...We discourage cormorants by rigging monofilament a few inches above wherever they might like to land. They trip on it and fly off. Ospreys in our harbor tend to chase them away as well
That's what I do too, a few inches above each spreader, tied to the rigging at each side, with some smaller pieces tied to the "root" of each spreader to keep the line over the spreader instead of purely going around the front of the mast.
I also run mono back and forth around the antenna's at the top of the mast, only a few inches above the top of the mast.
I attach a few loose pieces of mono to the top(s) of the antenna(s) at the top of the mast. The strands of mono drape down, coiling a bit, but they aren't so long that they can interfere with the windex.
Also, the new windex is the kind with the spike at the top.
All the above stays in place and I don't have to think about it. Your post reminded me.
When we are away for longer than a couple days, I use 1 long (reusable) length of mono from a spool and chris-cross the boat several times with mono, from the tops of the stanchions -- looping around each stanchion to keep tension without knots -- then from bow to backstay above the boom. I tuck the spool with any unused mono into a cockpit locker. When I come back, it's easy to wind it onto the spool. The only knot is near the bow, and I cut it with a knife and leave a little 6 inch pennant of mono in place.
After the first time implementing the "chris-cross at stanchion level" technique, there was a clump of "feather fuzz" on the mono. Some bird got the message. I think they get cautious when they see any mono, hence the pennants I leave on the bow.
Our problems with birds only got really bad when I left a pile of chain on the foredeck, after securing from a hurricane. Somehow, that looked like a rock or something and the birds felt at home. It took hours to scrub the boat with a brush and a bucket. There are still slight stains on the stack pack.
With the boat chris-crossed with mono, I once came on deck and saw a cormorant perched on our bow pulpit. I fixed that with a piece of monofilament going from bow pulpit to up a few feet on the furled head sail.