How big will my tort need to be before I can stop worrying about a predator picking him up and carrying him away? I have Hawks and a rather large great horned owl that lives around here.
Yours is 4lbs, huh? Well, my tort is 10" and weighs 5lbs...and I have no worries that a hawk will take him.
I do lock him up every single night though. I don't trust those sneaky night time predators!
I leave my Russians outside during the day in the summer and nevered worried about the hawks taking my torts I do bring them in at night though for tempeture reasons
An owl may just drop down and make a meal out of him/her on the spot.
You seldom read about a predatory bird doing something like this..And then you hear about someones pet small dog flying away.
Recent concerns about a hawk led me to build an 8' x 18' X 6.5' fully enclosed tortoise pen.
Up until that time I had my R/F tortoises outside all day. All week. Many as small as 500 grams.
No problems. Ever.
It's likely that such an event would never happen.
At 1800 grams you are probably safe from most ariel predators, but not from raccoons, coyotes or dogs. Every situation is really a case by case basis.
I live in the country and we are surrounded by all sorts of predators. I've never had a problem with any predator bothering any of my tortoises, but there are lots of people and other animals around during the day and they are locked up at night.