Increased sightings of birds usually found further south, such as the red-bellied woodpecker, are indicators of a trend years in the making, says the co-ordinator of the 2014 Christmas bird count in Kitchener.
The increase is partly a result of warming climates, said Mike Burrell.
"There's so much going on in the natural world, it's always hard to say this one thing is the cause for this change in population. But when we look at species that are slowly expanding northwards, there certainly seems to be evidence to suggest that's at least partly caused by climate change," said Burrell.
He added birds are good indicators of environmental change because they can be surveyed easily.
"When I was a kid [the red-bellied woodpecker] was a very, very rare bird. You had to go down to Lake Erie or Hamilton or even further south to see one," Burrell said.
"Now we get 20 or 30 every year on the Christmas bird count and this year we set another new record for that species in the Kitchener count with 45 red-bellied woodpeckers."
The bird count is carried out by hundreds of volunteers. Altogether, four bird species spotted for the first time in the 80-year history of the annual Christmas bird count in the region.
The ruddy duck, the common raven, the trumpeter swan and the Eurasian collared dove were the species that were seen for the first time, said Burrell.
"There's always unusual sightings. That's part of what makes bird watching so fun, you kind of expect the unexpected," said Burrell.
"But we had actually four new species this year – pretty amazing for an 80-year count. That's more new species than we've added in the last 15 years combined."
Bird count tracks trends
The bird count, which is conducted across North America each holiday season tracks migration trends and bird health. Among the trends for 2014 is a growing bald eagle population in Ontario, Burrell said.
"Fifteen or 20 years ago bald eagles were a very rare sighting," Burrell said. "Now we get many every year."
The most common species spotted by volunteers participating in the count was the American crow, with just over 13,000 of the bird counted.
"Anybody in the Waterloo area kind of around the University of Waterloo and Westmount area, they'll know there are a lot of crows in the region. There's a huge crow roost there so that's our most abundant species," said Burrell.
The crows are followed closely by Canada geese and mallard ducks as three most-seen species in Waterloo Region.