A swallow’s acrobatic flight was once a common sight in Canada, but according to a recent report, it’s just one of many avian species whose numbers have decreased over the past four decades. The State of Canada’s Birds, 2012, published by the North American Bird Conservation Initiative in Canada, draws on 40 years of data and 12 long-term surveys, ranging from large-scale continental to single-species surveys, and finds there are fewer birds now than there were in 1970, the year effective monitoring began in Canada for most species. On average, the number of birds has fallen nationally by 12 percent since then, with 44 percent of species decreasing and 33 percent increasing. The report, the first of its kind in Canada, divides the country into eight regions, and while the plight of birds such as the swallow can make for dispiriting reading, there are good news stories too. We’ve listed examples of both in each region for a quick snapshot on how our feathered friends are faring. For more information about the report and its findings, visit www.stateofcanadasbirds.org.

1. Southern Shield and Maritimes
Populations across all bird species in this region have decreased by 13 percent.

Thriving: American black duck
This is one of a number of waterfowl whose numbers have increased, due in part to careful management of hunting in Canada and the United States and habitat conservation.

Struggling: Olive-sided flycatcher
Aerial insectivores, including this threatened species, have decreased by almost 70 percent, possibly as a result of habitat change or a decline in insect prey because of pesticide use.

2. Lower Great Lakes-St.Lawrence
On average, all species in this region are up by 20 percent, but some groups are of great concern, such as aerial insectivores.

Thriving: Hooded merganser
Habitat conservation and improved nesting in urban areas have been a benefit to the species, which has increased by more than 50 percent.

Struggling: Chimney swift
The number of these aerial insectivores has declined by 95 percent. Factors in their decline may include a reduced insect population and loss of nesting habitat.

3. Eastern Boreal
Billions of nesting birds call this region’s forests, bogs and wetlands home, but it’s under threat, largely from industrial development.

Thriving: Sandhill crane
Thanks to the protection provided by the Migratory Birds Convention Act, this species’ numbers have increased by as much as 100 percent.

Struggling: Blackpoll warbler
A migrant forest species, this bird has decreased in population because of the loss of habitat from encroaching industrial development.

4. Western Boreal
Billions of birds use this massive region, the focus of some intense industrial development, as a breeding ground.

Thriving: Green-winged teal
This “generalist” species of duck has doubled its population over the past 22 years.

Struggling: Lesser scaup
This “specialist” species of diving duck has declined by more than 50 percent since 1990, possibly because of shifts in the aquatic food web caused by climate change.

5. Prairies
Grassland birds have declined by almost 40 percent, and the Prairie Pothole Region — an important waterfowl nesting area that stretches across parts of Manitoba, Saskatchewan, Alberta, British Columbia and five U.S. states — is under threat of being drained.

Thriving: Western meadowlark
This is one of many species to benefit from bird-friendly farming practices, such as planting cover crops to provide shelter for nesting and reducing the amount of pesticides used.

Struggling: McCown’s longspur
The population has plummeted by 90 percent, and the loss of its native grassland habitat to agriculture could be one of the biggest factors in its decline.

6. West Coast and Mountains
Characteristic species have declined overall by 10 percent, but along the Pacific coast, they’ve declined by 35 percent.

Thriving: Trumpeter swan
This species has been brought back from the brink of extinction through habitat restoration and legal protection in Canada and the United States.

Struggling: Red crossbill
The number of these birds has declined by 10 percent, mostly due to the logging of mature forests, which provide their main food source: cones.

7. Arctic
Climate change may be the biggest contributor affecting bird populations in this region.

Thriving: Snow goose
This population has increased by more than 300 percent — but at a cost to coastal salt marshes, where the birds engage in intense foraging.

Struggling: Whimbrel
Habitat loss, environmental pollutants and climate change have seen the numbers of Arctic shorebirds such as the whimbrel decline by 60 percent.

8. Oceans
The number of seabirds has increased, but the Pacific region has seen a minor decline due to introduced predators, such as rats and raccoons.

Thriving: Northern gannet
Almost 60,000 pairs of this species nest on Île Bonaventure in the Gulf of St. Lawrence, up from 16,000 in 1976. Reduced exposure to pesticides is one of the reasons the population has increased.

Struggling: Ancient murrelet
Fifty percent of the world population is found off the coast of British Columbia, and introduced predators — namely rats and raccoons — have significantly reduced their numbers.

2. Hooded merganser (Illustration: Ksenia Nigmanova)

2. Chimney swift (Illustration: Ksenia Nigmanova)

1. American black duck (Illustration: Ksenia Nigmanova)

1. Olive-sided flycatcher (Illustration: Ksenia Nigmanova)

4. Lesser scaup (Illustration: Ksenia Nigmanova)

4. Green-winged teal (Illustration: Ksenia Nigmanova)

3. Blackpoll warbler (Illustration: Ksenia Nigmanova)

3. Sandhill crane (Illustration: Ksenia Nigmanova)

5. Western meadowlark (Illustration: Ksenia Nigmanova)

5. McCown’s longspur (Illustration: Ksenia Nigmanova)

6. Trumpeter swan (Illustration: Ksenia Nigmanova)

6. Red crossbill (Illustration: Ksenia Nigmanova)

7. Whimbrel (Illustration: Ksenia Nigmanova)

7. Snow goose (Illustration: Ksenia Nigmanova)

8. Northern gannet (Illustration: Ksenia Nigmanova)

8. Ancient murrelet (Illustration: Ksenia Nigmanova)