I just read the article about kestrels and barn owls in the April 2006 issue and have a couple of thoughts of caution to share about this. While these predators can be an ally in some locations, they can also be of detriment in others; it just depends on where you live.
In northern Idaho, when warmer weather arrives, the mosquito population explodes. We have a dozen swallow houses and nesting boxes around the gardens and they fill up quickly with these wonderful mosquito-munching birds. The swallows make a considerable impact on the mosquito population for the season with their capacity to eat thousands of those pesky critters. Our challenge has been that the kestrels must be nesting not too far away and they find the baby swallows to be much easier access than hunting for voles!
Each year, when the first signs of hatchling swallows come, the kestrels return to have a feast. They land on the houses, the baby birds think it is Mom or Dad, poke their heads out to eat, and instead are eaten by the kestrels. We have not come up with an appropriate method to keep the kestrels from eating the baby swallows other than to chase them away whenever we can. I have devised a method that appears quite insane, but has gotten excellent response for keeping the kestrels away from the swallow houses.
We use large beach umbrellas for shade while working on hot sunny days in the gardens. These work great because they have long handles to stick in the ground so you can move them around as you harvest. When the predators come around, I grab one of these large umbrellas and run towards the kestrels pushing the umbrella up and down…..they have gotten the idea and now, as soon as they see me grabbing for an umbrella, they fly away. The object of this whole story is, inviting the predator birds in can impact other beneficial birds.
We also do not encourage owls, as in this part of the country, we have the great horned owl, which on several occasions has taken away a couple of our pet cats. We have even had bald eagles swoop down for an easy meal on a cat that was too attentive to the gopher they were watching. My point is, what is good for one part of the country, may not be appropriate measures for another.
Diane Green
Greentree Naturals
Sandpoint, Idaho