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Updated: Jul 11, 2026
11:56
Training Rats to Voluntarily Dive Underwater: Investigations of the Mammalian Diving Response
Published on: November 12, 2014
Circadian rhythms in diving behavior and ventilatory response to asphyxia in canvasback ducks
1Department of Zoology, University of Toronto, Ontario, Canada.
The American Journal of Physiology
|April 8, 1998
Summary
Canvasback ducks exhibit a daily rhythm in underwater feeding, with longer dives at night. This behavior is linked to reduced respiratory sensitivity during nighttime, suggesting circadian control of diving and breathing.
Area of Science:
- Animal Behavior
- Physiology
- Chronobiology
Background:
- Diving ducks exhibit complex behaviors influenced by environmental cues.
- Circadian rhythms regulate physiological and behavioral processes in many species.
Purpose of the Study:
- To investigate the daily rhythms in underwater feeding behavior of canvasback ducks (Aythya valisineria).
- To examine the relationship between diving behavior and respiratory responses to asphyxia in relation to circadian timing.
Main Methods:
- Observation of underwater feeding behavior and dive durations in captive canvasback ducks under a controlled light-dark cycle.
- Measurement of respiratory responses to progressive asphyxia using a closed-circuit barometric plethysmograph.
Main Results:
- Canvasback ducks showed a distinct daily rhythm in feeding activity, with 76% of dives occurring nocturnally.
- Nighttime dives were significantly longer than daytime dives.
- Respiratory chemosensitivity, indicated by the exponential rate constant for ventilation, was significantly lower at night compared to daytime.
Conclusions:
- Diving behavior in canvasback ducks is synchronized with a circadian timing system.
- Reduced respiratory chemosensitivity during the night may facilitate intermittent apneic exercise during nocturnal dives.
- Behavioral and respiratory control systems appear to be coordinated by the circadian system in diving ducks.
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