How big is that bird, really?
BirdView draws North American birds as stick figures — bill, head, neck, body, tail, and a wing crossbar — at one shared scale, so you can see size differences instead of imagining them from numbers. Is a Merlin bigger than a Blue Jay? Line them up and look.
It covers over a thousand species: those whose records recur in the US states, the Canadian provinces, five US outlying islands, and five stretches of open sea. Each figure is an abstract top-down view of a bird in flight, showing only what the data supports: no plumage, posture, or shape the sources cannot justify.
You need Go. From a clone of this repository:
go run ./cmd/birdview-ingest # builds the dataset from the sources in this repo
go run ./cmd/birdview # serves http://localhost:8080
Then open http://localhost:8080 and follow one of the suggestions under the title.
| If you are… | Read | It covers |
|---|---|---|
| using the site | docs/using.md | the controls, the stick figures, reading a tile, things to try |
| checking the science | docs/data.md | what is measured, what is modeled, what is invented |
| tracing a number to its source | docs/pipeline.md | every source, the fields read from it, and each step between |
| building or changing it | docs/building.md | build, run, deploy, the data's licenses, and the spec-driven workflow |
No openly licensed dataset publishes body length for these birds, so every length in BirdView is
a model built from measured parts. Bill, tail, and mass are measured for almost every species;
wingspan is measured for about a third and estimated for the rest; head, neck, and body are modeled
from mass. Every value is marked measured, near-match, or modeled, and clicking a bird shows
the source or formula behind each number. docs/data.md gives the full accounting,
including what is invented and
where the models are most likely to be wrong.
BirdView is built from sources under CC BY 4.0: names and taxonomy from AviList, body measurements from AVONET, wingspans from Fox et al. 2026, and where each bird is found from eBird and iNaturalist records via GBIF. It links to iNaturalist for photographs and copies none. Every source is credited on the site; docs/building.md lists them with licenses and what this repository keeps.
BirdView's own code and documentation are licensed under the Apache License 2.0.
Everything under third_party/ is not: each directory there carries its own
license and a README naming its source.
This is not an officially supported Google product.
Report problems and corrections as issues; corrections to the biology are especially welcome. See CONTRIBUTING.md to contribute code and CHANGELOG.md for major changes.
Eligibility for the Google Open Source Software Vulnerability Rewards Program is determined by the Google Open Source Software Vulnerability Reward Program Rules.