@Marie2020 How ya doin? Awww… you are so kind to animals. Have you been able to approach him at all? .Maybe try to corner Oliver with an tall gated open unfolded doggie kennel cage that swings out far enough to prevent any danger to you , or something that is tall and wide enough for oliver not to escape pushing him toward a cat carrier with a trail of tuna leading to the cat carrier set in a corner with more tuna food inside. (They can be tricky when wild . Is he a stray or feral cat? We have a lot of feral cats here .) Fishy food can distract them long enough to get him to go toward the cat carrier with yummy treats inside. If that doesn’t work ask your vet for a cat tranquilizer to put in his food to expedite the process. Is there a cat box for him to use. Usually the difference between a feral and stray cat is a stray cat will come to you where a feral cat with run away. Boy or girl?
Feral cats can be hard to corral and hazardous to your health. Be careful.