Chris, a company called Coveside Conservation Products makes
squirrel/predator guards for nest boxes. The slate guards keep things
(including woodpeckers) from enlarging the holes. They use defective /
discarded slate roofing tiles to make them. I think a flycatcher box uses
a 2.5” hole and they seem to have those in stock.
On Sunday, February 8, 2026, Christopher Hill <carolinabirds...>
wrote:
> Hi all,
>
> I have a box that Great Crested Flycatchers nest in every spring and
> summer. In the winter some squirrel always makes it their personal project
> to enlarge the hole and turn it into a squirrel nest. I would like to
> install a metal guard with 1 5/8" hole (or whatever, I'd have to go back
> and check the proper diameter) to prevent a third re-occurrence when I
> reclaim the box for flycatchers this spring. Just a piece of sheet metal
> with a hole and no sharp edges or burrs (so I don't want to try freehanding
> with tin snips, for example). Googling doesnm't work for any combination
> of words I have come up with - infinite places wanting to sell you baffles
> for a pole, but no metal hole guards. Anybody have an idea or a source?
>
> CH
>
> Chris Hill, Ph.D.
> Professor
> Biology Department
> Coastal Carolina University
> Office: Douglas 207H
> (843) 349-2567
> email: <chill...>
>
>
"These days I prefer to hunt with a camera. A good photograph demands more
skill from the hunter, better nerves and more patience than the rifle
shot." -- Bror Blixen
