Salvia Vandals

My gardening neighbour warned me that crimson rosellas would eat any red flowers or fruit in the garden. But today I discovered that they'll eat white salvias, too:

The photos aren't great because they were taken through the window without the flash fairly early this morning. The rosellas pick the flowers, and eat the nectar from the base. They haven't touched the blue ones, fortunately, even though they have been flowering longer, and are right beside the white ones.

It wouldn't be so bad if they just picked the flowers, but they bite through the stems as well,

killing off future flowers they (and the bees, and the humans) could have enjoyed.