Deportment is important here - the bird's bearing or demeanour is carefully scrutinised by the judges. They assess how it holds itself on the perch, where it positions its head, body and wings.

"I know it's a cliche, but the winning birds pick themselves," said Kathy Manton, a senior panel judge in the budgerigar division.

"The winner was the standout bird. Such substance and power. We're looking at the overall outline, the deportment."

It is deportment that allows a budgerigar or canary to distinguish itself from a row of other birds which look, to the untrained eye, almost identical.

"This one here is slouching, for instance," said Mrs Manton, pointing at one on the edge of his perch. "Terrible deportment."

The champion hen in the budgerigars, decided this week, was a opaline-cinnamon wing combination from Dee Why. It was a replacement bird, substituted at the last minute.

"The other one I was going to show is moulting," explained Gerry Lynch, a retired butcher who has been showing birds for a decade. "I'm extremely surprised. I haven't quite got over it yet."

The greater upset, however, was the winner of the African love bird division. Caleb Mantle, a 10-year-old from Belrose, won the grand championship with a jade peach face he bred with his grandfather last year. This is only his second Easter Show.

"You get a big ribbon about this big," Caleb said, stretching his arms as wide as they would go. "I'm just going to show it to my class first, then I'll put it in my room."

Glen Fuller, a stonemason who judged the love birds, applauded Caleb's youth. He said the breeders were competitive, but rivalries were not extreme.

"There's not a great deal of money on it," he said. "Some of the cattle and the sheep, [ribbons] make a lot of difference. If you win a Royal with these, it's not as prestigious."