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Poisonous Berries

August 12, 2008

A listener wants to know why some berries bother being poisonous.


Poison with a purpose…I’m Bob Hirshon and this is Science Update.

Kevin Limongeli of Brick, New Jersey, asked us why some berries are poisonous, since it would seem that would deter animals from eating them and helping to spread their seeds. We consulted Andrew Sanders, curator of the University of California, Riverside’s herbarium. He says just because a berry is toxic to us, doesn’t mean it’s toxic to every animal.

Berries in general are animal-dispersed fruits. And so it has to be, I think, almost logically, that any time you find a berry, there is some animal that can eat it.

The baneberry, for instance, makes people very sick, but has no effect on birds, squirrels or chipmunks. Sanders says berries have evolved characteristics that make them palatable to good seed dispersers and toxins to protect themselves from those that aren’t. I’m Bob Hirshon for AAAS, the science society.