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A REVIEW OF FOOD HABITS STUDIES IN NORTH AMERICA

• . [va/WilliS/I! can., 101: 195.215 (197;]

A REVIE'vV OF MOOSE FOOD HABITS STUDIES IN NORTH AMERICA I

J. M. PEEK2 Department of Entomology, Fisheries and Wildlife, University of , St. Paul, Minnesota,

Resume :';i ... .:.: q -.. ::t .-,; ,~~]. 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 'C etudes traitent des habitudes alimentair~estivales. alors que seulement quatre de cel­ ~ ., 0 .. 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 .. 1."; mentaires sont tres importantes et des gimeralisations concernant les especes pre­ ~-:; ..; ~ ferees, sans que soit corroboree I'information pour une region donnee, apparaissent ...... ~ - .. risquees. Unecombinaison des methodes utilisees semble pertinente, car chaque methode '.~.. ., a ses restrictions propres. Bien qu'une vue d'ensemble pour I'Amerique du Nord puisse ;,. .•. '~;"I etre tracee partir de I'information disponible, I'auteur conclut neanmoins que les ;_0' a }", donnees manquent pour comparer, entre differentes regions. les patrons d'utilisation .-\1 ~ annuels, saisonniers de meme qu'en fonction des differents types d'habitats. L'auteur e 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.

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.

Introduction be ascertained in order to fully under­ stand the interspecific, intraspecific Food habits express a fundamental and environmental relationships of the relationship between and· their species. A variety of moose food ha­ environment. The feeding habits and bit studies have become available since used by moose for food should Peterson (1955) compiled the availa-

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 , Moscow, Idaho 83843. '196 LE NATURALISTE CANADIEN, VOL. 10 '. 1974

ble data in the 1950's for North Ameri­ aspen and cottonwood supplied 95 per. ca. The purpose of this review is to cent of the winter forage in their studies. bring all known studies together for Conifers were apparently not important the continent and summarize the ma- in the diet of Alaskan moose, primarily jor findings. because the two major species present. white spruce (Picea glauca) and black It has been well established ,that spruce (Picea mariana), were not pala- moose are primarily a browsing spe­ table (Murie, 1944). . cies, especially during winter. Moose occupying western ranges seem to use Spencer and Hakala (1964) recorded (Salix spp.) 3 as a prima­ Salix depressa. S. scouleriana, S. ry food source (Hosley, 1949), while arbusculoides, and S. barclayi as trees such as paper birch (Betula pa­ particularly important species pyrifera), quaking aspen (Populus on the Kenai peninsula. These species tremuloides) and balsam fir (Abies attain small tree size in that area. Bog balsamea) assume importance on the birch (Betula glandulosa), dwarf birch eastern ranges (Pimlott, 1961). Forbs (B. nana), serviceberry (Amelanchier and aquatic plants may be important alnifolia), mountain ash (Sorbus seo­ during the growing season, while grass pUlina), and high-bush cranberry were and grass-like plants assume re­ considered of minor importance. Hosley latively little importance, with some (1949) reported work done by L. J. Pal- exceptions. Food habits studies have . mer on the Kenai in the 1930's which been summarized according to general indicates that tree and ground birches, region as follows: (1) Alaska; (2) the willows, mountain ash, red and black mountain states of Idaho, , currant (Ribes spp.) and serviceberry . and ; (3) were highly palatabl.e. The winter diet (­ according to Palmer was mainly willows, ); (4) eastern Canada, Isle ground birches, cottonwood and the Royale, Maine and Minnesota. green bases of bunch and marsh gras­ ses. .... Alaska food habits studies LeResche and Davis (1973) provide Spencer and Chatelain (1953) provide information on moose food habits data on moose food habits in south­ from Kenai peninsula. Summer foods central Alaska based on spring browse of three semi-tame moose were two surveys (Aldous, 1944). Willows and thirds birch leaves, one fourth forbs, Kenai birch (Betula kenaica) head including cloudberry, (Rubus chamae­ the winter preference list, and quaking morus), sundew (Drosera rotundifolia). aspen was· considered important be­ . fireweeds (Epilobium angustifolium and cause of the quantity of forage it pro­ E. latifolium) and rupine (Lupinus duced. Cottonwoods (Populus balsa­ nootkatensis). Mushrooms were eaten· mifera), high bush cranberry (Vibur­ whenever encountered and grasses, sed· num edule), red elder (Sambucus ra­ ges ,:lnd aquatics constituted about ten cemosa), rose (Rosa spp.) and rasp­ percent of the observed diet. berry (Rubus idaeus) were less impor­ tant browses in the diet. Willow, birch. Winter forages varied according to conditions of winter range. When snO'N ,I Scientific names follow Fernald depths were less than 30 cm sedges ('1950) for· eastern North America. Davis (1952) for the mountain states and Hulten (1968) for were used. After snow depths increa­ Alaska. sed beyond Blat figure, birch sterns PEEK: MOOSE FOOU HABITS 197 comprised 72 percent of the· use from utilized when in proximity to species February to' May, low-bush cranberry of higher palatability. Milke's analysis (Vaccinium vitis-Idaea) 26 percent. wil­ showed that the tallest plants (over lows and alder (Alnus spp.) 6% each, and 151 cm) were preferred. A positive occasionally ~ fruticose lichen (Peltigera . correlation between plant density and sp.) was taken on range considered to be intensity of browsing was also noted, representative of the wintering area. suggesting that the stands were not acting as barriers to moose. A combi­ On depleted ranges, browse con­ nation of high moisture, protein, and sumption declined to 23 percent of the caloric contents were possibly related diet between February and May, with to the high preference for Salix ala­ birch predominant, while lichen con­ xensis, and the low values of S. ni­ sumption increased to percent. In 24 phoclada could explain its low pala­ late April and May, when snow depths tability, although such conclusions declined, lichens and low bush cran­ were considered tentative. berry comprised most of the diet. The northern Kenai Peninsula wintering area exhibits moderate snow condi­ tions, which provide access to low­ Montana, Utah, Washington and growing and forbs and lichens. Wyoming food habit studies The more persistent snows of interior Alaska require that taller browse spe­ Since Peterson (1955) mentioned. the cies be available for moose in winter. lack of detailed moose food habit stu­ The Kenai work also reflects changes dies' on western ranges, several studies in food habits relative to availability, have become available. These studies where lower-growing forms were used generally support the contention that more on heavily used range. Murie moose primarily depend upon willows (1944) considered willows the major for forage on western ranges. The fee­ summer and winter food of moose in ding site examination method (Cole, Mt. McKinley Park. Dwarf birch was 1956) and rumen analysis (Martin'et al., regularly browsed. Quaking aspen 1946) have been the main means of ob­ (Populus tremuloides) and cotton­ taining data in the following studies. wood were used, but were less impor­ tant because of their limited occur­ Comprehensive food habits studies rence. Murie (1944) started that gras­ have been done in Jackson Hole, Wyo­ ses, sedges, various herbs and sub­ ming and southwestern Montana areas. merged vegetation was eaten in sum­ These areas represent two generally mer. different types of moose winter range in the intermountain west. The Jack­ The following willows, listed in or­ son Hole winter range (Harry, 1957; der of decreasing preference, were im­ Houston, 1968) was mostly an exten­ pertant forage species in interior Alas­ sive valley wherein floodplain vegeta­ ka near Fairbanks (Milke, 1969): Sa­ tion was the major area used by moo­ lix interior, S. alaxensis, S. arbusculoi­ se. Some use of adjacent forest com­ des, and S. pulchra.- The relative munities was also recorded (Houston, abundancG of a species did not seem 1968). Knowlton (1960) reported that to affect the utilization, perhaps due willow bottoms, the most extensively to inherent palatability differences de­ used winter range, were limited to tectable to the moose. However, less moist areas along streams and springs palatable species were more heavily in the Ruby River area of Montana.

.. :- - . ~.;:. -.-.. f~a;.....------i U ~. I 198 LE NATURALISTE CANADIEN. VOL. 101. 1974 ,i ~ ~. 2 f,. This s"cudy area of 148 km contained ten browsed heavily, the average per­ 58.3 hectares of willow bottom communi­ cent of browsed trees was light during !f ties along 33.5 km of streams (Peek, Houston's studies, which may indicate l 1961). While willow communities gener­ differences in palatability among indi­ p, ally typify moose winter range in the vidual fir trees. In this area, willow mountain west, some areas are much conditions have varied over the 1950­ h more extensive than others. This cau­ 1966 period, suggesting differential ses considerable variation in length browsing pressu reo In 1966, 3 to 5 year of time used, and degree of concen­ old blueberry willow stems were pro­ tration of moose on the- willow. Densi­ ducing most of the forage and receiving ties on the extensive willow commu­ most of the use for this species, older nity in Jackson Hole, ranged up to Jive stems being severely hedged and· 19.3 moose per km 2 in winter (Houston, younger stems being unbrowsed. 1968). Harry (1957) and Houston (1968) reported winter moose food habit studies Bitterbrush and chokecherry (Pru­ in Jackson Hole. Harry (1957) rated nus virginiana) were the only two spe­ serviceberry (Arne/anchier a/nifo/ia), cies which Chadwick (1960) observed red osier dogwood (Comus stolonifera), eaten by moose on the Juniper Buttes, mountain ash (Sorbus scopulina), bog Idaho winter range. birch (Betula glandululosa), snow­ Knowlton (1960) reported moose brush (Ceanothus velutinus) and bit­ winter food habits in the Ruby River terbrush '(Purshia tridentata) as "ve­ area of Montana. Early winter foods ry highly palatable" to moose in winter. of importance were willow, subalpine Since willows (Salix spp.) made up fir and currant (Ribes spp.). Later. over three quarters of the winter diet willows, silverberry (Eleagnus commu­ and were ext~nsively distributed on tata) and thinleaf alder (Alnus tenui­ winter ranges, he considered these the folia) were important. Willow constitued most important forage species. Hous­ 67 and 59 percent of the early and late ton (1968) regarded blueberry willow winter diets, respectively. This range was (Salix pseudocordata) as the "key" being heavily browsed at that time, with forage plant. Forage preferences were willow and silverberry plants deteriorat­ related to vegetative type and blue­ ing in condition (Peek, 1963). berry willow, interior willow (S. interior) subalpine fir (Abies lasiocarpa) and Browse constituted 99.8 percent of bitterbrush were species receiving 50 the observed diet in winter on the Red percent or more of the use observed on Rock Lake Refuge, Montana, with Sa­ the specific types in which they occur­ lix myrtillifolia, S. planifo/ia, S. beb­ red. While Harry felt that red-osier biana, and S. geyeriana each consti­ dogwood, service-berry, mountain ash, tuting over 10 percent of the use (Dorn, and bog birch were in danger of being 1970). Red osier dogwood was not im­ r-: eliminated from the winter range in portant because of its scarcity. Use of 1954. an indication of the degree of low-growing species like S. wolfii and . use these species received, Houston . bog birch was limited to early winter reported that condition of red osier when they were available to moose brow­ dogwood and interior willow plants im­ sing close to the snow level. Use of S. proved· from 1964 to 1966 suggesting wolfii in summer by cattle was also if: that. the winter. range was less inten­ heavy, probably because the low growth sively browsed during his study. While form renders it available. In the Dou­ individual subalpine fiJ trees were of- glas fir- type, subalpine fir received mo- 11pi iiJr~ . .. ',g:;~~-- ,~ .. - ...... ~.~.....:.~-~~...-..

PEEK: MOOSE FOOD HABITS 199

re use than Douglas fir (Pseudotsuga derived from six studies reported for menziessi), but use was restricted to five areas of the intermountain west. certain trees which seemed to be con­ While willows were the primary forage sistently browsed. plant in three of the four areas, all of the studies indicated that red-osier Smith (.1962) and Stone (1971) report­ dogwood was ·a more palatable forage ed moose food habits in the Rock Creek species, although it was less abundant area of western Montana. Willows com­ and therefore less important than prised the major share of the winter willows. Subalp·ine fir was an im­ . diet; Salix discolor and S. lemmoni portant forage species in the spruce­ were preferred to S. commutata. fir communities. Douglas fir received Plants less than 15 years old received only limited use in the Jackson Hole the heaviest use. Red osier dogwood and Gallatin studies, but Smith con­ was important in March. On this range, sidered it to be a palatable species. red osier dogwood was either very Lodgepole pine (Pinus contorta) re­ heavily llsed or, else, was in poor con­ ceived sparing utilization. dition affording only limited forage. Bog birch, silverberry, snowbrush, Stevens (1970) reported food habits serviceberry, chokecherry, currant, moun­ studies on a mountain winter range tain ash, mountain maple, and bitter­ in the Gallatin region of Montana. Tim­ brush are palatable browses to moose ber types received 82 percent of the and may be important locally. Salix observed use during the study period. discolor, S. lemmoni, S. myrtillifolia, Willow constituted 25 percent of the diet, S. pseudocordata, S. drummondiana, sub-alpine fir 16 percent, mountain maple S. geyeriana, and S. interior, all taI­ (Acer spicatum) 16 percent and red ler growing, seem to be preferred wil­ osier dogwood 11 percent. This winter low species. range was being heavily used. Forbs, grasses and grasslike plants Wilson (1971) reported that Salix receive only sparing use by moose in drummondiana made up 92 percent winter. Harry (1957) did not record use and S. geyeriana made up 4.7 per­ of these forage classes. but Houston cent of the total observed winter brow­ (1968) recorded use on bluegrass and se use in the Uinta Mountains of Utah. bromegrass on agricultural (hayfield) River birch (Betula occidenta/is) com­ situations in Jackson Hole. Green algae prised 2 percent of the use and 7 other received use in aquatic situations. These species were observed to be browsed. forage classes received less than one percent of the total winter forage in Poelker (1972) foundb-rowsing on fal­ Houston's studies. se box (Pachistima myrsinities) in thistle (Cirsium foliosum) and early fall in the Kalispell. Basin of north­ niggerhead (Rudbeckia occidentalis) eastern Washington. As snow covered received less than one percent of the this species, snowbrush, Douglas maple winter use in Knowlton's stUdy. Stevens (Acer glabrum) and. willows were ta­ (1967) however, reported that grass ken. In mid-winter, instances of brows­ and grass-like plants constituted 26 per­ ing on lodgepole pine (Pinus contorta) cento~ the contents of 10 moose ru­ and alders were noted. mens taken in December and January on a winter range associated with hay Table I provides a resume of impor­ fields in the Big Hole valley of Monta­ tant moose winter forage species as 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.) o o 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 m Montana Populus tremu/oides, E/eagnus commutata, forage late winter; Z ~ A/nus fenuifolia. 96% forage feeding site C examination ,..~ Ui Smith. 1962 Rock Creek Montana 1959 Salix spp:, Comus st%nitera, Populus Rumen analysis m-i tremu/oides, Shepherdia canadensis, Feeding sites; ~ Physocarpus ma/vaceus, Rosa spp., Pinus Salix 90% (S. disc%r. z :I> eontorta. S./emmonsi) 9 m ~ Harry, 1957 Jackson Hole. Wyo. 1954·54 Salix spp., Abies /asiocarpa. See text for additional o< details i r a 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, j I HouslOn (19G8:16) indicates that the following willow species may be synonymous in his data: Salix myrtillitolia and S. pseudocordala. I, "

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PEEK;' MOOSE FOOD HABITS 201 ;-::: .. ~;", .:

to make this forage class generally un­ cent, and grasses and grass-Ii ke plants available, haystacks were considered 0.6 percent of the summer diet in the the main source· of grass forage in Gravelly Range area. Willows com­ the area. Smith (1962) reported that prised 19.3 percent and sticky gera­ grasses. grass-like plants, and forbs nium (Geranium viscosissimum) 64.2 received less than one percent of the percent of the diet. This area is one ·-.{t~~;_~· ;ib:"'.;- o:Jserved winter diet on his study area, example of a western moose range !if..;:" _ .Z",.­ while Stone (1971) reported some use wherein aquatic vegetation is extre­ ~ .~> of bull thistle (Cirsium vulgare) and mely limited because of the high gra­ lupines. dient nature of streams. Browse species apparently cons­ titute increasingly greater percenta­ Houston (1968) reported that browse ges of the Shiras moose diet from early constituted the greatest share of the to late fall. Knowlton (1960), Houston summer moose diet in the Jackson (1968) and Smith (1962) reported that Hole area, with willow again receiv­ browse plants constituted from 70 to ing extensive utilization. Quaking as­ 90 percent of the fall diets. Willow, pen (PopUlus tremuloides) menziesia, subalpine fir, currant, aspen, huckle­ (Menziesia ferruginea), thimbleberry berry (Vaccinium scoparium) moun­ (Rubus parviflorus), Utah honeysuck­ tain ash, serviceberry, Ceanothus, bit­ le (Lonicera utahensis), and fireweed terbrush, buckthorn (Rhamnus sp.), ho­ (Epilobium spp.) were other impor­ neysuckle (Lonicera canadensis), pa­ tant items. Water crowfoot (Ranucu­ per birch (Betula papyrifera) and red Ius aquatilis) and leafy pondweed (Po­ osier dogwood were important fall for­ tomageton foliosus) were used exten­ age plants. Forbs and grasses compris­ sively in aquatic situations. 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. Knowlton (1960), comparing the va­ In Yellowstone National Park, McMil­ rious summer food habit studies of lan (1953) recorded willow as 88.5 per­ moose available, felt tliat variations cent, aquatics as 9.3 percent, and gras­ were attributable to differences in ve­ ses and forbs as 2.2 percent of the getation on the study areas. Subse­ diet, based on amount of time spent quently, Peek (1961) reported that on feeding on each forage class. Salix the Gravelly-Snowcrest study area, geyeriana was used three times more browse increased in importance du­ frequently than S. wolfii. BluegrassE;ls ring summers which were drier than and wheat grasses (Agropyron spp.) the 1958 summer from which Knowlton were the grass species utilized. obtained data. ·Consequently, it ap­ pears that annual variations in food Knowlton (1960) reported that browse habits of moose may occur within the constituted 28.6 percent, forbs 70.6 per- same area. -. ,.--

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J ~, ~ . t· j. ~ 202 LE NATURALISTE CANADIEN. VOL. 101,1974

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 chis- browse surveys along the 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 (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- t. 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 Moose food habits have been in~esti­ cey and Verbeek (1969). Aquatic plants gated primarily in winter in eastern appeared to form the bulk of the sum­ North America. Newfoundland studies mer diet. Burreeds were considered include those of Dodds (1960). Pimlott to be the chief aquatic food in Wells (1953), and Bergerud and Manuel Gray Park by these investigators. (1968). "3~+f~~;,:;%;~~j~;-~)I;;;'-~~f~ll

t- PEEK: MOOSE FOOD HABITS 203

Dodds (1960) recorded 35 species of ing eastern Minnesota where this spe­ woody plants browsed by moose based cies occurs infrequently on the major on examination of browsing intensities moose range as well as on areas where on woody plants within sampling plots. moose and deer are scarce. In an area of high moose density domi­ Ev.aluation of the ability of 12 year­ nated by balsam fir, winter browse old balsam fir to withstand varying use was chiefly on balsam fir (47 per­ amounts of browsing was determined cent), white birch (20 percent), and by Bergerud and Manuel (1968). Over raspberry (13 percent). In a lighter half of the trees from which 75% of moose density area dominated by un­ growth was removed died two years cu't white spruce (Picea glauca) and after clipping, while only one of ninety balsam fir, balsam fir constituted 44 clipped at10-50% levels died. It was percent, willows 22 percent and alder not stated whether current or total 11 percent of the winter browse use. growth was removed. Balsam fir trees On a cutover area of high moose den­ four-foot tall were found to withstand sity, fire cherry (Prunus pennsylvani­ up to 12 years of heavy browsing wi­ ca) was 29 percent, white birch 25 thout dying. A preference for balsam percent, ·oalsam fir 1"5 - percent and fir with dark green needles over chlo­ quaking aspen 10 percent of the diet. rotic, light green colored fir was noted. Pimlott (1953) considered balsam fir Crude protein content was lower in and white birch the two species of chlorotic fir, indicating that moose were universal importance to moose in New­ selecting the most nutritious plants. foundland. White birch was the most Clipping experiments resulted in some important browse species in habitats darkening of the foliage of chlorotic which had been burned or logged, con­ fir. Light browsing may improve pro­ taining low or moderate moose densi­ tein content by stimulating adventi­ ties (Pimlott, 1963). Balsam fir exceed­ tious nutrient-rich shoots. ed white birch in the diet where high It is significant that these investi­ density populations existed. Yew' (Ta­ gators doubted that an equilibrium bet­ xLis canadensis) was most seriously ween moderate moose densities and affected by moose browsing, being a quantity of highly palatable diver­ highly palatable and relatively into­ sified winter moose foods could be lerant to browsing (Pimlott, 1963). maintained in Newfoundland, because Pimlott thought it possible to classify of inaccessibility of many moose to browse conditions on the basis of use hunters, because foods such as yew of these three species. If yew was high­ and quaking aspen could not withstand ly or moderately used. the range was moderate use, and also because moose below carrying capacity and many pa­ tended to congregate on 'sites wherein latable browse species would be avai­ sought-after species were intensively lable. If white birch was available, utilised. However, the diet of balsam balsam would provide a small percen­ fir and white birch was considered ade­ tage of the winter food. If fir was heavi­ quate to maintain a healthy moose po­ ly browsed, yew would be killed out pUlatio~. and the palatable deciduous species would be severely overbrowsed and a Summer moose food habit data from portion eliminated from the habitat. eastern ranges are scarce. Dodds It should be noted that the absence (1960) stated that in Newfoundland Or scarcity of yew may not be attri­ moose fed on herbaceous materials butable to moose in some areas, includ- during summer. Grasses and sedges. 204 LE NATURALISTE CANADIEN. VOL. 101. 1974 leaves of shrubs were commonly taken. percent. Apparently these studies were There were few aquatic areas in New­ made at a time when heavy browsing found land: however, small ponds, Jakes by moose was occurring in the area. and rivers were frequented. On an DesMeuJes (1965) determined winter aquatic area used heavily within Dodd's moose food habits from browse sur­ study area, grazing was light until late veys in Laurentide Park, Quebec. In June. heavy during July and decreased four yards examined. balsam fir com­ in August. prised most of the winter diet. while Telfer (1967) reported winter range in four other yards, deciduous species surveys in . Speckled alder dominated the diet and balsam fir was (Alnus rugosa), Canada honeysuckle moderately .used. Mountain maple, (Lonicera canadensis), allegheny white birch and willows were the most blackberry (Rubus allegheniensis) commonly browsed deciduous species. sugar maple (Acer saccharum) and Red-osier dogwood, willows. and moun­ yellow birch (Betula a/leghaniensis) tain ash the highest palatability ra­ were the five most highly preferred tings where available. Balsam fir be­ browse species of nine species which came more heavily utilised as snow were used in a moose yard. Beaked depths increased to highs in late winter. hazel (Corylus cornuta) was ranked Fire cherry bark was used more com­ over balsam fir, mountain maple, Alle­ mo~ly than quaking aspen, mountain gheny blackberry and meadow-sweet ash or red maple bark, but all were (Spiraea latifolia). For the entire fed upon where palatable twigs were winter range, yellow birch, red maple available and hence were considered (Acer rubrum). sugar maple and moun­ preferred foods. No 'evidence of tain maple (A. spicatum) were im­ browsing on arboreal lichens was no­ portant forage species. ted although they were abundant in some areas studied. Dyer (1948) reported browse surveys DesMeules (1965) postulated that in Baxter State Park, Maine. Balsam heavy utilization of balsam fir in late fir, mountain maple. mountain ash, winter may save energy, since fir twigs white birch and fire cherry were the weigh eight to 13 times more than deci­ five most important browse species duous twigs of similar length and there­ for moose. Two types of moose yards fore require less time and efforts to were described in this region. .On consume equivalent amounts. In one high altitude yards, near summits late winter yard, balsam fir comprised 86 of mountain tops, snow depths of 2.5 and white birch 14% of the diet. This to 3.2 m limited browsing to repro­ yard was about ten acres in size and duction .above that height. Balsam fir was believed capable of supporting one was stripped of lateral branches up moose for 200 days of winter (DesMeu­ to 1.25 cm in diameter. Low altitude les, 1962). yards were the most common type of yarding situation in the region. Seven .Stomach analyses of 24 moose. species made up 99 percent of the food one Manitoba and one Quebec moose,' eaten: balsam fir, mountain maple, taken from October 19 to May 5 (Pe­ mountain ash, white birch, striped terson, 1953) indicated that balsam fir maple (Acer pensylvanicum). fire occurred in 21 of 23 stomachs where cherry and quaking aspen in that order the tree occurs, and white cedar (Thu­ of importance. Fir constituted 54 per­ ja occidentalis) occurred in small cent of the diet,. mountain maple 23 amounts in 4 stomachs, willow 'in 16.

:....:_.:~._...._:..::_.~.;. ~~_-._-..•.;.,:,~.. ~_... ~.~,~;'~~~~=k"'"!,,~i·"""~~~~~~5f~~;'5~f.-: _- - ".,,,.. ~~';:' .. ~:~. ~" ...... : .' PEEK: MOOSE FOOD HABITS 205

white birch in 11, beaked hazel in 10, black spruce on Isle Royale. Yew was quaking aspen in nine, fire cherry in considered a highly preferred moose four, bog birch and red-osier dogwood food, and was once widely distributed "in two and serviceberry and maple across Isle Royale (Murie, 1934). By in one each.. 1950, it was" not considered to be a source of food on the island. Mountain Browsing investigations in Ontario maple ranked higher on the palata­ on ·St." Ignace Island (Peterson, 1953) biiity lists than beaked hazel, but light suggested that balsam, fir constituted utilization for both species was encoun­ 27 percent of the available diet, white tered. birch 12 percent, 'mountain maple and red osier nine percent each and Krefting (1951) reported that stomachs highbush cranberry five percent. Consi­ of moose collected in the fall of 1949 con­ derable seasonal vari~tion was found in tained mountain maple. balsam fir and foods eaten. Conifers were practically quaking aspen. Murie (1934) reported untouched from early spring to late fall. stomach contents analysis of six moose Quaking aspen was commonly barked on taken between May 20 and August 10 St. Ignace. Mountain maple was most of the summers of 1929, 1930 and 1931. consistently barked, though mature trees Mostly browse species were found, in­ were very scarce. cluding quaking aspen, alder, fire cherry, yew, bush honeysuckle (Lonicera sp), The'lsle Royale browse studies (Al­ mountain maple. raspberries. beaked dous and Krefting, 1946; Krefting. 1951) hazel. and willow. Small amounts of illustrate annual variations in winter sedge. grass, mushrooms, horsetail utilization patterns of moose on the (Equisetum spp.) pondweeds and same range (Table II). The diet includ­ large-leaved aster (Aster macrophyl­ ed 33 woody species but seven species Ius) were also found. Murie (1934) (quaking aspen, white birch, balsam reported that. wood fern (Dryopteris fir, mouri-tain ash, willows, red osier sp.), and swamp horsetail (Equise­ dogwood, yew) contributed 80 percent tum sp.) sedges, marsh marigold (Gal­ of the total diet and three (quaking tha palustris), jewelweed (Impatiens aspen, white birch, balsam fir) contri­ sp.) and large-leaved aster were exten­ buted 48 percent, based on three years sively grazed. Large yellow pond lily of spring browse survey data. Chan­ (Nymphaea advena). sweetscented ges in importance of individual species white pond lily (Castalia odorata) and were primarily _related to the heavy Potamageton sp. were reported as ex­ browsing which occured during the pe­ tensively fed upon when available but riod (Krefting, 1951). Quaking aspen were rare due to heavy u·se by moose became less important in the diet af­ on Isle Royale (Murie, 1934). ter 1945 because the amount eaten up to then was in excess of production. Manweiler (1941) stated that the Quaking aspen accounted for 54 per­ main winter foods of moose in Minne­ cent of all trees and shrubs' destroyed sota were maples, ash, dogw,ood, hem­ by moose in very heavy browsing lock (Tsuga sp.) quaking aspen, bal­ situation. Conversely, ,whit birch, be­ sam poplar, birches, willows. june­ cause of its higher ability to withstand berry (Amelanchier sp.), fire cherry, browsing, increased in importance. chokecherry and basswood (Tilia sp.). Krefting (1951) concluded that balsam The' basis for this was not reported, fir could not withstand continued heavy and hemlock and basswood are rare browsing and was being replaced by on Minnesota moose ranges. The Red ""?: ~ ... ~~ ~,.:. .... - . ~~~~~~~~~~~~~;-:;~~~..,::;':-;-:"",'... _-~,~,?~~~.:~7~r~~~f~0·,~,~~.~~:?~,~,~,--:·~.:·~.~~5'2>2::rr..;::~:::::;:::1·~ ..~.~rzl!).:~~~~~::~~~oE:~~·.7:~k~;;"::·,.~~:=:~::'-!Z~:T~~~21~¥:,~~~'.:'%~~::'''~' .~",,..,_.. ;e,,,;.~-::.~.~J-;-$-!!I'~ .!i!!'...... ' ., .:"-' .. ~. - "l",-~"",:...,~ ------~-:-­ f. ~'11 ...... - -'- - t :

206 LE NATURALlSiE CANADIEN, VOL. 101. 1974

Lake area of northwestern Minnesota long. Balsam fir, almost entirely a wir consists of willow, quaking aspen and ter forage. received progressively mor bog birch communities interspersed use through the winter and was a with small stands of spruce and jack important late winter forage suppl~ pine (Pinus banksiana) (Ledin and Mountain maple was used most com Karns, 1963).- A browse survey in that monly in late summer and again du area in 1949 indicated that willow form­ ring the winter, but was never a rna ed 58 percent of the winter food, while jor item in the diet. balsam fir, white cedar, bog birch, bal­ Winter severity, especially snow deptt sam poplar, red osier dogwood, rasp­ and its rapidity of accumulation (Van berry. mountain ash, aspen and tama­ appear~ rack (Larix laricina) comprised 39 Ballenberghe and Peek, 1971), percent. while black spruce, black ash to have some influence on food habits Balsam fir and beaked hazel became (Fraxinus nigra), beaked hazel, white birch, highbush cranberry and alder important items in the diet at relati· comprised two percent of the diet. The vely later dates during two milder win· range was considered to be in good ters than during the severest winter condition. Although there was no .men­ of the study. Red osier dogwood remain­ tion of moose-deer competition for any ed important in the diet for a longer dominant species, one suspects that period during the mildest winter than during the others. Since movement to white cedar was probably used more dense cover occurred most rapidly du­ by deer than by moose. ring the severest winter, use of fora­ Peek (1971) investigated forage pre­ ge species characteristic of com­ ferences in northeastern Minnesota munities dominated by balsam fir and on a year long basis (Fig. 1), using the spruces also occurred earlier. Snow the feeding site examination. Willows depths appeared to be critical in use were the most important browse, year­ of red osier dogwood. since many plants long, but received greatest use in disappeared under one m of snow. September through December. Bebb Except in summer, browse constitut­ and pussy willows (, ed all of the observed diet. The relati­ S. discolor) were the most preferred ve importance of forbs in summer was willows. Quaking aspen was the most low, but aquatics were probably the important browse in June, declined in major forage source during early sum­ value through late summer, fall, and mer. Yellow pond lily (Nuphar va­ early winter, then received increased riegatum). wild rice (Zizania aqua­ use in mid-winter. White birch ranked fica), pondweeds, burreed (Sparganium third in importance year-long, and re­ spp.) and wild calla (Calla palustris), mained relatively constant throughout were commonly used. the year. Beaked hazel, fou rth in over­ all importance, was most intensively Table II lists the five most important used in mid-winter. Fire cherry was browse species for ten separate surveys important primarily in summer and. in six areas of eastern North America. early fall. Red osier dogwood was used White birch, mountain ash, mountain primarily in fall and though remaining maple and balsam fir occurred in four important. decreased in value as the of the five areas. The Nova Scotia stu­ winter progressed. Virtually no use oc­ dy area (Telfer. 1967) was lightly curred until twigs reddened. June browsed, and balsam was used only berry and mountain ash remained in sparingly. No mount3in ash or quaking the diet at low but constant levels year- aspen was reported in that study area ---~

PEEK: MOOSE FOOD HABITS 207 and Rowe (1957) does not mention not severely browsed by moose (Peek, mountain ash as being a common 1971). species in his description of Nova Sco­ Mountain maple, balsam fir, and tia area. Balsam. fir served mainly as willows were important in four areas. a late winter forage in northeastern Quaking aspen may be important only Minnesota. where forage supplies were locally in Newfoundland. With the ex-

70 QUAKING ASPEN 60 WILLOWS ~o 40 30 20 10

::x: I- 40 RED OSIER DOGWOOD BEAKED HAZEL ~ =.i: 30 a::: 20 w 0- 10 W 0 U) :J I- 40 FIRE CHERRY WHITE BIRCH ~ -l 30 a. 20 a w 10 a:::> w 0 U) CCl 0 -40 MTN. MAPLE MTN. ASH I- Z w 30 (,)a::: 20 w 0- 10 0

40 JUNEBERRY BALSAM FIR • 30 20 10 ..

«:I <:) ~ ::l :r c( :r <.) .... . c,) .... 1&1 1&1 > ...... a:: a. ... <.) CD a:: z: ~ a. ... > <.) z: CD a:: z: .... z c( Q. ::l ::l 1&1 <.) ~ 1&1 < 1&1 < f ::l ::l I&J <.) 0 1&1 < 1&1 ...... -

Figur~ J. Percentage use often important browse species by moose in Northeastern Minnesota as determined by feeding site examination, after Peek (1971). -- ,--

.. ~ .". ::.:',":.:.: -.

...-.-- ._. -. ·..

No Q) TABLE II

Important browse species to moose in eastern North America

Five most important browse species Reference Area in order or importance . Remarks

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 ash, willows Browse survey technique m ~ Krefting, 1951 Isle Royale Balsam fir, white birch, mountain ash, quaking 1948 higher moose population than 1945 c Michigan aspen, willows »:D C C/l -t Krefting, 1951 Isle Royale White birch, quaking aspen, red'osier dogwood, 1950 lower moose population than 1945. m Michigan willows, mountain ash ~ 2» Peterson. 1953 SI. Ignace Balsam fir, white birch, mountain ash, red·osier 1947·48. Most important species rather than mo Island, Ontario dogwood, mountain maple most palatable .2 o< Dyer. 1948 Maine Balsam fir, mountain maple, mountain ash, white 1940's. browse survey technique r birch, fire cherry o

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. J

I .. I' 'i, " -"

PEEK: MOOSE FOOD HABITS 209

ception of areas in which balsam fir and Peterson (1955) in Ontario and Peek and white birch occur only sparingly (1971) in northeastern Minnesota, or are absent, these two species appear moose appeared to begin and end use to be major forages of moose on east­ of aquatics earlier further south. ern North American ranges. Aldous Table III shows major aquatics used (1952) concluded that white birch pro­ in ten different areas of North Ame­ duces well under moderate to heavy rica. While considerable variation oc­ use and should be used at least curs and is to be expected, yellow pond moderately if plant growth is to be lily, pondweeds, and horsetail appear kept within reach of deer. Bergerud to be preferred wherever they occur. and Manuel (1968) indicate that bal­ sam fir has a strong survival tenacity. Discussion and conclusions This survey has covered 41 different The role of aquatics in the reports, 13 from the intermountain west, diet of moose six from Alaska, and 22 from Canada, Moose are so frequently observed Minnesota and Maine. Since Peterson's or photographed in water that it is (1955) review, at least 29 food habit easily assumed that the aquatic envi­ studies have become available. Only ronment is a necessity for the species. nine of these studies include informa­ However, major popUlations exist in tion on summer food habits; only four areas across the continent, such as studies contain information on year­ the Matanuska Valley of Alaska, the long food habits; only two were longer Gallatin Mountains of Montana, and than one year's duration. the Cobequid Hills of Nova Scotia, where Although the general conclusions are the aquatic habitats are of little sig­ that willows are important to Shiras nificance. By contrasts, aquatics on and Alaskan moose, and that balsam Isle Royale have been reduced, follow­ fir, quaking aspen, and paper birch ing heavy use by moose (Murie, 1934; are important to Canadian moose, local Krefting, 1951). variations in forage preferences are important. This is especially relevant Use of aquatic areas has been attri­ because habitat management should buted to escape from insect attack favor the locally preferred species. (Flook, 1959; Ritcey and Verbeek, 1969) However, species such as red osier and to the presence of palatable plants dogwood may be highly preferred items (Peterson, 1955; Murie, 1934; deVos, in the diet across the entire Canadian 1956). Use of aquatic vegetation has moose range, but may vary in abun­ been correlated with the pheno.logical dance enough between areas to affect state of the important forage species, management considerations. Some spe­ yellow pond lily and .wild rice, in cies such as juneberry, mountain maple northeastern Minnesota (Peek, 1971). and beaked hazel appear to be prefer­ Pond lily was used primarily before red in some areas and unimportant seed-set, and wild rice was used most in others. Although woody species are before plants floated on the water sur­ generally preferred, several studies face. Use of aquatics was variable be­ suggest that forbs and aquatics may tween years in that area, apparently be of high local significance to moose dependent upon water levels which may when available and palatable. control phenological development, but oecurred primarily in early summer. It therefore does not appear to be Based on observations by DeVos (1956) very illuminating from the mana-

'-~ '~' ·;t\r:'~~}~ ;;;":~:~;;~~;P~7~~~~~~~%f'.'~.f.~~.f.:I.:.~.g'"·:· ,:c:··'"~"·:;~;'t~~.c," ':'-" " ... ",C·· __ .. , . - ;.- -.~ . -- - . ..- - .. ~ ------.r_.. _-----_ .._--_ ... -....._.~ .._.. ~.-~:...... :~ f ~ ­ f; i _.'- -- ' .. 210 LE NATURAlISTE CANADIEN, VOL. 101, 1974

gement standpoint to generalize about Macon, 1956), which in turn will affect moose forage requirements, except the density of associated species, some that many preferred species appear of which may be more palatable than characteristic of successional stages. aspen. Response of various moose forage Even this may be misleading because species to various cutting treatments willows characteristic of riparian com­ and to prescribed burning should be munities, or, of alpine tundra may be further investigated. extremely long-lived, and mature bal­ Many of these studies do not give a sam fir plants may be important win­ measure of the intensity of utilization ter forage sources. . of the various species, which causes The various forage species may res­ problems in comparing food habits be­ pond to management practices in dif­ tween areas. Heavy browsing, to the ferent ways. For instance, quaking as­ point where forage preference and pen may sprout more readily and in availability has been affected, may pre­ denser stands from winter cutting than clude determination of true forage pre­ from summer cutting (Stoeckler and ferences for an area. Food habits stu-

TABLE III

Summarization of aquatic plants preferred by moose in ten areas of North America

Location Major plants used Reference

Bowron Lake. B.C. Swamp horsetail. burreed. Aitcey & Verbeek. 1969 pondweeds

Walls Gray Park. Burreed Aitcey & Verbeek, 1969 B.C. r,. Little Missinaibi Horsetail. eelgrass, pondweed. deVos, 1958 Lake. Ontario yellow pond lily. bullrush

SI. Ignace. Onto Pondweeds Peterson. 1955

Isle Royale Swamp horsetail. pondweeds. Murie. 1934 sedges. yellow pond lily. sweet-scented pond lily

Algonquin Park Yellow pond lily. watershield. Peterson. 1955 Ontario sweet-scented pond lily

Yellowstone Mud plaintain. water milfoil. McMillan, 1953 National Park bladderwort. pondweeds

Alaska Horsetail. rUSh. pondwced. Palmer (in Hosley, 1949) burreed

Jackson Hole, Water crowfoot. leafy Houston, 1968 Wyoming pondweed. hornwort. green algae

NE Minnesota Yellow pond lily, wild Peek. 1971 rice, burrecd J I

~..-..

PEEK: MOOSE FOOD HABITS 211 .

dies should include information on uti­ larger population which was intensive­ lization and availability of forage spe­ ly browsing the available forage in cies. Newfoundland (Dodds, 1960). The high use of balsam fir in both situations A related problem that involves con­ appeared to be primarily related to siderations beyond moose mana­ availability, and may not be a good gement is demonstrated by the New­ measure of the actual palatability of this f'Jundland studies. Apparently a pro­ species. Balsam fir appears to be less ductive and relatively dense moose po­ important when a variety of other spe- pulation can be maintained on a winter cies are present. . diet of paper birch and balsam fir, while other preferred, but less brow­ During the 1940's the use of balsam sing-tolerant species are being eli­ fir on Isle Royale was considered to minated. Since balsam fir was repro­ be causing deterioration and eli­ ducing itself satisfactoriIy from the mination of the species, while the New­ timber management standpoint, and foundland studies suggested that bal­ the moose population was being main­ sam fir could withstand veri heavy tained, by traditional criteria of wild­ use for as long as 12 years and su rvive. life management and forestry, the si­ On Isle Royale, heavy browsing had tuation appeared to be satisfactory. caused quaking aspen to become less However, when elimination or an im­ available and apparently white birch portant reduction occurs of other non­ was replacing it as the most used item merchantable species, the situation may because of this. • be considered to be unduly altered from the standpoint of species diversity. If Besides being influenced by species moose habitat management is to be composition and intensity of grazing, fully integrated into other land uses, forage preferences may be influenced perhaps forage. deterioration which by weather conditions, and general ac­ does not affect moose densities or tim­ tivity and whims of the (Stod­ ber resources should not be considered dart and Smith, 1955). For instance, the proper management goal. Of course, Peek (1971) found that increased use the problems of achieving adequate of alder during the rutting period in moose harvest to actually regulate den­ lowland types in northeastern Minne­ sities, distributions and forage re­ sota could be related to intensive rut­ sources are among the practical limi­ ting activity, wherein this highly abun­ tations which must probably be given dant species may serve as· displace­ more immediate priority. Nevertheless, ment feeding source during moments the wildlife biologist should be awa­ of high interaction between individuals. re that resources other than moose Many of these food habit studies were or merchantable timber may be adver­ made by examinations of browse in sely affected under such conditions. spring. The major disadvantage of this type of survey is that changes in forage There is also a need to distinguish preference which may occur during b~tween . the effects of natural suc­ the winter cannot readily be deter­ cession and of previous over-utilization mined, as these studies depict woody on forage preferences. For instance, stem use for the whole period when balsam fir was important in the diet woody stems are eaten. Moose may In an area of virgin timber supporting browse woody stems during the grow­ _a l.~~ density moose population, as well ing season, as well as during dor­ as In a logged area supporting a much mancy. When relating moose food ha- .... _-_ .. _-.---'-----

_.... - 212 lE NATURAllSTE CANADIEN, VOl. 101, 1974

bits to range condition-trend, it is im­ riod, the method does not readily de portant to know when a species is most termine forage preferences for eacl intensively browsed: th'e physiological habitat type. Forage availability an( response of a to browsing may feeding habits of the animals unde be expected to differ according to its various conditions are not considered phenological state. Young and Payne Ordinarily, only a small number 0 (1948) fOl,Jnd that summer use of four rumens can be obtained, and one a browse species by domestic sheep in two samples which may reflect aty northern Idaho had a more detri­ pical circumstances may misre· mental influ~nce upon the plant than present the usual diet. Analysis is time fall use. consuming and often only a small por­ tion of the'ru men is identifiable. Dodds (1960) listed several other pro­ blems with relying on this method to Feeding site examinations require obtain food habits data: 1) rebrowsing extensive field effort, but yield in­ of already browsed stems, 2) overlap formation which can be specific to a in food habits between two or more given habitat type. Problems using species present on the same area, 3) this technique include 1) determining early fall frosts may kill terminal what constitutes "fresh use" or use shoots of same plants, including ~Iders, by the individual which one is follow­ which may resemble browsing. Also, ing, 2) the fact that use on certain • this approach does not usually con­ species such as willows and balsam sider use of leaves. Yet, the major fjr may be more- readily observable advantage of the browse examination, than on species in the herbaceous is that one does not have to locate in­ stratum, such as mushrooms, 3) the dividual animals, a tedious procedure subjective determination of what cons­ in some habitat types; moreover, ade­ titutes a "bite" for each plant species, quate sample sizes may be relatively and 4) the problem of securing feed­ easy to obtain and only one exa­ ing sites an areas where tracks and mination of an area during the year sign are more readily observable but is necessary to obtain information. where the animal may only be curso­ Rumen analysis is also fraught with rily browsing on its way to a more certain problems. Several biases of preferred feeding area which is less this technique include: larger plant readily observable. fragments, being most easily identifia­ ble, may not be representative of the The use of "feeding minutes" as by entire rumen contents because of dif­ McMillan (1953) in Yellowstone Park ferential digestion between plants (Ber­ is applicable only to areas where the gerud and Russell, 1964). Although this animals and forage species can be rea­ may be a minor bias when only woody dily observed at close range, and wh8n , ~, ~:r .. -; stems are eaten, certain shrubs such plant composition is simple enough that _·'.!.~5t:~?~: l.·~ as elder and the honeysuckles may items in the diet can be readily iden­ . t '; '.:?'. . {;". be more quickly digested than balsam tified. Also, whether semi-domesticated 1: fir and willows and the smaller, more animals reflect forage preferences of 1 delicate stems may also be digested wild conspecifics or not remains to be more quickly than the coarser stems, evaluated. In view of the problems as­ .tt:'i' making identification more difficult. sociated with each method of obtaining ·.;}~}~~~;Ji For animals Wflich may frequent diffe­ food habits data, several approaclles . ..it rent habitat types during a feeding pe- should be LJsr.d wllenevcr possible. .~'~:-;~::., 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 213

It must also realized that a short­ The influence of weather, predpitation', term study may not provide adequate plant phenology and succession, as well information on the forage preferences as social behaviour, on forage use should of moose for any given area. Pref­ be further investigated. A knowledge erences have been found to vary be­ of forage requirements and preferences tween years in southwestern Montana is prerequisite to investigations of nu­ and on Isle Royale. And on areas as tritive values and d igestibility of forage close together as Yellowstone Lake, sources. the Ruby River of southwestern Mon­ tana, and Jackson Hole, Wyoming, summer food preferences appear to Acknowledgements be quite'different. I am indebted to J. L. Howard of the Manitoba Assessment of winter forage sources Department of Mines and Resources for providing unpublished information. alone may not provide enough in­ formation to determine whether fo­ rage supplies are a limiting factor or References not; spring, summer and fall diets may have an important influence on pro­ ALDOUS, S. E., 1944. A deer browse survey duction and survival, as indicated for method. J. ., 25 (2): 130-136. .deer (Klein, 1970). Most certainly a ALDOUS, S. E.. 1952. Deer browse clipping knowledge of year-long forage require­ study in the Lake States region. J. Wildl. Mgmt, ments will be important in effecting 16 (4): 401-409. proper management invo,lving habitat ALDOUS, S. E. and L. W. KREFTING, 1946. The manipulation. Peek' (1971) recommen­ present status of moose on Isle Royale. Trans. ded logging practices that would favour N. Am. Wildl. Cont., 11 :296-30~. creation of areas which could provide Van BALLENBERGHE, V. and J. M. PEEK, 1971. spring and fall habitats for moose as Radiotelemetry studies of moose in northeas­ an important management procedure in tern Minnesota.J. Wildl. Mgmt. 35(1):63-71. northeastern Minnesota. BARRETT, M. W., 1972. A review of the diet, con­ dition, diseases and parasites of the Cypress Food habits data are probably best Hills moose. 8th N. Am. Moose Works., interpreted when supporting infor­ Thunder Bay, Ontario. Onto Minis!. Nat Resour., p.60-79. mation on habitat condition and trend, and population performance are also BERGERUD, A. T. and F. MANUEL, 1968. Moose available.. Until .a measure of actual dam'age to balsam fir-white birch forests in central Newfoundland. J. Wildl. Mgmt. 32 (4): forage preferences of a population in 729-746. a given area can be obtained through experimental procedures, habitat and BERGERUD. A.T. and L. RUSSELL. 1964. Evaluation of rumen food analyses for New­ POpulation performance are meaning­ foundland Caribou. J. Wildl. Mgmt, 28 (4): 809­ ful ways of determining the adequacy 814. of a diet based on field observation. CHADWICK, H. W., 1960. Plant succession and big game winter movements and feeding habits It is concluded that these studies' do in the sand dune area in Fremont County, not depict food habits well enough to ILaho, M. Sc. Thesis, Univ. of Idaho, Moscow, adequately compare annual, seasonal 121 p. ~nd habitat-type forage use patterns COLE, G. F., 1956. The pronghorn antelope: its In all but a few instances. Trends in range use and food habits in central Montana food habits according to successional with special reference to alfalfa. Bull. Mont. S~q\Jence are inadequately reported. agric. Exp. Stn, No. 516.63 p. ..

214 LE NATURALISTE CANADIEN. VOL. 101. 1974 .- .• '1. _

COWAN, I, MeT., W. S. HOAR and J. HATIER, KREFTING, L. W., 1951. What is the future of thE 1950. The effect of forest succession upon the Isle Royale moose herd? Trans. N. Am. Wildl quantity and upon the nutritive values of woody Conf., 16: 461·470. plants used as food by moose. Can. J. Res. (D), LEDIN, D. and P. KARNS, 1963. On Minnesota': 28: 249-271. moose. Conserv. Volunt.. 26: 40-48. DAVIS. R. J., 1952. Flora of Idaho.·W. C. Brown LE RESCHE. R. E. and J. L. DAVIS, 1972. Impor Co.• Dubuque, Iowa, 828 p. tance of non-browse foods to moose. Alaski DesMEULES, P.. 1962. Intensive study of an Dept. of Fish and Game. Unpubl. manuscript. early spring habitat of moose in Laurentides LE RESCHE, R. E. and J. L. DAVIS, 1973. 1m· Park. Quebec. N. E. Wildl. Conf.. Monticello. portance of non-browse foods to moose on the New York. 12 p. (mimeogr.). Kenai Peninsula, Alaska. J. Wildl. Mgmt, DesMEULES, P.: 1965..Hyemal food and shelter 37(3):279-287. of moose (Alces americana CI.) in Laurentide MANWEILER, J.• 1941. The future of Minnesotc Park. Quebec. M. Sc. Thesis. Univ. of Guelph, moose. Conserv. Volunt.. 3: 38·45. 138 p .• unpubl. MARTIN, A. C.• R. H. GENSCH and C. P. BROWN. DeVOS, A.• 1956. Summer studies of moose in 1946. Alternative methods on upland game bird Ontario. Trans. N. Am. Wildl. Conf.• 21: 510-525. food analysis. J. Wildl. Mgmt, 10: 8-12. DODDS. D. G., 1960. Food competition and range McMILLAN, J. F., 1953. Some feeding habits of relationships of moose and snowshoe hare in moose in Yellowstone National Park. Ecology, Newfoundland. J. Wildl Mgmt, 24 (1): 52-60. 34 (1): 102-110. DORN, R. D.• 1970. Moose and cattle food habits MILKE, G. C., 1969. Some moose-willow relation­ in southwest Montana. J. Wildl. Mgmt, 34 (3): ships in the interior of Alaska. M. Sc. Thesis, 559-564. Univ. of Alaska, 79 p., unpubl. DYER, H. J.• 1948. Preliminary plan for wildlife MURIE, A.• 1934. The moose of Isle Royale. Misc. management on Baxter State Park. M. Sc. PubIs Mus. Zool. Univ. Mich" No. 25, 44 p. Thesis. Univ. of Maine, 79 p., unpubl. MURIE, A., 1944. The of Mount McKinley, FERNALD. M. L., 1950. Gray's Manual of Botany, U. S. Natn. Park Serv., Fauna Ser. No.5, 238 p. 8th ed. American Book Co.. New York. 1632 p. PEEK, J. M., 1961. Reproduction of moose in FLOOK, D. R.• 1959. Moose using water as refuge southwestern Montana. M. Sc. Thesis, Montana from flies. J. Mammal., 40 (3): 455. State Univ., Bozeman, 30 p.

HARRY, G. B., 1957. Winter food habits of moose PEEK. J. M.• 1963. Appraisal of a moose range in in Jackson Hole Wyoming. J. Wild/. Mgmt, 21: southwestern Montana. J. Range Mgmt, 16 (5): 53-57. 227·231. HOSLEY, N. W., 1949. The moose and its .... PEEK, J. M., 1971. Moose habitat selection and ·• ecology. Wildl. Res. Mgmt Leaf., No. 312, 51 p. relationships to forest management in north­ eastern Minnesota. Ph D. Thesis, Univ. of Min­ HOUSTON, D. B., 1968. The Shiras moose in t nesota, 250 p. P Jackson Hole, Wyoming. Tech. Bull. Grand •r.:~ Te~on Nat. Hi~s_s~,~_o.A N__ 1, 110 p .. _ E'EIE£lSON,-R.-b.-,-1-9Sa. -S{udies-of-the-food~ ------:·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- moo~e. }"· cular plants. Stanford Univ. Press, 1008 p. PETERSON, R. L., 1955. North American Univ. of Toronto Press, 280 p. KLEIN, D. R., 1970. Food selection by North f:. American deer and deer response to over­ PIMLOTT. D. H., 1953. Newfoundland moose. Tr;;!ns. i~: utili'zation of preferred plant species. 10th N. Am. W/ldl. Conf., 18: 563-581. Symp. Brit. Ecol. Soc., p. 25-46. j PIMLOTI, D. H., 1961. The ecology and mannge' i' . ment of moose in North America. Terre ot Vie. KNOWLTON, F. F., 1960. Food habits, move- ~'.~~ 246-265. ·t.. ments and populations of moose in the Gravelly Mountains, Montana. J. Wildl. Mgmt, PIMLOTT, D. H., 1963. Influt:nce of deer and· ~I 24 (2): 162·170. moo:;e on boreal forest vegetation in two are35

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PEEK: MOOSE FOOD HABITS 215 • of eastern Canada. Transactions of the Vlth STEVENS, D. R.. 1967. Ecology of moose in Congress. Intcrnationnl Union' of Game Biolog­ southwestern Montana. Mont Fish and Game ists. Bournemouth. Tho Nature Conserve-II1CY, Dept. Rep. Job. CampI. W98R, 28 p. London. p. 105-116. STEVENS, D. R.. 1970. Winter ecology of moose POELKER. R. J.. 1972. The Shiras moose in in the Gallatin Mountains. Montana. J. Wildl. Washington. Washington Game Dept.. 46 p. Mgmt. 34 (1): 37-46.

n1rCEY, R. W.• 1965. Ecology ·of moose winter STODDART, L. A. and A. D. SMITH, 1955. Range range in Wells Gray Park, British Columbia. 8. management. McGraw Hill, New York, 433 p. C. Fish and Game Branch report, 15 p. STOECKLER, J. H. and J. W. MACON. 1956. RlrCEY, R. W. and N. A. M. VERBEEK, 1969. Regeneration of aspen cutover in northern Wis­ Observations o~ moose feeding 9n aquatics in consin. J. For., 54: 13-16. Bowron ·Lake Park, British Columbia. Can. Fld Nat., 83 (4): 339-343. STONE, J. L.. 1971. Winter movements and dis­ tribution of moose in upper Rock Creek drain­ ROWE, J. 5., 1959. Forest regions of Canada. age, Granite County. Montana. M. Sc. Thesis. Bull, Can. Dep. Northern Affairs and National Univ. Montana, Missoula. 80 p. Ressources Forestry Branch, No. 123, 71 p.

SMITH, N. 5., 1962. The fall and winter ecology TELFER. E. 5 .• 1967. Comparison of moose and of Shirai; moose in Rock Creek drainage, deer winter range in Nova Scotia. J. Wildl. Granite County, Montana, M. Sc. Thesis, Univ. Mgmt, 31 (3): 418-425. of Montana, Missoula, 52 p. WILSON. D. E.• 1971. Carrying capacity of the SPENCER, D. L. and E. F. CHATELAIN, 1953. key browse species for moose on the north Progress in the management of the moose of slopes of the Unita Mountains. Utah. Res. PubIs .. southcentral Alaska. Trans. N. Am. Wildl. Cont., Utah- State Div. Wild/., No. 71-9. 18: 539-552. YOUNG. V. and G. F. PAYNE. 1948. Utilization of SPENCER, D. L. and J. B. HAKALA. 1964. Moose key browse species in relation to proper graz­ and fire on the Kenai. Proc. 3rd Ann. Tall Tim­ ing practices in cut over western white pine bers Fire Ecology Cont., 11-33. lands in northern Idaho. J. For.• 46 (1): 35-40.

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