A Continent of Birds

Shaped by Geography

The unique “triangular” geography of North America shapes the birdlife in our three nations. The vast expanses of northern Canada and Alaska support relatively few breeding landbird species added up over such a large area; however, their total numbers are enormous. In contrast, a tremendous diversity of bird species, many with very small global populations, thrives in the narrow region of southern Mexico, where temperate and tropical systems meet. These disparate regions of great abundance and diversity are joined through the annual migrations of billions of birds, funneling southward across the continent each fall and expanding back into the northern latitudes each spring. Preserving this spectacle of birdlife requires a tri-national vision for conservation action.

Landbird species richness is strongly associated with latitude. Over the course of the year, more than 350 landbird species may be found in southern Mexico, whereas a similar-sized area in the high arctic will host fewer than 45 landbird species.

		Abundance Among North America’s most abundant birds, the Yellow-rumped Warbler is a continental ambassador. Each summer, well over 100 million breeders fill the expansive northern forests, while each fall and winter, throngs of “yellow-rumps” pour into the southern United States, Mexico, the Caribbean, and Central America. Linkage Each fall, more than 5 million raptors funnel through a narrow geographic bottleneck in Veracruz, Mexico. The monitoring of this “River of Raptors” is directly supported by an ecotourism program that contributes to the local economy. Diversity The extremely high diversity in Mexico includes numerous representatives of primarily  neotropical families such as motmots, trogons, woodcreepers, parrots, and antbirds.

The total number of North American landbirds is staggering. PIF estimates that more than 10 billion birds are present at the end of each breeding season, with numbers receding as many die during migration and winter. This great abundance of birds is critical to the ongoing provision of fundamental ecosystem services, such as pollination, seed dispersal, and pest control, that support productive and resilient habitats throughout the continent.

Spectacular Linkage

Billions of birds—and almost 40% of all landbird species—traverse the continenttwice a year in spectacular migrations. Many of these birds move from breeding grounds in the vast boreal “nursery” to wintering grounds in the tropics, followingseasonal peaks of food availability. This migration, which links habitats throughout the hemisphere, has persisted for millennia and is one of the most complex and dynamic natural phenomena on the planet.

Spectacular Diversity  

North American landbirds of our three nations are incredibly diverse, representing58 taxonomic families and 75% of the global landbird orders. Sparrows (78 species), flycatchers (76 species), wood warblers (64 species) and hummingbirds (57 species) are especially well represented