TY - JOUR
T1 - Paradoxical escape responses by narwhals (Monodon monoceros)
AU - Williams, Terrie M.
AU - Blackwell, Susanna B.
AU - Richter, Beau
AU - Sinding, Mikkel Holger Strander
AU - Heide-Jørgensen, Mads Peter
PY - 2017/12/8
Y1 - 2017/12/8
N2 - Until recent declines in Arctic sea ice levels, narwhals (Monodon monoceros) have lived in relative isolation from human perturbation and sustained predation pressures. The resulting naïvety has made this cryptic, deep-diving cetacean highly susceptible to disturbance, although quantifiable effects have been lacking. We deployed a submersible, animal-borne electrocardiograph-accelerometer-depth recorder to monitor physiological and behavioral responses of East Greenland narwhals after release from net entanglement and stranding. Escaping narwhals displayed a paradoxical cardiovascular down-regulation (extreme bradycardia with heart rate ≤4 beats per minute) superimposed on exercise up-regulation (stroke frequency >25 strokes per minute and energetic costs three to six times the resting rate of energy expenditure) that rapidly depleted onboard oxygen stores. We attribute this unusual reaction to opposing cardiovascular signals—from diving, exercise, and neurocognitive fear responses—that challenge physiological homeostasis.
AB - Until recent declines in Arctic sea ice levels, narwhals (Monodon monoceros) have lived in relative isolation from human perturbation and sustained predation pressures. The resulting naïvety has made this cryptic, deep-diving cetacean highly susceptible to disturbance, although quantifiable effects have been lacking. We deployed a submersible, animal-borne electrocardiograph-accelerometer-depth recorder to monitor physiological and behavioral responses of East Greenland narwhals after release from net entanglement and stranding. Escaping narwhals displayed a paradoxical cardiovascular down-regulation (extreme bradycardia with heart rate ≤4 beats per minute) superimposed on exercise up-regulation (stroke frequency >25 strokes per minute and energetic costs three to six times the resting rate of energy expenditure) that rapidly depleted onboard oxygen stores. We attribute this unusual reaction to opposing cardiovascular signals—from diving, exercise, and neurocognitive fear responses—that challenge physiological homeostasis.
UR - http://www.scopus.com/inward/record.url?scp=85037626845&partnerID=8YFLogxK
U2 - 10.1126/science.aao2740
DO - 10.1126/science.aao2740
M3 - Journal article
C2 - 29217577
AN - SCOPUS:85037626845
SN - 0036-8075
VL - 358
SP - 1328
EP - 1331
JO - Science
JF - Science
IS - 6368
ER -