How's this for a hypothesis? GSH only spawn once a year, North or South. But down South predators have a longer warm season in which to eat many more GSH than their Northern cousins can during a year.

As opposed to BG - They get hammered more days per year down South, but they get extra spawns in as well to make up for it.

We need more data points (read "ponds"), both ends of the country.

"Live like you'll die tomorrow, but manage your grass like you'll live forever."
-S. M. Stirling
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