Archive for the ‘Barn Owl Articles’ Category

Barn Owl Nest Boxes, Gopher Control or Just Another Gimmick??

I recently read an article in a well respected vineyard and winery publication that featured barn owl nest boxes.  In the article the author speculated that not only will a healthy population of barn owls eliminate a gopher problem but they’ll also greatly reduce the need for pesticide use in the vineyard.  By pesticides, the author was actually inferring rodenticides, not insecticides or fungicides-although it was a pretty broad statement.

I refuted this claim by writing a letter to the editor and got an interesting response from an individual in Pennsylvania who is much more well versed in population dynamics than I am.  This response, combined with the empirical data we’ve collected dealing with growers over the years leads me to ask the question, are barn owl nest boxes really that effective for gopher control or are they just another gimmick.

Rex Marsh asserted years ago that promoting barn owls to control rodents was a mistake. (Sept. 1998 The Probe) In fact, the title of the article was “Promoting Barn Owls to Control Rodents is Deception”.  Rex’s point was that not only will barn owls not control rodents, but the growers belief that they may is detrimental overall to the cause of rodent control because the individual will let the rodent population explode, while vainly hoping for a biological solution, and eventually have to use significantly more rodenticides to bring the problem into balance than if proper measures had just been used initially.

Rex is a pretty well respected guy-I mean he knows more than, well, anyone, in most people’s opinion, when it comes to rodent control.  Few people have made a career of teaching other people how to kill gophers.  Rex has-and is one of the most respected people in the vertebrate control world.

So, there’s a point in the gimmick corner.

The problem as I see it here is that Barn Owls eat gophers.  We all know that-and if you don’t just go check out the base of an owl box in the spring.  You’ll find hundreds of gopher bones-along with other rodent parts-but gopher skulls, legs, ribs-heck you could probably build a gopher skeleton, something every wildlife control professional needs, out of what you find at the base of an owl roosting point or nest box.  So we know they do eat gophers.

The assertion in the article I read a couple months ago was basically what I like to call the “Field of Dreams Theory”.  If you build it, they will come.  So, if theoretically you had an area with a high population density of gophers or other pest rodents and you had barn owls in that part of the country (Barn Owls are in most parts of the country) then the more boxes you built-the more would get used because you are creating good nesting habitat-Barn Owls are cavity nesters-and there is an abundant food source with the aforementioned gopher population-so see, if you build it they will come!

Now we have our field of dream….uh, gophers, and we have a great gopher predator, and what will happen is the barn owls will thrive, to the point that they eat thousands of gophers per year.  So many gophers that there is no way that the hapless little rodents can keep up from a breeding standpoint and you’ve attained control.  Right?? Well, could be.

Let’s look at a couple things.  We know species adapt-so a percentage of these gophers are going to get wise to the “death from above” threat and adapt their habits to be less vulnerable.  We also know that predators will move away from an area that provides a decreasing prey base, due to competition from other predators, territorial disputes and so on.  So we have some changing variables here that are going to affect the outcome in our field.  I think this is the point at which the goal, effectively managing a rodent problem, gets lost sight of in the discussion.  If the owls have reduced the gophers to acceptable levels-then, we have a winner don’t we?  I’m not aware of anything, short of extinction, that controls a single pest species until the end of time, so for a moment in time, the owl nest box deal worked.  So, a point for the owls then.

Ultimately, there are a couple larger questions at work here.  The first is the predator/prey relationship.  So I ask you.  Does a large prey base control/attract the predator population, by supporting a high number of predators?  Or do predators control the prey population by keeping fluctuating numbers of prey at a steady predictable/declining level?

In my conversations with the gentleman in Pennsylvania he brought up his support for the reintroduction of wolves to the eastern seaboard in an effort to help control the white tailed deer population explosion that we all are so familiar with.  I couldn’t help but think of a gentleman by the name of Frank Glaser.  Frank was a government trapper and hunter from the mid 1920’s through the early 50’s in Alaska.  Frank was charged with tracking the migrating caribou populations and recording the effect of wolves on caribou and moose.

In his autobiography, Alaska’s Wolf Man, the Real Life Adventures of Frank Glaser (Jim Reardon) Glaser, who is refreshingly not in any way shape or form, politically correct (it was 1950 after all) blows away any notion that wolves only kill what they need and then only the sick, old or orphaned animals.  In fact, Glaser often shot them out of disgust or more correctly distain, after watching them kill caribou and moose strictly for sport-or for a display of territorial dominance.  Young caribou were routinely killed out of frustration, when the adults were too fast, and then left, untouched, by sulking wolves looking for an apparent “good or worthy kill”.

And the moose-they nearly wiped them out in parts of Alaska.  Wolves won’t take on moose in the summer or fall, they wait until the winter or early spring, when the prime adult males are exhausted from the rut and mating and can’t move around much in the deeper snow.  Then the wolves simply run them down, feed on their hindquarters while their still alive and then leave.  The moose dies in a couple days from the injuries, but the wolves won’t feed on a dead moose or even finish one off and feed on the hundreds of pounds of meat available-they just want a couple prime chunks out of the hindquarters, while it’s still warm…

So it would seem that our hope, that a predator, like a wolf or a barn owl, could be focused on a certain pest species is a little more hope and a little less biologically founded than we might be willing to admit.  Now, for perspective here, no one is worried about a declining gopher population due to “owl abuse”.  So the comparison kind of runs out of steam at this point, but I wasn’t the one who brought it up-the zoological expert from PA. made the comparison, so I’m just passing it along here for thought.

The next, much more difficult thing in my opinion to look at is the subjective nature of the term control.  What is control?  First of all, as wildlife damage professionals we all have an idea of what we think control is-but in most cases it’s the customers idea of control that matters the most.  Problem is few people spend as much time defining control as we do, so we’re all left with this interpretation variance to deal with.

I know in my experience with people with gopher problems, control is seeing dead gophers.  They (the customer) haven’t taken time to quantify the problem, they just see dirt mounds, or holes, or plant damage and want it to stop.  So if I install a Barn Owl nest box and they see owls-well then it must be working.  Notice I didn’t say anything about dead gophers.  If they see owls actually eating a gopher, I should be nominated for some sort of award.  If they see owls eating gophers and fewer mounds (cause I kicked them all down) and no more plant damage, I am some sort of animal control God.

Since I’m a God now, I’m filled with the wisdom and knowledge that I actually may have only started to scratch the surface of their problem.  Or that I could have used a rodenticide or traps and achieved the same results more quickly and consistently at a lower cost.  Or it could be that their problem was never really that large in the first place because I know that one pocket gopher makes several mounds and if you have 3-5 gophers in an area it looks like you have 100.

I guess the bottom line here is that Barn Owl boxes do work for gopher control, for some people, in some situations.  In other areas, it’s a feel good gimmick, because either the owls don’t exist in large enough numbers to offer any measure of control or the problem is simply to vast and varied for one type of control.  At the end of the day, that’s why you need a professional on site, to give you honest and informed feedback about what tools and options are available and how and why they should be used.

I guess the answer here is that before we label something either a sure thing, or a gimmick, we need to spend some time assessing the problem, the options and the goal.  Then we’ll know for sure whether or not what we’re getting ready to use is the best tool for the job. 

Published February 24th,2010 In the Iowa Farm Bureau Spokesman.

Operation Barn Owl Nest box
By Tim Love of Love’s Wildlife Control

Love’s Wildlife Control is proud to announce the involvement of Farm Bureau into the Operation Barn Owl Nest box project. Marion County Farm Bureau has graciously awarded a $500 community Enhancement Grant to LWC. The grant is good on a first come first served basis for $25 off a purchase of a Barn Owl Nest box or boxes for the first 20 Marion County members who get involved. The boxes are sold and installed by Love’s Wildlife Control. All sales and donations are put directly back into the project. Donations are greatly appreciated. Actual retail costs of these boxes are over $100 dollars each, but are currently being sold and installed by Love’s Wildlife Control locally for $70.

The Creation- My name is Tim Love, owner and operator of Love’s Wildlife Control (LWC). I resolve conflicts between humans and wildlife. I specialize in pocket gopher and mole control. Last spring (09’) while attending the Hawkeye Farm Show in Cedar Falls, a visitor to my booth told me that he used Barn Owls to keep his gophers in check in his hayfields. This conversation led me to begin research on the Barn Owl. I spent a great deal of time on the Internet and the telephone learning as much as I could about these amazing birds. I came to the conclusion that here in Iowa the barn owl has an abundance of prey available but few and dwindling numbers of nesting sites. I believe I am fortunate to operate a business doing what I love to do and feel compelled to give back to Mother Nature. I want to help the Barn Owl. Operation Barn Owl Nest box is a part of my business that I have set aside to operate at cost, to give back to nature.

The Plan- Give the Barn Owls a Home. Barn Owls are an endangered bird in Iowa. Barn Owls are very “wimpy” birds and have a high mortality rate but this high mortality is off-set by being highly prolific. 200 years ago, Iowa had large numbers of old hollow trees in which the barn owl could call home. In time, many of these trees were cleared by humans for development either for residential or agricultural use. As these trees were eliminated the Barn Owl adapted and took advantage of barns for protection, thus the name Barn Owl. Today many of the old barns have been remodeled with steel siding and access has been denied to the Barn Owl. The barns that have not been updated either are destroyed or left to ruin. This basically has left the Barn Owl homeless in Iowa. My plan is to erect as many nest boxes as I possibly can. This is the only logical thing we can do to help the Barn Owl. I believe that once these birds begin to find and use the boxes their natural abilities will bring their population back to acceptable levels in Iowa. This comeback will take years to happen and be slow in the beginning but once we have significant numbers of these birds reproducing, and continue to create homes for them, the population can thrive.

The Benefits- Having Barn Owls living on or near your property is very beneficial because these birds diet consists of nearly 100% rodents. A pair of Barn Owls feeding young, account for literally thousands of rodents consumed a year. The main rodent on their diet is the vole but mice, rats, moles, shrews, and gophers fit the bill as well. Rodents take refuge in terraces, waterways, fencerows and outbuildings. When larger predators such as the badger, fox, coyote, and skunk pursue these rodents in those places, considerable damage is done to your property. Rodenticide spread over the land is costly and unsafe to non targets, humans included. Control has different meanings to different people. I do not want to give the impression that Barn Owls will end all your rodent problems but that Barn Owls do provide a balance and make a considerable dent in the rodent population. Barn Owls in my opinion are a farmers best friend and employee as they work 24/7/365 consuming rodents.

Guarantee- There is no guarantee that you will get a Barn Owl to use the boxes. I can guarantee if there is no nest site available on your property you will not have them reproducing and thriving on your land. In my mind I see zero nest sites now. If we put two boxes in an area and 1 pair raises one brood of 5 young we are now short 4 boxes. You can clearly see the challenges that the Barn Owls face, all revved-up and nowhere to go! Since Barn Owls can have 2 broods a year you can understand why I think it is important to get as many boxes up as possible. Even one box in an area is a good start as more can be added later if a mated pair is known to exist.

Jessica Love after installing Nest box near Beech, IA.

To Date- Currently we have 26 boxes installed and 9 more boxes sold and ready to put up when the weather is fit. We can mount the uprights to an existing fence post but have found that it is best to mount the box on a 16’ 4X4 and set this in the ground. The boxes are made with ½” plywood sun shades built onto them. The box openings always face east to avoid the bad weather. The boxes are constructed of ¾” CDX plywood in such a way that water is shed off; they are screwed and glued together. They are stained gray with a very high quality stain made by “Super Deck” which features Carnauba oil. The upright posts are mounted to the bottom of the box with a steel bracket and are wrapped with a sheet of 24” aluminum flashing to keep climbing predators and unwanted guests out. This is the beginning of this project, so I do not know of any boxes being used but I have spotted 4 barn owls since last fall. Next fall (2010) Marla and I will be checking all the boxes for signs of use.

Pastures, next to row crops, provide plenty of rodents for Barn Owls.

Conclusion- Barn Owls need our help. Seeing a Barn Owl is like a religious experience to me and other bird lovers I have talked too. They are cavity dwellers and operate by cover of darkness so they are seldom seen. Many people I have talked with remember when they were young having a pair of Barn Owls in their barn. The main predators of Barn Owls are the Great Horned Owl and the raccoon. Since most hollow trees and old barns are currently occupied by the Raccoon, safe nest sites are very limited for the Barn Owl. Keeping these boxes out in the grasslands and away from the big woods offers the best protection from the Great Horned Owl and the aluminum flashing on the box post keeps the raccoon at bay. If you are a Marion County member and are interested in purchasing one or more boxes contact Farm Bureau at 641-842-6214. If you are not a Marion County FB member you may contact Love’s Wildlife Control at 641-891-7194.
Acknowledgements-The success of this project would not be possible without these people and I want to thank them for their help so far. First Lloyd Philips of Knoxville, IA has afforded me the use of his woodworking shop to build these boxes. Lloyd’s input of the box design and the hours that he volunteers towards this project, Bruce Ehresman of the IDNR for his past Barn Owl research and input into this project, Marla Mertz the Naturalist for Marion County Conservation Board, for here encouragement and very helpful presentation ideas, John Schuster of “Wild Wing Co.” of CA for his input of the boxes as well as information on the Birds, Paul Vitek of Spahn and Rose Lumber and Jeff Isley of Isley Welding and Repair both of Knoxville for the charitable contributions. Thank you all very much, Tim

Tim Love and Lloyd Phillips with the first box installed in Kay Harsin’s pasture.

For further information on the Barn Owl and the Operation Barn Owl Nest box project visit www.absolutegophercontrol.com and click on the Operation Barn Owl Nest box tab. Here you will find more in-depth details of the project and links to other sites about Barn Owls and information on how to order the video “Backyard Barn Owls” by Bert Kersey. This video is fantastic and worth every penny.

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