Island bird watchers are catching glimpses of an unusual number of snowy owls this year.

The owls, rarely seen so far south, have appeared from one end of P.E.I. to the other. Provincial wildlife biologist Rosemary Curley told CBC News Tuesday usually only three or four birds are seen a year on the Island. This year there have been about 100 confirmed sightings in the Maritimes.

While that's a thrill for birders, it is not a good sign for the birds.

"On P.E.I. we've seen them from Souris West to Alberton," said Curley.

"The birds from those two areas were turned into the vet college, and they were quite emaciated — one of them subsequently died. Probably few of the birds will actually make it back north; probably a good portion of them will succumb."

Most of the birds showing up are young and P.E.I. does not provide their main food supply, lemmings.

It's not known why the birds are travelling south of their normal range, but there is a theory that the lemming population has crashed.