -,,..., '. J.',., :d () t\ " d Within the high-density caving areas, caribou were concentrated near the coast (Fig. 4). This pattern aso characterized the reativey ow-density caving area south of Mikkesen Bay. However, ow-density caving in the vicinity of Prudhoe Bay and the Covie deta was distributed sc'mewhat farther inand (Fig. 4/. The absence of caving near the coast at Prudhoe Bay has been interpreted previonsy as an avoidance re-.ction to industria activity in the PBC (Cameron and Whi t.ten 979b, 98b; Cameron et a. 98; Appendix B). Locaized avoidance of-road and camp areas in the Kuparuk region has aso been identified (Cameron and Whitten 979b; Cameron et a. 98), but the area in genera remains a major component of the CAH caving grounds.. Generay, few caribou were observed on tranects through the Covie deta area except for Transect A (Figs., 4); a fairy arge caving concentration was observed at the southern end of that transect in a we-drained, hiy area south of the coasta pain. This may refect a preference for upand sites over the fooded and sparsey vegetated deta. A simiar inand caving concentration was observed near Frankin Buffs. Each of these areas was occupied by about caribou. soated caving concentrations may have been present eisewhere as we, athough observations by fixed-wing indicated that very itte caving occurred more than 4 km from the coast. East-west fight ines cosest to the southern end of the north-south transects intercepted caribou groups, a tota of 6 aduts and caves; ony 9 groups with aduts (no caves) were observed on southernmont fight ines.,;: i.j., : )! (' {..., i ) r.' [ ' { '.i ; '"" ' : ' '. \. Lc Apparenty, weather patterns over tbe past 4 years have had a considerabe effect on caving distribution. n years of mid spring weather, the coasta pain is preferred for caving. Such was the case in 98, when snow had me ted by June, and the coasta areas were snow-free and we-drained. Weather conditions were simiar in 979, as was the pattern of caving distribution (Cameron and Whitten 98b). Conversey, during years of adverse weather, at east part-of the CAH did not use preferred coasta caving areas. nstead hiy inand sites, such as Frankin Buffs. and the area south of Transect A, which were ony ighty used. in dry years were occupied preferentiay. Thus, during caving in 978 and 98, with substantia snow/ice cover and extensive fooding, reativey few caribou used the coasta pain (Cameron and Whitten 979b; Cameron et a. 98). n a years, however, reative distribution of caribou utiizing coasta caving areas has been simiar: that is, caving caribc have been most numerous in the Kuparuk and Canning River areas near the coast, with few or none in the Prudhoe Bay area (Cameron et a. 98) Estimated boundaries of the Kuparuk caving concentration have remained remarkaby constant since 978 (Fig. 5). Caribou density within this area has fuctuated roughy in proportion to overa occupancy of the coasta pain (Tabe 4a) J. ( '-

18 G! J Composition of caribou using the CAH caving grounds (Tabe 4b) shows that 98 was another year of exceent caf production. Few adut bus have appeared on the caving grounds in any year of study {see aso Cameron and Whitten 979b; Cameron and Whitten 98b), whie most yearings have accompanied adut cows to these areas in the spring. An exception was noted in 979, when, in spite of high overwinter caf surviva, reativey few yearings appeared on the caving grounds. Summer Distribution West of the Kuparuk River Regiona Group Composition: Counts during the 98 photo census indicate that at east,67 CAH caribou summered in the KDA region. An additiona 4, 4 7 caribou were counted east of the Sagavanirktok River. Composition estimates east and west of Deadhorse yieded simiar caf:cow and yearing:cow ratios, but the bu:cow ratio was substantia.y higher to the east (Tabe 5) Resuts of the census and composition counts are summarized in Appendix A of this report. An estimate of 7% caves was obtained in the coasta area west of the Kuparuk River {Tabe 5). Since there is apparenty itte or no movement of caribou through the PBC during the months after caving (Whitten and Cameron 98; Part, this report), this percentage is assumed to be representative of reative caf numbers in the KDA region during summer 98 and wi be used as a basis for assessing simiar data obtained aong the WSH. Distributio'n and Group CompositiJn Aong the (West Sak Road): Between 5 June and 7 August, 86 compete surveys were conducted from the WSR. We observed a tota of 4,966 individua caribou in, groups, approximatey times the respective tota for 98, but with ony twice the survey effort (see Cameron et ao 9a). n part, this increase is a refection of continued growth of the CAH, but is probaby aso a function of generay greater insect activity in 98, bringing caribou in sight of the road more frequenty (see beow). A tota of 4,966 caribou were observed from the WSR. Excuding groups with individuas of "unknown" age,,74 caribou, or 7% of the tota; were cassified as either aduts or caves; 8% were caves, substantiay ower than the corresponding regiona estimate of 7% caves (see above). Thus, for the st time in 4 years of summer surveys aong the vsr, the reative number of caves observed ocay was not repesentative of the surrounding popuation west of the Kuparuk River. n 98, ve suppemented the standard road survey route with partiay redundant coverage. The newy constructed Kuparuk Pipeine is routed east fro"7 the Cent!:'8. Processing Faciity (CPF), aong the access road a:d fo,.;t;ines from Dri Site C., 4

19 t : tf - "''-,.._,_,...,...,...,_.., j ;:. " ;;'....,-." -,.,_ joining the WSR just west of Grave Site B (see Fig.. ). This 8-km section. of road was aso driven on a routine basis, and survey observations were recorded in a separate fie. Coverage aong this road segment was added principay because, in severa areas, the associated pipeine (s) restricts the northery view from the corresponding southern portions of the main WSR.. Unfortunatey,.these separate observations cannot simpy be added to the main data bank, as effective coverage to the north woud then extend we beyond the norma viewabiity. Legitimate be.tween-year comparisons wi require data adjustment based on a standard coverage area reative to the WSR itsef, that is, incuding ony those observations that meet specific distance criteria. n any case, 947 caribou were sighted from this section of road during summer 98.. Caves composed 4% of the tota, even ower than the overa vaue of 8%. The foowing discussion of 98 data pertains ony to caribou observed from the WSR. For a summary of observations, the reader is referred to Fig. 7 in Cameron et a. 98..,,J i.. '. L.' i :.i.; '.j. i... '. - Fig. 6 depicts the summer 98 distribution of caribou among 4-km segments of the WSR and the caf percentage appicabe to each. Of the tota caribou observed, 6% were north of the road, 7% vere south, and % were west of the road terminus; respective caf proportions were 9, 4, and %. t is noteworthy that.the percentage of tota caribou sighted to the west was the highest recorded to date and, as in 98, the associated caf percentage was aso high reative to most other segments of the WSR--exceeded ony by that for the km interva. n terms of.the overa pattern of caribou distribution aong the WSR, 98 was quite simiar to 98. Excuding the aforementioned differences in sightings to the west, highest numbers of caribou were observed aong the initia and termina. segments of the WSR in both years, athough the individua peaks were more distinct in 98. n fact, despite considerabe variabiity in the occupancy of intermediate road segments, those portions encompassing the Kuparuk River (-4. km) and Ugnuravik River (8.-. km) hve been sites of high caribou use for the past 4 summers. Peaks in caribou occupe.ncy did not necessariy correspond to those in caf representation. Thus, athough the proportion of caves among reativey numerous caribou pbserved in the vicinity of the Ugnuravik River was simiar to the overa mean of 8%, the peak at the Kuparuk River was associated with the owest caf percentage recorded (9%). The atter data are simiar to resuts obtained previousy. The Kuparuk drainage has been the site of consistenty high occupancy, prominent amung the various nodes identified, yet the corresponding caf percentages have been generay at or near the owest recorded for any road segment. Lower caf epresentation in this area is thought to be a response to typicay high eves of nearby construction activity, traffic, and the presence of other faciities/ disturbances in 6r near the foodpain (Cameron et a. 98). 5 ' /;.::.::,L...

20 r-- \d+w...:: -:::JL ,...;.-;..,_.:_.._ -- - ::;;,,..,.._,...,:-...:....,...,...,.....i\... : ,_._._ _ :...,._...""--"- -'--'- :_..,.;''""""' n 978 and 979, peaks in caribou occupancy west of the Kuparuk River coincided with the ocation of rivers and streams and were characterized by reativey high caf percentages. We hypothesized that cow/caf groups preferentiay moved aong these riparian areas, whereas nonmaterna aduts were ess seective. Shifts in the ocation and magnitude of these nodes were inked to the distribution of construction activity (Cameron and Whitten 979b, 98b). n 98, a noda pattern of occupancy was...{not discernibe-; and caribou distribution shifted generay westw.ard, with a sight increase in reative numbers of caribou sighted beyond the road terminus; this, we beieved, was a response to the. increasing eve of KDA-reated activity (Cameron et a. 98}. By 98, the reative numbers of caribou in the vicinity of the Ugnuravik River increased, but the associated caf percentage did not change correspondingy. Rather, the proportion of caves among caribou observed from the adjacent road interva (i.e., krn) increased to the highest vaue recorded for any segment (Fig. 6). The atter, however, is probaby not meaningfu in terms of an overa 98 trend, but is attributabe to a singe group response to what may have been an unusua set of circumstances (see beow). The overwheming majorit:y of WSR crossings occurred within the -4. and 4:.-8. km segments (Tabe 6). Crossings at the Kuparuk foodpain coincide with an area of high caribou occupancy, but with reativey few caves, whie the crossing. area east of the CPF was associated with ony moderate numbers of caribou with a high proportion of caves {Fig. 6). t shoud be noted Ehat the atter crossing site was identified as a resut of a singe event: a group of 97 caribou {% caves) crossed the road northbound, with considerabe miing in the vicinity of the Kuparuk Pipeine. Caves composed 5% of the tota caribou in crossing groups, a vaue approaching the regiona estimate of 7% caves. n fact, since 978 the overa percentage of caves in crossing groups has been consistenty higher than the aggregate vaue for road observations (Cameron and Whitten 979b, 98b; Cameron et a. 98). This indicates that, athough some cows and caves are apparenty reuctant to approach and cross the WSR, other materna groups are highy motivated to do so. t is possibe that bus and nonparous femaes, despite a greater toerance for disturbance, generay have a weaker natura impetus for movement. Hence, a higher percentage of caves among crossing groups may refect ony reative tendencies for movement, irrespective of disturbance considerationse The genera decine in oca caf representation and other abnormaities observed in 98 may be attributabe to growth of the KDA. Among the more obvious changes were the instaation of the Kuparuk Pipeine, expansion of CPF faciities, construction of additiona we pads, reinstaation of a permanent Kuparuk bridge, and cuvert repacement in various sections of the WSR. As a resut of these and reated activities, road traffic increased subsantiay (from. veices/day in 98 to 7.8 vehices/day in 98). gregate disturhane accruing from the 6 L

21 . " c )L"-:.-,_,.,_ ""." -o "' "- ---: ,... """'. '. L.. m ' J i.' :J :.r. 'i.. J..}.., 't i) ,.., ,_,_, ;_ various component activities and structures may have exceeded the toerance threshod of cows and caves, effectivey reducing the number of options for oca occupancy. n other words, some cow/caf groups may be simpy avoiding the road system. The reativey high number of caribou sightings west of the WSR terminus suggests that many of these groups may be "end-running" the compex. For exampe, in mid-juy we observed a mixed group of approximatey, caribou move south to within sight of the Kuparuk bridge and then essentiay parae the WSR to the west; athough some southward crossings occurred enroute, the majority continued to, or around, Dri Site A (See Fig. ). A simiar incident invoved a northbound group of about, that paraeed the road/pipeine eastward for most of its ength; the majority eventuay crossed northward near the Kuparuk River. These and reated observations, incuding data on group composition, suggest an increase in oca conficts between caribou and industria acti vi t.y, athough neither the precise stimui invoved nor the behaviora mechanism has been ceary defined. n fact, with rapid oca and regiona deveopment, and an increase in the intensity and diversity of disturbance stimui, it is becoming increasingy difficut to distinguish between the emergence of new patterns of caribou distribution and short-term, aberrant occurrences. Perhaps the absence of a cear trend is, in itsef, symptomatic of a transition process. nsect-nduced Movements: As in previous _years, caribou distribution aong the WSR was affected by weather-induced changes in insect activity. Sudden changes in weather/mosquito activity induced rapid movements of caribou to or from the coast and through the vicinity of the WSR. Thus, reativey high numbers of caribou were seen aong the road on 8-9,, and 7 Juy when severe insect harassment foowed periods of ow insect activity; caribou were moving across the road toward insect reief areas on the coast. On 4 Juy, sudden cooing temperatures brought numerous caribou inand to within sight of the road. After about Juy r warbe fies repaced mosquitoes as the dominant insect pest, resuting in genera dispersa of caribou, and few were seen aong the road. Coared caribou resightings aso refected the infuence of insect eves on caribou movements. A coared caribou known to be west of the Kuparuk River were north of the road near the coast on,, and 7 Juy when insect harassment was severe. When mosquitoes were not active, coared caribou were found :farther inand. Thus, 8 of 9 coared caribou moved south on 4 Juy and had either crossed the road to the south or had circumvented the CPF to the west by 5 Juy. They remained south and west unti insect eves increased on the 7th.. f' c '.. [ ) : " :! <;. Chronoogy and direction of road crossings were aso obviousy infuenced by insect activi tye Athough neary a observed crossings were northbound (Tabe 6), genera movement/ sighting patterns and coared caribou resightings indicated that south- 7

22 .. j.':j,.-,....:.... bound movements aso took pace. One possibe expanation is that coo weather, ow insect activity, and resuting southward movements occurred during ate night or eary morning hours when no road surveys were conducted. Aso contributing to the preponderance of observed northbound crossings was the tendency for inand moving caribou to first parae the road and pipe to the west be :fore finay turning south around the CPF (see previous section). Compared to other years, 98 had a more even distribution of insect harassment eves during the peak mosquito season (Tabe 7}. Frequent changes between days of moderate to severe harassment and days of itte or no harassment resuted in increased caribou movements and frequent encounters with the road. Thus, the caribou sighting rate in 98 was the highest observed since WSR surveys began (Tabe 7},. Since 978, the CAH has increased about %/year (Appendix A), and some increase in s:jhting rate woud thus be expected. However, even with adjustments for herd growth, the sighting rates in 979, and especiay in 98, woud sti be higher than in 978 or 98. Thus, it appears that annua changes in patterns of insect harassment as they affect the frequency of caribou movements on the coasta pain argey determine the number of caribou observed from the WSR. During years of either continuous harassment or of ong periods of no harassment, reativey few caribou encounter the road.. nterestingy, if sighting rates w ere adjusted for herd growth, the rate in 98 (generay ow 'harassment) woud actuay be ower than in 978 (generay high harassment). n retrospect, frequent short periods of ow harassment (i.e, during ate night hours) reguary brought some caribou inand near the road in 978 (see Cameron and Whitten 98a}. n contrast, the proonged periods of ow harassment in 98 resuted in generay itte movement during the summer. Disturbance and Loca Group Composition: The disturbance indexing system reported previousy (Cameron et a. 98) has been revised to accommodate various combinations of pipeines and other structures, higher rates of vehicuar traffic, and other unforeseen disturbance circumstances that emerged in 98. As of this wrtng, anayses of the reationship between oca caf representation and disturbance eve are incom?etei as in 98, sampe sizes within a number of the disturbance/insect harassment categories are insufficient for the cacuation of reiabe mean \"aues. After compiing the 98 data, we wi attempt to standardize the disturbance index and adjust the units of caf representation to permit pooing of observations from a years. Hopefuy, through such adjustment and reorganization we can perform some meaningfu statistica comparisons. A preiminary anaysis of the 98 data (using a sighty modified index) indicates that, unde::: ight insect harassment, the perce!tage of caves among caribou associated with disturbance cassed as nhigh" (9%) vas somewhat ower than under B, i 4 '., ' ''. --- """"......,..,_.,.,.._..., f r. '

23 those eves designated as "ow" or "medium" (6% and 4%, respectivey). Caf percentages for other insect/disturbance categories having sufficient sampe sizes (i.e., moderate insects/medium disturbance; severe insects/high disturbance) were both higher (i.e., % and 4%, respectivey) than those associated with ight insect harassment under any degree of disturbance. This provisiona anaysis of imited data is consistent with our premise that cows with caves tend to progressivey avoid areas of increasing disturbance, with an apparent attenuation in sensitivity to those same stimui when subjected to the competing adverse stimuus of insect harassmento t remains to be seen, however, if we can, in fact, detect any shifts in the disturbance threshod within each of the insect categories.. This anaysis wi hopefuy assist in carifying the responses of caribou to combinations of natura and artificia stimui, and may utimatey be usefu in predicting the responses of caribou to proposed deveopment. RECOMMENDATONS i...' j :! i The authors, with assistance from staff of the Divisions of Game and Habitat, are in the process of preparing a Department issue paper on "Caribou and Petroeum Deveopment" (Appendix E). The draft document presents an anaysis of the various concerns reated to existing and probabe future conficts based on a review of reevant iterature and theoretica considerations regarding the habitat requirements of caribou.. Athough the focus is on the caving and summer ranges of the CAH, the other Arctic herds are considered in the context of overa deveopment on the Arctic Sope. Aso incuded is a description of the present scope of petroeum deveopment on State and and, more: importanty, the potentia for massive future deveopment considering the arge tracts of State and Federa and identified as having oi and gas potentia. Foremost among the recommendations is a pea for interagency surface use panning of the Arctic Sope to ensure that adequate and appropriate habitats remain avaiabe. Limits on the tota amount of regiona deveopment shoud be firmy estabished, principay on the basis of management goas for the various caribou herds (i.e., optima size, primary use, etc.). Protection of specia use areas (e.g., caving grounds, movement corridors, insect reief habitat) shoud receive particuar attention. This comprehensive pn woud be impemented through a strategic easing program foowed by carefu prepanning of individua production units, each with a set of broad deveopment standards and essee responsibiities. Crucia to the utimate success of deveopment panning is a continuing program of basic and appied research on the behavior and habitat requirements of caribou, together with a mechanism for input to, and revision of, various poicy guideines. The 9

24 ,,,i:.-.:",_,..;j.... ".r: ;,,!!'i!'""..;;;;t-- ''' ; v-.!' :)"" ' ,...;..,...,_.; Jf' ' -: ,.:._..,... _. -\, ' overa effectiveness of any panning system _ requ,ies forma interagency recognition, but with sufficient fexibiity to be refined on the basis of new knowedge. An estabished panning framework shoud greaty simpify and faciitate the routine permitting process. Given a set of deveopment guideines that are estabished prior to unitization, site-specific mitigation (e.g., road/pipeine routing ad design, faciities pacement, construction scheduing, traffic reguation, etc.) need invove itte more than direct appication through various permits and strict enforcement of the appropriate stipuations. Previousy estabiehed principes of deveopment, together with specific imitations, shoud eave few actions subject to industry or agency interpretation. n direct contrast to these proposed poicy changes; prnt and renewabe subsurface eases on State ands ire extremey vague in terms of habitat protection. As industry is neither bound by specific forma agreement nor incined toward vountary sefrestriction of its activities, the present course and character of oified deveopment wi ikey prevai in these areas. Unfortunatey, technica needs, procedura phiosophies, and economic pressures are frequenty inconsistent with what we perceive as adequate protection of caribou and caribou habitat. Thus, with no ega or officia poicy base!, the ony reguatory option is a sie-specific, case-by-case approach to mitigation; that is, reaction to individua proposas rather than impementation and enforcement of an operating framework that is formuated and accepted before the fact. The present inefficient--and argey ineffective--approach to mi tiga tion is exacerbated by a tendency fo:r the burden of proof to be paced squarey on the permitting ag.encies rather than on the essee. t is incongruous, to say the east, that accountabiity be greater for a defending agency than for the deveopment aggressor. Renewabe resource agencies are incined to err on the conservative side, and this cautious approach to permitting is apparenty unpaatabe to bgth industry and the State and rnanagex. s. Aso, on most environmenta issues, the Department of Fish and Game is itte more than advisory to the Department of Natura Resources, acking the authority to insist on protective measures. n practice, however, the Habitat Division, recognizing its weak position, frequenty settes for unacceptabe compromises before the fact rather than forcing the issue and thereby risking a compete oss of mitigation. Because of the Department's present inabiity to infuence oified panning, and despite the inadequacies of the pe.r.mitting system, advisory input to permit stipuations appears to be the ony reguatory option on State ands. n an attempt to inform industry of Department views on various permitting issues and to standardize stipuations pertaining to cariboti (and otht species) on the centra Arctic Sope, staff from the Division of Habitat drafted a nnorth Sope Lands Guideine Document" (excerpts, Appendix F). Whie this document has never been t

25 sf 4( t t.,,., ;, -! '. i <. ;L.. " ' '! {j. u: ". i ' ' j i.'... - j ' accepted as Department poicy, it is consuted reguary by the permitting staff as an interna reference. Seaman et a. (98) prepared a comprehensive anaysis of the coasta habitats between the Covie and Kuparuk Rivers and cited this same set of recommendations. By and arge, we support the intent and substance of these quideines. The reader is referred to these documents for specific operating principes and stipuations. The cent.ra Arctic coasta pain (i.e., between the Co vie and Canning Rivers) coincides very cosey with and ownership by the State. The overwheming majority of caving and summer range of the CAH is within this area, particuary that portion of State ands within about 5 km of the Arctic coast. Because of the magnitude of ongoig and probabe future deveopment in this region, conficts during caving and midsummer continue to be of primary concern (see Appendix E) The foowing is an overview of what we perceive as chronic, recurrent probems resuting from i-conceived devopment procedures and/or agency ineffectiveness. Discussion of the nature and status of each broad issue is foowed by some genera suggestions aimed at resoution. Admittedy, these probems wi be difficut to resove without a comprehensive panning approach, as discussed above, but shoud certainy be addressed by appropriate action within the existing permitting structure.. Oified Design and Deveopment Procedures We have repeatedy recom.tuended that the rout:ing of various roads and pipeines, as we as the siting of various temporary and. permanent faciities, be such that to t:a disturbance is minimized. This appies not ony to individua processing/ support faciities, discrete compexes and oified uni ts, but' aso to cntiguous and proximate production areas, irrespective of unit boundaries. Few attempts have been made to achieve this goa. The progress of oified deveopment to date demonstrate; ceary that many actions are soey for the sake of convenience. Unit operators continue to :request and receive permits for redundant access, new airports, additiona docks, uxurious iving accommodations, and temporary camps/equipment storage areas, to cite just a few exampes. Simiary, surface easing to commercia interests frequenty resuts in additiona unnecessary sources of disturbance in adjacent areas: specific exampes are the recent proiferation of storage sites south of Deadhorse airport and tentative approva for a North Sope Borough "industria park" in the Kuparuk area'" The proposed pacement of any permanent road or processing/support faciity shoud teceive more carefu scrutiny. The nature and extent of any potentia confict with caribou shoud be examined in the context of both present and future deveopment in the area. Except in rare cases, permit appications for estabishing t.emporary camp or storage faciities outside of

26 existing compexes shoud be denie,d.. Further, it shoud be the responsibiity of the appicant to provide evidence for the necessity of each proposed action by assessing the aternatives. Caims of economic advantage may not, and simpe convenience shoud not, be sufficient. r. Linear Structures Roads and pipeines shoud be designed and routed so as to maximize caribou passage. An essentia eement of the panning process is eary impementation of an industry-funded fied surveiance program to estabish preferred routes of caribou movement through each area in question. Every attempt shoud be made to preserve these natura movement zones. Unfortunatey, the practica question of optima pipeine design and caribou crossing success remains open, despite an assortment of usefu studies conducted over the past decade. As an absoute minimum requirement, eevated pipe shoud be such that physica passage is assured; most caribou, considering maximum Sitage of anter deveopment, can physicay pass beneath a pipeine with a 5-cm (ca. 5 ft) surface-to-pipe cearance. Howeve.r, specia crossing provisions (e.g., buried sections, ramps, greater cearances) may be required particuary in major movement zones and in areas where drifting snow woud otherwise restrict passage. To ensure the effectiveness of secia crossing structures, it is essentia that the ocation of existing and proposed structures/disturbances be considered in the panning pk"ocess $ t makes itte sense ::o modify pipeine design in t()ta ignorance of subsequent actions that might nuify or seriousy compromise those efforts. One garing exampe is the construction of an extremey expensive buried crossing in the TAP (just south of Pump Station ), ony to have a we pad appea:r in the immediate vicinity a few years ater. There are numerous other instances where some reasonabe foresight woud have greaty improved both economic efficiency and mi tigat:i.ve effectiveness. Mitigat.ion may aso ivove strategic pacement of roads and other faciities. Simpy meeting the minimum criteria for physica passage of caribou has, in a number of instances, proven inadequate because of compications resuting from the presence of other adverse stimui. Nearby roads and processing/support faciities, traffic and construction activity (see, beow) as we as the overa character of proxima deveopment (see, above) can greaty infuence accommodation, irrespective of oca road or pipeine design. Curatoo et a. (98) tentativey concuded that in areas where the Kuparuk Pipeine was separated from the WSR, pipeine crossing success did not improve at cearances above 5 em; accordingy, preiminary recommendations were for spatia separation of the pipeine and road/traffic stimui. We agree that, athough crossing success can be reduced

27 Additiona unproductive traffic and construction activity aso resut from engineering errors in faciities design. Specificay, since 978, many bridges and cuverts aong the WSR have been of insufficient size to accommodate water from spring runoff and summer storms. As a resut, major road repairs and cuvert/bridge repacement have become annua summer exercises. t is ony recenty that most of these water crossings have been finay repaced with what, hopefuy, wi prove to be adequate structures. Underdesigning of cuverts and bridges, whether intentiona or otherwise, is inexcusabe. n many instances, the necessary repairs and reconstruction activity are in direct confict. with cari.bou, which tend to preferentiay occupy, and move aong, riparian systems. Reated practices with simiar consequences invove the aforementioned propensity for nonessentia construction. Hence, optiona/redundant roads, new transportation faciities, oca commerciaization, and storage pads a necessitate a concomitant increase in demands on everythng from grave resources to sewage disposa. Aside from an undesirabe proiferation of permanent faciities within an oified, the intensity of activity must aso increase correspondingy. n short, any construction project, however minor in its physica characteristics, must so be viewed in terms of its indirect impact on a variety of support requirements and, utimatey, the) ne t disturbance increment. A construction proposas require coser examination as to need, feasibiity, soundness of design, and environmenta tradeoffs. To reemphasize, given the present easing poicy and permitting structure on State ands, we beieve that the ony rationa approach to maintaining caribou habitat is a carefu reexamination of current deveopment practices. Actions that can be confirmed as procedura essentias shoud be streamined, whie those which are superfuous shoud be abandoned. n the ong term, and particuary in a regiona context, strategic and use panning at the easing and unitization stages is the most viabe approach to recon :::iing conficts between caribou and industria deveopment. ACKNOWLEDGMENTS Primary funding for the various components of this study was provided through Federa Aid in Widife Restoration Projects W-- and W-7 -. Additiona support was provided by the Aaska Coasta Management Program (Office of Coata Management), Northwest Aaskan Pipeine Company, the Aaska Department of Transportation/Pubic Faciities (Division of Panning and Programming), the U.S. Fish and Widife Service (Arctic Nationa Widife Refuge), and ARCO Aaska, nc. The authors are gratefu to R. Stearns, D. Ha, J. Davis, P. Vakenburg, S. Fancy, J. 'f7right, and R. Zarnke for vauabe technica assistance. We aso thank the hepfu staff of Air 4

28 . ' Logistics of Aaska, the Aaska Department of Transportation/ Pubic Faciities, and Arctic Sope/Aaska Genera, nc. for aid in fied ogistics. LTERATUR.E CTED Cameron, R. D., and K. R. Whitten. 979a. Seasona movements and sexua segregation of caribou determined by aeria survey. J. Wd. Manage. 4:66-6o, and. 979b. Distribution and movements of caribou in reation to the Kuparuk Deveopment Area. First nterim Rep. to ARCO, EXXON, and SOHO/BP, March 979. pp =--- ( f L i \ , and. 98a. nfuence of the...-.,-':""'"--- Trans-Aaska Pipeine Corridor on the oca distribution of caribou. n E. Reimers, E. Gaare, and S. Skjenneberg, eds. Proc.. Second nt. Reindeer/Caribou Symp., R ros, Norway, 979., and. 98b. Distribution and movements of caribou in reation to the Kuparuk Deveopment Area. Second nterim Rep. to ARCO, EXXON, and SOHO/BP, May 98. Aaska Dep. Fish and Game, Fairbanks.. 5pp. ----=--, and. 98c. Effects of the Trans-Aaska Pipeine on caribou movements. Aaska Dep. Fish and Game. Fed. Aid in Wid. Rest. Prog. Rep. Proj. W--, Job.8R. Juneau. 6pp ::-:--: ,. -', and W. T. Smith. 98. The distribution and movements of caribou in reation to the <uparuk Deveopment Area. Third nterim Rep. to ARCO, EXXON, and SOHO/BP. Aaska Dep. Fish and Game, Fairbanks. 5pp..,, and 98. Effects ot the --T r... ans-aaska Pipeine on caribou movements. Aaska 'Oep. F'ish and Game. Fed. Aid in Wid. Rest. Prog. Rep. Proj. W-- and W--, Job a8r. Juneau. pp.,,..,...,,, and D. D Roby. 979 Caribou distribution and group composition associated with construction of the Trans-Aaska Pipeine. Can. Fied-Nat. 9:55-6. Chid, K. N. 97. The reactions of barren-ground caribou (Rangifer tarandus granti) to simuated pipeine and pipeine crossing structures at Prudhoe Bay, Aaska. Comp. Rep.., Aas-"a Coop. Wid. Res. Unit, Uni v.. Aaska, Fairbanks. Spp. 5

29 ; - ' Curatoo, J. A., s. M. Murphy, and M. A. Rebus. 98. Caribou responses to the pipeine/road compex on the Kuparuk oified, Aaska, 98. Fina Rep. to ARCO Aaska. Aaska Bioogica Research, Fairbanks. 64pp. Davis, J. L., and P. Vakenburg Western Arctic caribou studies. Aaska Dep. Fish and Game. Fed. Aid in Wid. Rest. Fina Rep. Proj. W-7-8 and W-7-9, Job.9R,.R, and R Juneau. 95pp. Gavin, A widife survey, Prudhoe Bay of Aaska. Atantic Richfied Co. pp. Hemming, J. E. 97. The distribution and movement patterns of caribou in Aaska. Aaska Dep. Fish and Game. Wid. Tech. Bu.. 6pp. Seaman, G. A, G. F. Tande, D. L. Causen, and L. L. Trasky. 98. Mid-Beaufort Coasta Habitat Evaua_tion Study: Covie River to Kuparuk River. Rep. to North Sope Borough. Aaska Dep. Fish and Game, Anchorage. 99pp. White, R. G., B. R. Thomson, T. Skogand, s. J. Person, D. E. Russe, D. F. Hoeman, and w. R. Luick Ecoogy of caribou at Prudhoe Bay, A.aska. n Ecoogica investigations of the tundra biome in the ;?rudhoe Bay region, Aaska. Bio. Pap., Spec. Rep. No. Univ. Aaska, Fairbanks. Whitten, K. R., and R. D. Cameron. 98. Movements of coared caribou in reation to petroeum deveopment on the Arctic Sope of Aaska. Can. Fied-Nat. (n press). PREPARED BY: Raymond D. Cameron Game Bioogist APPROVED BY: SUBMTTED BY: Research Ch vision of Game j\tayne L. Regin Regiona Research Coordinator 6 \

30 : i i ;), LO " {' -.. a:... f/) Q) > - u SPRNG Year t Fig.. Seasona changes in reative af representation among caribou associated with the Trans-Aaska Pipeine Corridor, NOTES: %R:%A = ratio of caf percentage observed from the Daton Highwy tg that determined by aeria survey. Higher ratio for summer 98 incudes data on a arge transient group (see text) and is excuded in cacuation of the ower ratio. 7

31 .--., ' - ' ,..... J... " t A,.. ' "=."JJ -. - rt >\:. W T me rt.., : _,. <, '\,. ""'... J - \ ' 'f..., (J. ) -. -."_ t A,.. ' '' "',;...,. ' ',, ".. "'-:.... "\ '.. '.,.,.,..._,...., "-;,',.....,..,...-. '_. D '-.._f. :_!_----' ":'=.-- \. "' i -- po J..,. "":.!'.,.!r:q "'.-...,r: :.(;;... 4bN:-dt!. ntfif",..;it &&;,..;; ;;p,,aq!;'s"'>' :-..:" -.:.,;,,::,,. 'i:;oc'ct;.,,_;..,..",.,.,"*'.rw " '...,,, - \ - i i ' ,-- t ---, 5 W OLKTOK 49 W 48 W 47 W f46 W rqruta BULLEN ('..) co ii:, C) (..) E D \.., \). -Q: B, _ Mios 5 8 km r -.J ,, ti r:;:. ",, --;:.. Fig.. Aeria survey transects, -4 June 98. coverage. heicopter coverage; fixed-wing &ra:w;;;;a;:jwwa. Qc 4W A za suaaz:sana.&td& oc;cu.ta.ewwn w.44a'j J"""" "" *... ;

32 _j -,r., --::._--:, -"'.. ' *... c."... -, --., - ; JiM ji - :a-.jra5.....f"t ;aa.. - "", },, \ \\ \ "" Q; +.. "'.,.P ; Mies Kiometers + ) 6 :.-Jf' :..: :. "': :::..bo -: ::... :-t::::.....,.... :..... :. t,y._:: :,,:::::;:; ) t:}\ :::.:.;; i r! ' Fig.. The West Sak Road and dssociated faciities, summer Kuparuk Pipeine; dri pads or faciities. road; *; 44, ; -k>mfk..., A ;caa,.._. L4QJ!& AQ 4 do i.j p $Jitijttf'iCfidFt7if'S'fifiJW:ii'HiU... Jii--isti -, ;"\ fii U.

33 '..,, -.. ' ' _...J' i..... i -... ';!! L a 644 Distance from Coast f} (km) Covie - River _L Kuoruk_jru.dhoJL Mikk-esen _j L_ Coning -r- Raver -r- Boy r Boy Raver w :J..a -- \ '- Q)..a E :J z 5 Aduts J Caves,{._,,,. r.r! Q L W i rjitj8uft'jkttvwyu! U hi U J z U [J fz [d.:. u w E D C B A ' "''''"4 4'4"5 5' 6 6' West Transect Number East (i Fig. 4. Distribution of caribou on the Centra Arctic Herd caving- grounds, -4 June i +4!!<,;. t 4iiPRD+W' L +»A* At 4Wt 7f;a;p)$4 CAP 4.F,... -""tus;t;a i j, QW&_.CJ$ JS( f J..,..,_ t-,d-- """' =

34 f < : ;r ''. Fig. 5. MtU t Uft Caving concentrations of the Centra Arctic Herd, < T «! ' 't;,,, }, J

35

36 "- J.::, "'4i.""\!, CJ --;"b-wcmam sd' '8 8MCiiW'! N'J? t't:>a"""$ Mfi'<Ahmu:-t.i!MTif:.."' t#!in8t "?""""!"'--..c.'-'---:..i-c- ;_.,.o,_..&._..c., _: t JJi i'ilj iifdjn.... i f.8 f.a......_. iiiiid!ibiii ,.,. ',... f- r ''.. Tabe. Numbers of caribou and group compositin determined by aeria survey ncusive Tota obs. Tota cassified dates N G N G %B %C %Ca y N a Group wjcaves G %B %C %Ca %Y b Groups wo/catves N G %B %C %Y!{ i 4/-4// /7-7/8/8 7/7,59, /8,8 8, Tota/Mean 4, /5-/7/8,7 45,' ,59,86 4,45, '! w a b Tota caribou in'groups with or more caves present. Tota caribou in groups with no caves. c d Tota west of Prudhoe Bay Compex. Tota east of Prudhoe Bay Compex. --r-/:> f Note: N = number of caribou, G = number of groups, B = bu+s, C = cows, Ca = caves, Y = yearings. '...,:{ "''WfUM!U &Wi!M(.iO tuh9f!ou QX 4, OWUU "W i -C-4JfJ:t"itfifJW't:Vr iiitii:yf v i' 8-Ww;i:-.. ;;..wt wf-ii.-;;cw:*'!t4f._...,..,...,.a;::t!iw JJ z jf(bjj A):A ,::..,... i'\$ t f At h ewau. t w& ird J"_.t\..,,

37 ., ' Tabe. Number and group composition of caribou observed aong the Daton Highway, February-December 98. Tota obs. Tota cassifieda Survey dates N G N G %B %C %Ca %Y %A /8 - / d Winter summary b Group w/caves N G %B %C %Ca %Y %A J'"d:.., _,,:;.:.,_;;.;;4"'-:-- '"f,, '. c Group w/o caves N G %B %C %Y %A ,,.;".... ' "'<;.,.i : Ki' p,; w ' f '. w /-/ /5-/6 4/9-4/ 4/-4/4 5/-5/4 5/7-5/8. e S prng means 6/9-6/ 6/4-6/5 7/-7/ 7/8-7/9 8/8-8/9 8/6-8/9 e Summer means 9/-9/4 9/7-9/8 /-/ /8-/ /-/ /-/4 e Fa means as d : \) [ f t j? '""' /-/d : Excudes groups with any "unkn_owns" (uncassified as to sex or age). Tota caribou in groups with or more caves present. Tota caribou in groups with no caves. One survey period ony. e Mean seasona percentage for each sex/age cass. Note: N = number of caribou, G = number of groups, B = bus; C = cows, Y = yearings, Ca = caves, A = aduts t: r f.{ f '

38 Tabe. Estimated daiy traffic on the Daton Highway, a s. b Summer c Fae prj.ng d Totas \ ( :.:_ a b c d e Data compied from Community Research Quartery, Fairbanks North Star Borough, Vo. V, No., Apri 98, Fairbanks, Aaska. Estimates are based on enroute vehice counts at highway check points south of the Brooks Range; additiona oca traffic is not incuded. March-May. June-August. Traffic count was taken at Disaster Creek bridge rather than the Yukon Ri rer bridge. September-November. J - t 5 \' ;)

39 , ':'. Tabe 4a Caribou densities in the Kuparuk caving concentration-area, Year Caribou/ km Cow-caf pairs/ km

40 - Tabe 4b. Group composition of Centra Arctic Herd caribou on caving grounds, Year % caves Caves/ cows Bus/ cows Yearings/ cows (4)a 6 (6) 48 (5) (4) a Numbers in parentheses are yearings/ cows estimated from overwinter caf surviva counts. J ' :..; 7

41 ,, ) X '. 't ] ' 'j.-; ' J ' X' '--- " '> Tabe 5. Composition of 98 C postcaving aggregations east and west of the Prudhoe Bay Compex Region % COWS Kaubik River 4 to West Dock Caves % / cows 7 64 Bus Yearings Tota % / cows % / cows samped ,59 Deadhorse to 6 Canning River

42 .., J..... '..,. C. "\,' r;., :...;,;, ;,;*t" '!!:._. t?'>.i!:"!u<ev&5eriefe dsi'd.. ' Tabe 6 Observed caribou crossings of the West Sak Road and/or the Kuparuk Pipeine, summer 98. From: To: Road interva (km) 8.. 6o Tota No. of caribou , % of tota 7 < % northbound % caves 9 4 5, J. i :,. : 9

43 Tabe 7. Caribou sighting rates and insect harassment eves in the Kuparuk area during the period 8 Juy-S August, nsect harassment (no. days) Year Light Moderate Severe Sighting rate (caribou/km) , }

44 ... APPENDX A POPULATON DYNAMCS OF THE CENTRAL ARCTC HERD, K. R. Whitten and R. D. Cameron....,.. Presented at the Third nternationa Reindeer/Caribou Symposium, Saariseka, Finand, -6 August 98 Acta Zoo. Fenn. (in press) i 4

45 ' i Popuation dynamics of the Centra Arctic Herd, Kenneth R. Whitten and Raymond D. Cameron hitten, K. R. & Cameron, R. D. 98: Popuation dynamics of the Centra Arctic Herd, Acta Zoo Fennica :-. The Centra Arctic Caribou (Rangifer tarandus granti) Herd (CAH) ranges on Aaska s Arctic Sope in the vicinity of the Trans-Aaska Pipeine Corridor and Prudhoe Bay Oified. n 975 the CAH was identified as a distinct subpopuation. By 978, the herd numbered about 4,6 aduts; the aut sex ratio was unusuay high--a minimum of bu per cow. A census conducted in 98 indicated continued herd growth to an estimated 6,66 aduts, with a decine in the adut sex ratio to about 8 bus/ cows. Yearing recruitment averaged % between 978 and 98. Actua herd growth was approximatey % per year, impying an annua adut oss of 9%. Factors affecting this high rate of increase are discussed, as are the inherent difficuties in obtaining reiabe popution data, even from an intensivey surveyed caribou herd. Kenneth R Wh'itten and Raymond D. Cameron, Aaska Department of Fish and Game Coege Road, Fairbanks, Aaska 997. ntroduction The Centra Arctic Caribou Herd (CAH) inhabits the region surrounding Prudhoe Bay and the Trans-Aaska Pipeine on Aaska s Arctic Sope (Cameron & Whitten 979). Despite changes in range use patterns resuting from petroeum deveopment (Cameron & Whitten 98), ampe aternative range remains avaiabe and the herd is increasing. This report deas with popuation dynamics of the CAH between 975 and 98.. Methods CAH distribution and sex/age composition were examined reguary from 975 through 98. A surveys (Cameron & Whitten 979, 98) were conducted by heicopter. Groups of ess than about caribou were counted directy from the air. Otherwise, we anded nearby and used binocuars or a spotting scope to count and cassify caribou. Sexjage cassification was based on externa genitaia and body size/morphoogy. Minimum herd size was estimated during the postcaving period when most of the herd was aggregated in a few arge, discrete groups. n 978, the size of each aggregation was estimted from the air, foowed by a direct count from the ground. n 98, groups were either directy counted or photographed and counted ater.. Resuts. Popuation composition and productivity Proportions of maes and femaes varied widey among seasons within each year, and aso within a season between years (Tabe ), primariy due to variabe distribution of maes and femaes among the count areas. Bus were generay distributed farther south than cows during a seasons (Cameron & Whitten 979). Therefore, bus were underrepresented in surveys of the coasta caving and postcaving ranges. Attempts to obtain an accurate adut sex ratio were aso frustrated by anomaies in oca caribou distribution. Caribou were often eveny distributed over most of the coasta tundra during fa, but were concentrated aong foodpains in the foothis and mountains. Since fa survey routes were aong drainages, the southern groups were disproportionatey counted; thus, {""' 4

46 ) _,.,_", -,-:,..,,...,.,....._.,..,,_.,,,..--. : t C:.' \,,_.,, bus were overrepresented. During fa 976, for exampe, 5 bus/ cows were observed aong the survey route; hcwever, thre were 4 bus/ cows in the foothis and ony 6 bus/ cows on t coasta pain. Weighting these ratios according to the estimated proportion of caribou in each area yieded a sex ratio of approximatey bus/ cows. This unusuay high ratio (Bergerud 978) coud have resuted from an infux of caribou from the adjacent Western Arctic and/or Porcupine herds in the ate 96's and eary 97's. f so, the bu:cow ratio shoud have decined in the mid- to ate 97's as oder mae cohorts began to die of od age. ndeed, the preponderance of very arge bus observed in 976 was no onger apparent by 98. The adut sex ratio in fa 98 was estimated at 8 bus/ cows, and no geographic variation was apparent. Miscassification of yearings and young bus as cows probaby occurred during midsummer. However, during caving, fa, and spring surveys, smaer groups were cassifi-ed at cose range by heicopter, and sex identification was positive. Resuts from those surveys provided the best estimates of caf surviva. nitia productivity and over summer surviva were high for the caf cohorts. Overwinter caf surviva was exceent from 977 through 979 and moderatey good in the 976 and 98 cohorts (Tabe )v. Popuation size and rate of growth The CAH numbered about 5, tota caribou in midsummer 975 (Cameron & Whitten 979). During postcaving aggregation in 978, the herd was estimated at 5,-5,8. No census was attempted in 979 or 98. The tota count in summer 98 was 8,57 caribou, substantiay higher than in 978. Neither the 978 nor the 98 count was an accurate census of the entire herd, however, because caribou dispersed inand were not counted. D ifficuty in obtaining accurate composition data and/or the rapid dispersa of oscaving groups into periphera areas precuded use of either standard or modified aeria photo-direct countextrapoations (Davis et a. 979). Thus, tota popuation size coud ony be subjectivey extrapoated We conservativey estimated 6, caribou (4,6 aduts) in 978 and 9, (6)66 aduts) in 98. The neary 5% increase in the number of adut caribou in ony years can be accounted for by exceent productivity and recruitment. Assuming adut mortaity of 7-% per year in a ighty expoited popuation with moderate wof predation (Bergerud 978), recruitment woud have been between 5 and 8% per year. Starting with n estimated 4,6 aduts and bus/ cows in 978, &nd assuming 9 bus/ cows in 979 and 8 bus/ cows in 98, the 98 adut popuation woud have been bett'een 5,97 and 7,94. Simiary, cacuating backwar from 6,66 aduts in 98 yieds 4,6-5,5.aduts in 978. Both sets of cacuated vaues bt acket the actuai estimates. The % annua increase and % average r\.!!cr'u i tment in the CAH between 978 and 98 indicate annua adut oses of about 9%. 4. Concusins Adut sex ratios in the CAH proved difficut to estabish in spite of frequent composition counts based on 5-67% of the herd Yearing cassification was ureiabe; consequenty, rates of recruitment were cacuated using ate winter caf counts. ReGruitment was undoubtedy good, and the CAH surey increased between 97) and 98. From 978 to 98, the observed growth rat of the CAH was about % per year. Potentia ii'( t.ase, based on?.mpirica vaues of mortaity, was even 4