1. What degree of gopher control might I logically expect from Barn Owls?
Barn Owls by themselves will not completely eliminate a rodent challenge. Nevertheless Barn Owls can and will make a drastic difference in areas where excessive rodent populations exist, and will help keep the rodent populations in balance. Barn Owls are a farmers best friend and will reduce gophers and other rodent pests to tolerable levels eliminating the need for expensive baits, traps, and labor.
The conditions for success with Barn Owls depends on and includes rodent density, available Barn Owls in your area, available nesting sites, and if Great Horned Owls are in the vicinity.
Barn Owls do not migrate (to any significant degree) and they are very selective as to what they will hunt as they swallow their prey whole. Harsh winter weather conditions and removed habitat play a factor in a successful Barn Owl program. If they can not hunt because it is to windy, rainy, or if snow blankets the ground (for long periods of time), Barn Owls will generally starve to death rather than relocate or switch to other prey.
A seriously nocturnal bird, Barn Owls like to take cover by day in outbuildings or trees that they feel safe in (ie. old barns, old oak trees with cavities and evergreen trees) where they can hide during the day light hours. Removing these safe havens disturbs Barn Owls, so they simply move elsewhere. Therefore and under these conditions, if you put in a managed Barn Owl nest box program it may take sometime before the Barn Owls will return, but once they move back they generally stay.
2. If I have gophers in my garden and I put up a Barn Owl nest box to lure Barn Owls, and once the Barn Owls moves in, will the Barn Owls pick off the gophers in my garden?
The Barn Owls may catch some, but not to any significant level that would make you happy. Barn Owls hunt for food over 3 to 4 miles away from their nesting sites and they will not hunt for food under their nesting sites.
Barn Owls generally like to glide out about 50 to 100 yards away from their nesting sites (to avoid detection from predators) before going into their hunting glide, so nest box spacing is everything. Large populations of Barn Owls can consume large amounts of rodents if their nest boxes are positioned properly and the colony is thriving. However, to expect them to pick off a single rodent may prove to big a challenge for these avian of the night. If you have a problem with a pesky gopher you might want get it yourself.
3. What do I need to do to bring Barn Owls to my vineyard so they can get my gophers?
We are blessed here in the United States as Barn Owls are rather prevalent in the lower 48 states, so simply putting nest boxes up is a good start. Don't think that you have to wait either as anytime is a good time to put up Barn Owl nest boxes.
However, your best chances of success would be if you put the nest boxes up before winter comes, so the Barn Owls have a place to roost over the winter months. By placing your nest boxes up in the fall, this will virtually guarantee that you will have Barn Owls for the spring nesting season which begins in February and ends late in June. After that the Barn Owls will use the nest box for roosting during the day and will perch on them at night.
4. What about ground squirrel and will Barn Owls help?
Sorry, Barn Owls are nocturnal and because squirrels are active during the day one doesn't even know the other exists. You'd have better luck employing other raptors like Golden Eagles and Red-tailed Hawks because they will hunt ground squirrels (rattlesnakes too) as they are their main predators. Try erecting multiple cross perches (Raptor Perches) 21 to 25 feet high near the ground squirrel colonies to help these raptors do their job more efficiently.
5. Will Barn Owls attack my pets or me?
This is a very common question and I'd have to say that cats, and dogs are just to big to swallow whole, so the answer is No. However, any parent (bear, deer, mountain lion or human) will defend their young, so if Felix the Cat or & Rover the Dog get too close to the Barn Owls nesting site, it could get attacked and would attack you for the very same reason (provided it can do it without injury to itself and has the element of surprise on it's side.)
Barn Owl attacks on humans are very rare, but not unheard of. However, like a rattlesnakes they will give you a raspy hiss to let you know that you are to close for comfort. My general rule about Barn Owls is to just leave them alone and they will do the same.
6. Where is the best place to mount one of these Barn Owl nest boxes?
Barn Owls will just about live anywhere that you mount one of these nest boxes. I tell people to put them where it is easy and convenient for you to clean and service the nest box. Trees, posts, and buildings all work, but each location has it positives and negatives.
You can mount nest boxes in trees, but you run the risk of predators like Raccoons, Opossum and Great Horned Owls getting at the nest. Mounting nest boxes on posts in vineyards or orchards will help with predator challenges, but in hot regions, you run the risk of excessive heat inside the nest box. Mounting nest boxes on buildings works, but anything that is under the nest boxes will be soiled with feces and other offensive items.
For faster occupancy I also suggest that people mount all of their nest boxes facing East. The reason for this is that the jet stream rarely moves directly east to west, so the front of the nest boxes is always protected from rain and wind. Furthermore, the moon and sun both rise in the east. This illuminates the front of the nest box during a full moon or earlier dawn helping the Barn Owls find the nest box faster.
7. Are there places that I shouldn't put a Barn Owl nest box?
Do not put the nest box over your favorite tractor, or your BMW as the fecal mater is very corrosive. Put the nest boxes above areas where vehicles or equipment are not parked.
Do not put the nest box near your bedroom or near an area where you do not want to be disturbed at night. The Barn Owl owlets will drive you nuts with all the racket that they make when the parents return with food.
Do not put the nest box near Great Horned Owl habitat. Great Horned Owls like to live in heavily wooded, riparian regions. It is advised to locate Barn Owl nest boxes a 1/4 to 1/2 mile away from such areas. Great Horned Owls are the largest predator of the Barn Owl and it is king of night sky. You know you have Great Horned Owls when you hear the Hoot Hoot sound that they a famous for, while Barn Owls make raspy hissing sounds.
As mentioned earlier, do not put the nest box right in the middle of your worst gopher challenged areas. Remember that Barn Owls will not hunt under their nest sites. Placing more nesting boxes in an area is preferable as Barn Owls are not territorial and nesting pairs will overlap the area while hunting. I call this the Overlapping Kill Zone, which will be in full swing when the colony is in full bloom.
8. Will routine farm operations disturb the Barn Owls?
No, regular farming practices will not bother the Barn Owls unless you bump into a post with your tractor or tiller. Barn Owl are seriously nocturnal birds, so they generally remain still during the daylight hours.
9. Are Barn Owl's territorial and will having several nest boxes in the same field be a problem?
Barn Owls are not suppose to be territorial. In fact, it has been found that if there is a shortage of male Barn Owls in an area the male will mate, feed and protect multiple females (luck guy.) Barn Owls have a very high mortality rate and they seem to instinctually know that their survival as a species depends on numbers. The more nesting sites you have, the more Barn Owls you will get and that means your rodent populations will decline.
10. How many nest boxes should I invest in?
As my colleagues and I like to say, a single nest box will accommodate the "Fuzz Balls", but it will not impact your rodent problem, so you should put up as many nest boxes as your rodent population will support. Nesting pairs is what you are trying to attract and the more pairs you have the better they will thump your rodents. A single Barn Owl only needs 150 grams of protein a night (equals 1 pocket gopher), but because of the high metabolisms of the Barn Owl owlets they each will eat up to four or five (depending on the size of the owlet) rodents a night. Multiply that by 3 to 7 owlets per nest box and you can see how fast the Barn Owls will impact your gophers.
Some of my colleagues recommend 6 nest boxes for every fifty acres, while another likes spacing nest boxes every 80 yards apart. Both are acceptable able, but I like to recommend between 100 to 200 yards apart with 200 yards being a good starting point. That way when the Barn Owls emerge from their nest boxes they will fly away from their nest boxes 50 to 100 yards before going into their hunting glide. Now the Overlapping Kill Zone will be in effect and your gopher challenges will be in check. A good percentage of occupancy should be 80% to 90%.
11. How about maintenance and what do I need to do to keep things rolling?
I recommend that you clean out your nest boxes and replace the bedding with wood chips (oak is best, pine is OK too, but never use cedar wood chips for your bedding) in late June, or July after the owlets have fledged. .
Check the nest boxes again in November for wasps. If you have wasps use Pyrethrin-based products as they are the only products recommended for use in boxes. Spray them, take down the nest and remove unwanted debris.
During the nesting period beginning in February and ending in March you should not bother the nesting hen.
Generally I just tell people to leave the nest boxes alone.
12. Is there a time when it is safe to look at the Barn Owl owlets?
It is best to just leave the Barn Owls alone. This is particularly true concerning the hen who is sitting on her eggs, during the nesting season (This is particularly true concerning the hen who is sitting on her eggs, during the nesting season (January, February, March, April and May.) Frightening her away at this critical stage will result in her rejection of the nest. After the chicks have hatched, you can safely look inside the nest box to see how many owlets you have without fear of the adult Barn Owls leaving the nest.
13. Can I still bait rodents after the Barn Owls have moved in?
You can still bait if your problem persists. Do not use a bait that accumulates in their system after multiple feedings. Use the fast acting bait that kills rodents inside their tunnels.
14. What do I do when I find a young owl that has fallen out of the nest box?
Do not worry because the parents probably know where the owlet is and will continue to feed and take care of it so just leave the owlet alone.
On the other hand if the owlet looks injured or is in danger, take the owlet to your nearest raptor recovery center.
15. How do I capture a barn owl that has landed on the ground?
All you need to capture a grounded barn owl is a bed sheet, a pair of heavy gloves and one large paper grocery bag.
Throw the bed sheet over the owl. Now 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 obtain more information?