Heart rates in the captive, free-ranging beaver

Area of Science:

• Physiology
• Animal Behavior

Background:

• Understanding the physiological responses of semi-aquatic mammals like the beaver (Castor canadensis) to different environmental conditions and behaviors is crucial for ecological studies.
• Previous research has explored heart rate variability in various species, but specific data on beavers across a range of activities and temperatures remains limited.

Purpose of the Study:

• To investigate the heart rate patterns of beavers (Castor canadensis) under various conditions, including activity levels, diving, resting (in water and on land), and thermal challenges.
• To determine if environmental factors and behavioral states significantly influence cardiovascular function in beavers.

Main Methods:

• Heart rates of beavers (Castor canadensis) were monitored under free-ranging captive conditions.
• Data was collected during active behaviors, resting in water and on land, diving, sleeping, and when threatened.
• Physiological responses were recorded across different temperatures (approximately 0°C and 20°C).

Main Results:

• Beaver heart rates were significantly higher during active behaviors and resting in water (approx. 121 bpm) compared to resting on land (100 bpm).
• Bradycardia was observed during sleep (75 bpm), diving (61 bpm), and when threatened (57 bpm).
• Cold temperatures (approx. 0°C) resulted in higher heart rates during active, non-diving behaviors compared to warmer temperatures (approx. 20°C).

Conclusions:

• Beaver heart rate is highly adaptable, reflecting distinct physiological states associated with different behaviors and environmental conditions.
• The study highlights the significant impact of aquatic environments and thermal stress on beaver cardiovascular function.
• Findings provide valuable baseline data for understanding beaver physiology and their ecological adaptations.