3.4. Temperature regulation

A thermocouple (32 gauge) was inserted through the cloaca into the rectum of the grey partridge chicks, whereafter the chicks were transferred into a chamber of 0 °C. The cooling speed of the chicks was measured at the age of 1, 7, 11, 15, 18 and 21 days. The body temperature was monitored for 20 minutes or until it dropped to +25 °C in 1-day-old chicks, to + 30 °C in 7- and 11-day-old chicks, to 33 °C in 15-day-old chicks, and to + 35 °C in 18-day-old chicks. At the age of 21 days the body temperature was expected to remain above + 35 °C for 20 minutes in every chick. Also wild chicks were exposed to cold at the age of 7 days.