Behavioral aspects of sleep in bottlenose dolphin mothers and their calves.

TitleBehavioral aspects of sleep in bottlenose dolphin mothers and their calves.
Publication TypeJournal Article
Year of Publication2007
AuthorsLyamin O, Pryaslova J, Kosenko P, Siegel J
JournalPhysiol Behav
Date Published2007 Nov 23
KeywordsAnimals, Animals, Newborn, Behavior, Animal, Blinking, Bottle-Nosed Dolphin, Electroencephalography, Eye Movements, Female, Male, Motor Activity, Postpartum Period, Sleep, Swimming, Time Factors

Adult dolphins are capable of sleeping with one eye open and exhibiting slow wave activity in the electroencephalogram (EEG) of one hemisphere at a time. The aim of this study was to examine the postpartum sleep behavior of bottlenose dolphin calves and their mothers. The behavior of three dolphin mother-calf pairs was monitored from birth to 13 months postpartum. Dolphin mothers and their calves exhibited a complete disappearance of rest at the surface for a minimum of 2 months postpartum, swimming in echelon formation on average in 97-100% of the observation time. Calves surfaced to breathe more often than their mothers between the postpartum age of 2 and 8 weeks. During the first postpartum month two dolphin mothers surfaced with both eyes open on average in 93 and 98% of the time while in their calves both eyes were open in 90 and 60% of the cases. In calves, the eye directed toward the mother was open more often (on average in 95% of all observations in calf 1 and 99% in calf 2) than the eye directed to the opposite side (82% in calf 1 and 60% in calf 2). Our data indicate that dolphin mothers and calves are highly active and vigilant during the initial period of the calf's life, continuously monitoring their position relative to each other by sight during wakefulness and sleep. We hypothesize that episodes of EEG slow wave activity at this time are likely to be brief, fragmenting EEG defined sleep into short episodes.

Alternate JournalPhysiol. Behav.
PubMed ID17599365
Grant ListNS42947 / NS / NINDS NIH HHS / United States
R01 MH064109 / MH / NIMH NIH HHS / United States
R01 NS042947 / NS / NINDS NIH HHS / United States
R01 NS069640 / NS / NINDS NIH HHS / United States