Environmental temperature modulates onset of independent feeding: warmer is sooner.
Individual dams and their litters were observed from Days 14-22 in a seminatural environment consisting of a nestbox attached to a larger, open 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 was monitored 12 hr/day by time-lapse video recording. The pups' egressions 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 duration feeding. Pup growth was unaffected by the temperature regimes. Environmental temperature has emerged as a determinant for early nest egressions and weaning onset.
Gerrish
C J
CJ
Department of Psychology, Indiana University, Bloomington 47405, USA.
Alberts
J R
JR
D000818:Animals; D004777:Environment; D005247:Feeding Behavior; D005260:Female; D051381:Rats; D017207:Rats, Sprague-Dawley; D013696:Temperature