Nearly every purple martin colony I have personally managed has been raided by either barred or great horned owls. My current colony in northwest Louisiana is hit every season and Bob my next door neighbor’s colony has been attacked, too. These Louisiana owls do NOT hang on the housing or try to pull out martins from gourds or houses. These owls hunt like hawks and grab martin fledglings and adults that try to roost out in the open on house porches/gourd racks or some male martins that stupidly sit out on the porches and advertise their location in the early morning darkness with loud dawn song vocalizations. Most male martins in our colonies leave the colony and dawn sing high in the sky where they are safe from owls.
This season I have tried something different to try to ward off attacks by great horned and barred owls later in the nesting cycle when large numbers of martins are roosting all over my gourd racks/houses. And so far it has worked even though at least two great horned owls which had been attacking both our colonies earlier still come within several hundred yards of the martins but no closer…yet. I still hear them hooting to each other in the woodlots located across the pasture in front of our martin colonies.
What I have done is install three great horned owl decoys on poles around the perimeter of my martin colony, including one across the road on a fence pole that faces the woodlot where the owls often launch their deadly attacks. These owls have rotating heads when the wind blows and I can’t help thinking of Linda Blair as the possessed girl in the old move “The Exorcist”!
Two of the owl decoys are located about twenty feet from my martin housing and these decoys are on eight to ten foot poles. As stated previously the other owl is located across the road and about 100 feet away from both our colonies and on a taller pole about 12 feet high.
The martins totally ignore the owl decoys and don’t seem to view them as a danger. If the decoys had been hawks, then the martins probably would have mobbed them since martins are more “aware” of daytime avian predators which they deal directly with.
Way back in 2004 when I lived in Tallahassee, Florida I tried to stop resident Cooper’s hawks from attacking my martin colony by placing great horned owl decoys on tall poles nearby; great horned owls are deadly enemies of Cooper’s hawks and will kill and eat them if they can be caught on the nest or when roosting at night. However, these martins mobbed the owls and I had to move the owls farther back near the woods and out of view of the martins. I couldn’t tell if the owls had any impact on the Cooper’s hawks which were seriously damaging my martin colony when the martins were feeding young.
Well, I have had the owl decoys in place for several weeks now and have not noticed any more attacks by the real great horned owls. Right now we probably have a 1000+ martins roosting all over our houses/gourd racks and many of my gourd racks are COMPLETELY covered with martins. Last year and in the past during this time, great horned or barred owls attacked these martins and eventually caused the martins to stop roosting in our colonies. However, the great horned owls are still HERE and I sometimes hear them hooting several hundred yards away in the nearby woodlot early in the mornings. But so far I have seen no evidence they are coming into the colonies and the martins are still here each morning and during the night. In the past nearly all the martins would be gone when I got up early in the mornings to check on them; this indicated an earlier nocturnal attack by owls.
Last evening July 5, 2016 a HUGE number of martins came in and roosted all over my gourd racks and Trendsetters. I believe there were 1000+ martins here. It looks like we have a mini-roost! No owls bothered the martins and this morning July 6, 2016 at around 5:00 am I came out and heard two great horned owls hooting several hundred yards to the east in a woodlot. They never came any closer that I noticed.
Why would owl decoys possibly deter real owls? Probably relates to territorial factors and even fear since multiple decoys are being used in my case. I use three decoys and this multiple approach may better “convince” a real owl that this territory is taken and more owls may create more possible fear. One of the enemies of a great horned owl (or barred owl) is another great horned owl. Great horned owls are dominant over barred owls and could probably kill and even eat them! Even if our martin colonies are in the territory of the real owls, perhaps multiple owl decoys intimidates the real ones.
I don’t know if the decoys will continue to work and will have a few more weeks to find out. The huge number of roosting martins in our colonies will end soon as they go to larger roosts.
If the decoy owls continue to keep the real owls away for the remainder of this season, I plan on installing more all around my colony for next season and will add some to Bob’s colony, too. I want to present any real great horned or barred owl with a “flock” of great horned owl decoys to hopefully convince him/her that our martin colonies are already “taken” and in the territory of other owls so KEEP AWAY! I am thinking about at least six great horned owl decoys on poles surrounding my martin colony and some over at Bob’s colony, too.
Could there be problems using great horned owl decoys? Well, such decoys may frighten some martins and you would have to test “your colony” and see. If you only use the decoys when it is already dark, then this may lessen the chances martins would be frightened. The decoys could attract a local great horned owl which may try to defend its territory and attack the decoys. I haven’t notice that yet and the real owls are staying away for now.
Now I do realize that fake owl/hawk decoys often fail to keep birds away from crops/buildings. The birds eventually learn that the decoy is harmless and they start to ignore it. However, with the owls that raid our martin colonies, they are attacking from a distance and perhaps the silhouette of the decoy owls is enough to “convince” the real owls that another owl has claimed this territory. Also multiple decoy owls may even have some fright value against a single real great horned/barred owl or a pair of them. My owl decoys are most realistic from a distance, particularly when you see the ear tufts sticking up. However, the decoys could fail any night and only time will tell. So I really don’t know at this time if great horned owl decoys would be an effective owl deterrent for martin colonies and great horned and barred owls from different areas may behave differently when confronted with decoys. Just experimenting at this time and that is the way we find solutions to problems.
Here are some photos showing my owl decoys:
This photo shows the owl decoy on the fence post across the road from our martin colonies. This one is probably the first that the real owls notice from several hundred yards away.
This photo shows how close the decoy owl is to some of my martin housing.
And another photo.
Steve
