If you build it, they will come. Barn owls, I mean.
Gray boxes on tall steel poles, holes facing east, loom over many of my vineyard blocks. These are designed to lure barn owls to live and raise their young in my vineyards. The Carneros is open country and there are not many places to nest, thus the owls inhabit the boxes as fast we can build them and put them up.
Barn owls, while not being very bright, are voracious rodent predators. The classic heart shape of their faces, beyond being adorable, has a practical application. Those ridges concentrate vibrations, making the owl able to find a rodent in the dark without sight or hearing but by feeling it moving.
Gophers have been a scourge of North America as long as there have been people farming here – early pioneers would plant their crops only to find the little buggers running behind them and stuffing in as many seeds or potato starts as their cheeks would hold. (That’s how they got the name “pocket gopher”). In the wild, gophers are natural cultivators – moving soil around isn’t always a bad thing. But it’s not good when it’s in the middle of the field that grows your livelihood. Many ways have been invented to trap gophers – including blowing up the tunnels. Not a terribly effective way, somewhat dangerous, but really fun. Other means include anti-coagula
nt baits that can also be a menace to raptors, as they can die when they feed on the bodies of the poisoned rodents.
While cultivating will help break up their tunnels and reduce populations, the most effective means I’ve seen for gopher control is trapping – trap, then trap, then trap some more. If the problem is really bad, you’ll need to check your traps several times a day. We had one block where we trapped over 50 gophers in less than a week.
But why take all that time and energy to trap when I can let Nature do the work for me? By adding owl boxes to our vineyards, we are using the predator/prey relationship to our advantage. With the owls patrolling, our gopher populations remain at an economically acceptable level – it’s not like you’ll never see one in our vineyards, but a few gopher mounds here and there hardly do much harm. Plus, we need some level of population to keep the barn owls and their babies fed. And abandoned gopher and other rodent holes will often be used by amphibians (toads and frogs) as well as snakes, adding yet more predators to my vineyards.
By inviting the barn owls into our vineyards, we’ve created a place for the pocket gophers and other rodents. No longer just pests to be thwarted, they become a vital part of the cycle of life, the living system, of the RSV vineyards.