Re: erect posture and its implications

[SL Nyveen <lawrence@dsuper.net>]

At 14:43 -0400 19/6/98, Jack wrote:
>On Thu, 18 Jun 1998, Larry Dunn wrote:
>
>> Agreed, but are they then migrating to exploit various stationary food
>> sources?
>
>oops, sorry, guess I should've read the original post; didn't realize you
>were discussing stationary food sources.  I have no idea about any
>carnivore which migrates to take advantage of a stationary food source.

While not strictly stationary, the following food sources are locally
constrained:

- Whale sharks cruise to the coral reefs off Western Australia during coral
spawning season to feed on the coral gametes.

- Californian elephant seals mate and raise their young on the Pacific
coast, but swim to Hawaiian or Alaskan waters to feed when not mating,
birthing, nursing, or building harems.  (I think females go to Hawaii and
males to Alaska.  No gratuitous comments, please.)

- How far will grizzly bears travel to find a salmon run?

- I believe Atlantic humpback whales birth and mate and fast in the
Caribbean and eat in the plankton-rich North Atlantic.

These marine examples don't hold much relevance to dinosaurs or even any
other terrestrial animal, but the seals and whales do raise at least one
question in my mind: are they migrating to the food from the mating
/birthing grounds or from the food to the mating/birthing grounds?

I'd have to think that the choice of mating ground came first, possibly
when such were adjacent to food.  As the food gradually moved away with
climate or other envronmental change, the animals had to follow it.  This
almost has to be the case when considering the sexually divided feeding
strategy of the elephant seals - the two sexes were not likely divided at
first, and met randomly on the California coast to make babies.

OK, I think this is off-topic enough.


Laurie Nyveen                                  lawrence@dsuper.net
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