To see two is as rare as seeing a hen floss those teeth.
One was spotted in Mosgiel at the weekend by Chris Harvey, and the other was discovered by Maori Hill resident Jennifer Bannister in her backyard yesterday.
"When I looked out the window, I couldn’t quite believe it at first.
"It was flying with the silvereyes and feeding with the silvereyes.
"I thought it may have been some sort of escaped pale canary, but it had the wrong beak, so it wasn’t."
She said it was the silver band around its eyes that gave her the clue it was a leucistic silvereye.
The only difference was its usual green/grey/brown feathers had been transformed into mainly white and light yellow feathers as a result of the leucism.
"It was lovely to see."
"Now it appears it’s in silvereyes.
"This is the first time I’ve ever heard about it in the silvereye population."
Mr McKinlay said it was caused by a partial loss of pigmentation, leaving animals with whitish fur, plumage or skin.
"When the feathers are developing, the pigment colours (for whatever reason) don’t set in the feathers."
It disadvantaged the birds, particularly silvereyes, because they needed their coloured feathers to help camouflage them, he said.
"Leucism makes them more obvious to predators. It might also lead to social dislocation within the flock."
But in this case, they appeared to be birds of a feather and were very happy and healthy, he said.
