You can get a Fearow in the Kisara Plains Capture Challenge
after getting 50,000 points in the capture arena (extra loops is key!!) , go back to the safari capture challenge, northern area there should be a fearow. there is no other place to capture it.
The largest arena in Rome was/is the "Colosseum".
Capture Arena
It is to the west of Harabu Desert. First you must complete the game then Chairperson Erma will give you a ticket to go to the capture arena. Then you to Harabu Desert and go to the east dock and a wailord will be waiting for you. Ride it and it will take you to the capture arena.
To get to the Capture Arena you have to complete the story mode in Pokemon Ranger: Shadows of Almia. Then you have to go to Haruba Village. Go to the east exit and go to the dock. A Wailord will be waiting for you. Get on it and it will bring you to the Capture Arena.
That's up to you to decide
easy capture every poke assist then capture the bosses
After beating the capture arena in Shadows of Almia, one can finish the quests. Once done with all the quests, get all the Pokemon on Rank S.
to be easy, just catch gloom and then use sun stone on it, it will evolve into bellossom
It is a place where you can improve your capturing skills.
In Shadows of Almia, you have to ride Wailord in Hakuba Dessert.
The Capture Arena can be accessed only after you have beaten the story. Once you have done this, go to Haruba Village and go right. Keep following the trail (should be a dock) down until you reach a Wailord. It will ask you if you want to go to the Capture Arena. Say yes, and the Wailord takes you there. To leave, either capture the Staraptor flying in front of the building and use its Field Move, or go back to the dock and use Wailord to return to the beach just east of Haruba Village. Once you get to the Capture Arena the first time, you can go back either the same way you first got there, or you can now use Staraptor to go to the Capture Arena from anywhere in Almia.