Key points are not available for this paper at this time.
R. Langvatn, S.D. Albon, T. Burkey, T.H. Clutton-Brock, Climate, Plant Phenology and Variation in Age of First Reproduction in a Temperate Herbivore, Journal of Animal Ecology, Vol. 65, No. 5 (Sep., 1996), pp. 653-670
Langvatn et al. (Sun,) studied this question.