question - whales - sleep

From: Greg Early (
Date: Wed Oct 22 2003 - 10:05:16 EDT

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    As you can see there is some disagreement. Some species appear to spend more time inactive at the surface than others (pilot whales and sperm whales come to mind as ones that seem to spend a lot of time at the surface). Fact is, most of this is based on fairly short term observations. We are getting better at figuring out animals basic daily activity by using remote sensing, and longer periods of observation, but we are still a way off from having the whole picture.


    -----Original Message-----
    From: Mary Vogas <>
    Sent: Oct 20, 2003 10:53 AM
    To: Greg Early <>
    Subject: Re: question - whales - sleep

    Thanks for the suggestion. I did look back at the archives.

    I looked at by
    Pieter Folkens in which he states that "They also don't need as much
    sleep. An hour or so twice a day is probably enough compare to the 7 to
    10 hours needed by humans."

    On by Aldemaro
    Romero, Ph.D., he states that They tend to sleep 20-30% of the time per
    day (a little less than a human would).

    Dr. Romero's comment seems to state that whales need a lot more sleep
    than Folkens. Is Folkens, you think, referring to just dolphins in his


    Mary Vogas

    Pieter Folkens

    On Friday, October 17, 2003, at 09:22 AM, Greg Early wrote:

    > BTW,
    > I noticed that there is a goog answer to your question on WhaleNet's
    > archive. You might check there for more information.
    > ge
    > -----Original Message-----
    > From: Mary Vogas <>
    > Sent: Oct 17, 2003 7:50 AM
    > To: Greg Early <>
    > Subject: Re: question - whales - sleep
    > Greg,
    > Thanks for your quick reply! I certainly do appreciate it! I do talk
    > about how the bottlenose dolphins sleeps and then recently I read that
    > it occurred also in gray whales, so I was wondering if I could make a
    > blanket statement about all whales concerning it. But, now I know I
    > can not do that.
    > Thanks,
    > Mary
    > On Wednesday, October 15, 2003, at 01:07 PM, Greg Early wrote:
    >> Mary,
    >> This is sort of a trick question ... The problem is that only
    >> bottlenose dolphins have been studied in this way. So what we think
    >> we know is really only based on that. The rest is guess. Most
    >> scientists seem to agree that whales and dolphins must do something
    >> like sleep at some time, and also feel that (based on studies again
    >> only condicted on bottlenose dolphins) that cetaceans breathe only
    >> when conscious ... so go to sleep completely and breathing stops.
    >> Observations of whales and dolphins seem to show that they have short
    >> times of inactivity. The guess has always been that whales and
    >> dolphins spend short times "cat napping", and/or resting one half of
    >> their brain at a time. So basically this is a long way to say "we
    >> just do not know for sure".
    >> ge
    >> -----Original Message-----
    >> From: Mary Vogas <>
    >> Sent: Oct 15, 2003 11:25 AM
    >> To:,
    >> Subject: question - whales - sleep
    >> Hello,
    >> I give programs on endangered animals to students in the Houston area.
    >> I have read that both bottlenose dolphins and gray whales rests one
    >> half of its brain, then the other, while swimming all the while. Do
    >> all whales that have been studied sleep "sleep" in this same way?
    >> Thanks,
    >> Mary Vogas

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