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Related Experiment Video

Updated: Jun 23, 2026

Automated Measurements of Sleep and Locomotor Activity in Mexican Cavefish

Automated Measurements of Sleep and Locomotor Activity in Mexican Cavefish

Published on: March 21, 2019

Behavioral sleep in the walrus.

Julia P Pryaslova¹, Oleg I Lyamin, Jerome M Siegel

¹Utrish Dolphinarium Ltd., 33 Leninsky Prospect, Moscow 119071, Russia.

Behavioural Brain Research

|May 12, 2009

Summary

Walrus sleep patterns show a strong preference for land-based rest, with the majority of sleep occurring out of water. This study details their unique sleep behaviors and breathing patterns, distinguishing them from other pinnipeds.

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Area of Science:

Marine Mammal Behavior
Sleep Science
Comparative Physiology

Background:

Walruses (Odobenidae) are unique marine mammals with limited research on their sleep behavior.
Understanding walrus sleep is crucial for comparative studies of pinniped adaptations.

Purpose of the Study:

To investigate and characterize the behavioral sleep patterns of captive walruses.
To compare walrus sleep and breathing to other seal families (Otariidae and Phocidae).

Main Methods:

Continuous video recording of four young captive walruses for 7-17 days.
Behavioral scoring of sleep (quiet and REM sleep) in 1-minute epochs.
Analysis of sleep distribution between aquatic and terrestrial environments.

Main Results:

Walruses spent significantly more time sleeping on land (40-74%) than in water (11-22%).
Sleep occurred in bouts, alternating long swimming periods with land-based rest.
Breathing patterns differed significantly between land and water, with longer apneas in water, especially during REM sleep.

Conclusions:

Walrus sleep architecture and breathing are adapted to their semi-aquatic lifestyle.
On land, walrus sleep resembles Otariidae seals; in water, it resembles Phocidae seals.
Environmental context (land vs. water) profoundly influences walrus sleep and respiratory patterns.