Trends in Canada's bird populations

Key results

From 1970 to 2022, the trends in bird species groups varied:

• The following groups experienced an increase: waterfowl (by 46%), birds of prey (by 35%), and wetland birds (by 21%)
• The following groups experienced a decrease: grassland birds (by 67%), aerial insectivores (by 43%), shorebirds (by 42%), long-distance migrants (by 29%), and Arctic birds (by 28%)
• Marine and forest birds showed little change overall (less than 1%)^{Footnote 1}

Trends in bird populations by species group, Canada, 1970 to 2022

How this indicator was calculated

Note: Data for shorebirds are only available beginning in 1980. This analysis is based on 331 species that are representative of their ecological groups and for which adequate monitoring data are available. Of the 331 species, 193 species are included in more than 1 species group based on their feeding or habitat requirements. For example, species included in the aerial insectivores feeding behaviour category may also be included in the forest birds group. For a complete list of bird species, please refer to the supplementary data table.
Source: Birds Canada and Environment and Climate Change Canada (2024) State of Canada's Birds.

Since 1970, 5 groups (grassland birds, aerial insectivores, shorebirds, long-distance migrants, and arctic birds) have shown large declines. Canadian grassland birds have declined more rapidly (67% total decrease) than other groups, primarily due to habitat loss and fragmentation as a result of land conversion for agricultural land, urban expansion, roads, and the oil and gas industries. Climate change has also contributed as droughts and floods have become more frequent and severe. Grassland birds that depend solely on native grasslands for breeding and wintering have declined by 90%. Even species that can slightly tolerate agricultural lands have declined by 42%.

Aerial insectivores, like swallows, are birds that feed by catching insects in the air. This group has decreased by 43% since 1970, with swifts, swallows and nightjars representing most of the group's decline (60% decrease). Reductions in insect prey populations, presumably because of pesticide use, harmful farming practices, habitat loss and habitat degradation, are likely a key reason for the group's decline.

Canadian shorebirds, like plovers and sandpipers, primarily live along the coastlines of oceans, lakes, rivers and marshes. They have declined by 42% since 1980, when the earliest comprehensive data became available. Shorebirds live in varied habitats and have long migrations, making them vulnerable to many threats like habitat loss and disturbance at migratory stopovers.

Long-distance migrants include species that migrate to tropical regions, like Mexico, South America and, in some cases, Africa or Asia. Short-distance migrants include those that migrate to temperate regions of North America and Europe. Long-distance migrants have declined more since 1970 (29% decrease) than short-distance migrants (12% decrease) or species that remain in Canada (9% increase).^{Footnote 2} These migrants face many threats across many countries and landscapes, and require international cooperation for their conservation.

Arctic birds, hardy birds that live in Canada's expansive tundra, are hard to monitor. More than a quarter of these species have insufficient data for a trend analysis. Those species that do have data show that populations have dropped by 28% since 1970, with a notable steep decline in the mid-2000s, primarily due to the reduction in arctic shorebird populations (54% decrease). This may be a warning sign of the effects of climate change on the Canadian Arctic. Improved monitoring and the adoption of Traditional Ecological Knowledge to data collection practices are essential to conserving these unique birds.

Bird populations fluctuate naturally in response to ecological conditions, but negative changes in bird populations reflect the overall effect of many different factors. Some of these factors include habitat loss and disturbance, pollution, agricultural impacts, climate change, invasive species, unsustainable hunting and declines in prey populations. Other sources of direct mortality, such as collisions with windows and cat predation, also affect bird populations. These factors act both in Canada and internationally, in countries where birds that breed in Canada migrate through and/or spend the non-breeding season.

Waterfowl, birds of prey and wetland birds are groups that show increases relative to 1970. These groups include species like geese, eagles, and herons. Waterfowl and birds of prey experienced a decline in their populations in the mid-1900s and have been recovering from this decline since the 1970s. Due to wetland habitat protection and restoration and increased waste grain in agricultural areas, wetland birds and waterfowl populations have increased by 46% and 21% respectively, though both groups are influenced by several goose and swan populations that have grown substantially (by 573%) since 1970. The birds of prey group has increased by 35%, thanks in part to endangered species legislations and policies that ban the use of the chemical pesticide dichlorodiphenyltrichloroethane (DDT).

Trends within species groups

Each species group includes both decreasing and increasing species, which are averaged into a composite mean annual rate of change for the group. Changes in bird populations can also be viewed as the percentage of species whose populations have increased, have decreased or showed little to moderate change.

Key results

Overall, from 1970 to 2022 of the species for which sufficient data are available:

• 31% (104 species) had showed an increase
• 27% (88 species) showed little to moderate change
• 42% (139 species) had showed a decrease

Long-term changes in bird populations by species group, Canada, 1970 to 2022

How this indicator was calculated

Note: ^[A] Data for shorebirds are only available beginning in 1980. This analysis is based on 331 species that are representative of their ecological group and for which adequate monitoring data were available. Of the 331 species, 193 species are included in more than 1 species group based on their feeding or habitat requirements. For example, species included in the aerial insectivores feeding behaviour category may also be included in the forest birds group. For a complete list of bird species, please refer to the supplementary data table.
Source: Birds Canada and Environment and Climate Change Canada (2024) State of Canada's Birds: Species accounts.

Overall, 51% of bird species have either increased or shown stable populations since 1970. The 2 species group with the greatest proportions of species that have increased are the birds of prey (49%) and waterfowl (46%). On the other hand, the 3 groups with the greatest proportions of species that have decreased are aerial insectivores (71%), grassland birds (71%) and shorebirds (68%).

About the indicator

What the indicator measures

The indicator reports population trends of Canada's native bird species from 1970 to 2022. Bird species are categorized into species groups based on their feeding and/or habitat requirements.

Why this indicator is important

Birds provide ecological benefits by controlling insect and rodent populations, dispersing seeds, pollinating plants and playing other key roles in the functioning of ecosystems. Not only do these ecosystem services contribute to our economy and our physical and mental well-being, but birds themselves do so as well.^{Footnote 3 Footnote 4} Bird watching is a popular activity and millions of Canadians feed birds in their backyards.^{Footnote 5} Waterfowl hunting contributes to tourism, provides food and maintains traditions.

Because birds are sensitive to environmental changes, the health of bird populations can be used as an indicator of ecosystem health and the state of biodiversity. Many long-term monitoring programs exist because most bird species communicate via song and are easily detected; these provide data on population change dating back to the 1970s (or, in some cases, even earlier). Tracking the state of Canada's birds can help to identify the impacts of these changes, and can also help to set conservation priorities, evaluate management actions and track the recovery of species at risk.

Related initiatives

This indicator supports the measurement of progress towards Goal 15 of the 2022 to 2026 Federal Sustainable Development Strategy: Protect and recover species, conserve Canadian biodiversity.

This indicator contributes to the Kunming-Montreal Global Biodiversity Framework. It is linked to Target 4: "Ensure urgent management actions to halt human induced extinction of known threatened species and for the recovery and conservation of species, in particular threatened species, to significantly reduce extinction risk, as well as to maintain and restore the genetic diversity within and between populations of native, wild and domesticated species to maintain their adaptive potential, including through in situ and ex situ conservation and sustainable management practices, and effectively manage human-wildlife interactions to minimize human-wildlife conflict for coexistence." It is also linked to Target 21: "Ensure that the best available data, information and knowledge, are accessible to decision makers, practitioners and the public to guide effective and equitable governance, integrated and participatory management of biodiversity, and to strengthen communication, awareness-raising, education, monitoring, research and knowledge management and, also in this context, traditional knowledge, innovations, practices and technologies of indigenous peoples and local communities should only be accessed with their free, prior and informed consent, in accordance with national legislation."

Related indicators

The Population status of Canada's migratory birds indicator reports the proportion of bird species listed in the Migratory Birds Convention Act whose populations fall within, or are above or below national population goals.

The General status of wild species indicator reports extinction risks across a broad set of species and can reveal early signs of trouble before species reach a critical condition.

The Changes in the status of wildlife species at risk indicator tracks changes in the status of species at risk assessed by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC).

The Species at risk population trends indicator shows whether population and distribution trends of species at risk that are listed under the Species at Risk Act are consistent with recovery or management objectives.

Data sources and methods

Data sources

The indicator is based on data from many different monitoring programs that use a range of methods designed to survey different bird species in different habitats. The indicator presents the best available estimate of population trends across species groups of native bird species occurring in Canada from 1970 to 2022.

Methods

The 2024 State of Canada's Birds report considers 463 species of birds that are native to North America and that regularly occurred in Canada in 1970. They were classified into 10 ecological groups based on their habitat and/or feeding requirements: aerial insectivores, arctic birds, birds of prey, forest birds, grassland birds, long-distance migrants, marine birds, shorebirds, waterfowl, and wetland birds.

Of the 463 species, 84 generalist species were difficult to classify into ecological groups, and as such were excluded from the analysis. Forty-eight (48) additional species did not have sufficient data to calculate trends from 1970 to 2022. Therefore, the analysis was based on the remaining 331 species. For a more complete list of all bird species included in the 2024 State of Canada's Birds report and how they are considered in the indicator, please refer to the supplementary data table.

The most appropriate data source for each species was selected from the available monitoring programs. To be comparable among species and data sources, each species population trend was modelled as a proportional change from the base year of 1970 to create a species index. These were then combined into a single composite index for each species group. The overall, long-term trends for each species group were determined based on the change in the final year relative to 1970.

Recent changes

The State of Canada's Birds 2024 presents the best state of knowledge of birds in Canada, which has evolved since 2019. More precisely, the methods for analysis and assessment have improved. New data for many species that were data deficient before, like nocturnal owls, have also been added. The current indicator is revised to consider 2 additional bird groups: long-distance migrants and arctic birds. The group known as seabirds in the previous iteration was renamed marine birds. Furthermore, generalist species, which were previously classified under "all other birds", were excluded in the current indicator. Finally, the data sources of previous iterations of the indicator relied on population-based reporting. This update instead leverages species-level assessments to report population trends.

Caveats and limitations

Population trend estimates contain some uncertainty and results should be interpreted with this in mind.

For some bird species, a best estimate of their population status was imprecise and/or based on a small proportion of the Canadian population. This is often the case for species that breed in isolated northern regions. Species with insufficient data to estimate indices were excluded, including those that were either difficult to survey (like those that breed in remote areas or are very rare) or species for which surveys had only recently been developed and did not yet have long-term trend information (like many owls and pelagic marine birds). Generalist species that are also able to thrive in a variety of environmental conditions and habitats, like American robins, are difficult to classify to specific ecological groups. As such, 84 species were also excluded from the indicator. For a complete list of bird species included in the State of Canda's Birds 2024 report, please refer to the supplementary data table.

Seventeen (17) species that expanded their ranges into Canada after 1970 were also excluded because of their influence on the composite index. These include: Anna's hummingbird, black vulture, black-necked stilt, blue-gray gnatcatcher, blue-winged warbler, California scrub-jay, Carolina wren, dickcissel, Eurasian wigeon, fish crow, gray flycatcher, great egret, red-bellied woodpecker, tufted duck, tufted titmouse, white-faced ibis, and wild turkey. For these species, the estimates of the percentage change in population size since 1970 were extremely large, because their Canadian populations in 1970 were approximately 0. Because the composite index is the average of the percentage change values across species, these extremely large values, if included, would overwhelm the influence of the other bird species within the group.^{Footnote 6}

Resources

References

Birds Canada and Environment and Climate Change Canada (2024) State of Canada's Birds. Retrieved on January 9, 2025.

Birds Canada and Environment and Climate Change Canada (2024) State of Canada's Birds: Methods. Retrieved on January 9, 2025.

Hammoud R, Tognin S, Burgess L, Bergou N, Smythe M, Gibbons J, Davidson N, Afifi A, Bakolis I, and Mechelli A (2022) Smartphone-based ecological momentary assessment reveals mental health benefits of birdlife. Scientific Reports 12: 17589. Retrieved January 28, 2025.

Sauer JR and Link WA (2011) Analysis of the North American Breeding Bird Survey Using Hierarchical Models. The Auk 128: 87 to 98. Retrieved on January 9, 2025.

Statistics Canda (2023) Flocking to their houses in the subirds. Retrieved on January 28, 2025.

Stobbe E, Sundermann J, Ascone L, and Kühn S (2022) Birdsongs alleviate anxiety and paranoia in healthy participants. Scientific Reports 12: 16414. Retrieved January 28, 2025.

Related information

Bird conservation partnerships

Birds in Canada's forests

Birds protected in Canada

Migratory birds