North America is home to an incredibly diverse array of bird species. From tiny hummingbirds to massive California condors, birds have adapted to fill ecological niches across the continent. But exactly how many bird species inhabit North America? Getting an accurate count is challenging, but estimates range from around 914 species to over 1,200 species depending on how you define the geographic boundaries of North America.
Quick Answer
The best current estimate is that there are between 914-929 species of birds regularly occurring in the main North American landmass (Canada, the continental United States, and Mexico). However, when including nearby oceanic islands and Central American countries, the species count rises to over 1,200.
Defining the Geographic Boundaries
The first challenge in counting the number of bird species in North America is defining what geographic area is included. For this discussion, we will start with the three main countries that occupy the bulk of the continent – Canada, the United States, and Mexico. This can be considered “mainland North America.”
However, there are some important bird habitats located on nearby islands and coastal regions that are sometimes lumped in with mainland North America. These include the Hawaiian Islands, the Aleutian Islands off Alaska, Bermuda, the Bahamas, and other Caribbean islands.
In addition, Central American countries south of Mexico like Guatemala, Belize, Honduras and others contain many tropical bird species also found in parts of Mexico. So depending on how broadly you define “North America”, the species counts can vary significantly.
Mainland North America Species Count
Most authoritative sources estimate the number of regularly occurring bird species in Canada, the continental United States, and Mexico at between 914-929 species. This includes both native species and introduced species that now have self-sustaining populations.
The American Birding Association’s checklist currently includes 929 species in this region as of 2022. The United States Geological Survey estimates 914 native species just for the United States and Canada. Partners in Flight, a cooperative landbird conservation effort, tallies 949 species for the mainland North America total on their Watch List.
So while the exact number varies slightly depending on the source, 914-929 species is a solid estimate for the diversity of birds inhabiting mainland North America.
Factors Influencing Mainland Species Count
Why does the mainland North America bird species count clock in around 920 species? Several key factors influence this number:
- Diverse habitats – From arctic tundra to temperate rainforests to dry deserts, mainland North America contains an incredibly varied array of habitat types for birds to occupy.
- Geographic barriers – Geographic features like mountain ranges and large bodies of water help divide up populations and enable greater speciation.
- Latitudinal range – Mainland North America spans over 40 degrees of latitude, allowing both northern and southern bird species to find suitable habitat.
- Migratory birds – Many tropical bird species migrate to and from Central and South America seasonally.
- Introduced species – At least 84 non-native species like house sparrows, European starlings, and rock pigeons have established breeding populations.
The combination of diverse habitats, barriers, a huge latitudinal span, migratory routes, and introductions support the high mainland bird diversity.
Including Oceanic Islands and Central America
If we expand our definition of North America to include oceanic islands and Central American countries, the species count rises significantly.
Hawaii alone contains over 140 endemic species, meaning birds found nowhere else. Many Central American countries are home to dozens of tropical species, particularly hummingbirds, tanagers, and other neo-tropical birds.
By including these peripheral regions, estimates for the total number of North American bird species exceed 1,200:
- Audubon Society – 1,227 species
- American Bird Conservancy – 1,250 species
- Partners in Flight – 1,154 species
Expanding our geographic scope to include Central America and the oceanic islands clearly captures many additional tropical species not found on the mainland, increasing the species counts by over 25%.
The Most Diverse Bird Families
With over 900 species inhabiting mainland North America, which bird families contribute the most to this species richness? Several stand out for their diversity:
Parulidae – Wood Warblers
- Around 50-60 species regularly breed in North America
- Brilliantly colored but tiny, often less than 5 inches long
- Migrate long distances, many traveling from Canada to Central or South America
- Specialize in gleaning insects from trees and shrubs
Icteridae – Blackbirds, Orioles, etc.
- 46-48 regularly occurring species
- Medium-sized chunky songbirds with pointed bills
- Males frequently brightly colored to attract mates
- Diverse diet includes insects, fruits, nectar
Fringillidae – Fringilline and Cardueline Finches
- 35-40 regularly occurring species
- Small-medium songbirds that specialize in cracking seeds
- Males with bright red, yellow, or orange plumage
- Includes grosbeaks, goldfinches, siskins, redpolls
Tyrannidae – Tyrant Flycatchers
- About 38 species breeding in North America
- Aerial insectivores that catch prey on the wing
- Plain plumage but often bright wing patches
- Includes kingbirds, phoebes, peewees
These four diverse songbird families each contribute around 35-60 breeding species to mainland North America’s avifauna. Warblers, blackbirds, finches, and flycatchers collectively make up over 25% of the total mainland species count.
Threats to North American Bird Species
Sadly, almost 40% of North America’s bird species are facing serious population threats and have been placed on conservation Watch Lists. Some key threats include:
- Habitat loss and degradation – Logging, development, agriculture
- Climate change – Migratory timing, range shifts
- Predation by invasive species – Cats, rats, snakes
- Collisions with buildings and vehicles
- Pesticide poisoning
Conserving our incredible North American bird diversity in the face of these threats will require a coordinated effort across borders and habitats. Protecting remaining intact ecosystems, restoring degraded lands, and mitigating climate change impacts will give birds the best chance.
Public interest in birds can also help promote conservation. Simple actions like keeping cats indoors, reducing building collisions, and providing bird habitat in backyards can protect local species. Appreciating the incredible diversity of North American birds is the first step.
Conclusion
Determining a precise count of bird species in North America is challenging, given the huge geographic area involved and lack of comprehensive surveys. However, the best current estimates for mainland North America tally between 914-929 regularly occurring species. Expanding our scope to include oceanic islands and Central America boosts the total above 1,200 species.
A few bird families contribute disproportionately to North America’s high diversity, including warblers, blackbirds, finches, and flycatchers. However, habitat destruction, climate change, pollution, and other threats put nearly 40% of our avian diversity at risk. Conservation action based on sound science will be key to preserving North American bird populations for the future. Simply appreciating the amazing variety of bird life across North America can help inspire much-needed conservation efforts.