Tatshenshini and Alsek Rivers of Alaska

ASSESSING THE RISKOF BEAR-HUMANINTERACTION AT RIVERCAMPSITES A. GRANTMacHUTCHON, 237 CurtisRoad, Comox,BC V9M3W1, Canada, email: [email protected] DEBBIEW. WELLWOOD, P.O. Box 3217, Smithers,BC VOJ2N0, Canada,email: [email protected] Abstract: The Alsek and Tatshenshinirivers of Yukon, British Columbia, and Alaska, and the Babine River, British Columbia, are seasonally importantfor grizzly bears(Ursus arctos) and Americanblack bears(Ursus americanus). Recreationaltravelers on these rivers use riparianhabitats for camping, which could lead to bear-humaninteraction and conflict. During visits in late summer 1998-99, we used 4 qualitativeindicators to assess risk of bear-humaninteraction at river campsites: (1) seasonal habitatpotential, (2) travel concerns, (3) sensory concerns, and (4) bear sign. We then rated each campsite on a 5-class scale, relative to other campsites, for the potential to displace bears and the potential for bear-human encounters. We used these ratingsto recommendhuman use of campsites with relatively low risk. Ursus 13:293-298 (2002) Key words: Alaska,American black bear, bear-human conflict, British Columbia, grizzly bear, habitat assessment, river recreation, Ursus americanus, Ursus arctos, Yukon Riparianhabitats in manyriver valleys in westernNorth 1997). The Tatshenshiniand Alsek river valleys com- America are seasonally important for grizzly bears prise a large proportionof available bear habitatwithin (Hamilton and Archibald 1986, Reinhart and Mattson the parksthrough which they flow, and the importanceof 1990, MacHutchon et al. 1993, Schoen et al. 1994, riparianhabitats to bearsis high (Simpson 1992, Herrero McCann 1998, Titusand Beier 1999) andAmerican black et al. 1993, McCann 1998). The main period of human bears (Reinhartand Mattson 1990, MacHutchonet al. use coincides with seasonalmovement of grizzly bearsto 1998, Chi and Gilbert 1999). Humansfrequently use riv- low elevations (McCann 1998). McCann(1994) recom- ers for recreationaltravel and use riparianhabitats for mendedevaluating the risk of bear-humaninteraction at camping. Management agencies are concerned about campsites because of these overlaps in bear and human potential negative effects that increasing human use of use. Seeing grizzly bearsis a main attractionof travelon riversmay have on bears,other wildlife, and the physical the Babine River, British Columbia. Most recreational environment. They also want to maintainhuman safety tripsoccur in late summerand fall when grizzly bearsare by minimizingbear-human encounters. Interactionwith at the river feeding on salmon (Oncorhynchusspp.). An- humans can negatively affect bears by displacing them glers also intensively use the river at this time from importantriparian habitat (Reinhartand Mattson (MacHutchon 1998). Consequently, British Columbia 1990, Olson and Gilbert 1994, MacHutchonet al. 1998, (BC) Parksrecognized a need to assess risk of bear-hu- Chi and Gilbert 1999), changing bear activity patterns man interactionat campsites along the Babine River (A. (MacHutchonet al. 1998, Olson et al. 1998, Chi and Gil- MacDonald, BC Parks, Smithers, British Columbia, bert 1999), changing bear habitats(Schoen et al. 1994), Canada,personal communication, 1998). This paperde- or when conflictsoccur, leading to the destructionor trans- scribes our method for qualitativelyassessing and rating location of bears. Interactionscan negatively affect hu- the potentialfor displacementof bears and for bear-humans throughdestruction of property,human injury,or man encounters at river campsites on the Tatshenshini, death(Herrero 1985). We define bear-humaninteraction Alsek, and Babine rivers (MacHutchon 1998, 2000; as any activity and its effect involving bearsand humans, Wellwood and MacHutchon1999a,b). including observations, encounters, and conflicts. We define a bear-humanencounter as a situationwhen a bear is awareof humanpresence, regardless of whetherpeople STUDYAREAS are aware of the bear. During encounters,bears can be displaced, may ignore people, or may approachpeople. Tatshenshiniand AlsekRivers We define a bear-humanconflict as a more serious inter- The Tatshenshiniand Alsek rivers(59?25'N, 137?40'W) action where a bear chargespeople, people take extreme bothoriginate in the Yukonand flow approximatelysouth evasive action in response to a bear, people use a deter- throughBritish Columbia. The TatshenshiniRiver joins renton a bear,property is damaged,or a bearmakes physi- the Alsek River upstreamof the Alaska border,and the cal contact with a person. Alsek River empties into the Gulf of Alaska at Dry Bay, Popularity of the Tatshenshini and Alsek rivers of Alaska. Thereis a transitionfrom a dry,cold, continental Yukon, British Columbia, and Alaska, for recreational interiorclimate to a wet, warmer,maritime climate along travel has increasedsubstantially since 1989, coinciding the Tatshenshiniand Alsek rivers, and vegetation com- with world-wide publicity generated to protect the munitiesreflect this climatic transition.The Tatshenshini TatshenshiniRiver from mining development(Dill et al. Riverhas runsof sockeye (Oncorhynchusnerka), chinook 294 Ursus 13:2002 (0. tshawytscha),and coho salmon (0. kisutch). Small dance)of individualbear foods as high, moderate-to-high, numbers of chum (0. keta) and pink salmon (O. moderate,low-to-moderate, or low. Based on food avail- gorbuscha) occur on the lower Alsek River. Common ability (Herreroet al. 1986), we then rated the overall mammalsalong both riversinclude grizzly bears,Ameri- potential of the habitatto supportbears in spring, sum- can black bears, moose (Alces alces), and Arctic ground mer, and late summeror fall. Along the Tatshenshiniand squirrel(Spermophilus parryii). Alsek rivers,we consideredspring to be 15 May-14 June, summerto be 15 June-21 July, and late summerto be 22 BabineRiver July-30 September based on grizzly bear research of The BabineRiver (55?20'N 126?50'W)is in northcen- McCann(1998). We consideredspring in the BabineRiver tral British Columbia,Canada, and flows northand west drainageto be May and June, summerto be July and Au- to the Skeena River. The upperBabine River has a mod- gust, and fall to be Septemberand October (Resources erately dry continentalclimate and the lower river has a InventoryCommittee 1999). We assumed that seasonal moderately wet-to-dry climate transitionalbetween the availability of bear foods was a reasonableindicator of coast andinterior. The BabineRiver has runsof 6 species the likelihood of a bear feeding near a campsite. Habitat of salmon,including sockeye, chinook,coho, chum,pink, assessment relied on our experience with the range of and steelhead (0. mykiss). Common mammals include habitatsavailable in local ecosystems as well as our re- grizzly bears, black bears, and moose. search experience and a literaturereview of bear habitat use and diet within the ecosystems surveyed or ecologi- cally similar areas (Herreroet al. 1986). We compared METHODS andrated habitats relative to a benchmarkhabitat we con- We documentedcampsites through interviews with park sidered the best available in a particularecosystem (Re- staff, river guides, and other local people. We visited sources InventoryCommittee 1999). We used a 5-class campsitesduring 21-31 August 1998 on the Alsek River, rating scale. High value habitat was considered to be 7-11 September1998 on the Babine River, and 30 July- withinapproximately 81-100% of the potentialof a bench- 11 August 1999 on the TatshenshiniRiver. We identified markhabitat. Otherclasses were moderate-to-high(61- campsites as spots with featuressuch as a shorelinewith 80%), moderate (41-60%), low-to-moderate(21-40%) slow-moving water or a back-eddy for safe boat moor- and low (0-20%). age, reasonableaccess from the river,clear and flat areas Travel concerns.-We identified geographic features for tents, wind and weather protection, clear water for thatinfluenced the likelihood thata beartravelling a river drinking,and firewood. Presence of fire scars, unnatu- would pass through or near a campsite, such as valley rally arrangedrocks or logs, and disturbedvegetation, junctions and constrictionsin terrain,including rock out- surfacelitter, or soil confirmedcampsites. crops, cliffs, cut banks, moraines,and peninsulas. Loca- We evaluated24 campsitesalong the TatshenshiniRiver, tion of well-used bear trails and marktrees and potential 43 along the Alsek River, and 16 along the Babine River. travel routes influenced the travel concerns rating. We We assessed the potential for bear-humaninteraction at ratedtravel concerns as high, moderate,or low regardless campsites and within approximately250 m of the camp- of the season. site perimeteron the side of the river with the campsite. Sensory concerns.-We defined sensory concerns as Riverssurveyed were not a majorphysical barrier to bears featuresthat reducedthe ability of bears and humans to (river channel widths varied from 100-500 m), but we detect each other,such as vegetationand topographythat assumed bears on the opposite side of a river would not limited visibility,noise from riversor creeks thataffected be encounteredby people and would be less likely to be hearing,or wind thataffected hearing and smell. We rated displaced by human activity. We sketched and photo- visibility concernsindependently from other sensory con- graphedareas around campsites to indicaterelative posi- cerns and ratedeach campsite as high, moderate,or low tion of habitats, bear foods, trails, mark trees, and with no distinctionmade between seasons.

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