Effective owl guard for gourd racks

[Kent Justus]

Last year my 100% occupied colony of 68 gourds was devastated by both Great-horned and Barred owls. I had owl guards in place that I thought were effective at the time. They consisted of three horizontal strands of 18-gauge wire approximately 15” in front of the gourds. The concept was to keep hovering owls from getting close enough to make contact with the gourds. However, I began to notice piles of martin feathers under a couple of different trees on several different occasions and wondered how the owls could still be catching the martins. My question was answered one evening when I arrived home and glanced at the gourd rack in twilight and saw a Great-horned owl sitting on one of the very thin pieces of wire facing the gourds! I scared it away, but I’m sure it returned later as I found evidence of its kill the next morning. Another evening I arrived home and glanced at the rack and saw a Barred owl sitting on top of the rack and then saw it hop down inside of the rack and actually walk out on one of the inner rack arms to the gourds. It had figured out how to defeat the horizontal wires.

Desperate measures were then in order, so I decided to enclose the top and sides of my gourd rack with 16-gauge 2”x3” hardwire cloth. This would stop the owls from dropping down inside of the rack from the top, and it would also prevent them from perching and facing the gourds to scare martins out into their talons.

The results have been fantastic this season with practically no predation evidence found both through nest monitoring, observations of the gourds for scratch marks, blood, etc., and no evidence of martin feathers on the ground this season under the trees where owls took their kills to pluck last year. However, the most convincing evidence of their effectiveness is seeing large numbers of fledglings return to roost several nights in a row when the last two years practically no fledglings returned to roost in the gourds that were under nightly siege by the owls. The fledglings that happen to not enter gourds at night but stay toward the center of the rack are also protected as the owl simply cannot reach them. I also have wire on the bottom level of the rack that prevents owls from being able to fly up underneath and walk out to the gourds from the inside.

It is interesting watching the martins easily navigate the guard. When coming in at speed to feed nestlings the adults simply leapfrog through the wire in a split second onto their gourd porches and in. There is no hesitation or inconvenience in their movement. When exiting the gourds they simply drop straight down off of their porches and out of the “cage.” I witnessed a hawk attack a couple of days ago by a mature female Cooper’s hawk and the martins were able to exit so quickly that the hawk couldn’t even get close enough to single out a target for pursuit and left with a flock of angry martins mobbing it.

Attached is a photo of one of my racks. I can highly recommend this type of guard to anyone who has experienced severe owl predation. This guard is also effective against owl, hawk, and crow predation of nestlings. As long as we continue to attract more and more martins each season the question is not if flying predators will attack, but when. It is a mistake to assume that owls do not live nearby simply because they haven’t been seen or heard. Owls and hawks are everywhere, and sometimes we find that out the hard way. I hope my positive experience this season with this type of guard will help others who are having predation problems. - Kent

[Guest]

Kent, I think that you have a very effective owl guard.

I wonder what you think of my method. I mount the gourds so that they do not swing at all. With a tunnel and porch, I don't think an owl can reach the babies. I am considering a longer tunnel, instead of a 3in tunnel, I am considering making all future gourds with a 5 or 6in tunnel. Do you think that owls can defeat this system? The tunnels are very secure, I have not had any damaged tunnels. By mounting them securely, the martins may still flush, but its unlikely. I would like your comments. I would consider what you have, but may not have the skills to build it.

[Tim Mangan-Kansas]

Hi Kent:

I recall in our conversation last year all the trouble you were having with the owls. Thanks for sharing the pictures as I have often tried to picture what the hardware cloth around your gourd racks looked like.

I have seen owls around our neighborhood but so far my colony has been free of any owl predation. I am assuming by placing the wire above the lower level of gourds clear in to the pole that this would prevent you from doing nest checks, at least to the upper level of gourds. Is this correct?

I have a roll of hardware cloth in the garage and plan on building a barrier for my gourd rack over the winter. I doubt if I will put it up but I want it all measured, cut and ready to go in the event I start experiencing any owl predation.

It appears you can put it together with three pieces; one going completely around both levels of gourds, one for the top and one going over the lower level of gourds. Is this correct and is this how you would recommend building it if you were to do it again? How much additional weight do you think was added to the pole with the hardware cloth?

Did you cut any of the vertical pieces of wire to make the openings 4" x 4" instead of 2" x 4" to make it easier for the martins to get in and out? I put up an owl guard around my Sunset Inn house and made a 4" x 4" opening for each level of the house. I have seen the adult male with a nest in this house fly straight through this 4" x 4" without stopping and still have time to pull up and land on the house porch.

Again, thanks for sharing the pic's.

Tim

[Peggy Riley]

Very nice Kent. Is the top wire stationary or does it come down with the rack when it is lowered?

Peggy

[Kent Justus]

BJ - Sounds like you are thinking outside of the box and that is good. I definitely feel that the longer tunnel will make the martins feel more secure, and by making the gourds stationary they are less likely to bolt if attacked by owls. However, like you said, without experimenting with the longer tunnels without a guard to prevent any contact with the gourd it is hard to tell if the adults would still bolt from the gourd if an owl were hanging on the porch and scratching at the entrance and beating its wings. Let us know how that works out.

Tim - It is hard to see in the low res. photos, but the wire around the outside is not one solid piece. You can tell by looking at the top photo gourd rack on the left, left side. There are two separate solid pieces for each level of the rack, and I have filled in the gaps between the two with smaller sections. There are gaps between those sections that are large enough to stick my arms through when the rack is lowered so I can still conduct next checks, even though I usually have a sore back when I'm through! I really don't know exactly how much weight is added to the rack, but if you recall I use a much lighter-weight wire from Lowes than the 2"x4" wire that is traditionally used to make dog fencing. My poles are 2" schedule 80 steel and withstood some fierce winds earlier this spring.

No, I have not cut any vertical wire for 4" tall x 3" wide. I have seen no inconvenience to the martins by the 2" vertical wire and have seen them bring in large dragonflies and nesting material without problems. Since my colony suffered big losses last year I don't want to chance enlarging the spaces in the guard since I've seen that they work very well as is. I'm really afraid that if I enlarge to 4"x3" then the martins might also tend to want to fly straight out of the cage into the owl's claws instead of straight down and out of the cage, so I assume that since it is easier to drop down and out instead of straight through then in the end it would be safer for the martins. I wouldn't want to defeat the purpose of the guard if it made it easier for the martins to fly straight out. When they panic they tend to try to make the quickest escape from their housing.

Peggy - Since the wire is attached directly to the rack it does come up and down with it when I raise and lower. - Kent

[Matt@atx]

Your guard covers look very nice and effective and took lots of work for you to make that happen. I am sure your Martins appreciate that a lot. Imagine the fear from death you have eleviated from your birds.
I was thinking how could one protect a gourd rack system from Owls. ..to keep the Owls completely off the gourds seems the only sure way and best way to protect them. Doing the same for housing is much easier.
It seems that you have got it here. Thanks for the pictures and how to information.

[DAVE]

Thanks for the pictures, I'm new at Martining so I use the Forum to learn all I can. I'm a very handy guy so I can build this guard. Also I like your Rack design. This is what I was think of building. The pictures help me to make a working print. We just put up 5 gourds this year to see if we would attract Martins and much to our suprise we have 2 Breeding pairs and at least 5 to 10 vistors each day. We are going to put up 10 more gourds next year.

Thanks for the info
Dave

[kratz71]

I've thought about a new owl guard for some time and think I might have an idea. What if you made a second hole in the back of the gourd to be used as an escape route? If an owl, snake or racoon were to reach into the gourd, the adult martins could bolt out the rear door. Not sure if the martins would use the hole or even like a gourd with 2 entrances. What do you think?

Mike

[snowbug]

Thanks to all for your replys! The orentiation of the fencing on my project is 2" wide x 4" high. I really did not think much about it until I see some comments that now make me think about it. I will probably take the wait and see approach as to how well it works in regards to the orientation since I am already built.

I do have a way to close in the bottom if the owls fly up from down under. Again, probably wait and see how this works will be my plan.

The great horned owl problem got to be so bad I either need to provide a guard system that works or remove the housing. I elected to try a fenced guard. In addition to the 36 rooms of lonestar housing, I have a gourd rack with 21 porched plastic gourds that also has an owl problem even with the typical owl guards in place. (all purchased at PMCA shop) A fenced cage around the gourds will be my next project if the first system proves successful.

I am located in north Ohio so it will be April 2012 till I see how the martins react to the fence guard