Osprey Repellant
Posted: Mon May 07, 2012 5:11 pm
Below are some photos of a contraption I built and installed to try and prevent ospreys from sitting on my mast head equipment. It consists of a ¾"x¾"x9 ½" base and a ¼-20 threaded rod about 13" long with a PVC plumbing plug and cap mounted on top. Several long and short thin iron wires about 1/16" diameter are stuck in holes drilled in the PVC plug and cap. The wires are those with little flags on top used to mark underground pipes during construction. I used two screws with fender washers on the base bottom to clamp it to the mast head plate. My masthead plate is ¼" thick and 7 ¼" wide. All the gear is available at most any hardware store. The device seems to be generally working but two enhancements are needed.
First, the threaded rod needs to be longer, maybe 18". As shown in pictures 8 & 9, the wires are fairly close to the Raymarine wind vane and actually interfere with the Windex vane. I took the Windex off and a longer rod will allow it to be reinstalled. A longer rod will also prevent the forward wires from getting caught under the Raymarine rotor. Twice I've seen the outboard forward wires under the rotor and the rotor jammed, but a day or two later the rotor would be free with no harm done. I think Crackles or Crows are trying to perch on the wires which bend down and catch under the rotor. Also, one occasion I saw an osprey sitting on the Raymarine wind vane during a very light wind flowing perpendicular to the boat. I think he was able to straddle the center forward wire because it is so close to the vane. If the wire is 5" or so higher, I don’t think he can do that.
Second, the threaded rod and the wires need to be stainless steel. I used ferrous metal because that is what I had and painted it but doubt that will last long.
The device has sustained a few 20+ knot winds with no apparent problem. The longer wires dance around some but probably don't deflect more than an inch or so in a pretty brisk breeze. If you try this, it is definitely worth a scouting trip up the mast to take some measurements. I did not and guesstimated dimensions from drawings and pictures. I got close but no cigar. Good luck.
First, the threaded rod needs to be longer, maybe 18". As shown in pictures 8 & 9, the wires are fairly close to the Raymarine wind vane and actually interfere with the Windex vane. I took the Windex off and a longer rod will allow it to be reinstalled. A longer rod will also prevent the forward wires from getting caught under the Raymarine rotor. Twice I've seen the outboard forward wires under the rotor and the rotor jammed, but a day or two later the rotor would be free with no harm done. I think Crackles or Crows are trying to perch on the wires which bend down and catch under the rotor. Also, one occasion I saw an osprey sitting on the Raymarine wind vane during a very light wind flowing perpendicular to the boat. I think he was able to straddle the center forward wire because it is so close to the vane. If the wire is 5" or so higher, I don’t think he can do that.
Second, the threaded rod and the wires need to be stainless steel. I used ferrous metal because that is what I had and painted it but doubt that will last long.
The device has sustained a few 20+ knot winds with no apparent problem. The longer wires dance around some but probably don't deflect more than an inch or so in a pretty brisk breeze. If you try this, it is definitely worth a scouting trip up the mast to take some measurements. I did not and guesstimated dimensions from drawings and pictures. I got close but no cigar. Good luck.