Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!uakari.primate.wisc.edu!unmvax!nmt.edu!wgpsy471
From: wgpsy471@nmt.edu (Bill Grother)
Newsgroups: sci.bio
Subject: Re: DST Harmful?
Message-ID: <1991Apr8.235622.8809@nmt.edu>
Date: 8 Apr 91 23:56:22 GMT
References: <1991Apr7.180823.1462@cs.rochester.edu>
Followup-To: sci.bio
Organization: New Mexico Institute of Mining and Technology
Lines: 29

In article <1991Apr7.180823.1462@cs.rochester.edu> brown@cs.rochester.edu writes:
>Jetlag and shift work -induced disorientation are noticeable factors in human
>performance. I'm wondering if any work has been done on the effects of the
>twice-yearly switch between standard and daylight-savings times on wildlife.
>Do the lost and gained hours disturb their alertness or reproductive cycle?
>The spring switch could be especially bad for birds. Since animals are often
>more sensitive than we know to even subtle environmental changes, I'm 
>wondering if our messing with their circadian rhythms in this way
>has had any documented effects.
>
	I'm not sure that the DST switch is going to affect wildlife...animals
in the wild don't keep track of time [unless the deer are wearing digital
watches nowadays] except through the natural day-night cycle and that develops
over the lifetime of the animal and is very resistant to small changes. As for
lab animals, I imagine that if they are used to having something happen at a
particular time each day (feeding, weighing, injections, etc.), a conscientious
experimenter will alter the schedule to keep the event at the same time 
relative to the animals [good experimental technique].

	The bottom line is that very few animals are going to become directly
affected by us humans changing the clock back and forth by an hour [except
for animals such as cows, chickens, pigs, etc., which are found in farms where
chores are scheduled to begin at the same time each day]. As a matter of fact,
it was the farm lobby which had a big hand in getting daylight savings time
so that during the summer, there would be more daylight in the afternoon to
allow crops to be harvested, as most normal farm chores are performed in the
morning.

	Bill Grother