Likely effects of standing and lying on the radiating heat load experienced by a resting kangaroo on a summer day

Abstract

A study was carried out to examine the effect of posture (standing or lying) on the radiation heat load which would be experienced by a kangaroo resting under a small desert tree during a summer day. Measurements were made to assess the temperature and radiation characteristics in three situations judged to be equivalent to the following: (1) a kangaroo standing in the sun in open country; (2) an animal standing in the shade of a small tree; (3) an animal lying in the same shade. The overall pattern of results was shown by the effective radiation temperature measurements made at midday: 78.3, 57.6, and 52.5C for positions (I), (2), and (3) respectively. The relative contributions of solar and long-wave infrared radiation to the pattern of results are discussed.