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The Great Backyard Bird Count runs over four days in mid-February, Friday through Monday. You watch birds for at least fifteen minutes on one or more of those days, count the highest number of each species you see at once, and submit the list through eBird or Merlin. It is free, it takes a quarter of an hour, and you do not need to be able to identify everything.
The Great Backyard Bird Count is run jointly by the Cornell Lab of Ornithology, the National Audubon Society and Birds Canada. It began in 1998 as one of the first citizen science projects to collect and display bird data online in real time, and it now draws participants from most countries in the world.
It is also the easiest entry point into bird recording there is. Fifteen minutes, no fee, no equipment beyond what you already have, and no requirement to identify every bird you see.
The essentials
- When: four days in mid-February, Friday to Monday. Check the official site for this year’s dates
- How long: a minimum of 15 minutes, on any of the four days
- Where: your yard, a park, a trail, a window — anywhere
- Cost: free
- What to count: the highest number of each species seen at one time
- How to submit: eBird or Merlin, both free apps from the Cornell Lab
How to do it
Before the weekend. Create a free Cornell Lab account, which works across eBird, Merlin and Project FeederWatch. Download Merlin Bird ID if you want identification help, and eBird if you want to submit from your phone. You can also submit from a computer afterwards using notes on paper.
On the day. Pick a spot and a stretch of at least fifteen minutes. A window overlooking a feeder is completely legitimate — there is no requirement to go anywhere.
Counting. This is the part people get wrong, and it matters. Record the highest number of each species you can see at the same moment, not a running total. If three cardinals are on the feeder at once, then two, then three again, the answer is three. Counting every arrival separately would count the same bird repeatedly and inflate the data.
Submitting. Enter the list in eBird or Merlin with the date, location and how long you watched. Do more than one count if you like — separate lists for separate sessions, or different locations.
You do not need to identify everything. Record what you are confident about and leave the rest out, or use Merlin to work it out. A short list of correctly identified common birds is more useful than a long list of guesses. Nobody is being assessed.
What the data is used for
A single February weekend produces a snapshot of bird distribution across a continent that no research team could gather on its own. Because it has run annually since 1998, those snapshots stack into a long series, and that is where the value is.
Uses researchers have made of it include:
- Tracking irruptions — winters when boreal species such as Pine Siskins, redpolls and Evening Grosbeaks push far south. February is well positioned to catch these
- Range shifts over time, including species moving north across decades
- Winter distribution in a way scattered individual records cannot show
- Disease and mortality events, since unusual absences and reports of sick birds show up in the data
- Feeding into eBird, which is one of the largest biodiversity datasets in existence and underpins a great deal of published research
Getting more out of it
A few things that make the count more enjoyable, none of them required:
- Fill the feeders the day before. Birds visit a reliably stocked feeder more consistently
- Count early. Feeder activity peaks in the first couple of hours after sunrise
- Put water out. It brings in species a feeder never will
- Do more than one session across the four days — different birds turn up in different weather
- Sit still. Fifteen minutes without moving produces a noticeably longer list than fifteen minutes of wandering about
Binoculars are not required and plenty of people take part without them. If you want a pair, 8×42 is the standard backyard specification, and close focus matters more than magnification — many pairs will not focus nearer than fifteen or twenty feet, which is useless when the feeder is on the deck rail. The honest drawback: cheap binoculars often have misaligned barrels that cause eye strain within minutes, which is worse than using none at all.
Where it sits among the other counts
| Project | When | Commitment |
|---|---|---|
| Great Backyard Bird Count | Four days, mid-February | 15 minutes. Free |
| Project FeederWatch | November to April | Regular counts through the season. Small annual fee |
| Christmas Bird Count | Mid-December to early January | A full day in an organized circle. Free |
| NestWatch | Breeding season | Monitoring nests every few days |
| eBird | Year-round | Whenever you want. Free |
The GBBC is the lowest-commitment of them by a distance, which is the point of it. If it goes well, Project FeederWatch is the natural next step.
Common questions
When is the Great Backyard Bird Count?
Four days in mid-February, running Friday through Monday. The exact dates shift each year, so check the official GBBC site or the Cornell Lab for the current year.
Do I have to count for all four days?
No. A single fifteen-minute count on one day is a complete, valid contribution.
What if I cannot identify a bird?
Leave it out, or use Merlin Bird ID, which identifies from a photo, a sound recording or a few questions. Accurate short lists are more useful than long uncertain ones.
How do I count birds that keep coming and going?
Record the highest number of that species visible at one moment. Counting each arrival separately would count the same individual repeatedly.
Does it have to be my backyard?
No, despite the name. A park, a trail, a lake or a window all count, and you can submit separate lists for different places.
Is it free?
Yes, entirely. Project FeederWatch, which runs across the whole winter, carries a small annual fee; the GBBC does not.
Related guides
- Project FeederWatch: what it is and how to join
- Common backyard birds of North America
- Small brown birds: how to tell them apart
- When to feed backyard birds
Sources: Cornell Lab of Ornithology, National Audubon Society and Birds Canada, Great Backyard Bird Count; eBird and Merlin Bird ID, Cornell Lab of Ornithology; Project FeederWatch; National Audubon Society Christmas Bird Count.
Want a closer look?
A pair of 8x42 binoculars is the single thing that changes backyard birding most. Close focus matters more than magnification when the bird is fifteen feet away.
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