Herman,
I wish you luck with Garfield.
But as a warning,
they are more pain than gain.
Cats will urinate and deficate in your
garden beds if you have them,
especially in the fall and early spring.
They also will use your containers as their toilets.
Males will also mark the containers and your trees trunks.
They do help a little with the birds and squirrels,
but Garfield will roam the neighborhood,
so he is not always on watch.
Also during lazy days of summer when figs are ripe,
during the heat of the day,
Garfield is napping not hunting,
but birds are still eating.
I have two cats as pets indoors.
As for using cats as fig watch dogs,
they cause far too much damage to the property
compared to a few figs they might save.
Either way, good luck,
and don't feed garfield too much food,
he will get lazy like the real garfield.