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RE: Big is beautiful - bioenergetics again (long)
On Mon, 17 Sep 2001 09:48:13 +0200 (METDST) Martin Baeker
Some very interesting ideas! I had a quick question
regarding running in small vs. larger species (clip
attached below). What happens if the small animal has
stride that is relatively huge? To take an example from
extant taxa: A modern hare (genus Lepus) can run at 59km/hr
(roughly). This is a faster absolute speed than many
larger species, and a much faster relative speed. The
somewhat unique bounding gate gives these animals a huge
stride length, which explains the speed increase (I
believe), but they still have a low mass, so I'm curious
about what happens to the required reaction times for such
an animal (which might also be say...a very long-legged
> So to run at the same equivalent speed the small animal needs more strides
> per second than the large one and, as the cost of moving one unit of mass
> through one stride is more or less constant, has to have a higher
> metabolic rate.
> However, something I did not find adressed anywhere is the following
> question: Why cannot the smaller animal run at the same speed in relation
> to its own body size. I.e., if the large animal can do 1000 body lengths
> per hour, why cannot the small animal function at the same relative speed?
> It will cover the same area as does the large animal, relative to its
> size, so there is no scaling problem here.
> So our slow-going mouse will have
> to react VERY quickly whenever the ground is uneven, even if it would like
> to be slow.