re: "pollinator species are clearly going extinct at an apparently accelerated rate."
Evidence, please?
I ask because while there is great hyperbole about a "sixth mass extinction", I have seen no actual data supporting that claim (and a very convincing article by Smithsonian paleontologist Doug Erwin that the current evidence is nothing like the five mass extinctions in the geological record). I've also seen a very compelling analysis of (mostly mammalian and avian) extinctions that correlates the documented extinction rates quite precisely to the Age of Exploration. In other words, we killed a bunch of island species when sailing ships introduced pigs and rats to places they'd never been before but once the globe was fully explored, the extinction rate began declining back to [what the author thought was] the pre-anthropogenic norm.
For context, that author calculates the current rate of mammalian+avian species at about 0.2 species per year, down from a peak of 1.6 at around 1900. Knowing how close the current rate is to the theoretical pre-anthropogenic rate is, of course, a difficult question because it's very hard to estimate how many species died before we thought (or were around) to start looking for them. The analysis is even more hard because very few of the publicly-available species extinction lists include insects at all.
So I guess I'm really asking two questions.
1. What evidence establishes the baseline of pollinator species extinction rates? Do we in fact know of any insect-pollinator species that have gone extinct (not merely been listed as threatened or endangered) in the last hundred years?
2. What evidence establishes that the current measured rate is different from the baseline?

Mike Rossander



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