CARIBOU RESPONSES TO THE PIPELINE/ROAD COMPLEX IN THE KUPARUK OIL FIELD, ALASKA, 1 982

Transcription

1 CARIBOU RESPONSES TO THE PIPELINE/ROAD COMPLEX IN THE KUPARUK OIL FIELD, ALASKA, ALASKA BIOLOGICAL RESEARCH P.O. Box Fairbanks, Aaska 99708

2 I I I I I II I I I I I I I I I I CARIBOU RESPONSES TO THE PIPELINE/ROAD COMPLEX IN THE KUPARUK OIL FIELD, ALASKA, 1982 FINAL REPORT Prepared for and funded by: ARCO Aaska, Inc. P.O. Box 360 Anchorage, Aaska Prepared by: ames A. Curatoo and Stephen M. Murphy ALASKA BIOLOGICAL RESEARCH P.O. Box,81934 Fairbanks, Aaska G- t-3::;- tis/ c g?i ;q!a,,, I u ARLIS Aaska Resources Library & Information Services Anchorage, Aaska

3 " i --, ACKNOWLEDGEMENTS _;, C! -, -" -, - This proect was funded by ARCO Aaska, Inc. We wish to thank ARGOs Senior Environmenta Coordinators, Don Keene and, especiay, Scott Ronzio, for their support and vauabe input during a phases of this study. We are aso gratefu to Cathy Curby, Louise Smith, and Brian Lawhead for their capabe fiedwork, to Amy Reges who assisted with fiedwork and heped with technica aspects of report preparation, to Mary Moran our draftsperson, and to Patricia Dyer-Smith who typed the report. We thank Ray Cameron, Aaska Department of Fish and Game, Fairbanks; im Dau, University of Aaska; and Martha Robus, Aaska Bioogica Research, Fairbanks for providing additiona data. We aso wish to thank oe Morgan and Kirk Barker, the managers of ARGOs Kuparuk Camp; and im Pimberton, ARCO Aaska, Inc. who offered their hospitaity to our fied crew. -"

4 ii TABLE OF CONTENTS Page Acknowedgements i List of Tabes iv List of Figures v Executive Summary vi INTRODUCTION STUDY AREA METHODS. 6 TERMS DEFINED ) " GROUP GROUP COHESION CROSSING SUCCESS..... : BURIED PIPE PIPELINE CROSSING IN RELATION TO PIPE HEIGHT SELECTION COW-CALF GROUP BULL GROUP ROAD ROAD WITH TRAFFIC PIPELINE PIPELINE ASSOCIATED WITH TRAFFIC RESULTS \ND DISCUSSION GROUP SIZE AND COMPOSITION PIPELINE CROSSINGS Comparison between Study Areas Crossing by Group Type and Group Size t>utip1e Crossings PIPELINE CROSSING SITE SELECTION Eevated Pipeine Buried Pipe1 ine BEHAVIOR Group Cohesion Rate of Movement Di recti ona 1 Trave Use of Grave Habitat Caribou Reactions whie Crossing Roads and/or Pipe1ines Roads Pi pe 1 in e s Road with Traffic Pipeine Associated with Traffic Caribou Reactions in the Study Area

5 iii., _ co Page SUMMARY AND CONCLUSIONS THE RELATIONSHIP BETWEEN CARIBOU AND LINEAR STRUCTURES Crossing Success Crossing Site Seection THE ROLE OF INSECTS APPENDIX A. APPENDIX B. APPENDIX C. A compiation of data forms used and a description of data coected in the Kuparuk Oi Fied caribou study, Aaska, A description of statistica tests used for data anaysis and summary of test :resuts A summary, by season, of caribou routes through the four study areas in the Kuparuk Oi Fied, Aaska, LITERATURE CITED ::.:; "" -...).

6 iv LIST OF TABLES "., 1 :1.. "" _.. 1 _, -- " _. -, "" Tabe 1. Tabe 2. Tabe - Tabe 4. Tabe 5. Tabe 6. Tabe 7. Tabe 8. Tabe 9. Tabe 10. Tabe 11. Page Group size of caribou observed in the Kuparuk Oi Fied, Aaska, 1981 and ; Age and sex of caribou observed in the Kuparuk Oi Fied, Aaska, 1981 and Percent of caribou that crossed the pipeine at the pipe-road site and pipe site or northern border of the contros in the Kuparuk Oi Fied, Aaska, 1981 and Percent of caribou groups, by group type and group size, that crossed the pipeine within the;sites in the Kuparuk Oi Fied, Aaska, 1981 and A summary of pipe height seection by caribou in the Kuparuk Oi Fied, Aaska, 1981 and Pipeine crossings in reation to pipe height and insect abundance at the pipe site in the Kuparuk Oi Fied, Aaska, 1981 and A summary of habitats occurring at eevated pipeine crossings in the Kuparuk Oi Fied, Aaska, 1981 and A summary, by season, of caribou reactions whie crossing pipeines and/or roads, Kuparuk Oi Fied, A comparison, by season, of the number of groups entering the study areas versus the number of groups exiting the study areas in the Kuparuk Oi Fied, Aaska, Speed of caribou groups observed in the Kuparuk Oi Fied, Aaska, 1981 and A summary of directiona trave and the average distance traveed by groups in the Kuparuk Oi Fied, Aaska, 1981 and

7 v LIST OF FIGURES Figure 1. The Kuparuk Oi Fied study area, Aaska, Page! p Figure 2. Figure 3. Figure 4. Figure 5. Figure 6. Figure 7. Figure 8. Figure 9. Figure 10. Figure 11. Figure 12. Daiy insect eves observed in the Kuparuk Oi Fied, Aaska, 1981 and Mutipe pipeine crossings, (sites) and northern border Grossings (contros) by caribou in the Kuparuk Oi Fied, 1981 and Crossing site seection in reation to pipe height in the Kuparuk Oi Fied, Aaska, 1981 and A summary of caribou routes in reation to pipeine height at the pipe site in the Kuparuk Oi Fied, Caribou crossings at the pipe site in the Kuparuk Oi Fied, Aaska, 1981 and Caribou crossings at the pipe-road site in the Kuparuk Oi Fied, Aaska, 1981 and Habitat seection by caribou as they crossed under the pipeine in the Kuparuk Oi Fied, Aaska, and Caribou crossings of an eevated pipeine with respect to their abiity to view the tundra on the other side of the pipeine in the Kuparuk Oi Fied, Aaska, 1981 and Use of grave by caribou groups in the Kuparuk Oi Fied, Aaska, 1981 and Severe caribou reactions to various stimui, based on 105 groups in the pipe-road site and 57 groups in the pipe-road contro, Kuparuk Oi Fied, Severe caribou reactions to various stimui, based on 225 groups in the pipe site and 102 groups in the pipe contro, Kuparuk Oi Fied, Aaska,

8 _]., vi EXECUTIVE SUff\1ARY _,; _. _ ""!..,.....,.. -" _ Introduction The deveopment of the Kuparuk Oi Fied provides an opportunity to study the interaction between caribou and an east-west pipeine/road compex. This study was initiated to determine the effects of the Kuparuk Pipeine and associated road and traffic on the movements and behavior of the Centra Arctic Caribou Herd. The specific obectives of this study were: 1. to determine the effects of the Kuparuk Pipeine/Road compex on caribou movements with specia interest in crossing success and routes of trave; 2. to determine if caribou preferred specific habitats, pipe heights, or pipe configurations (i.e., raised vs. buried) for crossing sites; and 3. to determine the reactions of caribou to the pipeine and road under various environmenta conditions (e.g., insect harassment). The study consisted of two study area sites and two study area contros which were simutaneousy monitored from observation towers. The northern boundary of the study area sites were bounded by the Kuparuk Pipeine at the pipe site and the Kuparuk Pipeine and Spine Road at the pipe-road site. The study area contros were ocated 1.5 mies south of the sites and resembed the sites in a aspects except there were no roads or pipeines aong the northern border. -..;

9 vii Caribou sex and age composition, behavior, movement patterns, habitat preferences, and reactions to environmenta and man-made stimui were recorded. Observations were made during ate caving/post-caving season (4 une-28 une), mosquito season (29 une-23 uy), and eary Oestrid fy season {24 uy-1 August). ".., _) -., Resuts. There was a s1gnificant reduction of pipeine crossings at the piperoad site as compared to a other study areas during the mosquito season (29 une-23 uy) [i.e., frequency of crossings at a pipeine associated with traffic (35%) was significanty ower than a pipeine (80%), a road with traffic (89%), or the contros (82% and 84%)]. There were no significant differences in the frequency of crossings during Oestrid fy season (24 uy-1 August). ;; 2. The proportion of caribou crossing the pipeine was simiar for a group types (i.e., cow-caf, bu groups) and group sizes. ",i 3. There was no apparent seection by caribou groups for specific pipe heights at the pipe-road site. (Pipe height ranged from 60 to 110 inches.) -" -".)

10 viii 4. Caribou seected for higher pipe heights at the pipe site during periods when insects were absent, but there was no apparent seection for specific pipe heights when either mosquitos or Oestrid fies harassed the caribou (pipe height ranged from 60 to 170 inches). 5. Caribou showed a strong seection for crossing at paces where the pipe was buried beneath the road. Sixteen and(1six pnt f the groups crossing at the pipe,site and pipe-road site, respectivey, used these buried sections even though buried pipe constituted ess than one percent of the tota ength of the pipeine in the stud.v areas. 6. The percent of caribou exhibiting severe reactions when crossing different types of inear structures were: 0 percent for roads; 15 percent for pipeines; 47 percent for a road with traffic; and 51 percent for a pipeine associated with traffic. 7. Resuts of the 1982 study were simiar to Concusions 1. Pipe height (witin the range we examined) was not a factor that affected caribou in seecting pipeine crossing sites. 2. The two most important factors infuencing the seection of pipeine crossing sites are insects and topography. Caribou typicay foow topographic features (e.g., ridges) when insects are absent. Pipeine

11 ix crossings generay occur in those areas where the pipeine intersects preferred topographic features. Caribou under insect attack tend to trave through a habitats in an effort to escape insects, and encounter the pipeine in a random fashion. f 3. The severity of caribou reactions to inear structures varied depending on the type of structure. 4. Of the inear structures that we examined (road, pipeine, road with traffic, and pipeine associated with traffic), ony a pipeine associated with traffic appears to adversey affect caribou movements Caribou react to oi fied disturbance most during mosquito season; it is during this season that approximatey 80 percent of the caribou movements through the oi fied occur 1 i :.. Recommendations 1. Caribou passage through areas where the pipeine/road compex intersects maor caribou movement corridors can best be faciitated by: a) separation of heaviy traveed roads from eevated pipeines and/or; ) I "

12 X b) strategic pacement of caribou crossing ramps (i.e., reativey short sections of buried pipe). 2. A region wide anaysis of caribou movements, distribution, and habitat use woud provide a basis for determining where site specific mitigative measures described in the above recommendation woud be most effective. Concentating mitigative efforts in important areas woud faciitate caribou movements and minimize the construction costs invoved.., - "! _ "... _, _;! _,

13 1 INTRODUCTION The most recent expansion of oi deveopment on Aaskas North Sope.:... : has been in the Kuparuk River region, approximatey 20 mies west of Prudhoe Bay. This is an area of rapidy expanding deveopment;. that presenty incudes 15 mies of 16-inch, east-west aboveground oi pipeine, a gathering faciity, and road system (Figure 1). The pipeine and raad syitem intersect the spring and sur movements of th.e Centra.. - ::-...,...-. Arctic Caribou (Rangifer tarandus) Herd (CAH). The CAH presenty numbers about 9,000 animas (Barnett 1983). Caving has been reported to occur on the coasta pain between the Covie and Canning rivers (Cameron and Whitten 1979), with a suspected area of high density between the Kuparuk River and Oiktok Point (Cameron and Whitten 1980a). Productivity in 1982 was high, with a caf/cow ratio averaging 75 caves per 100 cows in mid-une (Dau pers. comm.). The maority of the CAH spends the summer on the coasta pain, moving north to the coast during periods of mosquito (Aides spp.) harassment and drifting south during mosquito-free periods.(chid 1973: Roby 1978; Cameron and Whitten 1980a; Curatoo et ). The CAH generay overwinters in the foothis of the Brooks Range, athough some animas are reported to use the coasta pain (Cameron and Whitten 1980a). Spring and fa migration routes between the caving and wintering grounds foow a northsouth direction aong the maor river systems (Cameron and Whitten 1977). An extensive summary of the history and status of the CAH can be found in Chid (1973), Cameron and Whitten (1979), and Roby (1978).

14 c..,),;,) /,,.: Beaufort SfO - STUDY AREAS... PIPELINE e DRILLPAD o Spine -... Rood i.:o,,,..- 3 CPF I\.. ::-:-r.-;:n... ITII.::" y/., f!r.i : Kuptrur Riv r NORTH 1 6 mies 1 11,! ALASKA Figure 1. The Kuparuk Oi Fied study area, Aaska, [1 :,pipe site; 2 =pipe contro; 3 =pipe-road site; 4 =pipe-road contro; 5 =river-road site.] N

15 1 3 -, "! -, _ - "!, _ - _ " _;; Athough the CAH is reativey sma, it has recenty gained attention because of the North Sope oi fieds within its home range. Caribou research has been conducted in the Prudhoe Bay compex (Chid 1973; Fancy et ; Fancy 1982) and aong the Trans-Aaska Pipeine (Cameron and Whtten 1979, 980a,b,c; Roby 1978). Some researchers have stated that caribou, especiay the cow/caf segment of the CAH, tend to avoid the Prudhoe Bay Oi Fied-Ayeska Pipeine compex (Roby 1978; Cameron and Whitten 1979). deveopment of the Kuparuk Oi Fied provides an opportunity to study the interaction between caribou and an east-west pipeine/road compex. CAH caribou traverse this corridor during spring migration to the caving grounds, and mosquito and Oestrid fy (warbe fy,oedemogena tarandi; nose bot, Cephenomyia trompe) seasons. No other caribou herd in North America interacts with oi deveopment on such a reguar basis. Data concerning caribou-pipeine interactions in or near caving grounds, when caribou are perhaps most vunerabe to disturbance (Lent 1964; Thomson 1973; Bergerud 1974), coud aso provide important input into the formuation of strategies to minimize potentia conficts. This study was initiated in 1981 to determine the effects of the Kuparuk Pipeine and associated road and traffic on the movements and behavior of the CAH. Fied investigations were continued in 1982 to coect additiona data to substantiate the 1981 findings, and to observe caribou during the caving and post-caving periods. _ -, _ - -

16 4 The specific obectives of this study were: 1. to determine the effects of the Kuparuk Pipeine/ Road compex on caribou movements with specia interest in crossing success and routes of trave; 2. to determine if caribou preferred specific habitats pipe heights, or pipe configurations (i.e., raised vs. buried) for crossing sites; and 3. to determine the reactions of caribou to the pipeine and road under various environmenta conditions (e.g. insect harassment)...

17 5 STUDY AREA ; The study area was ocated on the Arctic Coasta Pain, west of the Kuparuk River and approximatey 10 mies south of the Beaufort Sea coastine (Figure 1}. a modified coasta regime. The cimate of the region is cassified as The mean annua temperature is 8 F, and mean daiy temperatures are above the freezing point from une through September ( Wa 1 ker et a }. Even during the sunmer months, temperatures average ony a few degrees above freezing because of the maritime infuence of the Beaufort Sea and the effectiveness-of the Brooks Range to imit the passage of warmer air masses from the Interior. The prevaiing wind direction in summer is ENE and wind speeds generay decrease with distance from the coast. About 35 percent of the annua percipitation (approximatey seven inches) fas during summer (Waker et 1980). The terrain on the Arctic Coasta Pain is neary fat except for pingos, river evees, and man-made structures such as grave pads and roads. Patterned microreief resuts from frost action that forms high center and ow center poygons, the atter being the most common andform on the Arctic Coasta Pain. Microreief differences between poygon troughs and ridges are typicay ess than two feet, but even these differences are ceary refected in the degree of saturation of the soi and differences in pant communities.

18 1 6 1ETHODS -. Data coection -in comnenced- on.--une-anci -conffnued-hrot.gh-c- -- _; "] :;, ; ""!., " 1 August. The same four study areas deineated in 1981 (Curatoo et ) were used, except the pipe contro and its observation tower were shifted 0.25 mies to the east in an attempt to increase the number of observations in the study area.. The for study areas consisted of two study sites, each with its own contro.- Everywhere in this report a site refers to one of the two study areas bordering the Kuparuk Pipeine and a contro refers to one of the two study areas to the south of the sites that encompasses a reativey undisturbed area. A study area refers to any of the two sites or two contros. The pipe site was situated near the Kuparuk River with the Kuparuk Pipeine at the northern boundary (Figure 1). In this area the Spine Road and pipeine are about two mies apart, aowing for observations of caribou-pipeine encounters without the additiona effects of the road or road traffic. This study area is approximatey 1.4 mies ong and 0.7 mies wide. The contro was estabished 1.5 mies to the south. The pipe-road site was situated three mies from the pipe site where the Spine Road and pipeine are adacent to each other. The pipeine and road served as the northern border of the study area (Figure 1). Encounters of caribou with the pipeine and a road with traffic were observed in this study area. This site is approximatey 1.5 mies ong and 0.7 mies wide. The contro was estabished two mies to the south..)

19 7 \ _) 1 -" The contros were simiar in size and shape to the study sites, athough some border adustments were made to the contros to insure compete visibiity in the study area. The pipe site and pipe contro were about 0.96 and 0.90 square mies in area, respectivey, and the pipe-road site and pipe-road contro were about 1.06 and 0.91 square mies in area, respectivey. The perimeters of the study sites and contros were marked at 200 yard intervas using wooden stakes painted forescent orange. The pipeine vertica support members (VSMs) were numbered at each study site so that a caribou crossings coud be accuratey ocated. Pipe height was measured at each VSM from the bottom of the pipe to the ground. An average pipe height between neighboring VSMs was determined, and caribou crossing between any two VSMs were recorded as having crossed under the pipeine at the average height of those VSMs. The observation towers erected in 1981 within each of the four study areas were used again in Each tower consisted of a 6x6x7 foot cubice on a 10-foot high patform. A towers were within waking distances of an existing road. It was assumed that these structures woud not greaty ater caribou behavior. Variabe-power spotting scopes and binocuars were used to observe caribou. Each tower was equipped with an anemometer and a thermometer. CB radios were used for communication between towers.. _,,

20 8.)., Generay, a four towers were manned simutaneousy. Observation times were not set, rather an effort was made to observe caribou when they were in the vicinity and for as ong as they were present. A fifth study area (river-road site) was deineated aong the Spine Road near the Kuparuk River Bridge (Figure 1 ). The study site began at the west end of the bridge and ran west approximateyione mie, incuding 0.25 mies on either side of the Spine Road.:., A arge grave1 pie near the river was used as an observation point. The spi-e Road is about) two mi-es north of the pipeine in this area, aowing for observations of caribouroad encounters. Caribou movements through each study area were mapped. Data coected for each group incuded date, group size, group composition, route of movement, and time entered and exited the study area. In addition, 10 minute point-in-time scans were taken of caribou activity patterns, weather, traffic, and insect eves (Appendix A). Reactions of caribou to various stimui (e.g., roads, pipeine, vehices) were categorized in the foowing manner:.).... Reaction none mid moderate severe Reative Degree of Response none head raised to aert position movement at a wak movement at a trot/run.....)

21 9 ; 1 The habitat under the pipeine was cassified into five categories: water, grave, wet sedge, dry sedge, and ridge. The pipeine aso was described as to whether or not it was bocking a view of the tundra on the other side in an attempt to determine if obstruction of the caribous fied of view beyond the pipeine infuenced crossing site seection. From a point 50 feet south of the pipeine and at a height of five feet (approximatey the. height of a caribous head), we determined if the tundra. was visibe beyond the pipeine. A;: pipe sections between _ adacent VSMs were categorized as either "tundra visibe" or "tundra not visibe." An exampe of data forms and a description of the data coected are shown in Appendix A. Three seasons were identified in the 1982 fied season based upon caribou activities and the presence or absence of mosquitos and Oestrid fies; caving/post-caving {4 une-28 une), mosquito {29 une-23 uy), and fy season (24 uy-1 August) (Figure 2). These dates appeared to best deineate the various periods, athough there was overap between mosquito and fy seasons (24 uy-28 uy). For purposes of minimizing subective biases, mosquitos were considered absent at eves of "none" and "ow" and present at eves of "moderate" and "high" (Appendix A). Data were often grouped by season before anaysis. Chi-square anaysis, Kruska-Wais test, and the Kruska-Wais pairwise comparisons were the statistica procedures used to anayze the data. These tests are described in Zar (1974) and Conover (1980) and are outined in Appendix B.

22 ,. 10 -, -, DAILY INSECT LEVELS 1981 ] _ -,. R I UN rr o UL o., 5 AUG -, -, 1982 _) 0 E u _ I 5 UN UL i.:..: OESTRID FLIES OBSERVED= MOSQUITO LEVEL: D. B 1w \"" moaera high Figure 2. Daiy insect eves observed in the Kuparuk Oi Fied Aaska, 1981 and "

23 11 " TERMS DEFINED -..,.,.> ; " GROUP A group is defined as two or more animas that function spatiay and behavioray as a unit. Caribou groups are dynamic both spatiay and temporay and thus the groups expand and contract, both in numbers and density, due to changes in various environmenta factors, such as mosquito eve s-;,fbit, weather, or the carib s PhYsioogica.. state.> The group numbering system used in this study refects group dynami.cs by having group and subgroup cassifications. Subgroup numbers having the same group number signify that those subgroups were once part of the same group during the observation. : A new subgroup number was given to a group every time it changed its composition as individuas either oined or eft..) -,.. GROUP COHESION Group cohesion is the tendency for individua caribou to aggregate with other caribou and synchronize their movements and behavior..)... CROSSING SUCCESS A successfu crossing occurred when more than 50 percent of the group crossed the pipeine. Crossing success was determined at the group eve rather than the subgroup eve. Subgroup crossings were not considered ;..

24 12 since subgroups were continuay changing within a group, precuding a meaningfu anaysis. To be considered successfu, haf of the individuas in the main group woud have to cross, regardess of the subgroup they were in when crossing. This criteria was seected as we fet that if the maority (.>50%) of a group crossed a pipeine, it shoud be considered successfu. BURIED PIPE Buried pipe is used in this report to refer to sections of pipe that have been covered with grave for road crossings. Sections of buried pipe occur in the pipe site and pipe-road site and comprise ess than one percent of the tota ength of pipeine in the study areas. Each section of buried pipe was 1 ess than feet in 1 ength. PIPELINE CROSSING IN RELATION TO PIPE HEIGHT SELECTION A singe pipeine crossing was considered to have occurred when one or more caribou crossed under the pipeine (between the same two VSMs) in a more or ess cohesive manner. Thus, if a group crossed the pipeine between two different sets of VSMs, then two pipeine crossings occurred, regardess of how many individuas were in each crossing. The numbers of individuas at each crossing were disregarded to minimize the bias caused by the ack of statistica independence between individuas as they cross the pipeine. One anima typicay seects a crossing point, and the other animas foow in its path, rather than active seection by every individua.

25 13 COW-CALF GROUP A cow-caf group was defined as a group with more than 50 percent cows, caves, and yearings. BULL GROUP A bu group was defined as a group with more than 50 percent bus. " -" ROAD A grave road that is free of vehices, ROAD WITH TRAFFIC A grave road with vehicuar traffic. -, ) PIPELINE vehices. A pipeine with a grave road adacent to it. The road is free of.. _, PIPELINE ASSOCIATED WITH TRAFFIC A pipeine with a grave road adacent to it. The road has vehicuar traffic. _, _ - -

26 14 RESULTS AND DISCUSSION GROUP SIZE AND COMPOSITION Mean group size for the overa study period (4 une to 1 August 1982) was 15 caribou. Groups were smaest (X=3) during ate caving and postcaving season (4 une.to 28 une). Mean group size increased (X=20) during mosquito season {29 une to 23 uy) as aggregations fonned in reaction to.. mosquito hrassment and decined (X=7) during Oestrid fy season (24 uy to 1 August) as caribou dispersed under warbe fy and nose bot attack. Tabe 1 summarizes group size statistics by season for both 1981 and Differences in deineation of seasons between the two years refect differences in the phenoogy of insect emergence. A tota of 3,723 observations of caribou were made in the study areas for cassification of sex and age (Tabe 2). An overa caf/cow ratio of 68/100 cows was cacuated from these observations. Twenty-two percent of the caribou observed were cassified as yearings; this is unusuay high. Severa factors may have infuenced this high estimate for this age cass: (1) disproportionate number of yearings in the study area, (2) good overwinter surviva of caves, (3) groups that were densey aggregated, and (4) individuas (e.g., 2-year-ods) as yearings. difficuty in cassification of arger miscassification of younger The overa number of caribou recorded in the study areas decreased in 1982 compared to 1981 (Tabe 2), despite the onger fied season in In 1982, there were fewer cow-caf groups but more bu groups than in Differences between the two years were most pronounced.

27 15 Tabe 1. Group size of caribou observed in the Kuparuk Oi Fied, Aaska, 198and OVERALL Location Mean n S.D. Mean n S.D. Pipe site Pipe contro Pipe road site Pipe road contro , _; CALVING/POST CALVING Location Mean n S.D. Mean n S.D.... Pip sit. no data Pipe contro Pipe road site Pipe road contro MOSQUITO SEASON Location Mean n S.D. Mean n S.D. Pipe site Pipe contro Pipe road site Pipe road contro ". OESTRID FLY SEASON Location Mean n S.D. Mean n S.D. Pipe site Pipe contro Pipe road site , Pipe road contra D data from Curatoo et a. (1982). 4 une-28 une, 1982!2 uy-19 uy, 1981; 29 une-23 uy, uy-5 August, 1981; 24 u1y-1 August 1982 ".I.,

28 16 -, " Tabe 2. Age and sex of caribou observed in the Kuparuk Oi Fied, Aaska, and COW/CALF GROUPS Location Cow Caf Yearing Bu Cow Caf Yearing Bu Pipe site Pipe contro "1 Pipe -road site Pipe-road contro Tota 1,506 1, , Percent of tota (a sites) 42% 30% 14% 14% 36% 26% 22% 17% "" "! -- BULL GROUPS Location Cow Caf Yearing Bu Cow Caf Yearing Bu Pipe site Pipe contro Pipe-road site Pipe-road contro Tota , ,030 Percent of tota (a sites) 6% 5% 10% 78% 1% 0% 22% 77% 1 PERCENT OF TOTAL 32% 23% 13% 32% 23% 16% 22% 39% (ALL GROUPS) _ "1,) -..; --- INDIVIDUALS Location - Cow Caf Yearing Bu Cow Caf Yearing Bu Pipe site Pipe contra 1 1 D " Pipe-road site , Pipe-road contro Tota Percent of tota (a individuas) 5% 0% 30% 64% 19% 1% 38% 42% data from Curatoo et "

29 17 in the two study areas that ie aong the Kuparuk River, which is a maor corridor for caribou movements (Cameron and Whitten 1977). PIPELINE CROSSINGS Comparison between Study Areas " _) I -., ] ". :... " -... _... Tabe 3 summarizes the reative frequency of caribou crossing the northern borders of the study areas in 1981 and 1982 (the northern border of the pipe site and pipe-road si:te was deineated by the Kuparuk Pipeine and associated road). The crossing frequency data were anayzed (chi 2 ) according to seasons defined by mosquito and Oestrid fy eves because caribou exhibit distinctive patterns of movement and varying reactions to man-made structures under different eves and types of insect harassment (Fancy et 1981, Curatoo et 1982, Fancy 1982). Crossing frequency was owest in a the study areas during the caving/post-caving season, athough sampe size was sma. Caribou were reativey sedentary during this period, which may have contributed to the fewer crossings observed and sma sampe size. Crossing frequency increased during mosquito season, but was significanty ower in the pipe-road site than a other study areas (p<0.05, Appendix B). These resuts are consistent with 1981 findings (Curatoo et 1982). The combined effects of traffic and the pipeine probaby account for the ower crossing frequency at the pipe-road site during mosquito season. - _. : -

30 18 Tabe 3. Percent of caribou that crossed the pipeine at the pipe-road site and pipe site or northern border of the contros in the Kuparuk Oi Fied, Aaska, and CALVING/POST-CALVING (4 une-28 une) Location Groups n2 Individuas n Groups n Individuas Pipe site no data Pipe contro Pipe-road site Pipe-road contro n MOSQUITO SEASON -:..,,., (2 uy-19 uy) (29 une-23 uy) Location Groups n Individuas n Groups n Individuas Pipe site , Pipe contro Pipe-road site Pipe-road contro River-road site no data n 2, ,646 " ". OESTRID FLY SEASON (20 uy-5 August) (24 uy-1 August) Location Groups n Individuas n Groups n Individuas Pipe site Pipe contro , Pipe-road site Pipe-road contro n " -.. _, OVERALL INSECT (2 uy-5 August) (29 uy-1 August) Location Groups n Individuas n Groups n Individuas Pipe site , Pipe contro , Pipe-road site , Pipe-road contro River-road site no data n 2, , From Curatoo et - (1982). 2 n =Tota number of groups or individuas observed in each study area.,},;

31 19- There were no significant differences in crossing frequency between.::_; study areas during Oestrid fy season in 1982 (p<o.o, Appendix B). In 1981, crossing frequency in the pipe-road site was significanty ess than at the other study areas (p 0.01, Appendix B), athough it did. increase from 29 percent during mosquito season to 46 percent during Oestrid fy season (Curatoo et ). The increase in crossing frequency at the pipe-road site may be reated to the behavior of caribou under Oestrid fy harassment. They often ignore stimui other than the fies and frequenty seek out shade near structures such as the pipeine (Curatoo et 1982). In 1982, significant seasona differences in crossing frequencies were recorded at the pipe site and pipe-road site and not in.the two contros (p<0.05, Appendix B). Interestingy, the reative differences between seasons at the two sites were not the same. At the pipe site, crossing frequency during the mosquito and Oestrid fy seasons was simiar, whie it was consideraby ower during the caving/post-caving season (Tabe 3). At the pipe-road site, crossing frequency was simiar during the caving/postcaving season and mosquito season, whie it was higher during the Oestrid fy season. We fee that these resuts are expainabe in ight of the different eves of stimui associated with man-made structures and the behaviora differences exhibited by caribou under different insect conditions. Our theories reating to this phenomenon are presented in the Summary and Concusions section.

32 20 " Crossing by Group Type and Group Size The percent of cow-caf groups and bu groups that crossed the pipeine was simiar within each site for both 1981 and 1982 (Tabe 4). d These resuts differ from Roby (1978) who found that bu groups crossed the Trans-Aaska Pipeine more often than cow-caf groups. Other studies have aso identified cow-caf groups to be the most easiy disturbed segment of the herd (Bergerud 1974; Curatoo 1975). The apparent ack of difference in crossing success between bu and cow-caf groups may be reated to the recent construction of the pipeine, which was buit in the winter of Negative responses may deveop over time as postuated by Kein (1971), or conversey, a trend toward accommodation coud occur if the caribou have earned from their past experiences with oi deveopment -, in the area (akimchuk 1980). The pipeine traverses important routes to _) -., _ mosquito reief habitat and a potent ia caving concentration area. The urge to reach favored habitat can be strong enough to overcome barriers (Mier et 1972) and this stimuus may be an important factor in overcoming disturbances caused by the pipeine-road compex. The percent of crossings between various size groups was simiar -" in 1981 and 1982 (Tabe 4). Chid (1973), on the other hand, concuded that smaer groups crossed more often than arger groups. However, the differences in these observations can be expained by the different _. criteria for crossing success. By Chids (1973) definition, group crossings were successfu ony if every individua in a group crossed, so these resuts coud have been biased toward sma groups and individuas.,.-

33 , 21 ".;.,:..:;. Tabe 4. Percent of caribou groups by group type and group size that crossed the pipeine within the sitesf in the Kuparuk Oi Fied Aaska 19811:and PIPE SITE Category % I n % Cow-caf groups Bu groups : Individuas Group size Group size Group size Group size > " n _,; "! _;, _ -, PIPE -ROAD SITE Category % n % n. Cow-caf groups _.. Bu groups Individuas , Group size Group size , Group size Group size > " from Curatoo et (1982) -

34 ., 22 C --, Mutipe Crossings The cumuative frequency of mutipe pipeine crossings (repeated crossings by the same group) that occurred in 1981 and 1982 are presented in Figure 3. A mutipe crossings invoved groups of one or two individuas. Most mutipe crossings occurred during the Oestrid fy season when caribou sought the shade of the pipeine for reief from fy attacks.! C.c - -, - -

35 k..".: r:, PIPE SITE UN :] PIP CONTROm no ID UN UL AUG 45-, PIPE-ROAD en 40 <!> z LL. 0 0: 25 w CD 2 :::::) 20 z SITE Number of Crossings by One Group.:.... I I I UN UL PIPEROAD CONTROL n ) I 5 UN UL AUG Figure 3. Mutipe pipeine crossings (sites) and northern border crossings (contros) by caribou in the Kuparuk Oi Fied, 1981 and 1982.

36 24 PIPELINE CROSSING SITE SELECTION Eevated Pipeine 1 ) 1 ; i : ,.. Cearance of the eevated portion of the pipe ranged from 60 to 110 inches at the pipe-road site, and from 60 to 170 inches at the pipe site (Figure 4). These heights were categorized into 10-inch intervas (Tabe 5) and the frequenci.es of crossings by caribou groups were tested (chi 2 ) to determine if caribou were eecting for specific ptpe heights when crossing. Caribou showed no preference for any particuar pipe height category during both study years at the pipe-road site (p<o.o, Appendix B). Test resuts at the pipe site for 1981 and 1982 indicated that height seection was not random (p<o.o, Appendix B), but there were no consistent trends toward seection of ow or high pipe heights (Tabe 5). The variabiity in crossings at different pipe heights suggested that other factors are infuencing crossing site seection. The data were anayzed to determine the effects of insects on pipe height seection. Each pipe crossing at the pipe site was cassified as either occurring during the presence or absence of mosquitos and Oestrid fies. Crossing data were then tested to determine if there were significant differences between crossings under the higher 50 percent of the pipeine (i.e., greater than 100 inches) or the ower 50 percent of the pipeine (i.e., ess than 100 inches) (Tabe 6). There were no _

37 L 1 L..,.,,- 1.i L c I. L...,. L),) L z L< PIPE SITE -PIPE CROSSINGS 5 BURIED >140 PIPE PIPE HEIGHT (INCHES) PIPE-ROAD SITE- PIPE CROSSINGS, BURIED < PIPE PIPE HEIGHT (INCHES)! PIPE FREQUENCY SS; 1981 CROSSING FREQUENCY CROSSING FREQUENCY Figure 4. Crossing site seection in reation to pipe height in the Kuparuk Oi Fied, Aaska, 1981 and \) (1.

38 _, 26 Tabe 5. A summary of pipe height seection by caribou fn the Kuparuk Oi Fied, Aaska, and Crossings Crossings Number of VSMs Observed (Expected) Observed (Expected) Pipe Site Buried 1 24 (1) 28 (3) < (12) 29 (26) (31) 44 (72) (27) 31 (61} (6) 14 (13) (6) 21 (13) (28) 62 (64) _ (29) 88 (67) (17) 39 (40) > (6) 17 (13) _y ""\ Tota _ --, f.!qe Road Site Buried 2 5 (1) 5 (1) _d < (45) 41 (38) (37) 22 (32) (9) 13 (8) _) (1) 2 (1) (5) 1 (1) _) Tota _ data from Curatoo et - {1982). 2 0f one or more individuas... --" :;

39 .., 27 _; "I.., _; -, Tabe 6. Pipeine crossings in reation to pipe height and insect abundance at the pipe site in the Kuparuk Oi Fied, Aaska, and 1982 NUMBER OF CROSSINGS Oestrid Fies Insects Absent 2 Mosquitos Present 3 Present Observed (Expected) Observed (Expected) Observed (Expected) 1981., _; High Pipe 4 Low Pipe High Pipe Low Pipe 77 (52.17) 21 (45.83) 135 (100.09) 53 ( 87.91) 22 (13.84) 4 (12. 16) 38 (34.45) 27 (30.40) 10 ( 7.99) 5 ( 7.01) 53 (47. 91) 37 (42.09) " _ High Pipe Low Pipe 127 (114.38) 53 ( 65.62) 20 (20.28) 22 (21. 72) 18 (18.35) 14 (13.65) _.) data from Curatoo et - (1982). 2 Incudes days with ow eves of mosquitos. 3 Incudes days with moderate or high eves of mosquitos. 4 A pipe heights over 100 inches, representing 53 percent of the pipeine in the study area. 5 A pipe heights under 100 inches, representing 47 percent of the pipeine in the study area. 6 Based on pipe heights that were within miies of caribou groups before crossing. Mutipe crossings were not incuded; ony the first crossing by a group was used. _) _) _)

40 , 26 Tabe 5. A summary of pipe height seection by caribou in the Kuparuk Oi Fied, Aaska, and " 1981 Crossings Crossings Number of VSMs Observed (Expected) Observed (Expected) -, PiQe Site - Buried 1 24 (1) 28 (3) < (12) 29 (26) (31) 44 (72) (27) 31 {61) (6) 14 (13) "" (6) 21 (13) (28) 62 (64) (29) 88 (67) {17) 39 (40) > (6) 17 (13) - Tota , PiQe Road Site Buried 2 5 (1) 5 (1) - < (45) 41 (38) ( 37) 22 (32) (9) 13 (8) d (1) 2 (1) (5) 1 (1) Tota "" data from Curatoo et E]_. (1982). 2 0f one or more individuas. -,.....

41 28 significant differences {p<o.o, Appendix B) in seection of ow or high pipe height when either mosquitos or Oestrid fies were present in There was a significanty greater crossing frequecy of high pipe in 1981 when mosquitos and Oestrid fies were present, athough the sampe size was sma. Caribou used higher pipe heights with significanty greater frequency (p<o.o, Appendix B) when insects were absent in both 1981 and The apparent seection for high pipe heights at the pipe site during insect-free periods may be reated-to the infuence of topography on caribou routes of trave. When insects were absent, caribou routes through the pipe site were reativey direct and were custered in the eastern portion of the study area near the Kuparuk River (Figure 5). Most of the high pipe in the pipe site was aso in the eastern section of the study area (Figure 5). Thus, caribou generay crossed under high pipe in the absence of insects because their preferred routes of trave, as mediated by topography, intersected the higher portion of the pipeine. When mosquitos and Oestrid fies were present, however, harassed caribou encountered a simiar frequency of ow and high pipe heights because they tended to para 11 e 1 the pipe and/or 1 eave their preferred route of trave (Figure 5). Furthermore, there was no seection for high pipe versus ow pipe heights, regardess of insect occurrence, when the frequency of pipe heights that caribou actuay encountered were anayzed (i.e., a VSMs within /8 mie of a groups movements) (Tabe 6).

42 29 IGH PE I I I HIGH PIPE ---1 LOW. PE I I PE SITE INSECTS A8S NT.ow{ PIPE HIGH PE II --L--HIGH PIPE LOW PIPE I I Figure 5. A summary of caribou routes in reation to pipeine height at the_pipe site in the Kuparuk Oi Fied, 1982.

43 .., 30..., -, -, _ --" _} -- _; Habitat under the Kuparuk Pipeine was cassified into five habitat types (Figures 6 and 7). The frequency of use of each habitat type by caribou groups crossing the pipe (Tabe 7 and Figure 8) was tested to determine if caribou were seecting specific habitats for crossing sites. Caribou groups showed a significant degree of seection for certain habitats and avoidance of others when crossing the pipe at the pipe site in 1981 (p<0.05; Appendix B) and 1982 {p<o.o, Appendix B). ory sedge was used more than expected in both 1981 and 1982, and ridgetops were used more than expected in The pattern of habitat seection by caribou crossing under the pipeine at the pipe-road site was simiar to the pipe site, athough the degree of seection was significant ony in 1982 (p<0.05, Appendix B). In addition, caribou showed a significant degree of avoidance of water at both sites during 1981 and 1982 when crossings in areas of water were tested against the sum of crossings in a other habitat types (p<0.05, Appendix B). Group crossings in 1981 and 1982 were tabuated, reative to whether or not the tundra north of the pipeine was visibe (Figure 9), and tested to determine if the visua fied affected caribou crossing site seection. No significant differences in caribou use of the two visua fied categories were detected at the pipe site or pipe-road site in either year (p<o.o, Appendix B). These resuts differ from Surrendi and DeBock (1976) and Hanson (1981) who suggested that caribou avoid high berms that restrict their vision.. --"

44 \,., C. I. L I. - "" _) " L. 1.,._,,) L --", I " PIPE SITE (/) 13 (.) ::t: 110 (!) BURIED PIPE CARIBOU CROSSING 1982 HABITAT TYPE ADACENT TO PIPE : c::: DRY SEDGE rwd WET SEDGE -WATER i RIDGE GRAVEL. fiqure 6.. Caribou crossinas at the pipe site in the Kuparuk.. Oifera ;-Aa.ska, T981 and 1982.

45 I.. _... " , 1...,_ I _d 1...,.. ""- 1..u,,_,; 1.._.,_,,; 1...,,..,!,.._,,,, ""- 1.> :I: (!) w :I: 70 LL. a: 60 PIPE- ROAD SITE N 50 nrl n no rn R ma an or m_ rfb m_n H_n_m_RRAf&n_rm_R Rfhnnn rn!fo 0- CARIBOU CROSSING 1982 no o b n rna oro o Rn nr nor df nmrm arrr-rm S,FRn as, ffb no RRR I r,1 f1 0 Wi!/11/A t!he E 0 M..,. I - HABITAT TYPE ADACENT TO PIPE: Fif!ure 7. Caribou crossings at the pipe-road site in the Kuparuk 6Tr-Fied, Aaska, 1981 and w N

46 33 Tabe 7. A SUI1ary of habitats occurring at eevated pipeine crossings in the Kuparuk Oi Fied, Aaska, 198 and Number of Caribou Crossings Grave wet Sedge Dry Sedge Ridge/Pingo Water Tota PiQe Site VSMs observations expected observations expected E.i_ge-road site " Tota VSMs observations " 1981 expected observations " 1982 expected _; data from Curatoo et {1982). _.) "I c.... -

47 _).,;>.. _::;. : es.!t so 45 11: PIPE SITE GRAva. WETSEDGE ORYSEDGE RIDGE/ WATER PINGO ) f«tf. HABITAT FREQUENCY 1981 CROSSING FREQUENCY CROSSING FREQUENCY PIPE-ROAD SITE _.. " ; :E GRAVEL WET SEDGE DRY SEDGE RIDG:/ WATER PINGO.. Figure 8. Habitat seection by caribou as they crossed under the pipeine in the Kuparuk Oi Fied, Aaska, 1981 and _;;..

48 "....., 35 "., -, -, _;..,.] I I I I I I I PIPE SITE i:.ti PIPE FREQUENCY! 75 I ISS! 1981 CROSSING FREQUENCY CROSSING 50 FREQUENCY ffi 45 CL.4Q TUNDRA VISIBLE TUNDRA NOT VISIBLE -, PIPE- ROAD SITE _, ;; TUNDRA NOT VISIBLE - Figure 9. Caribou crossings of an eevated pipeine with respect to their abiity to view the tundra on the other side of the pipeine in the Kuparuk Oi Fied, Aaska, 1981 and "

49 36 Buried Pipeine Caribou group crossings were cassified into two categories to determine if caribpu preferred specific pipe configurations for crossing sites. These categories were: {1) over the pipeine at road crossings, and {2) under the eevated pipe. Eighteen and 16 percent of the groups crossed over the buried pipeine at the pipe site in 1981 and 1982, respectivey; nd five and six percent crossed over the buried pipeine at the pipe-road site in 1981 and 1982, respectivey. The crossing frequencies were significanty more than expected considering the buried pipe constituted ess than one percent of the pipeine at both sites {p<o.o, Appendix B). This preference for buried pipe is simiar to the observations in Prudhoe Bay by Chid {1973). He found that 76 percent of the caribou actuay crossing a simuated pipeine {n=,303), crossed over ramps, which represented 22 percent of the tota ength of the simuation. The smaer percentage of crossings over the buried section at the pipe-road site may be reated to the pipe configuration. The pipe crossed under the road and reappeared on the opposite side where it paraeed the road before crossing back (Appendix A; page 65). Thus, caribou cimbing onto the roadway woud observe a pipeine rather than an unobstructed view of the tundra. We observed severa groups in both 1981 and 1982 that cimbed to the top of the roadway and turned back without crossing. The apparent seection of a buried pipeine for crossing versus a raised pipeine may, in theory, reate to inherent caribou behaviora traits. Caribou evoved in an open habitat with woves as their maor

50 37 predator.(bergerud 1974). Thus, caribou tend to avoid or be more aert in habitat that can concea a predator (Curatoo 1975). Our theory woud hod that two types of stimui in an oi fied that can cause simiar avoidance reactions are structures resembing conceaing habitat (e.g., raised pipeine) and moving obects resembing predators (e.g., vehices). Caribou may seect for buried pipeine to avoid conceaing habitat, which may expain the stronger reactions caribou exhibited whie crossing under the raised pipeine (55% moderate or severe reactions) as compared to over the buried section {9% moderate or severe reactions) (Tabe 8). A ramp aso decreases caribou reactions by eiminating the dua stimuus of raised pipeine and moving vehices....

51 .., -, 38 Tabe 8. A summary by season of caribou reactions whie crossing pipeines and/or roads Kuparuk Oi Fied , Percent of Reactions Location Season None Mid Moderate Severe n Road 2 Mosquito Road with traffic 2 Overa , 5016 Caving/ Post-caving Mosquito Oestrid fy Pipeine. Overa (incudes buried Caving/ -, and raised) Post-caving Mosquito " Oestrid fy Buried pipeine Overa _ Caving/ Post-caving Mosquito Oestrid fy Raised pipeine Overa Caving/ Post-caving Mosquito Oestrid fy Pipeine associ- Overa ated with traffic Caving/ Post-caving Mosquito _.; Oestrid The data on buried vs. raised pipeine was not separated due to the sma sampe size of the buried pipe (n = 19). 2 Incudes data coected from observations aong the Oiktok Road (Robus pers. comm.). w -".._;

52 39 BEHAVIOR Group Cohesion The degree that the pipeine or pipeine associated with traffic may have affected caribou group cohesion was estimated by a ratio of the number of groups exiting to the number of groups entering the study areas. Thus, if caribou groups traveed through the study area as a singe unit, the ratio woud be one. If groups entered and coaesced with other groups, the ratio woud be ess than one; an if groups entered and fragmentd before exiting, the ratio woud be greate.r than one. Large sampe sizes were avaiabe ony for mosquito season and these ratios indicated that there was a tendency for groups to fragment in the piperoad site. Group spitting at the pipe-road site is probaby reated to traffic aong the pipeine. Approaching vehices starte caribou as they cross, often spitting groups as they trave north toward the coast. Individuas, usuay yearings, were sometimes 11 eft behind 11 ; these animas often appeared disoriented, which may be attributed to the artificia breakup of socia bonds between group members (Espmark 1970). Rate of Movement Mean rate of movement of caribou groups in the four study areas during different seasons, insect eves and group types are presented in Tabe 10. Anayses (Kruska-Wais) reveaed that overa rates of movement were significanty different between each season (P<0.05,

53 40 Tabe 9. A comparison by season, of the number of groups entering the study areas versus the number of groups exiting. the study areas in the Kuparuk Oi Fied, Aaska, Number of Groups Ratio Location Season2 Entering Exiting Exit/Enter Pipe site Caving/post-caving Pipe contro Caving/post-caving Pipe-road site Caving/post-caving Pipe-road contro Caving/post-caving Pipe site Mosquito; Pipe contro Mosquito Pipe-road site Mosquito Pipe-road contro Mosquito Pipe site Oestrid fy Pipe contro Oestrid fy Pipe-road site Oestrid fy Pipe-road contro Oestrid fy ,. Pipe site Overa Pipe contro Overa Pipe-road site Overa Pipe-road contro Overa The ratio of the number of groups exiting a study area to the number entering a study area is a measure of the degree of cohesion that groups exhibit. Thus, a ratio of impies that groups trave through the study area as a singe unit; a ratio of ess than impies that separate groups are uniting as they trave through the study area; and a ratio greater than impies that groups are spitting apart as they trave through the study area caving/post-caving = 4 une-28 une Mosquito = 29 une-23 uy Oestrid fy = 24 uy-1 August ;.. )

54 -, 41 -, -, - -..,.) -- Appendix B). Rate of movement during caving/post-caving (0.7 mph) was extremey ow as compared to mosquito (3.0 mph) and Oestrid fy (2.4 mph) seasons, (Tabe 10). Caribou were sedentary during this period and spent most of their time feeding and ying. There were no significant differences in rates of movement between any of the study areas during caving/post-caving (p<0.05, Appendix B). Group speed increased to 3.0 mph during mosquito season as caribou traveed rapidy to the coast in response to mosquito harassment. There were no significant differences in group speed between the pipe site and pipe contro (p<0.05, Appendix B). However, caribou at the pipe-road site traveed significanty faster than caribou in the pipe-road contro and the pipe site (p<0.05, Appendix B). The greater group speed at the pipe-road site \as probaby due to the disturbance caused by traffic. Group speed decreased to 2.4 mph during Oestrid fy season, refecting the time caribou spent standing in response to fy harassment. There were no significant differences in rates of movement between study areas during fy season. Caribou under fy attack are ess responsive to other stimui, such as pipeines and traffic, which probaby accounts for the ack of differences between study areas (Curatoo et ). The data were aso separated intofour insect categories, regardess of season: days with no insects, days with mosquitos present, days with Oestrid fies present, and days when both mosquitos and Oestrid fies were present (Tabe 10). Once again, anayses reveaed that mean rates of movement were significanty different under dif- _

55 42 Tabe 10. Speed of caribou groups observed in the Kuparuk Oi Fied, Aaska,. 19aP and COMPARISON BY SEASON Caving/ Post-Caving Mosquito Season Oestrid Fy Season Insects - rate- rate rate rate Location (mph) n S.D. (mph) n S.D. (mph) n S.D. (mph) n S.D. Pipe site Pipe site Pipe contro Pipe contro Pipe-road site Pipe-road site Pipe-road contro Pipe-road contro COMPARISON BY GROUP TYPE Individuas Cow-Caf Groups Bu Groups -- rate :rate rate (mph) n S.D. (mph) n S.D. (mph) n S.D. Pipe site Pipe site Pipe contro 1981 d Pipe contro , Pipe-road site 1981 Pipe-road site Pipe-road contro 1981 Pipe-road contro COMPARISON BY PRESENCE OR ABSENCE OF INSECTS -, Oestrid Mosquitos and No Insects Mosquitos Present Fies Present Fies Present rate rate rate rate (mph) n S.D. (mph) n S.D. {mph) n S.D. {mph) n S.D. Pipe site Pipe contro Pipe-road site Pipe-road contro data from Curatoo et - (1982). - -" -

56 : -, 43 ferent eves and types of insect harassment (p<<0.05, Appendix B.) Group speed was owest (1.7 mph) when insects were absent and greatest (4.3 mph) during mosquito presence.., Directiona Trave The routes traveed by each caribou group were separated into north, south, east, and west components (Tabe -11). If the pipeine was 11 defecting 11 caribou, one might expect more east-west trave (the -, -, -,._,...) - - direction of the pipeine) in the pipe site and pipe-road site than at their corresponding contros. East-west trave was greater in the sites during 1981 and 1982 than the contros, athough the differences were not significant (p<.o.o, Appendix B). These resuts woud probaby change if a smaer zone was examined (e.g., within 0.25 mies of the pipeine) rather than the entire study area, since most of the east-west trave in the sites was near the pipeine (Appendix C). The mean distance traveed by caribou groups that entered the study areas from the south and exited to the north were examined. These groups were primariy groups traveing northward under mosquito attack. Groups in the pipe-road site traveed the farthest, compared to the other study areas (Tabe 11), and these differences may be due to the effects of vehices on group movement patterns. Caribou that make unsuccessfu attempts to cross the pipeine tend to parae it, and vehices traveing aong the road often cause caribou to run back away from the road. ) _;

57 44 Tabe 11. A summary of directiona trave and the average distance traveed by groups in the Kuparuk Oi Fied, Aaska, and Percent of Tota Mies Traveed in Each Direction Mean Distance Location N s E w Traveed 2 n Pipe site Pipe contro Pipe-road site Pipe-road contro Pipe site Pipe contro Pipe-road site Pipe-road contro data from Curatoo et {1982). O:.._ 2 0ny data from groups that entered from the south and exited to the north were used.

58 45 Use of Grave Habitat The extent of caribou use of grave habitats, namey grave pads, roads, and we sites, was examined (Figure 10). Approximatey 90 percent of the distance caribou groups traveed on grave in 1981 and 1982 occurred in ate uy and eary August, which coincides with the occurrence of Oestrid fies (Figure 10). Unvegetated grave areas appear to be seected, especiay for nose bot reief, because they provide an open area that aows for the caribou to stand with their noses cose to the ground and isten for approaching fies (Espmark 1968). Caribou Reactions whie Crossing Roads and/or Pipeines The severity of caribou reactions to inear structures varied depending on the type of structure (Tabe 8). Caribou showed the east reaction when crossing a road, foowed by a pipeine, a road with traffic, and a pipeine associated with traffic. Caribou showed significanty more severe reactions (p<o.o, Appendix B) to a pipeine associated with traffic than any of the other three inear structures.. Roads The reactions of 4,668 caribou were recorded as they crossed trafficfree roads (Tabe 8). Ninety-one percent of the individuas showed no reaction, whie three percent and one percent showed mid and moderate reactions, respectivey. The simiarity of a grave road to an unvegetated grave bar, which caribou naturay encounter, probaby accounts for the ack of reaction.

59 46 " PIPE-ROAD SITE """"1 PIPE SITE First day or_., 1981 * First day of_., 1982 I i i 350 :i "! 300 i I Z !:2.50 u z g2.00 I ,.} _; c I - i!. v i Iii UN UL UN UL o; PIPE-ROAD PIPE CONTROL I --, 2 :::;... I , I.40 I :a: 1!10-1 I 1.!50 fitoo -.80 it I! * I I I I 1 m I 1 U 0 s 0 I i I I I I i I UN UL AUG UN UL " ts AUG AUG., Figure 10. Use of grave by caribou groups in the Kuparuk Oi Fied, Aaska, 1981 and

60 47 Pipeines Reactions of 2,263 caribou were recorded as they crossed the pipeine (Tabe 8). Fifty-five percent and 76 percent of the caribou showed no or mid reactions during mosquito and Oestrid fy season, respectivey. The decrease in reactions to the pipeine between mosquito and Oestrid.. fy periods can be attributed to Oestrid fy attacks that cause caribou to ignore other stimui. Caribou aso reacted ess when crossi,g over the buried portion of the pipeine as compared to crossing under the eevated portion, with 75 versus 25 percent showing no reaction, respectivey. The differences observed can be reated to the seection of open habitat in the summer by caribou (Bergerud 1974). The eevated pipeine may resembe predator conceaing habitat, causing a greater reaction to this structure. Road with Traffic The reactions of 5,016 caribou were recorded as they crossed roads with traffic (Tabe 8). Caribou exhibited mosty severe or moderate reactions to traffic throughout a seasons investigated, athough the sampe size was sma for caving/post-caving and Oestrid fy seasons. The reativey high degree of reactions observed probaby reates to the motion of the vehice, which stimuates a predator avoidance response (Bergerud 1974).

61 48 Pipeine Associated with Traffic Reactions of 341 caribou were cassified as they crossed the pipeine associated with traffic at the pipe-road site (Tabe 8). Ninety-one percent showed moderate or severe reactions during mosquito season, whie 17 percent showed moderate or severe reactions during Oestrid fy season. Thus, caribou under the infuence of mosquito harassment are sti cognizant of other stimui (e.g., traffic and pipeine) whie they tend to ignore such stimui under Oestrid fy attack (Curatoo et ). Traffic eves averaged about one vehice every four minutes (n=865) on the Spine Road. Leves of traffic did not appear to affect the severity of caribou reactions. Rather, the severity of the reaction was dependent on the proximity of the caribou to the passing vehice. Typicay, severe reactions occurred when caribou encountered vehices whie trying to cross roads. The higher frequency of severe reactions recorded during Oestrid fy season aong a road with traffic, compared to a pipeine associated with traffic, probaby reates to differences in how caribou use these structures for insect reief. When a pipeine is present, caribou frequenty stand under it for shade and do not directy encounter vehices. Caribou often stand on the road when it is the ony structure present and run aong it when vehices approach. Caribou Reactions in the Study Areas Reactions to various stimui were aso recorded as caribou traveed through the study areas. Locations of severe reactions observed in each

62 49..,., study area are iustrated in Figures 11 and 12. The dots represent one or more severe reactions occurring between 10 minute observation scans. The figures dispay the ocation of the reactions reative to the structures present. The severe reactions recorded near the pipeine at the pipe-road site can be attributed to traffic, whie reactions occurring aong the pipeine at the pipe site were generay stimuated by the pipeine. The custer of reactions near the tower at the pipe site was primariy caused by human disturbance, and reactions to researchers as they waked to the observation towers were the most common cause of severe reactions in the contros. "" --: -" _.. _

63 .. - PIPE-ROAD SITE.I!TOWER 50 - PIPE- ROAD CONTROL I!TOWER I e = SEVERE REACTION Figure 11. Severe caribou reactions to various stimui, based on 105 groups in the pipe-road site and 57 groups in the pipe-road contro, Kuparuk Oi Fied, 1982.

64 51 PIPE SITE.:. PIPE CONTROL... TOWER = SEVERE REACTION Figure 12. Severe caribou reactions to various stimui, based on 225 groups in the pipe site and 102 groups in the pipe contro, Kuparuk Oi Fied, Aaska, 1982.

65 52 SUMMARY AND CONCLUSIONS THE RELATIONSHIP BET\EEN CARIBOU AND LINEAR STRUCTURES Crossing Success ) The man-made inear structures in the Kuparuk Oi Fied fa into four categories: roads, roads with traffic, pipeines, and pipeines associated with traffic. These form a hierarchy of stimui to which caribou respond with increasingy stronger reactions. A road is at one end of the spectrum, as it is crossed freey by caribou and usuay without reaction. Indeed, 91 percent of the caribou crossing a road showed no response (Tabe 8). The simiarity of the roadbed to an unvegetated riparian grave bar probaby accounts for the ack of hesitation to cross this type of structure. At the next eve in the reationship are two structures, namey, a pipeine and a road with traffic. Caribou freey cross these two structures (Tabe 3), athough they react more strongy when crossing a road with traffic than a pipeine (47 percent versus 15 percent severe reactions, respectivey). The apparent inconsistency in having simiar crossing success but different eves of reactions may be reated to the tempora and spatia characteristics of these structures. The pipeine is stationary, thus the stimuus is aways present, but not at a very high magnitude. Vehicuar traffic, on the other hand, is a reativey strong stimuus

66 53 -, -" when present (Tracy 1977; Horesi 1981). : oving vehices may be perceived as predators by caribou (Bergerud 1974}, but the stimuus decreases as vehices eave an area. During us in traffic, the road changes back to a reativey non-stimuatory structure. Thus, a pipeine is a stationary and reativey mid stimuus to caribou, whereas a road with traffic is a transient and reativey severe stimuus. At the other end of the hierarchy is a pipeine associated with traffic. As demonstrated at tpe pipe-road site, caribou cross pipeines associated with traffic with significanty ower frequency as compared to the other inear structures examined, especiay during mosquito season (Tabe 3). We fee that the ower crossing success observed at the piperoad site is reated to the synergistic effects of vehices and pipeine. Indeed, most parameters measured tended to show significant differences that reated to the pipeine-vehice combination. In summary, we found that caribou encountering a pipeine associated with traffic showed the foowing characteristics: o Decrease in frequency of pipeine crossings; 0 Increase in the number and severity of reactions when approaching the pipeine; 0 Increase in the number and severity of reactions when crossir.g the pipeine; 0 Increased rate of movement; 0 Increase in paraeing the pipeine; and 0 Increase in group spitting...ii "

67 54 Crossing Site Seection Caribou did show a strong seection for sections of pipe covered with grave for road crossings. Caribou tend to foow the path of east resistance when traveing (akimchuk 1980), and the buried sections of pipeine provide an area where adverse stimui are minima. Crossing site seection aong eevated sections of the pipe does not appear to be infuenced by pipe height. Rather, caribou tend to foow certain topographic features, such as river banks, and cross in areas where these features intersect the pipeine. During time of insect harassment, caribou may eave favored trave routes to escape insects and encounter and cross the pipeine in a more random fashion. The exact crossing ocation may be affected by the habitat under the pipeine, since caribou appear to avoid water and seect for the drier habitat types.

68 55 THE ROLE OF INSECTS This study covered the three time periods in the Centra Arctic Herds yeary cyce that are spent in the Kuparuk Oi Fied: caving/ post-caving, mosquito, and Oestrid fy seasons. Caving usuay occurs from 1 to 10 une (Whitten-- et a. 1981). Post-caving was characterized by ow rates of movement and a ack of directiona trave. Some individuas spent days in or near the study areas. Few cariboupipeine interactions were observed in our study areas during the caving/post-caving season since we were not situated within a maor spring migration route or caving area. 1 " Mosquito season generay coincides with the month of uy, athough some mosquitos may be present in ate une and eary August. The most important facet of mosquito season is that caribou have a strong urge to trave north to the coast for mosquito reief. These northward movements. intersect the pipeine/road compex and force caribou to interact with these structures; in fact, 80 percent of the caribou-pipeine interactions were recorded during this period. "-.. Caribou showed a drastic change in movement patterns, behavior, and group dynamics with the onset of mosquito emergence. Mosquito season in 1981 and 1982 was characterized by arger caribou group size, higher rates of movement, and highy directiona trave. Caribou under stress from mosquito harassment are sti cognizant of other stimui. Indeed, it is during this period that the greatest number of severe reactions to inear structures were recorded. -"

69 56 The presence of mosquitos aso dictates how often caribou wi be in or near the oi fied. Mosquito eves were high enough on 12 or 13 days in 1981 and 1982 (Figure 2) to cause maor northward movements. Large movements actuay occurred on six of these days since caribou were sti on coasta insect reief habitat during the other times. Thus, ong periods of high mosquito eves keep caribou near the coast and away from present oi deveopment, whie repeated fuctuations in mosquito eves cause caribou to move repeatedy through the area (Robus 1983). Oestrid fies have been observed as eary as 5 uy, but do not cause widespread reactions in caribou unti ater in the summer when fies are more numerous. In genera, Oestrid fy season begins the ast week of uy and asts unti about mid-august. This season is characterized by stereotyped behavior of caribou that incudes rigid standing on unvegetated grave bars, roads, we pads, or in the shade of buidings and pipeines. Aberrant or wid, nondirectiona running (Curatoo 1975) aso occurs as caribou fee from fy attack. Behaviora changes reating to oi deveopment that we observed incuded an increase in mutipe crossings of the pipeine, increased use of grave, and decreased reactions when crossing the pipeine and a pipeine associated with traffic. Pipeine crossing success aso increased. Indeed, there were no significant differences in crossing success between study areas during Oestrid fy season. Oestrid fy harassment affects caribou in such a fashion that they are more toerant of other stimui, such as vehices, and herein ies one of the maor differences between mosquito and Oestrid fy seasons. It is.).)

70 57 "! _ 1.., _..,..,.., aso during the Oestrid fy season when most of the CAH eaves the Kuparuk Oi Fied, dispersing to the southern portions of its range. Thus, insects are the maor mediators of movements and behavior for the maority of time caribou use the coasta pain. On the one hand, mosquitos drive caribou through the oi fied toward the coast. Caribou are in a disturbed state that is accentuated by interactions with pipeines and traffic. On the other hand, Oestrid fies cause caribou to ignore other stimui, and disperse to the south away from the oi fie 1 ds. Mitigative measures adopted to aeviate impacts of oi deveopment on caribou shoud emphasize mosquito season since it is the period of greatest interaction with the CAH. :>.., _,.., _). _) _} - _)

71 58 APPENDIX A " A COMPILATION OF DATA FORMS USED AND A DESCRIPTION OF DATA COLLECTED IN THE KUPARUK OIL FIELD,CARIBOU STUDY, ALASKA, 1982 i _; _; ""

72 59 CODING INFORMATION Data sheet and map information: _ - Date -- Date, day, and year Study Site -- Name of site where observations are recorded Group ID # -- A number assigned to an individua group of animas for as ong as that group is recognizabe. A group is any number of caribou which act more or ess as a singe unit. (If group divides, use.. a.. and 11 b 11 If two groups oin, use one of the numbers.) Time -- The time at which the animas enter and exit the study area, and the time, at 10-minute intervas (caed a scan), at which observations are recorded. Use 24 hour time. (For each entry and exit, note time for first and ast anima in the group.) Group composition: Activity: # Cow -- Number of adut femaes in group # Caf -- Number of newborn caves in group, either sex. #Yearing -- Number of animas in group that were born ast year, either sex # Bu -- Number of adut maes in group # Unknown -- Number of animas of unknown age or sex in the group Feed -- Foraging and searching for food Lie -- Lying Stand -- Stationary, not feeding Wak -- Head eevated, no ingestion of forage Trot/run -- Any form of running Insect eves: Mosquito -- (Try to estimate mosquito eves where the caribou are, by insect eves at tower.) 0 = none = ow 2 = moderate 3 = high Warbe fy -- (Caribou reaction to fies within past 10 minute scan.) 0 = absent 1 = present (Rigid standing, abberant running foot stomping, or head shaking.)

73 60 Habitat -- The habitat of the maority of individuas in the group 1 = natura 2 = grave pad 3 = road 4 = unknown 5 = under pipe Weather: Wind direction -- Direction wind is coming from 1 = north 2 = northeast 3 = east 4 = southeast 5 = south 6 = southwest 7 = west 8 = northwest Wind speed-- Recorded in mies per hour, 1.5 meters above ground Precipitation 0 = none 1 = fog 2 = rain 3 = snow 4 = other, or a combination Temperature -- Air temperature, in fahrenheit, measured in shade Disturbance: {Tota during scan) #Sma vehices -- Number pick-up truckcsize vehices seen #Large vehices -- Number of a other vehices seen Reaction to disturbances: (Number of animas showing each reative degree of reaction) No reaction -- Animas continue as before disturbance Mid reaction -- Animas ook toward disturbance Moderate reaction -- Anima waks away from disturbance Severe reaction -- Anima trots/runs away from disturbance Unknown reaction -- Reaction not known Severe group type_: Type of group exhibiting severe reaction to disturbance 1 = individua 2 = cow/caf dominant (over 50%) 3 = bu dominant (over 50%) 4 = cow or yearing dominant (over 50%) 5 = mixed 9 = unknown

74 t-1--tr-t--r-t--r-t--r-t--r-,_-t Time r-+--r-+-,_-r-+-1--r-+-,_ r- # Caf r-+--+r r-4--+ #Yearing -+--r-+--r-+--r ; r-+-4--t--r-,_-r # Unknown r-,_-+--+-,_-r r-+--r-+-,_ ,_ # Feed r-+--r r #Lie L r r r r--+ # Trot/run -+--P P Mosquito Warbe Fy Habitat Wind Dir Wind Speed Precip ,_-r-+--r ,_ r r--+ Temperature L #Sma Veh ,_-r-;--+--r-+ # Large Veh. # No Reaction r-+--r-+r-;--r ; r r-4--+ # Mid Reaction --+--r t--t t-1--t+-1---t-1--+ # Mod. Reaction r r ;--r-;--+--r-+ # Sev. Reaction -1--t _, # Unknown Reac. 9 0 rt 0 c rt c ro I -.. I"" I