Key points are not available for this paper at this time.
R. M. A. Gill, M. L. Thomas, D. Stocker, The Use of Portable Thermal Imaging for Estimating Deer Population Density in Forest Habitats, Journal of Applied Ecology, Vol. 34, No. 5 (Oct., 1997), pp. 1273-1286
Gill et al. (Wed,) studied this question.