How big a fish can this guy tackle?

After our scare with the Great blue heron (we lost two white koi), we now have the Green heron (       ) back at the ponds in the garden. While this is lovely for observing this beautiful bird, I greatly fear for our new koi, who are quite small.  What size fish can a Green heron gobble?  Unfortunately my internet research seems to indicate that they can take rather large fish. Green herons are remarkable, it seems, in that they are one of the very few tool-using birds. They take bits of vegetation and insects and drop them on the surface of the water as bait to lure their prey to the surface.

This species has been here before when we had only large koi. It ate considerable numbers of alumina and swordtails but these multiply rapidly in the natural environment of the pond and in any case are only there to control mosquito larvae. No worries, mate, as Aidan and my Aussie brothers would say.

The Green Heron is always here in the area. It prefers still water but it is a regular on the fast-flowing Rio Colorado in the town centre at Turrialba. Strangely, I have never seen it on the mountain streams here near San Antonio, even though they support the Fasciated tiger-heron and the Sunbittern.

Sunrise now finds me sipping coffee next to the ponds and guarding my recently acquired small but beautiful koi.

Many thanks to Karel Straatman for his fine photo, taken here in Costa Rica.

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