The war on birds continues, especially with the dreaded cormorants!  

The illustration below provides an illustration that has worked for many.  This takes the place of cumbersome and often unsightly methods for keeping birds from sitting on your spreaders (if they just sat it wouldn't be so bad!).  It's permanent, at least for the season, and can easily be removed. Instead of the line you can use a thin stainless-steel (call or drop a note, we can get it for you but it's not on the site) or bronze wire strung tightly from the shroud to a small padeyes on the mast about 6 inches above the spreader keeps birds away.  Use stainless steel self-tapping screws or rivets. You should string several as shown.  If the line is horizontal they will still sit on it, you have to have a sufficient slope so that they can't.  Also, if it is high enough they can sit under it. Bring it out far enough to the shrouds that they can't sit in the "V" on the end.

It is almost invisible and also works on multi-spreader rigs.