Conclusions tine studies. Nordic Council for Wildlife Research, Foetus growth rate in wild reindeer up to around age Stockholm. 1977. 27 pp. 130 days and weight 550-750 g appears not to be Lenvik, D. & Aune, I. 1988. Selection strategy in domes- influenced by the mothers body weights. Later in tic reindeer. 4. Early mortality in reindeer calves related pregnancy females in very poor condition (mean car- to maternal body weight. – Norsk Landbruksforskning 2: cass weights around 25 kg) support a foetus growth 71-76. rate which is significantly lower than among females Nissen, Ø. 1994. NM - Statpack. Norges landbruk- with mean carcass weights of 29 kg or above. Foetus shøgskole. weight variations within areas and years indicate Reimers, E. & Nordby, Ø. 1968. Relationship between that conception in two year or older females mostly age and tooth cementum layers in Norwegian reindeer. occur within two eustrous cycles. Yearling females – J. Wildl. Manage. 32: 957-961. conceive within a week later than older females Reimers, E. 1972. Growth in domestic and wild reindeer while calves apparently conceive 3-4 weeks later. in Norway. – J. Wildl. Manage. 36: 612-619. Reimers, E. 1983a. Growth rate and body size differences in Rangifer, a study of causes and effects. – Rangifer 3 (1): Acknowledgments 3-15. I am indebted to two anonymous referees and J. E. Reimers, E. 1983b. Reproduction in wild reindeer in Comparative response of Rangifer tarandus and other northern ungulates Colman for critical review of earlier drafts of the manu- Norway. – Can. J. Zool. 61: 211-217. to climatic variability script. Financial support was provided by E. Reimers Reimers, E. 1997. Rangifer population ecology: A Reindeer Research Fund. Scandinavian perspective. – Rangifer 17: 105-118. Reimers, E., Klein, D.R. & Sørumgård, R. 1983. Calving Robert B. Weladji1*, David R. Klein2, Øystein Holand1 & Atle Mysterud3 time, growth rate, and body size of Norwegian reindeer References on different ranges. – Arctic and Alp. Res. 15: 107-118. 1Department of Animal Science, Agricultural University of Norway, P.O. Box 5025, N-1432 Ås, Norway. Eloranta, E. & Nieminen, M. 1986. Calving of the exper- Røed, K. H. 1986. Genetisk struktur i norske villrein. – 2Institute of Arctic Biology, University of Alaska Fairbanks, P.O. Box: 757000, Fairbanks, AK 99775, USA. imental reindeer herd of Kaamanen during 1970-85. – Hognareinen 2: 4-6. 3Department of Biology, Division of Zoology, University of Oslo, P.O. Box 1050 Blindern, N-0316 Oslo, Norway. Rangifer Spec. Issue No. 1: 115-121. Rognmo, A., Markussen, K. A., Jacobsen, E., Grav, H. *corresponding author ([email protected]). Espmark, Y. 1980. Effects of maternal pre-partum under- J. & Blix, A. S. 1983. Effects of improved nutrition in nutrition on early mother-calf relationships. – In: E. pregnant reindeer on milk quality, calf birth weight, Abstract: To understand the factors influencing life history traits and population dynamics, attention is increasingly Reimers, E. Gaare & S. Skjenneberg. (eds.). Proceedings growth and mortality. – Rangifer 3 (2): 10-18. being given to the importance of environmental stochasticity. In this paper, we review and discuss aspects of current from the 2nd International Reindeer/Caribou Symposium, Ropstad, E., Lenvik, D., Bø, E., Fjellheim, M. M. & knowledge concerning the effect of climatic variation (local and global) on population parameters of northern ungu- Røros, Norway, 1979. Direktoratet for vilt og ferskvanns- Romsås, K. 1991. Ovarian function and pregnancy lates, with special emphasis on reindeer/caribou (Rangifer tarandus). We also restrict ourselves to indirect effects of cli- fisk, Trondheim, pp. 485-496. rates in reindeer calves (Rangifer tarandus) in southern mate through both forage availability and quality, and insect activity. Various authors have used different weather vari- Holthe, V. 1975. Calving season in different populations of Norway. – Teriogenology 36: 295-305. ables; with sometime opposite trends in resulting life history traits of ungulates, and few studies show consistent wild reindeer in South Norway. – In: J. R. Luick, P. C. Ropstad, E., Forsberg, M., Sire, J. E., Kindahl, H., effects to the same climatic variables. There is thus little consensus about which weather variables play the most sig- Lent, D. R. Klein & R. G. White. (eds.). Proceedings from Nilsen, T., Pedersen, O. & Edqvist, L. E. 1995. nificant role influencing ungulate population parameters. This may be because the effects of weather on ungulate pop- the First International Reindeer/Caribou Symposium, Plasma concentrations of progesterone, oestradiol, LH ulation dynamics and life history traits are scale dependent and it is difficult to isolate climatic effects from density dependent factors. This confirms the complexity of the relationship between environment and ecosystem. We point Fairbanks, Alaska, 1972. Biological Papers of the and 15-ketodihydro-PGF-2alpha in Norwegian semi- out limits of comparability between systems and the difficulty of generalizing about the effect of climate change University of Alaska. Spec. Report No. 1, pp. 194-198. domestic reindeer (Rangifer tarandus tarandus) during the broadly across northern systems, across species and even within species. Furthermore, insect harassment appears to be Jacobsen, E., Hove, K., Bjarghov, R.S. & Skjenneberg, first reproductive season. - J. Repr. Fert. 105: 307-314. a key climate-related factor for the ecology of reindeer/caribou that has been overlooked in the literature of climatic S. 1981. Supplementary feeding of female reindeer on Skjenneberg, S. & Slagsvold, L. 1968. Reindriften og dens effects on large herbivores. In light of this, there is a need for further studies of long time series in assessing effects of lichen diet during the last part of pregnancy. – Acta naturgrunnlag. Universitetsforlaget, Oslo. 332 pp. climate variability on reindeer/caribou. Agriculturae Scand. 31: 81-86. Skogland, T. 1984. The effects of food and maternal con- Krog, J., Wika, M. & Savalov, P. 1980. The development ditions on fetal growth and size in wild reindeer. – Key words: body mass, caribou, climate change, fecundity, insect harassment, moose, NAO, North of the foetus of the Norwegian reindeer. – In: E. Rangifer 4 (2): 39-46. Atlantic Oscillation, red deer, reindeer, sex ratio, survival, weather. Reimers, E. Gaare & S. Skjenneberg. (eds.). Proceedings White, R. G. 1991. Nutrition in relation to season, lacta- from the 2nd International Reindeer/Caribou Symposium, tion and growth of north temperate deer. – In: R. D. Rangifer, 22 (1), 2002 Røros, Norway, 1979. Direktoratet for vilt og ferskvanns- Brown (ed.). The biology of deer. Springer-Verlag, New fisk, Trondheim, pp. 306-310. York, pp. 407-417. Langvatn, R. (ed.), Leth Sørensen, P., Nygren, K., White, R. G. & Luick, J. R. 1984. Plasticity and con- Reimers, E. & Stålfelt, F. 1977. Criteria of physical con- straints in the lactational strategy of reindeer and Introduction well as identification of the important factors influ- dition, growth and development in Cervidae, - suitable for rou caribou. – Symp. Zool. Soc. Lond. 51: 215-232. Determining the causes of spatio-temporal varia- encing the traits (Loison et al., 1999a). Most of the tion in life history traits among individuals is one life history traits are influenced by a great number Manuscript received 27 July, 1998 of the main goals of ecology (Begon et al., 1996). of intrinsic and extrinsic interactions that deter- accepted 22 November, 2000 This requires long-term studies, accurate estimates mine the developmental process of populations of population sizes and demographic parameters, as (Cappuccino & Price, 1995). In efforts to under- 28 Rangifer, 22 (1), 2002 Rangifer, 22 (1), 2002 29 stand the importance of factors influencing life his- Stenseth (1999). Furthermore, we discuss the indi- influences timing of emergence of forage plants such as reindeer more in contrast to browser, which tory traits and population dynamics of northern rect effect of climate through insect harassment on (Klein, 1985; Langvatn et al., 1996; Post & Klein, could be more flexible. ungulates, attention is increasingly being given to reindeer/caribou, an aspect that has been largely 1999). Most importantly, in years of deep snow the importance of environmental stochasticity overlooked by reviews in this field. Indeed, climate there is a prolonged period of access to newly emer- Global climatic change (Murdoch, 1994; Turchin, 1995; Putman et al., also acts indirectly on some ungulates, as in the gent forage due to a variable time of snow melt. and plant quality and quantity 1996; Sæther, 1997). Density-independent varia- case of reindeer and caribou, through interaction Finstad et al. (2000a) found that annual variations Models of climate change predict that global tem- tion in phenotypic traits can, if persistent, con- with insects that affect their population parameters in summer weather influenced forage availability perature and precipitation will increase within the tribute substantially to population fluctuations in (Anderson et al., 1994; Gunn & Skogland, 1997; and digestibility through, for example the varia- next century, the changes being more pronounced ungulates (Sæther, 1997). Some general patterns Mörschel & Klein, 1997; Mörschel, 1999; Colman, tion in the Growing Degree Days in May and June. in northern latitudes and during winter have emerged showing, for example, that recruit- 2000). A more thorough understanding of these Sand et al. (1996)