A first-time report on the state of Canadian bird populations confirms that grassland bird species, including greater sage grouse and burrowing owls, are declining on the Prairies and in danger of further loss.
Forty-four percent of Canadian bird species are declining and 33 percent are increasing. Overall numbers have declined about 12 percent since the 1970s.
On the Prairies, grassland bird populations have shrunk by an average of 40 percent since 1970, according to a Bird Studies Canada report entitled The State of Canada’s Birds 2012. Most prairie waterfowl continue to hold their own.
“It was the first time we’d actually tried to gather all these disparate data sets together and look at all birds,” said Dick Cannings, senior project officer with Bird Studies Canada.
“We assume with the grassland birds, most of the problems seem to be just a steady loss of habitat and habitat quality. A lot of the really large areas of grassland have been cut up for roads for oil and gas exploration.”
Habitat loss for grassland species is also a factor in the United States and Mexico, where the birds migrate, Cannings added.
“It’s mainly a habitat issue, from various angles. That’s pretty much across the board what the problem for grassland birds is.”
The June report indicates bird numbers are heavily influenced by human activity, which helps some species and hinders others.
Migratory shore birds and aerial insectivores have also declined in the past 40 years, by 40 percent on average and up to 90 percent in some species, the report said.
However, conservation efforts have increased the number of peregrine falcons, ospreys and bald eagles that were once in severe decline.
The report had this summary about the prairie situation:
“Grassland birds are in trouble. Since 1970, populations on the Canadian Prairies have declined by almost 40 percent on average.
“Historical population declines were likely even larger as much native grassland habitat was lost prior to the start of bird monitoring in 1970.”
Dave Howerter, national manager for wetland and waterfowl research with Ducks Unlimited Canada, was on the steering committee for the report.
He said he is encouraged by waterfowl numbers that show an increase among some species. Ruddy ducks and gadwalls are up 50 and 70 percent, respectively, after years of decline in the 1980s.
“It is generally good news,” said Howerter.
“Like all of these kind of reports that lump all bird groups together, some of the devil is in the details.”
Howerter said ducks have responded to recent wet conditions on the Canadian and U.S. Prairies and have seen several consecutive high production years.
However, he is cautious in his enthusiasm.
“The information shows that wetlands are still being lost across all three prairie provinces. I think there’s certainly a lot more discussion of that now, on whether that’s a good idea or not, but the fact remains that wetlands continue to be lost.”
Howerter said Ducks Unlimited is “anxiously awaiting” results of the most recent federal census of agriculture to see if farmers are converting more wetlands to cultivation because of higher commodity prices.
Preservation of native grasslands is also key to maintaining species, said Cannings. The report specifically mentions the benefits of livestock grazing for bird habitat, and Cannings said the public should monitor land use decisions to ensure native grasslands are maintained.
Recent moves by the federal government to turn community pastures over to the provinces will bear watching to ensure bird habitat is not reduced, he said.
People can also help birds by observation, Cannings added. The health of birds can inform them about the health of their own environment.
“Birds just happen to be the best group of animals for us to monitor. They’re brightly coloured, easy to identify, there’s lots of different kinds so they cover all sorts of different habitats and niches.
“They are active during the day, they sing loudly … they’re very conspicuous compared with things like mice and insects and worms.”
Cannings, a biologist, has been monitoring grassland birds for more than a decade and helped assemble data for the report. It contained few surprises for him.
Raised in Penticton, B.C., he said he has always been interested in grassland species.
“One of the iconic birds of those grasslands is the western meadow lark. … It’s still nice to hear those meadowlarks singing, but knowing that there’s only half the number there was 40 years ago is very concerning to me, so it sort of makes it personal.”
A bit about birds
- Canada has billions of birds in about 450 regularly occurring native species
- 66 species are endangered, threatened or of special concern
- since 1970, 44 percent of species have lower populations, 33 percent have increased and 23 percent have shown little change
- grassland birds, aerial insectivores and shore bird numbers are declining
- waterfowl, raptors and colonial seabirds are increasing
- since 2001, the number of at-risk species has increased but some species have recovered from previous declines
- the highest proportions of at-risk species are in the lower Great Lakes, the West Coast, the mountains and the Prairies
- only 22 percent of Canadian bird species spend the whole year in Canada. Most migrate to the United States, Central America and Mexico
- Greater sage grouse
- Burrowing owl
- Loggerhead shrike
- Sprague’s pipit
- Wood thrush
- Piping plover
- Ivory gull
- Whooping crane
- Common nighthawk
- Eastern whip-poor-will
- Chimney swift
- Barn swallow
- Olive-sided flycatcher
Source: State of Canada’s Birds 2012