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[]{]&OO~&c ~IID&~©@ Susitna Joint Venture Document Number Please Return To DOCUMENT CONTROL • A REVIEW OF MOOSE FOOD HABITS STUDIES IN NORTH AMERICA .< :';i -....:.: ..::tq ,~~]..-,; ~~., ...': 'C ~ 0 ..., ..:~ 1."; ~-:;..;-~........~.... '.~.,;,..•.'~;"I;_0'~}",\1.-e be ascertained in order to fully under- stand the interspecific,intraspecific and environmental relationships of the species.A variety of moose food ha- bit studies have become available since Peterson (1955)compiled the availa- Cet article passe en revue 41 etudes portant sur les habitudes alimentaires de I'orignal,qont 13 ont ete effectuees dans la cordilliere interieure.6 en Alaska et 22 au Canada,au Minnesota,a I'Isle Royale et dans Ie Maine.Seulement neuf de ces etudes traitent des habitudes alimentair~estivales.alors que seulement quatre de cel- les-d traitent de la pMnologie annuelle des habitudes alimentaires de I'orignal et seule- ment deux etudes s'etendentsur plus d'un an.Les variations locales des habitudes ali- mentaires sont tres importantes et des gimeralisations concernant les especes pre- ferees,sans que soit corroboree I'information pour une region don nee,apparaissent risquees.Une combinaison des methodes utilisees semble pertinente,car chaque methode a ses restrictions propres.Bien qu'une vue d'ensemble pour I 'Amerique du Nord puisse etre tracee a partir de I'information disponible,I'auteur conclut neanmoins que les donnees manquent pour comparer,entre differentes regions.les patrons d'utilisation annuels,saisonniers de meme qu'en fonction des differents types d'habitats.L'auteur estime qu'it est essentiel d'evaluer les habitudes alimentaires avant d'apprecier les conditions du milieu et leurs changements,ou,avant d'entreprendre des recherches portant sur la valeur nutritive et la digestibilite des dilferentes especes vegetales concernees. Department of Entomology,Fisheries and Wildlife, University of Minnesota,St.Paul,Minnesota,United States J.M.PEEK2 Abstract This review covers 41 studies of moose food habits.including 13 from the intermountain west,6 from Alaska,and 22 from Canada,Minnesota.Isle Royale,and Maine,Only nine of these studies include information on summer food habits.only four on year-long food habits and only two studies were longer than one year,Local va- riations in forage preferences were very important,and generalizations about prefer- red food items without confirming data for any given area appeared risky.A cQmbi- nation of methods for obtaining food habits data appears the most useful.since any given method in use has limitations,It was concluded that.although a generalized pic- ture of moose forage preferences for the North American ranges can be obtained from the data on hand,there was not enough information to compare the annual, seasonal,or habitat-type forage use patterns between areas,Evaluation of forage preferences is a prereq·uisite to evaluating habitat conditions and trends,and inves- tigations of nutritive values and forage digestibility. Resume A REVIE'vV OF MOOSE FOOD HABITS STUDIES IN NORTH AMERICA I 1 Paper No,SHO,Scientific Journal Series.Minnesota Agricultural Experiment Station.St.Paul, Minnesota 55101,. :Present address:College of Forestry,Wildlife and Range Sciences.University of Idaho,Moscow, Idaho 83843. Introduction Food habits express a fundamental relationship between animals and·their environment.The feeding habits and plants used by moose for food should .[va/WilliS/I!can.,101:195.215 (197;] Winter forages varied according to conditions of winter range.When snO'N depths were less than 30 cm sedges were used.After snow depths increa- sed beyond Blat figure,birch sterns aspen and cottonwood supplied 95 per. cent of the winter forage in their studies. Conifers were apparently not important in the diet of Alaskan moose,primarily because the two major species present. white spruce (Picea glauca)and black spruce (Picea mariana),were not pala- table (Murie,1944).. Spencer and Hakala (1964)recorded Salix depressa.S.scouleriana,S. arbusculoides,and S.barclayi as particularly important willow species on the Kenai peninsula.These species attain small tree size in that area.Bog birch (Betula glandulosa),dwarf birch (B.nana),serviceberry (Amelanchier alnifolia),mountain ash (Sorbus seo- pUlina),and high-bush cranberry were considered of minor importance.Hosley (1949)reported work done by L.J.Pal- .mer on the Kenai in the 1930's which indicates that tree and ground birches, willows,mountain ash,red and black currant (Ribes spp.)and serviceberry were highly palatabl.e.The winter diet according to Palmer was mainly willows, ground birches,cottonwood and the green bases of bunch and marsh gras- ses. LeResche and Davis (1973)provide information on moose food habits from Kenai peninsula.Summer foods of three semi-tame moose were two thirds birch leaves,one fourth forbs, including cloudberry,(Rubus chamae- morus),sundew (Drosera rotundifolia). .fireweeds (Epilobium angustifolium and E.latifolium)and rupine (Lupinus nootkatensis).Mushrooms were eaten· whenever encountered and grasses,sed· ges ,:lnd aquatics constituted about ten percent of the observed diet. LE NATURALISTE CANADIEN,VOL.10 '.1974 ,I Scientific plant names follow Fernald ('1950)for·eastern North America.Davis (1952) for the mountain states and Hulten (1968)for Alaska. Alaska food habits studies Spencer and Chatelain (1953)provide data on moose food habits in south- central Alaska based on spring browse surveys (Aldous,1944).Willows and Kenai birch (Betula kenaica)head the winter preference list,and quaking aspen was·considered important be- cause of the quantity of forage it pro- duced.Cottonwoods (Populus balsa- mifera),high bush cranberry (Vibur- num edule),red elder (Sambucus ra- cemosa),rose (Rosa spp.)and rasp- berry (Rubus idaeus)were less impor- tant browses in the diet.Willow,birch. ble data in the 1950's for North Ameri- ca.The purpose of this review is to bring all known studies together for the continent and summarize the ma- jor findings. It has been well established ,that moose are primarily a browsing spe- cies,especially during winter.Moose occupying western ranges seem to use willows (Salix spp.)3 as a prima- ry food source (Hosley,1949),while trees such as paper birch (Betula pa- pyrifera),quaking aspen (Populus tremuloides)and balsam fir (Abies balsamea)assume importance on the eastern ranges (Pimlott,1961).Forbs and aquatic plants may be important during the growing season,while grass and grass-like plants assume re- latively little importance,with some exceptions.Food habits studies have been summarized according to general region as follows:(1)Alaska;(2)the mountain states of Idaho,Montana, Utah.Washington and Wyoming;(3) western Canada (British Columbia- Manitoba);(4)eastern Canada,Isle Royale,Maine and Minnesota. '196 .... PEEK:MOOSE FOOU HABITS comprised 72 percent of the·use from February to'May,low-bush cranberry (Vaccinium vitis-Idaea)26 percent.wil- lows and alder (Alnus spp.)6%each,and occasionally ~fruticose lichen (Peltigera sp.)was taken on range considered to be representative of the wintering area. On depleted ranges,browse con- sumption declined to 23 percent of the diet between February and May,with birch predominant,while lichen con- sumption increased to 24 percent.In late April and May,when snow depths declined,lichens and low bush cran- berry comprised most of the diet.The northern Kenai Peninsula wintering area exhibits moderate snow condi- tions,which provide access to low- growing shrubs and forbs and lichens. The more persistent snows of interior Alaska require that taller browse spe- cies be available for moose in winter. The Kenai work also reflects changes in food habits relative to availability, where lower-growing forms were used more on heavily used range.Murie (1944)considered willows the major summer and winter food of moose in Mt.McKinley Park.Dwarf birch was regularly browsed.Quaking aspen (Populus tremuloides)and cotton- wood were used,but were less impor- tant because of their limited occur- rence.Murie (1944)started that gras- ses,sedges,various herbs and sub- merged vegetation was eaten in sum- mer. The following willows,listed in or- der of decreasing preference,were im- pertant forage species in interior Alas- ka near Fairbanks (Milke,1969):Sa- lix interior,S.alaxensis,S.arbusculoi- des,and S.pulchra.-The relative abundancG of a species did not seem to affect the utilization,perhaps due to inherent palatability differences de- tectable to the moose.However,less palatable species were more heavily ..:-- .~.;:.-.-.. 197 utilized when in proximity to species of higher palatability.Milke's analysis showed that the tallest plants (over 151 cm)were preferred.A positive .correlation between plant density and intensity of browsing was also noted, suggesting that the stands were not acting as barriers to moose.A combi- nation of high moisture,protein,and caloric contents were possibly related to the high preference for Salix ala- xensis,and the low values of S.ni- phoclada could explain its low pala- tability,although such conclusions were considered tentative. Montana,Utah,Washington and Wyoming food habit studies Since Peterson (1955)mentioned.the lack of detailed moose food habit stu- dies'on western ranges,several studies have become available.These studies generally support the contention that moose primarily depend upon willows for forage on western ranges.The fee- ding site examination method (Cole, 1956)and rumen analysis (Martin'et al., 1946)have been the main means of ob- taining data in the following studies. Comprehensive food habits studies have been done in Jackson Hole,Wyo- ming and southwestern Montana areas. These areas represent two generally different types of moose winter range in the intermountain west.The Jack- son Hole winter range (Harry,1957; Houston,1968)was mostly an exten- sive valley wherein floodplain vegeta- tion was the major area used by moo- se.Some use of adjacent forest com- munities was also recorded (Houston, 1968).Knowlton (1960)reported that willow bottoms,the most extensively used winter range,were limited to moist areas along streams and springs in the Ruby River area of Montana. Bitterbrush and chokecherry (Pru- nus virginiana)were the only two spe- cies which Chadwick (1960)observed eaten by moose on the Juniper Buttes, Idaho winter range. Knowlton (1960)reported moose winter food habits in the Ruby River area of Montana.Early winter foods of importance were willow,subalpine fir and currant (Ribes spp.).Later. willows,silverberry (Eleagnus commu- tata)and thinleaf alder (Alnus tenui- folia)were important.Willow constitued 67 and 59 percent of the early and late winter diets,respectively.This range was being heavily browsed at that time,with willow and silverberry plants deteriorat- ing in condition (Peek,1963). ten browsed heavily,the average per- cent of browsed trees was light during Houston's studies,which may indicate differences in palatability among indi- vidual fir trees.In this area,willow conditions have varied over the 1950- 1966 period,suggesting differential browsi ng pressu reo In 1966,3 to 5 year old blueberry willow stems were pro- ducing most of the forage and receiving most of the use for this species,older Jive stems being severely hedged and· younger stems being unbrowsed. Browse constituted 99.8 percent of the observed diet in winter on the Red Rock Lake Refuge,Montana,with Sa- lix myrtillifolia,S.planifo/ia,S.beb- biana,and S.geyeriana each consti- tuting over 10 percent of the use (Dorn, 1970).Red osier dogwood was not im- portant because of its scarcity.Use of low-growing species like S.wolfii and .bog birch was limited to early winter when they were available to moose brow- sing close to the snow level.Use of S. wolfii in summer by cattle was also heavy,probably because the low growth form renders it available.In the Dou- glas fir-type,subalpine fir received mo- LE NATURALISTE CANADIEN.VOL.101.1974198 This s"cudy area of 148 km 2 contained 58.3 hectares of willow bottom communi- ties along 33.5 km of streams (Peek, 1961).While willow communities gener- ally typify moose winter range in the mountain west,some areas are much more extensive than others.This cau- ses considerable variation in length of time used,and degree of concen- tration of moose on the-willow.Densi- ties on the extensive willow commu- nity in Jackson Hole,ranged up to 19.3 moose per km 2 in winter (Houston, 1968).Harry (1957)and Houston (1968) reported winter moose food habit studies in Jackson Hole.Harry (1957)rated serviceberry (Arne/anchier a/nifo/ia), red osier dogwood (Comus stolonifera), mountain ash (Sorbus scopulina),bog birch (Betula glandululosa),snow- brush (Ceanothus velutinus)and bit- terbrush '(Purshia tridentata)as "ve- ry highly palatable"to moose in winter. Since willows (Salix spp.)made up over three quarters of the winter diet and were ext~nsively distributed on winter ranges,he considered these the most important forage species.Hous- ton (1968)regarded blueberry willow (Salix pseudocordata)as the "key" forage plant.Forage preferences were related to vegetative type and blue- berry willow,interior willow (S.interior) subalpine fir (Abies lasiocarpa)and bitterbrush were species receiving 50 percent or more of the use observed on the specific types in which they occur- red.While Harry felt that red-osier dogwood,service-berry,mountain ash, and bog birch were in danger of being eliminated from the winter range in 1954.an indication of the degree of .use these species received,Houston reported that condition of red osier dogwood and interior willow plants im- proved·from 1964 to 1966 suggesting that.the winter.range was less inten- sively browsed during his study.While individual subalpine fiJ trees were of- r-: if: 11pir~.iiJ .. ',g:;~~-- f~a;.....--------------- i U ~.I i ~, ~. f,. !f lp, h PEEK:MOOSE FOOD HABITS ,~..-....... ~.~.....:.~-~~...-.. re use than Douglas fir (Pseudotsuga menziessi),but use was restricted to certain trees which seemed to be con- sistently browsed. Smith (.1962)and Stone (1971)report- ed moose food habits in the Rock Creek area of western Montana.Willows com- prised the major share of the winter .diet;Salix discolor and S.lemmoni were preferred to S.commutata. Plants less than 15 years old received the heaviest use.Red osier dogwood was important in March.On this range, red osier dogwood was either very heavily llsed or,else,was in poor con- dition affording only limited forage. Stevens (1970)reported food habits studies on a mountain winter range in the Gallatin region of Montana.Tim- ber types received 82 percent of the observed use during the study period. Willow constituted 25 percent of the diet, sub-alpine fir 16 percent,mountain maple (Acer spicatum)16 percent and red osier dogwood 11 percent.This winter range was being heavily used. Wilson (1971)reported that Salix drummondiana made up 92 percent and S.geyeriana made up 4.7 per- cent of the total observed winter brow- se use in the Uinta Mountains of Utah. River birch (Betula occidenta/is)com- prised 2 percent of the use and 7 other species were observed to be browsed. Poelker (1972)foundb-rowsing on fal- se box (Pachistima myrsinities)in early fall in the Kalispell.Basin of north- eastern Washington.As snow covered this species,snowbrush,Douglas maple (Acer glabrum)and.willows were ta- ken.In mid-winter,instances of brows- ing on lodgepole pine (Pinus contorta) and alders were noted. Table I provides a resume of impor- tant moose winter forage species as 199 derived from six studies reported for five areas of the intermountain west. While willows were the primary forage plant in three of the four areas,all of the studies indicated that red-osier dogwood was ·a more palatable forage species,although it was less abundant and therefore less important than willows.Subalp·ine fir was an im- portant forage species in the spruce- fir communities.Douglas fir received only limited use in the Jackson Hole and Gallatin studies,but Smith con- sidered it to be a palatable species. Lodgepole pine (Pinus contorta)re- ceived sparing utilization. Bog birch,silverberry,snowbrush, serviceberry,chokecherry,currant,moun- tain ash,mountain maple,and bitter- brush are palatable browses to moose and may be important locally.Salix discolor,S.lemmoni,S.myrtillifolia, S.pseudocordata,S.drummondiana, S.geyeriana,and S.interior,all taI- ler growing,seem to be preferred wil- low species. Forbs,grasses and grasslike plants receive only sparing use by moose in winter.Harry (1957)did not record use of these forage classes.but Houston (1968)recorded use on bluegrass and bromegrass on agricultural (hayfield) situations in Jackson Hole.Green algae received use in aquatic situations.These forage classes received less than one percent of the total winter forage in Houston's studies. Elk thistle (Cirsium foliosum)and niggerhead (Rudbeckia occidentalis) received less than one percent of the winter use in Knowlton's stUdy.Stevens (1967)however,reported that grass and grass-like plants constituted 26 per- cento~the contents of 10 moose ru- mens taken in December and January on a winter range associated with hay fields in the Big Hole valley of Monta- na.Since snow depths were high enough ·~-."-;~,.~~~.•",~,~:'~:.j~;..:;,.~::J."~~;'.~I:.:.'A~I:J...;~'~.~·!-;:~:~~··::.·~t"7~'~~~~1~7~;~·~~~~r;-;:l'~~.:r.~,7.~":t,f~'fJ.!~~::fY~·'u:.~·,~_~:~"'~:~~'.~?~:~~. i;:A ,;.' t.)oo TABLE I Winter food habits of shiras moose on western ranges Reference Location Years Most important species Remarks Houston.1968 Jackson Hole,Wyo.1967 Salix pseudocordata I,S.wolfi,S.interior.Feeding site examination S.lucida,Abies /asiocarpa. Knowlton.1959 Gravelly Range.1959 Salix ~pp.,Ribes spp.,Abies /asiocarpa,Early winter;95%of Montana Populus tremu/oides,E/eagnus commutata,forage late winter; A/nus fenuifolia.96%forage feeding site examination Smith.1962 Rock Creek Montana 1959 Salix spp:,Comus st%nitera,Populus Rumen analysis tremu/oides,Shepherdia canadensis,Feeding sites; Physocarpus ma/vaceus,Rosa spp.,Pinus Salix 90%(S.disc%r. eontorta.S./emmonsi) Harry,1957 Jackson Hole.Wyo.1954·54 Salix spp.,Abies /asiocarpa.See text for additional details i Stevens,1970 Gallatin.Montana 1966 Prunus virginiana.Comus sl%nitera,Dec.·M,arch feeding site Salix scou/eriana,S.myrtillifolia,examination S.drummondiana,Ribes spp.,Ame/anchier a/nifolia, OOr;),1970 'R('d Rock Refuge.1968·69 Salix myrtillifolia,S.geyeriana,S.Feeding site examination 1\10ntana p/anifolia.S.bebbiana,Betu/a g/andulosa Dec.20,1968 -March 17 1969, ,.. m Z ~ C ~,.. Ui -im ~z :I> 9 m ~ <or a j I, " " I HouslOn (19G8:16)indicates that the following willow species may be synonymous in his data:Salix myrtillitolia and S.pseudocordala. ._.--._If1_iW2~~~?¥~~i!~~~&1j~ PEEK;'MOOSE FOOD HABITS 201 ;-:::.. ~;",.: ·-.{t~~;_~· ;ib:"'.;- !if..;:"_.Z",.- ~.~> cent,and grasses and grass-Ii ke plants 0.6 percent of the summer diet in the Gravelly Range area.Willows com- prised 19.3 percent and sticky gera- nium (Geranium viscosissimum)64.2 percent of the diet.This area is one example of a western moose range wherein aquatic vegetation is extre- mely limited because of the high gra- dient nature of streams. Knowlton (1960),comparing the va- rious summer food habit studies of moose available,felt tliat variations were attributable to differences in ve- getation on the study areas.Subse- quently,Peek (1961)reported that on the Gravelly-Snowcrest study area, browse increased in importance du- ring summers which were drier than the 1958 summer from which Knowlton obtained data.·Consequently,it ap- pears that annual variations in food habits of moose may occur within the same area. Houston (1968)reported that browse constituted the greatest share of the summer moose diet in the Jackson Hole area,with willow again receiv- ing extensive utilization.Quaking as- pen (PopUlus tremuloides)menziesia, (Menziesia ferruginea),thimbleberry (Rubus parviflorus),Utah honeysuck- le (Lonicera utahensis),and fireweed (Epilobium spp.)were other impor- tant items.Water crowfoot (Ranucu- Ius aquatilis)and leafy pondweed (Po- tomageton foliosus)were used exten- sively in aquatic situations. to make this forage class generally un- available,haystacks were considered the main source·of grass forage in the area.Smith (1962)reported that grasses.grass-like plants,and forbs received less than one percent of the o:Jserved winter diet on his study area, while Stone (1971)reported some use of bull thistle (Cirsium vulgare)and lupines. Browse species apparently cons- titute increasingly greater percenta- ges of the Shiras moose diet from early to late fall.Knowlton (1960),Houston (1968)and Smith (1962)reported that browse plants constituted from 70 to 90 percent of the fall diets.Willow, subalpine fir,currant,aspen,huckle- berry (Vaccinium scoparium)moun- tain ash,serviceberry,Ceanothus,bit- terbrush,buckthorn (Rhamnus sp.),ho- neysuckle (Lonicera canadensis),pa- per birch (Betula papyrifera)and red osier dogwood were important fall for- age plants.Forbs and grasses compris- ed relatively larger percentages of the fall diets than winter diets.There was Darn (1970)found'that Salix myr- more variation in the fall diets bet-til/ifolia,Salix geyeriana,and Salix ween areas than in the winter diets,planifolia and bog birch leaves cons- perhaps because the use of a greater·tituted 86%of the summer moose diet number of vegetative types occurred at Red Rock Lakes Refuge.Montana. in the fall,and there was greater chan-Most leaf-stripping occurred on plants ce of variation in communities bet-over one m tall.Use of aquatics was ween areas.considered minimal. -.,.-- Summer food habits studies reveal even greater variation between areas. In Yellowstone National Park,McMil- lan (1953)recorded willow as 88.5 per- cent,aquatics as 9.3 percent,and gras- ses and forbs as 2.2 percent of the diet,based on amount of time spent feeding on each forage class.Salix geyeriana was used three times more frequently than S.wolfii.BluegrassE;ls and wheat grasses (Agropyron spp.) were the grass species utilized. Knowlton (1960)reported that browse constituted 28.6 percent,forbs 70.6 per- .,·,-.~.t:·rr~...~:~-.~-:~_.'-1¥~~"r:""'~"~:::G\'ESF_:'...~-~.Ji!":G*#;'n.:.?'''~~~~.~''~;.:'&.t.e,-....,,,.~>JIiC'IY,(~.1!".~..,f#.,.....lf~-1:'&.Soj .....~'~,f-"~..~a·4.~'.,~..,.~,"_.--'.",',:'~:._'~:':'.--_.•'..-"-'-:'-""'"-:'""'""!"W~:-".:".'..--~.;;;,;'!,."" ~:....':..~...:-::-... ~'. ~~~."i>~ J ~, ~. t· j.~202 LE NATURALISTE CANADIEN.VOL.101,1974 Moose food habits have been in~esti gated primarily in winter in eastern North America.Newfoundland studies include those of Dodds (1960).Pimlott (1953),and Bergerud and Manuel (1968). t. Western Can'adian food Analysis of 23 moose rumen content habit studies collected in February 1970 in Cypres In British Columbia,Hatter (fide Hills Provincial Park in southeasterr Hosley,1949)considereq red-osier dog-Albe~ta was reported by Barrett (1972) wood,paper birch,willows,service-Serviceberry comprised 56 percent 0 berry,quaking aspen,mountain ash the identified material on a dry weigh (Sorbus scopulina)and bog birch to basis,quaking aspen 21 percent anc be palatable winter moose forage plants.Prunus spp.12 percent.Red osiel Cowan,Hoar,and Hatter (1950)added dogwood,willows,honeysuckle,Cle- hazel (Corylus californica),high-matis spp.Rosa spp.and lodgepole bush cranberry (Viburnum pauciflo-pine contributed less than 10 percenl rum),and alpine fir (Abies lasiocar-of the identifiable material.Cypress pa).Scouler and Bebb willows (S.Hills form a low plateau surrounded scouleriana,S.bebbiana),were the by treeless grass plains,an island of important willow species.Douglas Fir moose habitat.The moose population (Pseudotsuga menziesii)was seldom increased from a transplant of four eaten on their study areas.These data animals in 1956 to 130-180 animals in suggest that moose food habits in Bri-1970,and severe browsing was com- tish Columbia more closely approach mon at the time of collections.This stu- those of moose on more eastern ran-dy represents the highest proportion of g~s,as will be reported.serviceberry reported in the diet of moose,and Barrett considered this Ritcey (1965)recorded instances of species to be preferred over willow. use of forage by moose on the Wells Gray P"ark,British Columbia,winter Howard (pers.comm.)reported that range.Willow and false box (Pa ch is-browse surveys along the Saskatchewan tima sp.)comprised over 75 percent River delta in northern Manitoba taken of the observed use,with paper birch,by J.E.Bryant in 1955,showed that red hazel and red osier dogwood also recei-osier dogwood and willows were the ving use.Extensive overlap in the diets main species eaten.Balsam fir,quaking (but not the areas of use)of moose aspen,Viburnum spp.box elder (Acer and mule deer (Odocoileus hemionus)negundo)balsam fir,balsam-poplar was found.An experimental clear-cut-(PopUlUS balsamifera)and raspberry ting increased browse production and (Rubus idaeus)were also commonly ta- utilization by moose for at least four ken.In more southerly portions of __~earsJoJlowil"'lg_the_cutting.-----------_mo_ose__range-in-ManitGsa,--mol:lfltain- ,.maple,quaking aspen and hazel appea- AquatiC specIes used by moose in red to be important. summer at Bowron Lake Park,B.C., included swamp horsetail (£quisetum fluviatile),burreed (Sparganium spp.),and pondweeds (Potorriageton Eastern Canadian,Isle Royale,Maina richardson;;,P.robinsii,P.9ramineus,and Minnesota food habit studies P.natans.and P.amplifolius,in order of importance)according to Rit- cey and Verbeek (1969).Aquatic plants appeared to form the bulk of the sum- mer diet.Burreeds were considered to be the chief aquatic food in Wells Gray Park by these investigators. 203 "3~+f~~;,:;%;~~j~;-~)I;;;'-~~f~ll t- ing eastern Minnesota where this spe- cies occurs infrequently on the major moose range as well as on areas where moose and deer are scarce. Ev.aluation of the ability of 12 year- old balsam fir to withstand varying amounts of browsing was determined by Bergerud and Manuel (1968).Over half of the trees from which 75%of growth was removed died two years after clipping,while only one of ninety clipped at1 0-50%levels died.It was not stated whether current or total growth was removed.Balsam fir trees four-foot tall were found to withstand up to 12 years of heavy browsing wi- thout dying.A preference for balsam fir with dark green needles over chlo- rotic,light green colored fir was noted. Crude protein content was lower in chlorotic fir,indicating that moose were selecting the most nutritious plants. Clipping experiments resulted in some darkening of the foliage of chlorotic fir.Light browsing may improve pro- tein content by stimulating adventi- tious nutrient-rich shoots. It is significant that these investi- gators doubted that an equilibrium bet- ween moderate moose densities and a quantity of highly palatable diver- sified winter moose foods could be maintained in Newfoundland,because of inaccessibility of many moose to hunters,because foods such as yew and quaking aspen could not withstand moderate use,and also because moose tended to congregate on 'sites wherein sought-after species were intensively utilised.However,the diet of balsam fir and white birch was considered ade- quate to maintain a healthy moose po- pUlatio~. Summer moose food habit data from eastern ranges are scarce.Dodds (1960)stated that in Newfoundland moose fed on herbaceous materials during summer.Grasses and sedges. PEEK:MOOSE FOOD HABITS Dodds (1960)recorded 35 species of woody plants browsed by moose based on examination of browsing intensities on woody plants within sampling plots. In an area of high moose density domi- nated by balsam fir,winter browse use was chiefly on balsam fir (47 per- cent),white birch (20 percent),and raspberry (13 percent).In a lighter moose density area dominated by un- cu't white spruce (Picea glauca)and balsam fir,balsam fir constituted 44 percent,willows 22 percent and alder 11 percent of the winter browse use. On a cutover area of high moose den- sity,fire cherry (Prunus pennsylvani- ca)was 29 percent,white birch 25 percent,·oalsam fir 1"5 -percent and quaking aspen 10 percent of the diet. Pimlott (1953)considered balsam fir and white birch the two species of universal importance to moose in New- foundland.White birch was the most important browse species in habitats which had been burned or logged,con- taining low or moderate moose densi- ties (Pimlott,1963).Balsam fir exceed- ed white birch in the diet where high density populations existed.Yew'(Ta- xLis canadensis)was most seriously affected by moose browsing,being highly palatable and relatively into- lerant to browsing (Pimlott,1963). Pimlott thought it possible to classify browse conditions on the basis of use of these three species.If yew was high- ly or moderately used.the range was below carrying capacity and many pa- latable browse species would be avai- lable.If white birch was available, balsam would provide a small percen- tage of the winter food.If fir was heavi- ly browsed,yew would be killed out and the palatable decid uous species would be severely overbrowsed and a portion eliminated from the habitat. It should be noted that the absence Or scarcity of yew may not be attri- butable to moose in some areas,includ- LE NATURALISTE CANADIEN.VOL.101.1974 _:....:_.:~._...._:..::_.~.;.~~_-._-..•.;.,:,~..~_...~.~,~;'~~~~=k"'"!,,~i·"""~~~~~~5f~~;'5~f.-: --".,,,..~~';:'..~:~.~"........:.' percent.Apparently these studies were made at a time when heavy browsing by moose was occurring in the area. DesMeuJes (1965)determined winter moose food habits from browse sur- veys in Laurentide Park,Quebec.In four yards examined.balsam fir com- prised most of the winter diet.while in four other yards,deciduous species dominated the diet and balsam fir was moderately .used.Mountain maple, white birch and willows were the most commonly browsed deciduous species. Red-osier dogwood,willows.and moun- tain ash the highest palatability ra- tings where available.Balsam fir be- came more heavily utilised as snow depths increased to highs in late winter. Fire cherry bark was used more com- mo~ly than quaking aspen,mountain ash or red maple bark,but all were fed upon where palatable twigs were available and hence were considered preferred foods.No 'evidence of browsing on arboreal lichens was no- ted although they were abundant in some areas studied. DesMeules (1965)postulated that heavy utilization of balsam fir in late winter may save energy,since fir twigs weigh eight to 13 times more than deci- duous twigs of similar length and there- fore require less time and efforts to consume equivalent amounts.In one late winter yard,balsam fir comprised 86 and white birch 14%of the diet.This yard was about ten acres in size and was believed capable of supporting one moose for 200 days of winter (DesMeu- les,1962). .Stomach analyses of 24 Ontario moose. one Manitoba and one Quebec moose,' taken from October 19 to May 5 (Pe- terson,1953)indicated that balsam fir occurred in 21 of 23 stomachs where the tree occurs,and white cedar (Thu- ja occidentalis)occurred in small amounts in 4 stomachs,willow 'in 16. 204 Dyer (1948)reported browse surveys in Baxter State Park,Maine.Balsam fir,mountain maple.mountain ash, white birch and fire cherry were the five most important browse species for moose.Two types of moose yards were described in this region..On high altitude yards,near summits of mountain tops,snow depths of 2.5 to 3.2 m limited browsing to repro- duction .above that height.Balsam fir was stripped of lateral branches up to 1.25 cm in diameter.Low altitude yards were the most common type of yarding situation in the region.Seven species made up 99 percent of the food eaten:balsam fir,mountain maple, mountain ash,white birch,striped maple (Acer pensylvanicum).fire cherry and quaking aspen in that order of importance.Fir constituted 54 per- cent of the diet,.mountain maple 23 leaves of shrubs were commonly taken. There were few aquatic areas in New- found land:however,small ponds,Jakes and rivers were frequented.On an aquatic area used heavily within Dodd's study area,grazing was light until late June.heavy during July and decreased in August. Telfer (1967)reported winter range surveys in Nova Scotia.Speckled alder (Alnus rugosa),Canada honeysuckle (Lonicera canadensis),allegheny blackberry (Rubus allegheniensis) sugar maple (Acer saccharum)and yellow birch (Betula a/leghaniensis) were the five most highly preferred browse species of nine species which were used in a moose yard.Beaked hazel (Corylus cornuta)was ranked over balsam fir,mountain maple,Alle- gheny blackberry and meadow-sweet (Spiraea latifolia).For the entire winter range,yellow birch,red maple (Acer rubrum).sugar maple and moun- tain maple (A.spicatum)were im- portant forage species. 205 Manweiler (1941)stated that the main winter foods of moose in Minne- sota were maples,ash,dogw,ood,hem- lock (Tsuga sp.)quaking aspen,bal- sam poplar,birches,willows.june- berry (Amelanchier sp.),fire cherry, chokecherry and basswood (Tilia sp.). The'basis for this was not reported, and hemlock and basswood are rare on Minnesota moose ranges.The Red black spruce on Isle Royale.Yew was considered a highly preferred moose food,and was once widely distributed across Isle Royale (Murie,1934).By 1950,it was"not considered to be a source of food on the island.Mountain maple ranked higher on the palata- biiity lists than beaked hazel,but light utilization for both species was encoun- tered. Krefting (1951)reported that stomachs of moose collected in the fall of 1949 con- tained mountain maple.balsam fir and quaking aspen.Murie (1934)reported stomach contents analysis of six moose taken between May 20 and August 10 of the summers of 1929,1930 and 1931. Mostly browse species were found,in- cluding quaking aspen,alder,fire cherry, yew,bush honeysuckle (Lonicera sp), mountain maple.raspberries.beaked hazel.and willow.Small amounts of sedge.grass,mushrooms,horsetail (Equisetum spp.)pondweeds and large-leaved aster (Aster macrophyl- Ius)were also found.Murie (1934) reported that.wood fern (Dryopteris sp.),and swamp horsetail (Equise- tum sp.)sedges,marsh marigold (Gal- tha palustris),jewelweed (Impatiens sp.)and large-leaved aster were exten- sively grazed.Large yellow pond lily (Nymphaea advena).sweetscented white pond lily (Castalia odorata)and Potamageton sp.were reported as ex- tensively fed upon when available but were rare due to heavy u·se by moose on Isle Royale (Murie,1934). PEEK:MOOSE FOOD HABITS ""?: ~...~~~,.:.....-.~~~~~~~~~~~~~;-:;~~~..,::;':-;-:"",'..._-~,~,?~~~.:~7~r~~~f~0·,~,~~.~~:?~,~,~,--:·~.:·~.~~5'2>2::rr..;::~:::::;:::1·~..~.~rzl!).:~~~~~::~~~oE:~~·.7:~k~;;"::·,.~~:=:~::'-!Z~:T~~~21~¥:,~~~'.:'%~~::'''~'.~",,..,_..;e,,,;.~-::.~.~J-;-$-!!I'~.!i!!'.......' .,.:"-'..~.- Browsing investigations in Ontario on ·St."Ignace Island (Peterson,1953) suggested that balsam,fir constituted 27 percent of the available diet,white birch 12 percent,'mountain maple and red osier nine percent each and highbush cranberry five percent.Consi- derable seasonal vari~tion was found in foods eaten.Conifers were practically untouched from early spring to late fall. Quaking aspen was commonly barked on St.Ignace.Mountain maple was most consistently barked,though mature trees were very scarce. The'lsle Royale browse studies (Al- dous and Krefting,1946;Krefting.1951) illustrate annual variations in winter utilization patterns of moose on the same range (Table II).The diet includ- ed 33 woody species but seven species (quaking aspen,white birch,balsam fir,mouri-tain ash,willows,red osier dogwood,yew)contributed 80 percent of the total diet and three (quaking aspen,white birch,balsam fir)contri- buted 48 percent,based on three years of spring browse survey data.Chan- ges in importance of individual species were primarily _related to the heavy browsing which occured during the pe- riod (Krefting,1951).Quaking aspen became less important in the diet af- ter 1945 because the amount eaten up to then was in excess of production. Quaking aspen accounted for 54 per- cent of all trees and shrubs'destroyed by moose in very heavy browsing situation.Conversely,,whit birch,be- cause of its higher ability to withstand browsing,increased in importance. Krefting (1951)concluded that balsam fir could not withstand continued heavy browsing and was being replaced by white birch in 11,beaked hazel in 10, quaking aspen in nine,fire cherry in four,bog birch and red-osier dogwood "in two and serviceberry and maple in one each.. ",:...,~......--------------------------------~-:-"l",-~" f.~'11 .--'-- t : LE NATURALlSiE CANADIEN,VOL.101.1974206 Lake area of northwestern Minnesota consists of willow,quaking aspen and bog birch communities interspersed with small stands of spruce and jack pine (Pinus banksiana)(Ledin and Karns,1963).-A browse survey in that area in 1949 indicated that willow form- ed 58 percent of the winter food,while balsam fir,white cedar,bog birch,bal- sam poplar,red osier dogwood,rasp- berry.mountain ash,aspen and tama- rack (Larix laricina)comprised 39 percent.while black spruce,black ash (Fraxinus nigra),beaked hazel,white birch,high bush cranberry and alder comprised two percent of the diet.The range was considered to be in good condition.Although there was no .men- tion of moose-deer competition for any dominant species,one suspects that white cedar was probably used more by deer than by moose. Peek (1971)investigated forage pre- ferences in northeastern Minnesota on a year long basis (Fig.1),using the feeding site examination.Willows were the most important browse,year- long,but received greatest use in September through December.Bebb and pussy willows (Salix bebbiana, S.discolor)were the most preferred willows.Quaking aspen was the most important browse in June,declined in value through late summer,fall,and early winter,then received increased use in mid-winter.White birch ranked third in importance year-long,and re- mained relatively constant throughout the year.Beaked hazel,fou rth in over- all importance,was most intensively used in mid-winter.Fire cherry was important primarily in summer and. early fall.Red osier dogwood was used primarily in fall and though remaining important.decreased in value as the winter progressed.Virtually no use oc- curred until twigs reddened.June berry and mountain ash remained in the diet at low but constant levels year- long.Balsam fir,almost entirely a wir ter forage.received progressively mor use through the winter and was a important late winter forage suppl~ Mountain maple was used most com monly in late summer and again du ring the winter,but was never a rna jor item in the diet. Winter severity,especially snow deptt and its rapidity of accumulation (Van Ballenberghe and Peek,1971),appear~ to have some influence on food habits Balsam fir and beaked hazel became important items in the diet at relati· vely later dates during two milder win· ters than during the severest winter of the study.Red osier dogwood remain- ed important in the diet for a longer period during the mildest winter than during the others.Since movement to dense cover occurred most rapidly du- ring the severest winter,use of fora- ge species characteristic of com- munities dominated by balsam fir and the spruces also occurred earlier.Snow depths appeared to be critical in use of red osier dogwood.since many plants disappeared under one m of snow. Except in summer,browse constitut- ed all of the observed diet.The relati- ve importance of forbs in summer was low,but aquatics were probably the major forage source during early sum- mer.Yellow pond lily (Nuphar va- riegatum).wild rice (Zizania aqua- fica),pondweeds,burreed (Sparganium spp.)and wild calla (Calla palustris), were commonly used. Table II lists the five most important browse species for ten separate surveys in six areas of eastern North America. White birch,mountain ash,mountain maple and balsam fir occurred in four of the five areas.The Nova Scotia stu- dy area (Telfer.1967)was lightly browsed,and balsam was used only sparingly.No mount3in ash or quaking aspen was reported in that study area ---~ PEEK:MOOSE FOOD HABITS 207 WHITE BIRCH BEAKED HAZEL MTN.ASH BALSAM FIR • WILLOWS not severely browsed by moose (Peek, 1971). Mountain maple,balsam fir,and willows were important in four areas. Quaking aspen may be important only locally in Newfoundland.With the ex- JUNEBERRY FIRE CHERRY MTN.MAPLE RED OSIER DOGWOOD QUAKING ASPEN .. .".::.:',":.:.:-.~ .. «:I <:)~::l:r c(:r....c,)....1&1 ~<.).... 1&1 >f ...a::z:....a....~<.)z CD a::z:a....><.)z:CD a:: ::l ::l 1&1 <.)1&1 <1&1 <::l ::l I&J <.)0 1&1 <1&1 c(Q.......-<Il 0 z:c ...~2 <......<Il 0 z:Q ...~~< 70 60 ~o 40 30 20 10 ::x: I-40~30=.i: a:::20 w 100- W 0 U) :J I-40~30-la.20 a 10w>a:::0w U) CCl 0 -40 I- Z 30w (,)20a:::w 100- 0 40 30 20 10 Figur~J.Percentage use often important browse species by moose in Northeastern Minnesota as determined by feeding site examination,after Peek (1971).--,-- and Rowe (1957)does not mention mountain ash as being a common species in his description of Nova Sco- tia area.Balsam.fir served mainly as a late winter forage in northeastern Minnesota.where forage supplies were ...-.--._. -. , m ~c :D» C C/l-tm ~ 2»om .2 <or o No Q) J ·.. TABLE II Important browse species to moose in eastern North America Reference Five most important browse species RemarksAreainorderorimportance. Peek.1971 NE Minnesota Willows,quaking aspen,white birch,beaked hazel,Moderately high moose'population fire cherry Feeding site examination technique Aldous &Isle Royale Quaking aspen,white birch,balsam fir,mountain High moose population (1945) Krefting,1946 Michigan ash,willows Browse survey technique Krefting,1951 Isle Royale Balsam fir,white birch,mountain ash,quaking 1948 higher moose population than 1945 Michigan aspen,willows Krefting,1951 Isle Royale White birch,quaking aspen,red'osier dogwood,1950 lower moose population than 1945. Michigan willows,mountain ash Peterson.1953 SI.Ignace Balsam fir,white birch,mountain ash,red·osier 1947·48.Most important species rather than Island,Ontario dogwood,mountain maple most palatable Dyer.1948 Maine Balsam fir,mountain maple,mountain ash,white 1940's.browse survey technique birch,fire cherry Telfer.1967 Nova Scotia Mountain maple,yellow birch,sugar maple,red maple,1968 light browsing pressure, Canada honeysuckle slem counts in spring (his Fig.3) Pimlotl,1953 Newfoundland White birch,balsam fir,mountain maple,mountain Stem count method,heavy browsing ash,fire cherry pressure Dodds.1960 Newfoundland Balsam tir,white birch,raspberry,elderberry,High moose density,cutover area june berries 1953,'56, '57.Area different from below. Dodds,1960 Newtoundland Balsam lir.willows.alders,mountain maple,Low moose density,stem count method. rhododendron Area different from above. ..I' I'i, 209 This survey has covered 41 different reports,13 from the intermountain west, six from Alaska,and 22 from Canada, Minnesota and Maine.Since Peterson's (1955)review,at least 29 food habit studies have become available.Only nine of these studies include informa- tion on summer food habits;only four studies contain information on year- long food habits;only two were longer than one year's duration. Although the general conclusions are that willows are important to Shiras and Alaskan moose,and that balsam fir,quaking aspen,and paper birch are important to Canadian moose,local variations in forage preferences are important.This is especially relevant because habitat management should favor the locally preferred species. However,species such as red osier dogwood may be highly preferred items in the diet across the entire Canadian moose range,but may vary in abun- dance enough between areas to affect management considerations.Some spe- cies such as juneberry,mountain maple and beaked hazel appear to be prefer- red in some areas and unimportant in others.Although woody species are generally preferred,several studies suggest that forbs and aquatics may be of high local significance to moose when available and palatable. It therefore does not appear to be very illuminating from the mana- and Peterson (1955)in Ontario and Peek (1971)in northeastern Minnesota, moose appeared to begin and end use of aquatics earlier further south. Table III shows major aquatics used in ten different areas of North Ame- rica.While considerable variation oc- curs and is to be expected,yellow pond lily,pondweeds,and horsetail appear to be preferred wherever they occur. Discussion and conclusions PEEK:MOOSE FOOD HABITS ':'-""'-~...'~'·;t\r:'~~}~",C··;;;":~:~;;~~;P~7~~~~~~~%f__'.'~.f.~~.f.:I.:.~.g'"·:·,:c:··'"~"·:;~;'t~~.c,".., .-;.--.~.---...--.. " ception of areas in which balsam fir and white birch occur only sparingly or are absent,these two species appear to be major forages of moose on east- ern North American ranges.Aldous (1952)concluded that white birch pro- duces well under moderate to heavy use and should be used at least moderately if plant growth is to be kept within reach of deer.Bergerud and Manuel (1968)indicate that bal- sam fir has a strong survival tenacity. The role of aquatics in the diet of moose Moose are so frequently observed or photographed in water that it is easily assumed that the aquatic envi- ronment is a necessity for the species. However,major popUlations exist in areas across the continent,such as the Matanuska Valley of Alaska,the Gallatin Mountains of Montana,and the Cobequid Hills of Nova Scotia,where the aquatic habitats are of little sig- nificance.By contrasts,aquatics on Isle Royale have been reduced,follow- ing heavy use by moose (Murie,1934; Krefting,1951). Use of aquatic areas has been attri- buted to escape from insect attack (Flook,1959;Ritcey and Verbeek,1969) and to the presence of palatable plants (Peterson,1955;Murie,1934;deVos, 1956).Use of aquatic vegetation has been correlated with the pheno.logical state of the important forage species, yellow pond lily and .wild rice,in northeastern Minnesota (Peek,1971). Pond lily was used primarily before seed-set,and wild rice was used most before plants floated on the water sur- face.Use of aquatics was variable be- tween years in that area,apparently dependent upon water levels which may control phenological development,but oecurred primarily in early summer. Based on observations by DeVos (1956) -" TABLE III Summarization of aquatic plants preferred by moose in ten areas of North America _.'--- Aitcey &Verbeek.1969 Reference Aitcey &Verbeek,1969 Macon,1956),which in turn will affect the density of associated species,some of which may be more palatable than aspen.Response of various moose forage species to various cutting treatments and to prescribed burning should be further investigated. Many of these studies do not give a measure of the intensity of utilization of the various species,which causes problems in comparing food habits be- tween areas.Heavy browsing,to the point where forage preference and availability has been affected,may pre- clude determination of true forage pre- ferences for an area.Food habits stu- Swamp horsetail.burreed. pondweeds Major plants used Burreed LE NATURAlISTE CANADIEN,VOL.101,1974 Location Walls Gray Park. B.C. Bowron Lake.B.C. 210 gement standpoint to generalize about moose forage requirements,except that many preferred species appear characteristic of successional stages. Even this may be misleading because willows characteristic of riparian com- munities,or,of alpine tundra may be extremely long-lived,and mature bal- sam fir plants may be important win- ter forage sources.. The various forage species may res- pond to management practices in dif- ferent ways.For instance,quaking as- pen may sprout more readily and in denser stands from winter cutting than from summer cutting (Stoeckler and r,. ~----------.r_.._-----_.._--_...-....._.~.._..~.-~:......:~ f ~- f; i..' Little Missinaibi Lake.Ontario Horsetail.eelgrass,pondweed. yellow pond lily.bullrush deVos,1958 SI.Ignace.Onto Pondweeds Peterson.1955 Isle Royale Swamp horsetail.pondweeds. sedges.yellow pond lily. sweet-scented pond lily Murie.1934 Algonquin Park Ontario Yellow pond lily.watershield. sweet-scented pond lily Peterson.1955 Yellowstone National Park Alaska Jackson Hole, Wyoming NE Minnesota Mud plaintain.water milfoil. bladderwort.pondweeds Horsetail.rUSh.pondwced. burreed Water crowfoot.leafy pond weed.hornwort.green algae Yellow pond lily,wild rice,burrecd McMillan,1953 Palmer (in Hosley,1949) Houston,1968 Peek.1971 PEEK:MOOSE FOOD HABITS 211 . During the 1940's the use of balsam fir on Isle Royale was considered to be causing deterioration and eli- mination of the species,while the New- foundland studies suggested that bal- sam fir could withstand veri heavy use for as long as 12 years and su rvive. On Isle Royale,heavy browsing had caused quaking aspen to become less available and apparently white birch was replacing it as the most used item because of this. Besides being influenced by species composition and intensity of grazing, forage preferences may be influenced by weather conditions,and general ac- tivity and whims of the animal (Stod- dart and Smith,1955).For instance, Peek (1971)found that increased use of alder during the rutting period in lowland types in northeastern Minne- sota could be related to intensive rut- ting activity,wherein this highly abun- dant species may serve as·displace- ment feeding source during moments of high interaction between individuals. Many of these food habit studies were made by examinations of browse in spring.The major disadvantage of this type of survey is that changes in forage preference which may occur during the winter cannot readily be deter- mined,as these studies depict woody stem use for the whole period when woody stems are eaten.Moose may browse woody stems during the grow- ing season,as well as during dor- mancy.When relating moose food ha- larger population which was intensive- ly browsing the available forage in Newfoundland (Dodds,1960).The high use of balsam fir in both situations appeared to be primarily related to availability,and may not be a good measure of the actual palatability of this species.Balsam fir appears to be less important when a variety of other spe- cies are present.. J I A related problem that involves con- siderations beyond moose mana- gement is demonstrated by the New- f'Jundland studies.Apparently a pro- ductive and relatively dense moose po- pulation can be maintained on a winter diet of paper birch and balsam fir, while other preferred,but less brow- sing-tolerant species are being eli- minated.Since balsam fir was repro- ducing itself satisfactori Iy from the timber management standpoint,and the moose population was being main- tained,by traditional criteria of wild- life management and forestry,the si- tuation appeared to be satisfactory. However,when elimination or an im- portant reduction occurs of other non- merchantable species,the situation may be considered to be unduly altered from the standpoint of species diversity.If moose habitat management is to be fully integrated into other land uses, perhaps forage.deterioration which does not affect moose densities or tim- ber resources should not be considered the proper management goal.Of course, the problems of achieving adequate moose harvest to actually regulate den- sities,distributions and forage re- sources are among the practical limi- tations which must probably be given more immediate priority.Nevertheless, the wildlife biologist should be awa- re that resources other than moose or merchantable timber may be adver- sely affected under such conditions. There is also a need to distinguish b~tween .the effects of natural suc- cession and of previous over-utilization on forage preferences.For instance, balsam fir was important in the diet In an area of virgin timber supporting _a l.~~density moose population,as well as In a logged area supporting a much dies should include information on uti- lization and availability of forage spe- cies. ~..-.. • ...._-_.._-.---'----- _....- riod,the method does not readily de termine forage preferences for eacl habitat type.Forage availability an( feeding habits of the animals unde various conditions are not considered Ordinarily,only a small number 0 rumens can be obtained,and one a two samples which may reflect aty pical circumstances may misre· present the usual diet.Analysis is time consuming and often only a small por- tion of the'ru men is identifiable. The use of "feeding minutes"as by McMillan (1953)in Yellowstone Park is applicable only to areas where the animals and forage species can be rea- dily observed at close range,and wh8n plant composition is simple enough that items in the diet can be readily iden- tified.Also,whether semi-domesticated animals reflect forage preferences of wild conspecifics or not remains to be evaluated.In view of the problems as- sociated with each method of obtaining food habits data,several approaclles should be LJsr.d wllenevcr possible. Feeding site examinations require extensive field effort,but yield in- formation which can be specific to a given habitat type.Problems using this technique include 1)determining what constitutes "fresh use"or use by the individual which one is follow- ing,2)the fact that use on certain species such as willows and balsam fjr may be more-readily observable than on species in the herbaceous stratum,such as mushrooms,3)the subjective determination of what cons- titutes a "bite"for each plant species, and 4)the problem of securing feed- ing sites an areas where tracks and sign are more readily observable but where the animal may only be curso- rily browsing on its way to a more preferred feeding area which is less readily observable. lE NATURAllSTE CANADIEN,VOl.101,1974212 bits to range condition-trend,it is im- portant to know when a species is most intensively browsed:th'e physiological response of a shrub to browsing may be expected to differ according to its phenological state.Young and Payne (1948)fOl,Jnd that summer use of four browse species by domestic sheep in northern Idaho had a more detri- mental influ~nce upon the plant than fall use. Dodds (1960)listed several other pro- blems with relying on this method to obtain food habits data:1)rebrowsing of already browsed stems,2)overlap in food habits between two or more species present on the same area,3) early fall frosts may kill terminal shoots of same plants,including ~Iders, which may resemble browsing.Also, this approach does not usually con- sider use of leaves.Yet,the major advantage of the browse examination, is that one does not have to locate in- dividual animals,a tedious procedure in some habitat types;moreover,ade- quate sample sizes may be relatively easy to obtain and only one exa- mination of an area during the year is necessary to obtain information. Rumen analysis is also fraught with certain problems.Several biases of this technique include:larger plant fragments,being most easily identifia- ble,may not be representative of the entire rumen contents because of dif- ferential digestion between plants (Ber- gerud and Russell,1964).Although this may be a minor bias when only woody stems are eaten,certain shrubs such as elder and the honeysuckles may be more quickly digested than balsam fir and willows and the smaller,more delicate stems may also be digested more quickly than the coarser stems, making identification more difficult. For animals Wflich may frequent diffe- rent habitat types during a feeding pe- '.:?'. ,~, ~:r ..-; _·'.!.~5t:~?~:l.·~ .t ';.{;". 1:.tt1:'i' .·.;}~}~~~;Ji ..it .~'~:-;~::.,i j.:":..,:...'::J ·.f .(·"..._;:~:~.~,..~';~d;Ct;,:'.'!~m"t"~~~r;~~::;}:ir.;::~;~':~~~~~"7...'2·,:"37'"X"""".f'."'7"~":':;::".~7T:"~~T~;Z~·t!'~~:C.,,,,,~;.:,~;;.;7""·"-='···""'~~ <'":-......'~':"-';,,::.::-~..... .:< • PEEK:MOOSE FOOD HABITS• It must also realized that a short- term study may not provide adequate information on the forage preferences of moose for any given area.Pref- erences have been found to vary be- tween years in southwestern Montana and on Isle Royale.And on areas as close together as Yellowstone Lake, the Ruby River of southwestern Mon- tana,and Jackson Hole,Wyoming, summer food preferences appear to be quite'different. Assessment of winter forage sources alone may not provide enough in- formation to determine whether fo- rage supplies are a limiting factor or not;spring,summer and fall diets may have an important influence on pro- duction and survival,as indicated for .deer (Klein,1970).Most certainly a knowledge of year-long forage require- ments will be important in effecting proper management invo,lving habitat manipulation.Peek'(1971)recommen- ded logging practices that would favour creation of areas which could provide spring and fall habitats for moose as an important management procedure in northeastern Minnesota. Food habits data are probably best interpreted when supporting infor- mation on habitat condition and trend, and population performance are also available..Until .a measure of actual forage preferences of a population in a given area can be obtained through experimental procedures,habitat and POpulation performance are meaning- ful ways of determining the adequacy of a diet based on field observation. It is concluded that these studies'do not depict food habits well enough to adequately compare annual,seasonal ~nd habitat-type forage use patterns In all but a few instances.Trends in food habits according to successional S~q\Jence are inadequately reported. 213 The influence of weather,predpitation', plant phenology and succession,as well as social behaviour,on forage use should be further investigated.A knowledge of forage requirements and preferences is prerequisite to investigations of nu- tritive values and d igestibil ity of forage sources. Acknowledgements I am indebted to J.L.Howard of the Manitoba Department of Mines and Resources for providing unpublished information. References ALDOUS,S.E.,1944.A deer browse survey method.J.Mammal.,25 (2):130-136. ALDOUS,S.E..1952.Deer browse clipping study in the Lake States region.J.Wildl.Mgmt, 16 (4):401-409. ALDOUS,S.E.and L.W.KREFTING,1946.The present status of moose on Isle Royale.Trans. N.Am.Wildl.Cont.,11 :296-30~. Van BALLENBERGHE,V.and J.M.PEEK,1971. Radiotelemetry studies of moose in northeas- tern Minnesota.J.Wildl.Mgmt.35(1):63-71. BARRETT,M.W.,1972.A review of the diet,con- dition,diseases and parasites of the Cypress Hills moose.8th N.Am.Moose Works., Thunder Bay,Ontario.Onto Minis!.Nat Resour., p.60-79. BERGERUD,A.T.and F.MANUEL,1968.Moose dam'age to balsam fir-white birch forests in central Newfoundland.J.Wildl.Mgmt.32 (4): 729-746. BERGERUD.A.T.and L.RUSSELL.1964. Evaluation of rumen food analyses for New- foundland Caribou.J.Wildl.Mgmt,28 (4):809- 814. CHADWICK,H.W.,1960.Plant succession and big game winter movements and feeding habits in the sand dune area in Fremont County, ILaho,M.Sc.Thesis,Univ.of Idaho,Moscow, 121 p. COLE,G.F.,1956.The pronghorn antelope:its range use and food habits in central Montana with special reference to alfalfa.Bull.Mont. agric.Exp.Stn,No.516.63 p. .-.•'1._ KREFTING,L.W.,1951.What is the future of thE Isle Royale moose herd?Trans.N.Am.Wildl Conf.,16:461·470. LEDIN,D.and P.KARNS,1963.On Minnesota': moose.Conserv.Volunt..26:40-48. LE RESCHE.R.E.and J.L.DAVIS,1972.Impor tance of non-browse foods to moose.Alaski Dept.of Fish and Game.Unpubl.manuscript. LE RESCHE,R.E.and J.L.DAVIS,1973.1m· portance of non-browse foods to moose on the Kenai Peninsula,Alaska.J.Wildl.Mgmt, 37(3):279-287. MANWEILER,J .•1941.The future of Minnesotc moose.Conserv.Volunt..3:38·45. MARTIN,A.C .•R.H.GENSCH and C.P.BROWN. 1946.Alternative methods on upland game bird food analysis.J.Wildl.Mgmt,10:8-12. McMILLAN,J.F.,1953.Some feeding habits of moose in Yellowstone National Park.Ecology, 34 (1):102-110. MILKE,G.C.,1969.Some moose-willow relation- ships in the interior of Alaska.M.Sc.Thesis, Univ.of Alaska,79 p.,unpubl. MURIE,A .•1934.The moose of Isle Royale.Misc. PubIs Mus.Zool.Univ.Mich"No.25,44 p. MURIE,A.,1944.The wolves of Mount McKinley, U.S.Natn.Park Serv.,Fauna Ser.No.5,238 p. PEEK,J.M.,1961.Reproduction of moose in southwestern Montana.M.Sc.Thesis,Montana State Univ.,Bozeman,30 p. PEEK.J.M .•1963.Appraisal of a moose range in southwestern Montana.J.Range Mgmt,16 (5): 227·231. PEEK,J.M.,1971.Moose habitat selection and relationships to forest management in north- eastern Minnesota.Ph D.Thesis,Univ.of Min- nesota,250 p. PETERSON,R.L.,1955.North American moo~e. Univ.of Toronto Press,280 p. PIMLOTT.D.H.,1953.Newfoundland moose.Tr;;!ns. N.Am.W/ldl.Conf.,18:563-581. PIMLOTI,D.H.,1961.The ecology and mannge' ment of moose in North America.Terre ot Vie. 246-265. PIMLOTT,D.H.,1963.Influt:nce of deer and· moo:;e on boreal forest vegetation in two are35 LE NATURALISTE CANADIEN.VOL.101.1974214 KLEIN,D.R.,1970.Food selection by North American deer and deer response to over- utili'zation of preferred plant species.10th Symp.Brit.Ecol.Soc.,p.25-46. KNOWLTON,F.F.,1960.Food habits,move- ments and populations of moose in the Gravelly Mountains,Montana.J.Wildl.Mgmt, 24 (2):162·170. COWAN,I,MeT.,W.S.HOAR and J.HATIER, 1950.The effect of forest succession upon the quantity and upon the nutritive values of woody plants used as food by moose.Can.J.Res.(D), 28:249-271. DAVIS.R.J.,1952.Flora of Idaho.·W.C.Brown Co.•Dubuque,Iowa,828 p. DesMEULES,P ..1962.Intensive study of an early spring habitat of moose in Laurentides Park.Quebec.N.E.Wildl.Conf..Monticello. New York.12 p.(mimeogr.). DesMEULES,P.:1965..Hyemal food and shelter of moose (Alces americana CI.)in Laurentide Park.Quebec.M.Sc.Thesis.Univ.of Guelph, 138 p .•unpubl. DeVOS,A .•1956.Summer studies of moose in Ontario.Trans.N.Am.Wildl.Conf.•21:510-525. DODDS.D.G.,1960.Food competition and range relationships of moose and snowshoe hare in Newfoundland.J.Wildl Mgmt,24 (1):52-60. DORN,R.D .•1970.Moose and cattle food habits in southwest Montana.J.Wildl.Mgmt,34 (3): 559-564. DYER,H.J .•1948.Preliminary plan for wildlife management on Baxter State Park.M.Sc. Thesis.Univ.of Maine,79 p.,unpubl. FERNALD.M.L.,1950.Gray's Manual of Botany, 8th ed.American Book Co..New York.1632 p. FLOOK,D.R.•1959.Moose using water as refuge from flies.J.Mammal.,40 (3):455. HARRY,G.B.,1957.Winter food habits of moose in Jackson Hole Wyoming.J.Wild/.Mgmt,21: 53-57. HOSLEY,N.W.,1949.The moose and its ecology.Wildl.Res.Mgmt Leaf.,No.312,51 p. .. ·....•t HOUSTON,D.B.,1968.The Shiras moose inPJacksonHole,Wyoming.Tech.Bull.Grandr.:~A N 1 110 E'EIE£lSON,-R.-b.-,-1-9Sa.-S{udies-of-the-food~•Te~on Nat.Hi~s_s~,~_o.__,p .._----------:·R--I---------~habits and the habitat of moose in Ontario.t HULTEN,E.,1968.Flora.of Alaska and Contr.R.Ont.Mus.Zool.Paleont..No.36,49 p.f.neighboring territories;a manual of the vas- ·cular plants.Stanford Univ.Press,1008 p.}" f:. i~: ji'. ~'.~~ ·t.. ~I ~,·i ':'~~:.:'''':j:t;~'.....:::.~'.:~:;:~..;t~:'t':'?-.~:!L:.Y:~~~~::'·;~~;'?·~f.-..··,.,.....,-~·""r;;",:~.."".....""'~"',.:-.~-:..-'7'''".--~......~.-.- • ,'. • PEEK:MOOSE FOOD HABITS 215 .. of eastern Canada.Transactions of the Vlth Congress.Intcrnationnl Union'of Game Biolog- ists.Bournemouth.Tho Nature Conserve-II1CY, London.p.105-116. POELKER.R.J ..1972.The Shiras moose in Washington.Washington Game Dept..46 p. n1rCEY,R.W .•1965.Ecology ·of moose winter range in Wells Gray Park,British Columbia.8. C.Fish and Game Branch report,15 p. RlrCEY,R.W.and N.A.M.VERBEEK,1969. Observations o~moose feeding 9n aquatics in Bowron ·Lake Park,British Columbia.Can.Fld Nat.,83 (4):339-343. ROWE,J.5.,1959.Forest regions of Canada. Bull,Can.Dep.Northern Affairs and National Ressources Forestry Branch,No.123,71 p. SMITH,N.5.,1962.The fall and winter ecology of Shirai;moose in Rock Creek drainage, Granite County,Montana,M.Sc.Thesis,Univ. of Montana,Missoula,52 p. SPENCER,D.L.and E.F.CHATELAIN,1953. Progress in the management of the moose of south central Alaska.Trans.N.Am.Wildl.Cont., 18:539-552. SPENCER,D.L.and J.B.HAKALA.1964.Moose and fire on the Kenai.Proc.3rd Ann.Tall Tim- bers Fire Ecology Cont.,11-33. STEVENS,D.R..1967.Ecology of moose in southwestern Montana.Mont Fish and Game Dept.Rep.Job.CampI.W98R,28 p. STEVENS,D.R..1970.Winter ecology of moose in the Gallatin Mountains.Montana.J.Wildl. Mgmt.34 (1):37-46. STODDART,L.A.and A.D.SMITH,1955.Range management.McGraw Hill,New York,433 p. STOECKLER,J.H.and J.W.MACON.1956. Regeneration of aspen cutover in northern Wis- consin.J.For.,54:13-16. STONE,J.L..1971.Winter movements and dis- tribution of moose in upper Rock Creek drain- age,Granite County.Montana.M.Sc.Thesis. Univ.Montana,Missoula.80 p. TELFER.E.5 .•1967.Comparison of moose and deer winter range in Nova Scotia.J.Wildl. Mgmt,31 (3):418-425. WILSON.D.E.•1971.Carrying capacity of the key browse species for moose on the north slopes of the Unita Mountains.Utah.Res.PubIs Utah-State Div.Wild/.,No.71-9. YOUNG.V.and G.F.PAYNE.1948.Utilization of key browse species in relation to proper graz- ing practices in cut over western white pine lands in northern Idaho.J.For.•46 (1):35-40. ~:~:.'.-~..:. • ..•.:~:-.~.::".:~c;"~;':;':'2..:::~.ll7 .:~:,_~:s~;~~-::~.';7:-"::-~~::.:':?:,v_;--ry.~~:;~::;,~",":·:,::",,:::,~:.....-:'i.';::-~..r.:;:,;:·::'_;~·· ",::',':...~.",.:""'.;.-; ...._.-".