North American breeding birds — what's recovering, and what's vanishing
Six decades of population trends from the public-domain USGS Breeding Bird Survey, made readable. Search a species, then drill into how it's faring family by family, guild by guild, and state by state.
Three Ways to Explore Bird Population Trends
The data reads at different scales because the questions do. Pick the entry point that matches what you actually want to know.
Steepest Declines
The species losing ground fastest across surveyed states — the heart of the breeding-bird decline story.
See the declinesHow Guilds Are Faring
Birds grouped by how they live — grassland birds, aerial insectivores, forest species — and where each group is heading.
Browse guildsExplore By State
Trends, species lists, and survey routes for each of the 49 states the Breeding Bird Survey covers.
Pick a stateBiggest Bird Population Changes
The steepest declines and strongest recoveries across surveyed states.
How Bird Guilds Are Faring
Grassland birds and aerial insectivores are the cratering groups — the core of the BBS decline narrative.
Four Principles For Bird-Trend Data
The Breeding Bird Survey is rich, public, and underused outside ornithology. We built the analytics-and-narrative layer most people actually want into a single URL per bird.
Trend, Not Counts
Raw route counts are noisy year to year. We surface the multi-decade direction of each population, so the signal isn't lost in the static.
Guild-Level Signal
Single species wander, but ecological guilds move together. Rolling trends up to the guild reveals the structural story — who's cratering and who's holding.
One Public-Domain Source
Everything is built from the USGS Breeding Bird Survey: six decades of standardized roadside counts, run by volunteers, free for anyone to reproduce.
Methodology Open
Every trend window, baseline year, and caveat lives on the methodology page. Read the rules; reproduce the numbers.
Browse Birds by Family
Six decades of bird-trend data, with the analysis already done.
Free. No accounts. No tracking. Built on public-domain USGS data.