Make a mark on each side of the cover as close to the mast as possible.
Take the cover in and have them sew a zipper from there to the end of the
boom. Now when you put on your cover you're assured that it will be tight
around the mast and boom leaving no holes for the birds to climb in. When
you don't need to zipper the cover you can still use the fasteners you
always have. The zipper and cost to sew it on is cheap compared to the
tannin stains and bird poop on your main sail.

Jack

"Steve" wrote in message
...
I know the answer to this question is to do more sailing or less time with
the sail covers off.

This happened last spring but only came to mind (rainy day).

The problem started back in May/June and at first involved some small
birds
trying to make nests inside my alum. boom. A piece of duct tape took care
of
that but once I removed the sail cover and started doing some sailing ( I
returned to the same anchorage every day or so) these same birds would
start
building nests in the folds of my main sail. This would happen over night
or
during a single day.

When I would go to hoist the sail, I would get a shower of sticks, twigs
and
sometimes an egg or two.

The ultimate solution was to cover the sail tightly with the sail cover
and
even then they would try to get up under the cover.

Either I out lasted the mating season or I lost them when I move about 40
miles to another anchorage.

I guess my quesion is; Has an one else ever had this experience and how
did
you handle it (humanely).

If these birds are like other annoying creatures, they are probably
protected.

Steve
s/v Good Intentions