ENVIRONMENTAL-TEMPERATURE MODULATES ONSET OF INDEPENDENT FEEDING - WARMER IS SOONER

Individual dams and their litters were observed from Days 14-22 in a s eminatural environment consisting of a nestbox attached to a larger, o pen field in which powdered chow was available. Ambient temperature in the field was either warm (30 degrees C), moderate (21 degrees C), or cold (10 degrees C); nest temperature was always moderate. Behavior w as monitored 12 hr/day by time-lapse video recording. The pups' egress ions into the field and onset of independent feeding were temperature- related: Weaning was earliest in the warmth and increasingly late with decreasing ambient temperature. Among subjects in the cold condition, there was a positive correlation between duration in the field and du ration feeding. Pup growth was unaffected by the temperature regimes. Environmental temperature has emerged as a determinant for early nest egressions and weaning onset. (C) 1996 John Wiley & Sons, Inc.