The Great Backyard Bird Count (GBBC) is a free, four-day bird count held every February. Anyone, anywhere in the world, can watch birds for as little as 15 minutes and report what they saw online. It is run jointly by the Cornell Lab of Ornithology, the National Audubon Society and Birds Canada, and every report goes into eBird. The next count, which Audubon calls the 30th annual GBBC, runs February 12–15, 2027.
Quick read
When: Friday, February 12 to Monday, February 15, 2027.
Minimum: watch birds for 15 minutes or more, at least once over the four days.
How: submit with the free Merlin Bird ID app, the eBird Mobile app or the eBird website. No separate GBBC sign-up.
GBBC at a glance
| Fact | Detail |
|---|---|
| What it is | A four-day count of wild birds; the organizers call it the first online participatory-science project to collect wild-bird data and show results in near real time |
| Run by | Cornell Lab of Ornithology, National Audubon Society and Birds Canada (Birds Canada joined in 2009) |
| Started | 1998; went global in 2013, when the count began entering its data into eBird |
| Next count | February 12–15, 2027 |
| Minimum effort | 15 minutes or more, at least once over the four days |
| Where | Anywhere you find birds: a backyard, a park, a preserve, an office window |
| Cost and sign-up | Free (Audubon); no separate registration, but you need a free Cornell Lab account in Merlin or eBird |
| Data entry | Opens at midnight local time on the first day and stays open until March 1, for birds seen during the four count days only |
| Paper lists | Not accepted; an email address is needed so reviewers can confirm flagged reports |
How to take part, step by step
- Set up before the count. Install Merlin Bird ID or eBird Mobile and sign in, or create a free account. A login you already use for eBird or an earlier GBBC works. In Merlin, also install the Bird Pack marked "Recommended" for your region; without it you won't see bird photos, and Wi‑Fi speeds up the download.
- Decide where you will watch. You can count alone or with others. To join a group, look for local events on the GBBC Community Map, or add your own.
- Watch for at least 15 minutes on any of the four days. The FAQ notes that longer counts give a better picture of the birds in your area, and you can count on more than one day or at more than one place.
- Identify every bird you see or hear in your chosen time and place, and note how many of each. If you're stuck, try a field guide, Merlin or the Audubon Bird Guide app. If you still can't name it, enter a group such as "Downy/Hairy Woodpecker" or "hawk sp."
- Submit. In eBird Mobile: tap Start Checklist with Record Tracks on, add each species and its number, tap Stop, choose your location, confirm group size and duration, answer the complete-checklist question and tap Submit. No signal? Tap Close and the list waits under "Not Submitted" until you have reception.
If you already use Merlin or eBird, everything you enter over the four days counts toward the GBBC automatically; there is nothing to enter twice. New to checklists? Our eBird for beginners guide explains each checklist type and the counting rules in more depth.
- Count days: Friday, February 12 to Monday, February 15, 2027. Lists can be started from midnight local time on the first day.
- Pick a spot: anywhere you find birds, alone or with a group.
- Watch 15+ minutes: the minimum, at least once over the four days; longer counts give a fuller picture.
- List every species you see or hear and can identify, with how many of each.
- Submit online with Merlin Bird ID, eBird Mobile or the eBird website.
- Entry window: data entry stays open until March 1, but only for birds seen on the four count days.
Merlin, eBird Mobile or the eBird website?
| Tool | Suggested for | What you send |
|---|---|---|
| Merlin Bird ID (free app) | Beginners still learning to identify birds; the GBBC suggests it for new participants | Saved bird IDs, one species at a time, from Explore Birds, Sound ID, Step-by-Step ID or Photo ID. Sound ID birds need no count and are saved as incidental sightings |
| eBird Mobile (free app) | Experienced birders and current eBird users | A full checklist with numbers, time and distance, plus optional comments and media |
| eBird website | Anyone who keeps notes on a hike or at the feeder and enters them later on a computer | The same full checklist, entered at ebird.org/gbbc/submit |
Merlin covers birds from seven continents in 18 languages. Its Sound ID works the way our bird songs for beginners page describes: tap "This is my bird" for each match you can confirm, choose Merlin or eBird, set the location and save.
What counts as a checklist
A checklist is one counting session at one location. The GBBC FAQ gives these rules:
| Situation | What to do |
|---|---|
| New location, or a second session at the same spot | Submit a separate checklist for each, even on the same day |
| Birds at your feeder | Report the highest number seen at one time; count only clearly different individuals for a "conservative estimate." Birds flying over the feeder count too |
| Birds flying overhead | Count them only if you can make a positive identification |
| Walking a route | Use a Traveling count in one habitat, ideally under 5 miles; split longer routes and plot each segment at its center. When backtracking, enter the distance one way but the total time |
| Watching on and off | Estimate the time you actually spent watching birds |
| A huge flock | Count a small section, estimate how many equal sections make up the flock, and multiply |
| "Are you reporting all species?" | Yes if you listed every species you could identify, even if some birds stayed unidentified; No only if you deliberately left out species, such as House Sparrows |
| Counting as a group | One person enters the list and shares it with the others, who need their own accounts |
| You also do Project FeederWatch | Submit separately; the two projects use different protocols |
Stationary, Traveling and Incidental counts are all accepted; Historical counts are not used for the GBBC. Unusual species or very large numbers are flagged and reviewed locally before they appear publicly, but you will always see them in your own account. Photos and sound recordings you attach are archived in the Macaulay Library.
Why February, and what the data is used for
The count began in February to capture where birds are just before spring migration. Since it went global in 2013, it takes a February snapshot wherever participants are; Cornell's land-trust page calls it "a snapshot of late-winter bird populations across the world." According to the FAQ, the data helps scientists see:
- which species may be increasing or declining
- how ranges are shifting
- how birds in cities and suburbs compare with those in natural habitats
Past GBBC data can be explored with eBird's bar charts. GBBC data from before 2013 is no longer viewable because of an eBird database migration.
Past participation
Figures as published on birdcount.org's results pages. Participant numbers are the organizers' estimates.
| Year | Estimated participants | Checklists | Species identified |
|---|---|---|---|
| 2026 | 1,146,284 | 467,696 | 8,257 |
| 2025 | 838,113 | 387,652 | 8,078 |
| 2024 | 642,003 | 384,416 | 7,920 |
| 2023 | 555,291 | 390,652 | 7,538 |
| 2022 | 384,641 | 359,479 | 7,099 |
| 2021 | 300,000+ | 379,726 | 6,436 |
| 2020 | 268,674 | 249,444 | 6,942 |
| 2019 | 224,781 | 204,921 | 6,699 |
In 2026 the count also logged 1,239,329 saved Merlin Bird IDs from 216 countries or eBird subregions. The United States had the most checklists, 253,053, covering 696 species; California, Florida, Texas and New York led the states. The three birds most often identified in Merlin in the US were the Northern Cardinal, the House Finch and the Dark-eyed Junco.
Count-day checklist
Print this section or keep it open on your phone.
Before February 12
- Merlin or eBird Mobile installed and signed in to a free Cornell Lab account
- Merlin Bird Pack for your region downloaded (on Wi‑Fi)
- Counting spot chosen; local event checked on the Community Map (optional)
During the count (February 12–15, 2027)
- Timer set for 15 minutes or more; start time noted
- Every species seen or heard and identified is on the list
- Feeder birds counted at the highest number seen at once
- Flyovers included only if positively identified
- Uncertain birds entered as a group, such as "hawk sp."
After each session
- One checklist per location and session
- "Reporting all species?" answered honestly
- Submitted, or saved under "Not Submitted" until you have signal
- Everything entered by March 1, with birds from the four count days only
Sources
- Great Backyard Bird Count — home page (birdcount.org, Cornell Lab of Ornithology, National Audubon Society, Birds Canada)
- How to Participate — Great Backyard Bird Count
- About — Great Backyard Bird Count
- FAQs — Great Backyard Bird Count
- Merlin Bird ID app instructions and eBird Mobile app instructions — Great Backyard Bird Count
- 2026 Results — Great Backyard Bird Count and 2026 Final Results
- Past Results (annual archive) — Great Backyard Bird Count and 2025 Final Results
- About the Great Backyard Bird Count (updated July 2026) — National Audubon Society
- Great Backyard Bird Count (land trust resources, updated March 2026) — Cornell Lab of Ornithology