The results of analyses of rumen contents from 101 Peary caribou (Rangifer tarandus pearyi J. A. Allen 1902) collected on Banks Island are presented. Peary caribou on Banks Island were found to be versatile, broad spectrum grazers specializing on upland monocots, to ingest few lichens, and to exhibit significant seasonal and/or regional differences in diet

Penner, David F.

Shank, Christopher C.

Wilkinson, Paul F.

English

University of Calgary Journal Hosting

Diet Of Peary  Caribou, Banks Island, N.W.T. CHRISTOPHER C. SHANK',  PAUL F. WILKINSON2  and DAVID F PENNER3 ABSTRACT. The results of analyses of rumen contents from 101 Peary caribou (Rangifer tarandus pearyi J. A. Allen 1902) collected on Banks Island are presented. Peary caribou on Banks Island were found to be versatile, broad spectrum grazers specializing on upland monocots, to ingest few lichens, and to exhibit significant seasonal and/or regional differences in diet. RkSUMfi. On présente les résultats des analyses du contenu des pans de 101 Peary caribous (Rangifer tarandus pearyi), rassemblés sur I'Ile de Banks. On a  trouvé  que ce végétaux, en particulier les monocottes de montagne, ils mangent peu de lichens et caribou avait un régime alimentaire diversifié; il broute une gamme assez large de les régions. montrent des differences significatives dans leur régime alimentaire saisonier et suivant Traduit par Alain de Vendegies, Aquitaine Co. of Canada Ltd. INTRODUCTION Jonkel (1971) noted  correctly  that  Peary  caribou (Rangifer tarandus pearyi) of the Canadian  Arctic  Archipelago  have  been  neglected  by  game  managers and scientists; in particular, little information on their food habits is available. Analyses of rumen  samples  from 101 individuals  hot  on  Banks  Island between  autumn 1972 and  summer 1973 during an investigation of competition between  musk  oxen (Obivos moschatus Zimmermann) and  Peary  caribou (Wilkinson er al .  1976) are  reported  here. MATERIALS AND METHODS Rumen contents  were  analyzed  from  four  groups of caribou:  Sample I ,  29 individuals collected  near  the  confluence of the  Muskox  and  Thomsen  rivers between 18 and 20 March 1973; Sample II, 42 caribou  shot  in mid-August 1973 near  the  Thomsen  River  approximately 60 km south of its  junction with the Muskox  River;  Sample III, 7 individuals taken  near  Jesse Bay on 26 October 1972; and  Sample IV, 22 caribou  collected  on  the  Lennie  River  between  2 and 8 November 1972. Figure  1  shows  the  locations of the collection  sites. The  rumen contents  were collected  and  stored in the manner  suggested by Martin and Korschgen (1963). Prior to analysis, each sample was washed through a bank of screens, and the residue collected on a screen of 200 meshe46.45  cm2. A random  sample of 100 fragments per rumen  was  selected 'Faculty of Environmental Design, The University of Calgary, Calgary, Alberta T2N 1N4 *Suite 800, 1070 Bleury Street, Mohtreal, Quebec H2Z 1N3 'R.R. 3,  Sherwood Park, Alberta T8A 3H3 126 DIET OF PEARY CARIBOU for identification from  the material retained by the #4 (mesh size 4.76 mm2) sieve by means of a point frame  technique (Chamrad and Box 1964; Everitt and Drawe 1974). Each selected fragment was identified to genus and  species if possible; otherwise, fragments were assigned to forage classes (grasses, sedges, forbs) or listed as unidentifiable. Genera and species of monocots were identified only casually. Similarity indices (Gauch 1973) were used to compare  the  degree of similarity between samples: n 2 z m i n  (P. ., P. ) i=l 1.3 r,k "j,k = loo i=l f (Pi . + P. 1 ,I 1.k where PSj.k is the percent similarity of the two  diets  for forage groups which are shared, P j  and P . k  are the percentages of forage i in the samples j and k, and where n is  the number of forage classes  shared. DIET OF PEARY  CARIBOU 127 The  diversity of the  diet of each individual was inferred from the Shannon-Weaver  diversity index (Poole 1974): where H' is the diversity of plant groups in each rumen, and pi is the proportion of the ith forage  contained in the  rumen, and n  is  the  number of plant  classes  contained in the  rumen.  The  average  diversity of the  diet in each Samples I, 11, and IV was estimated  as follows: E =  2 n Hi t H' t ... E' N where is the mean diet diversity and N is the number of rumens in the sample. Differences in the  diversity of diet were tested by single-classification analysis of variance (Sokal and Rohlf 1969) at  the 5% level of probability. Differences between samples in mean  percentages of forage  groups  present were also  tested  at  the 5% level of probability by single-classification analysis of variance after the sample variances had been equalized by an arcsin transformation. Sample I11 was excluded from the  statistical  analysis  because of its small size (N=7) and large variances. RESULTS AND DISCUSSION Description of Diet Table 1 summarizes the analysis results  for  the  four  samples.  Monocots  are by far  the  most  important  component in each of the  four samples with grasses and sedges both comprising approximately equal proportions in  all but Sample 111. Table 2 lists  the  genera and species of grasses and sedges identified in the samples. This list  cannot be considered  as being comprehensive since identifications were not made  systematically. Following monocots in importance are willows (Salicaceae) and the forbs Astragalus alpinus L .  and Dryas  integrifolia M. Vahl Lichens and mosses make up  only a small fraction of the  total  diets.  The findings of Deardon et al .  (1975) indicate  that  the  observed lack of lichens  is unlikely to  have been due to rapid digestion.  They  also  state that mosses are nearly indigestible by caribou and therefore  are usually over-represented in rumen  contents. This would indicate  that mosses are  even less  important in the  diet of Peary caribou than is  indicated in Table 1.  The only other major study of Peary caribou diet  is  that of Parker (1978) who utilized a microscopic analysis of cuticular and epidermal fragments in faeces and rumen contents.  He found that  for caribou on  several high arctic islands,  the  summer diet consisted of 6489% Sulix arctica Pall . ,  5-10% forbs, 1-7% Dryus integrifolia, and from 5-18% monocots. By contrast, our summer data show more use of monocots and forbs and less use of Salix. Parker's winter diet data were taken from rumen samples preliminarily analyzed by 128 DIET OF PEARY CARIBOU TABLE 1. Contents of caribou rumens collected on Banks Island in 1972 and 1973. Sample I N=  29 Late March 1973 Lichens Thamnolia ver- micularis' Cladonia sp . Cetraria nivalis Pelrigera sp. Sub-total tr' tr Mosses 0.4 0.9 30.6 Sub-total 0.4 Grasses and Grass-like Gramineae 27.9  12.4  100.0 Cyperaceae 33.3 17.9  100.0 Juncus spp. Sub-total 61.2 Forbs Oxyria digyna Cerastium Stellaria sp.  tr Melandrium sp. Draba spp. Saxifraga spp. Potentilla spp. 0.1  0.4 6.8Dryas integrifolia 0.3 0.6 23.2 Astragalus al- pinus 11.9  11.0  93.2 Oxytropis sp . Epilobium [atifohm Cassiope  tet- ragona oxycoccus sp. Pedicularis spp. Petasites sp. Compositeae Sub-total 12.3 Woody Plants Salicaceae 25.0  13.5  93.2 Arctostaphylos SP. ( 3  Artemisia sp . Sample 11 N= 42 Mid- August 197: 8 a, 0 E 8 %  1.2 1.9 57.1 0.1 1.0 11.9 0.1 0.3 14.3 tr 2.4 1.4 0.4 0.5 54.8 0.4 1.1 7.1 100.0 4.2 11.7  100.0 tr 2.4 5.3 tr 2.4 0.1 0.5 7.1 tr 2.4 tr 2.4 0.1 0.3 14.3 0.4 0.8 23.8 3.0 2.3  90.5 0.8  7.3  1 0.0 tr  7.1 tr 2.4 tr 2.4 tr 2.4 tr 7.1 tr 2.4 tr 1 l.s - - 14.4 13.3 10.5 100.C 0.5 1.0 31.C 1.4  2.4 47.C ~ Sample 111 ,ate October 1972 N= 7 8 8 8 %  a, C i + $ E  0.0 0.7 0.8 57.2 0 .7 53.2  16.1 100.0 21.5 10.6 100.0 74.7 0.3  0.7  14.31.5 1.8  57.2 11.0  11.9  100.0 3.3 6.0 28.6 16.1 1.2 1.9  42.! 3.0 5.1 28.( Sample IV N= 22 ,ate November 197: ~~ R 8 8 %  a, C 3 %  E 0.9  1.4  4 .  0.9 2.2 1.7  92.0 2.2 19.7  7.8  00.0 25.1 6.4 100.0 44.8 0.4 0.6 32.2 0.5 1.2  18.4 16.9 4.6 100.0 18.5 11.7 95.4 1.3 3.5 13.8 0.4 1.9 4.6 38.0 7.7 6.2 95.4 0.8 2.5 9.2 DIET OF PEARY CARIBOU TABLE 1. Continued 129 Sub-total 25.0 Unidentified dicot 0.9 2.5  20 4Unidentified roots TOTAL Diversity Index 99.8 - (HI 1.13 3 -15.2 4.2  8.5 121  7.7 977:i 4.5  3.9 71.51 5.7  6.3  73.6 99.3 100.2 loo. 1 'tr indicates present in amounts less than 0.1%. 2all plant names follow Porsild (1964). 'not done  for Sample 111. TABLE 2. The grasses  and  sedges identified in the  caribou  rumens  collected  on Banks  Island  in 1972 and 1973. Sample I Sample 11 Sample 111 Sample IV Alopecurus alpinus n1 P' N N Deschampsia brevifolia P P N N Arctagrostis sp . N P N N Triseium spicaium P P N N Festuca rubra P N N N Festuca brachyphylla P P P N Agropyron laiiglume P P N N Kobresia myosuroides P N N N Carex stans P N N N Carex spp.) P P P P Luzula sp. P N N N lNot recorded. 'Recorded. 'Several small, usually upland species of Carex. Poa spp. P P N P Parker et aE. (1975) and  Thomas et al. (1976). His winter findings vary considerably  from island to island and  consist of  21-86% moss, 550% willow (wood and  leaves), 4-25% monocots,  and 2-17% forbs. By contrast,  our winter data shows neligible use of moss and, like the summer diet, less Salix and more  monocots  and  forbs  than  reported by Parker. Parker (1978)  concluded that during winter the  physical condition of Peary caribou is positively correlated with willow intake  and negatively correlated with  moss intake while monocots  and  forbs exhibited no  trend with physical condition. Our findings for Banks Island are somewhat enigmatic in this context as both willow and mosses were present in relatively low amounts together with a relatively large presence of monocots  and  forbs. Although it is of questionable validity to compare physical condition between populations by  marrow content  analysis  (Dauphine  197I),  the  data  reported by  Wilkinson et al. (1976) tentatively .suggest that Banks Island caribou collected during March 1973 were  intermediate in physical condition in comparison with 130 DIET OF PEARY CARIBOU samples from  other  arctic islands reported by Parker et  al. (1975) and  Thomas et al .  (1976). The relationship between winter diet and physical condition of Peary caribou may not, therefore, be as closely linked as was indicated by Parker (1978). Bergerud (1974), for  example, suggested that caribou could be the most versatile grazers among North American cervid species.  Peary caribou may then be quite capable of  maintaining physical condition by adapting their grazing patterns  to local conditions of forage availability. Published analyses of the diet of barren ground caribou ( R .  t .  tarandus) usually indicate a reliance on lichens for 30-60% of the  total  intake  (Scotter 1966; Deardon et  al. 1975). This differs greatly from the 0-1.4% lichen presence noted in this study. Parker’s (1978) analytical technique did not allow quantification of lichen in  the diet but the results of Parker et  al. (1975) and Thomas et al .  (1976) both confirm the usually negligible quantities of lichen ingested by Peary caribou. The only exceptions are  the lo+% lichen presence in the Prince of Wales Island sample and the 32% content in the Melville Island  sample reported by Thomas et  al. (1975). As Parker (1978) has noted, the low standing crop of lichens in most high arctic areas precludes their  use as a major food source. Seasonal  Diet  Differences The similarity index (PS) represents the percent similarity between two diets for  the forage groups that  are shared.  Table 3 shows that all  PS values are high but that  the  late March (Sample I)  and mid-August (Sample 11) diets were most similar (PS=79%) while the late March (Sample I) and early November (Sample IV) diets were least alike (PS=67%). The Shannon-Weaver diversity index (H’) indicates the variety and evenness of the forages present in the rumen. A high H’ value indicates that a large number of species is being eaten in  similar amounts and therefore implies that the animal is exploiting a broad food niche. Table 3 presents  the mean diversities (IT) for Samples I, 11, and IV. The diet of Peary caribou is least varied in late March (a= 1.13) and most varied in early November (a= 1.73) with summer occupying an intermediate position (IT= 1.63). Table 3 shows that only the differences between late March and mid-August and between late March and early November are statistically significant.  As the rumen samples were collected in different areas as well as at different seasons, we cannot  evaluate to what extent the  observed diversity in diet is attributable to season rather than to spatial differences in forage availability. Table 3 indicates several statistically significant between-sample differences in the use of forage classes, but, once again, it is uncertain whether they represent seasonal changes in preference or difference in the composition of the vegetation in the sample area. DIET OF PEARY CARIBOU 13 1 TABLE 3. Between-sample differences in mean percent presence of selected forage classes. Asterisks (*) indicate differences significant at the 5% level of probability. I vs I1 I vs IV I1 vs IV Late March- Late March- Mid- August Mid- August Early November Early November Monocots 61.2 - 55.3 61.2 - 44.8* 55.3 - 44.8' Salicaceae 25.0 - 13.3* 25.0- 7.7* 13.3 - 7.7* Salicaceae + unident- ified dicots 25.9 - 25.9  25.9 - 13.4* 25.9 - 13.4* Astragalus alpinus 11.9 - 10.8 11.9- 18.5 10.8 - 18.5* Dryas integrifolia 0.3 - 3.0* 0.3 - 16.9* 3.0 - 16.9* Similarity Index (PS) 79% 67% 74% Mean Diversity (i) 1.13 - 1.63* 1.13 - 1.73' 1.63 - 1.73 CONCLUSIONS Three major conclusions emerge from our  study: 1) Peary caribou on  Banks Island  do  not  eat large quantities of lichens  or mosses at any season, 2) there are  several significant seasonal  and/or regional differences in diet of caribou on Banks Island, and 3) Peary caribou on Banks Island are versatile, broad spectrum  grazers  that  concentrate  at ll seasons  on upland monocots. ACKNOWLEDGEMENTS This study was undertaken as a contract awarded to LGL Ltd, Environmental Research Associates (101100 - 124 Street, Edmonton, Alberta T5N 1P6) by the Game Management Division of the Government of the Northwest Temtories. We thank both organizations for financial and logistical support and for permission to publish our results. The Canadian Wildlife Service (Edmonton) kindly provided laboratory facilities. We acknowledge in particular the assistance of R. F. Schweinsburg (LGL Ltd.) and Mr. S. Miller (N.W.T. Game Management Division). E. Scheinberg (University of Calgary) gave statistical advice. REFERENCES BERGERUD,  A. T. 1974. Decline of caribou in North America following settlement. Journal of Wildlife CHAMRAD, A. D. and T. w. BOX. 1964. A point frame for sampling rumen contents. Journal of Wildlife DAUPHINE, T. c .  1971. Physical variables as an index to condition in barren-ground caribou. EVERITT, J .  H. and D. L. DRAWE. 1974. spring food habits of white-tailed deer in the South Texas Management, 38:757-770. Management, 28:473-477. Transactions of the North-east Section of the Wildlife Society, 28:91-108. plains. Journal of Range Management, 27:  15-20. ruminant food habits. Journal of Wildlife Management, 39:402-407. DEARDON.  B. L., R. E.  PEGAU. and R. M. HANSEN. 1975. Precision Of microhistological estimates Of GAUCH,  H. G., JR. 1973. The relationship between sample similarity and ecological distance. Ecology, 54~618-622. JONKEL, C. J. 1971. Mammal research activities in the Arctic, 1970-1971. Arctic Circular, 21:  16-19. 132 DIET OF PEARY CARIBOU MARTIN, A. c .  and L. J. KORSCHGEN. 1963. Food habits procedures. In: H. s. Mosby and 0. H. Hewitt. (eds.), Wildlife Investigational Techniques. 2nd ed. Washington, D.C.: The Wildlife Society, Pages 320-329, in. caribou populations in 1973-1974 on the Parry Islands, Arctic Canada. Ottawa: Canadian Wildlife Service (Progress Note No. 56). 10pp. PARKER, G .  R. 1978. The  diets of muskoxen and Peary caribou on some islands in the Canadian High Arctic. Ottawa: Canadian Wildlife Service (Occasional Paper No. 35). 21 pp. POOLE, R. W. 1974. An Introduction to Quantitative Ecology. New York: McGraw-Hill. PORSILD, A. E. 1964. Illustrated flora of the Canadian Arctic Archipelago. Ottawa: Natural History SCOTTER, G .  w. 1967. The winter diet of caribou in northern Canada. Canadian Field-Naturalist, SOKAL, R. R. and F. I. ROHLF. 1969. Biometry: The Principles and Practice of statistics in Biological PARKER, G .  R., D. C. THOMAS, E. BROUGHTON, and D. R. GRAY. 1975. Crashes Of muskox and Peary Museum of Canada (Bulletin No. 146).  218 pp. 81~33-39. Research. San Francisco: W. H. Freeman. 776 pp. populations on Canadian arctic islands, March-April 1975. Ottawa: Canadian Wildlife Service (Progress Note No. 64). 13 pp. Banks Island, N.W.T. Journal of Wildlife Management, 40:151-162. THOMAS, D.  C.,  R. H.  RUSSELL,  E. BROUGHTON, and P. L. MADORE. 1976. Investigations Of PeXy caribou WILKINSON, P. F . ,  C. C. SHANK, and D. E. PENNER. 1976. Muskox-caribou summer range rehtiOnS On 

Diet Of Peary Caribou, Banks Island, N.W.T.

https://journalhosting.ucalgary.ca/index.php/arctic/article/download/65699/49613

Diet Of Peary Caribou, Banks Island, N.W.T.

Abstract

Similar works

Full text

Available Versions

University of Calgary Journal Hosting