In message , Gill Hall
writes
A heron visited our pond last week and ate half the fish. The rest hid and are
still looking very nervous. I had just removed the netting that protected the
pond from falling leaves all winter. I would much prefer not to have to net the
pond all year round. Does anyone know of other, less unsightly but still
effective deterrents against herons?

A lot of pond retail companies sell plastic herons - based on the theory
that herons are territorial, or for a more expensive alternative there's
a device which shoots water. Examples are at http://tinyurl.com/399ze

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dave @ stejonda