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Catalog of Barn Owl Nest Boxes

Barn Owl Research

Controlling Rodents with Barn Owls

Frequently Asked Questions About Using Barn Owls for Rodent Control

What level of control can I expect from barn owls?
I have gophers in my garden. Will barn owls get rid of them?
I have gophers in my field. What do I need to attract barn owls?
Will barn owls help with my ground squirrel problem?
Will barn owls attack my cats/me?
Where do I put the nest boxes?
Where should I not put the nest boxes?
Will routine farm operations bother my owls?
How many nest boxes do I need?
If I put up several nest boxes in the same field, will the owls territorial instincts cause conflicts?
Do I need to do anything special once I attract the owls?
Can I peek in my nest boxes to check on owls?
Should I continue baiting rodents once the owls move in?
What do I do when I find a young owl on the ground?
How do I capture a grounded barn owl?
Where can I get more information?


1. What level of gopher control can I reasonably expect with barn owls?

Barn owls will NOT reduce a rodent problem to zero. However they can make a dramatic difference in an area with an extreme rodent problem and keep it under control. In a mature vineyard, gophers can be reduced to a tolerable level without the use of baiting.

Variables include population density of rodents, population density of barn owls, amount of available nesting places in your vicinity,and the presence of Great Horned Owls in the vicinity.


2. I have gophers in my garden. If I put up an owl box in my yard and attract an owl, will it get rid of them for me?

Although they may catch some of them, it probably won't be to the degree you would like. Barn owls hunt rodents over a large area, frequently flying as far as three or four miles in search of food. A large population of these owls can reduce a rodent population by a significant amount, but no one can be sure that they will catch a specific rodent. If you really want to get rid of a particular gopher, go after it yourself.


3. I have gophers in my fields. What do I need to do to attract barn owls?

If you live inside the range of the barn owl(ie: the lower 48 states in the US), simply put up nest boxes. You can put them up any time, but the nesting season is from February to June. The rest of the year, the adult owls will use them for roosting during the day and perhaps for perching during the night.


4. Will barn owls help with my ground squirrel problem?

No, barn owls will not affect your ground squirrel population because the squirrels are active in the daytime while the owls are active at night.

The Golden Eagle and the Red Tail Hawk are the main predators of the ground squirrel. Erect several 20 to 25 foot tall perches near the squirrel coloney to aid these raptors as they hunt.


5. Will barn owls attack my cats (or me)?

Although it is doubtful that a barn owls will attack a cat for food, it may do so if the cat gets too close to the owls' nest. It might also attack you for the same reason if it can do so safely and has the advantage of surprise. While barn owl attacks on humans are not common, they are not unheard of.


6. Where do I put the nest boxes?

Put the boxes up wherever it is convenient for you. They can go in trees, on posts out in the field, on the wall of a building. Each site has positive and negative points. In trees, the owls will receive some protection from the elements, but the young will be exposed to predators. On a post, the young will be protected from most predators, but the box may get hot during a heat wave. On a building, whatever is below the box will probably get splattered with fecal matter.


7.Where should I not put the nest boxes?

Don't put nest boxes above locations where vehicles or equipment is parked.

Outside your bedroom window is not a good idea either, because the young owls can compete very noisily each time the adults return to the nest with food.

In Great Horned Owl habitat, that is, in heavily wooded, riparian regions. Great horns are the largest predator of the barn owl.

In the middle of your worst gopher-infested area. Owls prefer not to hunt in the area of their nest box so as not to attract the attention of potential predators. Multiple nest boxes in this vicinity will solve this problem because the hunting areas of the different nesting pairs will overlap.


8. Will routine farm operations bother the owls?

No, regular farm activity will not bother the owls as long as the box or the post is not bumped. In most cases they will remain quietly inside the nest box.


9. How many nest boxes do I need?

One box will achieve the "warm fuzzy" thing but will not control your rodents. Your goal should be to attract as many nesting pairs of barn owls as your rodent population can support.

Remember that it is nesting pairs that you want to attract. Each adult will eat one rodent a night, but each chick will eat up to four or five, depending on the size of the chick and the size of the rodent.

Six boxes across fifty acres is a good start. Figure you have enough nest boxes when 20 to 30% are not being used at any time during the year.


10. If I put up several nest boxes in the same field, will the owls' territorial instincts cause conflicts?

Barn owls are not considered to be very territorial. The number of owls you attract is a product of the number of rodents in your field and the number of nest sites they can find in your area. This means that you can erect as many nest boxes as you have space for. And the more nesting pairs of owls you attract, the more rodents you will get rid of.


11. Do I need to do anything special once I attract the barn owls?

In late June, clean the boxes out after the young have left.

In November check the inside of the box for wasps. Spray them using a pyrethrin-based insecticide and take down the nest. Remove any other unwanted debris.

Don't bother the nesting hen between the beginning of February and the end of March.

In general, leave the nest boxes alone.


12. Can I peek in my boxes to check on the owls?

It is always best to leave the owls in your nest boxes alone. This is especially true while the hen is sitting on the eggs, during January February or March. Scaring her away at this time may result in her refusal to return. When the chicks have hatched, you can safely peek in to see how many you have without worrying whether the parents will return.


13. Should I continue baiting the rodents after the owls have moved in?

Only if you still have too many rodents. Use bait that kills the rodents in the tunnel with one feeding, not the kind that builds up in their system after several feedings.


14. What do I do when I find a young owl on the ground?

The chances are that the youngster's parents know where it is and they are probably taking care of it, so unless the owl is injured or in danger, just leave it alone.

If the owl appears to be hurt or is potentially threatened, take it to your nearest raptor rehabilitation center.


15. How do I capture a grounded barn owl?

To capture the barn owl, you will need a sheet, a pair of heavy gloves and a paper grocery bag.

Start by throwing the sheet over the owl. Wearing the gloves, grab the owl by both legs just above the feet while the bird is still covered with the sheet. Remove the sheet and turn the owl upside down. Put it into a paper grocery bag and fold the top of the bag over to keep the bird inside.


16. Where can I get more information?

Call Tom Hoffman at Bio-Diversity Products at (209) 369-8578.

Visit Barn Owl Headquarters on the web at http://members.tripod.com/~Tommy51/index.html