Heart Rate, Respiratory Frequency and Wing Beat Frequency of Free Flying Barnacle Geese Branta Leucopsis

Abstract

1. Two barnacle geese (Branta leucopsis) were successfully imprinted on a human and encouraged to fly behind an open-topped truck containing the foster parent. A two channel radio-transmitter was implanted into these geese so that heart rate and respiratory frequency could be recorded before, during and after flights of relatively long duration. The resting value for heart rate was 72 ± 4 (10) beats min−1 and for respiratory frequency, 8.5 ± 0.6 (10) breaths min−1. 2. Five flights of a mean duration of 14.4 ± 1.3 (5) min and at a mean air velocity of 18.7 ± 0.3 (54) m s−1 were performed. Both heart rate and respiratory frequency increased before the birds began to flap their wings for take off. Mean heart rate during flight was 512 ± 4 (54) beats min−1 (7.24 × resting). At take off, wing beat frequency was 356±7 (4) beats min−1 and respiratory frequency was 121 ± 10 (5) breaths min−1. Both of these variables then declined and reached average flight values of 287 ± 3 (37) beats min−1 and 99±2 (54) breaths min−1 (11.7 × resting) respectively. There was no relationship between any of the measured variables and flight velocity. There was however, a 3:1 correspondence between wing beat frequency and respiratory frequency and a tight phase locking between the two. The wings were fully elevated at 6.0 ± 1.1(20)%, 40.5 ± 1.1(20)% and 74.0±1.1(20)% the respiratory cycle. On two occasions the birds slope soared on the air rising over the top of the cab for a mean duration of 52 s and at a mean air velocity of 14.2 ± 0.5 (4) m s−1. Heart rate was 261 ± 18 (4) beats min−1 and respiratory frequency was 68 ± 5 (4) breaths min−1. 3. Upon landing, heart rate returned to its preflight value within 3 min. Respiratory frequency, however, increased as the birds began to pant and reached a maximum value of 255±11 (5) breaths min−1 4 min after landing.