A bird watcher in Lunenburg County says the once-common house sparrow is disappearing at an alarming rate in Nova Scotia.

James Hirtle, who co-ordinates the National Audubon Society's Christmas bird count in his region, said only 30 sparrows have been spotted in the most recent count.

"The last time I would have seen a house sparrow in Lunenburg County would have been before Dec. 1," he told CBC News.

"There is a steady decline. Every year there seems to be fewer and fewer."

Ian McLaren, an author and retired biology professor at Dalhousie University, said there are a variety of reasons for the drop in numbers, including a change in the way their food source — seeds — is treated by farmers.

"Grain is handled much more carefully now, it's not spilled all over the place like it used to be," said McLaren.

"There's less food for them."

Hirtle said the decline in the house sparrow population isn't unique to Nova Scotia — its numbers are dropping around the world.

"It tells me that there's something wrong with our environment when you see a species that declines so rapidly and so widespread," he said.

"There's a healthy population on one farm in the area in Lunenburg County, which seems to be remaining constant, but in Lunenburg itself and the surrounding areas they're really hard to come by in the winter."