Zookeepers tracked an eagle to a park after the bird escaped from its tether in north London.
Delilah, a six-year-old African Tawny Eagle, is thought to have freed itself from London Zoo at about 1230 GMT.
Londoners enjoying the sunshine watched as zookeepers wearing leather gloves and carrying food followed it to parkland at neighbouring Primrose Hill.
Delilah was safely recaptured at about 1545 GMT - after keepers spotted frightened birds circling the eagle.
Robert Goodchild, from London Zoo, said Delilah - who has a 6ft wing-span - had probably got carried away by the strong wind.
He and colleague Claire Horton easily found her, as seagulls and crows were making such a racket.
"She's been off work all winter so she's very unfit, Primrose Hill is about as far as her range would have taken her," said Mr Goodchild.
"We tried coaxing her down but because of the windy conditions she couldn't get close enough to land properly."
Eventually fatigue and the circling birds overhead forced her down on Primrose Hill.
He was surprised Delilah had managed to give them the slip by somehow untying her tether.
"It's very unusual. There's a special knot we use which is very difficult for a bird to be able to undo," he said.
Although tired, Delilah managed to eat all her food when she got back to the zoo which is a good sign, he added.
Eyewitness Kate Newman said: "There were lots of seagulls in the air and birds going mad and there was a big circle of people - in the middle was an eagle sat on the ground.
"[The keeper] just went straight up and got it and another guy came up in a van and fed it a couple of little chickens, then they left. "