Natural Science Forum / Biology / Biology / May 2004

What do you mean? The recent perfectly timed release of trillions of 17 year
cicadas would argue for a time sense of some sort.Fiddler crabs that keep their
activities in sinc with the tides even thouhgt they are in a lab 1000's of
miles away from the ocean would be a good example as well.

Moon

I breed dwarf crayfish for planted aquariums and grow trees in aquariums.
My groups
Mormyrids-subscribe@yahoogroups.com
mudpuppies-subscribe@yahoogroups.com
smallcatfishgroup-subscribe@yahoogroups.com
sturgeon-subscribe@yahoogroups.com

What do you mean by "time sense"?  Do you mean: "Wait here exactly
12.5 seconds, then go over there?  Or do you mean being able to
schedule activities to occur sometime in the future, based on some
sort of internal clock (even though that clock has the ability to
become synchronized to external periodic events?

The extremely widespread occurrence of the circadian clock mechanism
of organisms is evidence of a time sense.   Many different organism,
not just animals, change their activity patterns, biochemical
properties, reactiveness to environmental cues, etc. depending on the
time of day and have internal mechanisms to determine just what time
it is.  These mechanisms are synchronized so that the internal clock
does not drift with respect to the external clock set by the day/night
cycle.   Still, even without external cues, the internal clock
continues to run.  Just google on circadian clock mechanism or even
google on "per tim" for some of the genetic mechanisms.

Organisms can also synchronize activity to "tidal rhythms" (another
good google search term) which differs from the diurnal cycle.
Seasonal cycles are also important. Many intertidal organisms show
tidal rhythms even when removed from the seacoast.  Search for
"fiddler crab tidal rhythm".  Plants can judge day length by comparing
the duration of darkness with the duration of light and so determine
the season for flowering.  Search "long day short day plants" or
"phytochrome".  But, then I guess you specified animals.

Time sense?  Like an awareness of things that will happen in the future?

Well, I can't seem to find it, but I'm sure I read about some research in
Science News with birds.  Some kind of jays, I'm sure.  They were given
nuts and waxworms, which they hid in supplied sand.  It took them a while
to learn that the waxworms go bad before the nuts, and then they dug up
the waxworms, first.  Also mentioned was an experiment involving
researchers digging up fresh crickets that the birds had hidden, and
replacing them with spoiled crickets.

Some time earlier was an issue about blue jays that grew paranoid about
other jays watching them hide their food, but only if those jays had
previously stolen food.  If so, the paranoid jays would dig the food up
later when they were unobserved, and rebury it.

From my own experience, last summer I'd put out food at a construction
site for a family of foxes.  After a while the kids would come running out
almost immediately, and put on a show for me.  The mama fox was paranoid,
I had to wait a long time to watch her, and hide, because she didn't even
want me to see her from a distance.  But I've caught her zig-zagging
around in the food area when I'd arrived.  Apparantly they'd all figured
out that food appeared there around that time of day.  

One time the construction site was reconfigured a little, so I had to find
a new place to hide.  I heard footsteps in the woods, and assumed it was a
deer, because it's always a deer.  But when other people came on I decided
it was time to go, and stood up, and there she was laying down at the edge
of the woods, at the nearest point to where I'd been parking my bicycle.  
At that point I hadn't seen her in a long time, and I'm sure she was
waiting in the woods until she heard me ride off.

That little vixen even seemed to have figured out my camera.  I had set it
on automatic, with food in front, and watched from a distance as she made
a wide circle around the front, and ran back and forth behind it.  She
didn't go for the food, and I didn't get my pictures.

I know more about foxes than birds.  One hunting tactic, when a mouse
escapes into its burrow, is for the fox to walk a short distance downwind
and take a nap.  Eventually the mouse comes back out, and the fox pounces.

I don't know how strong any of that is.