In short: October Big Day 2026 is on Saturday, October 10. It's a free, worldwide day of birding run by eBird, the bird-sighting website of the Cornell Lab of Ornithology. You watch birds for as long as you like that day, from anywhere, your own yard included, and share what you find as checklists in the eBird or Merlin app. To be counted in the official results, eBird asks for your checklists before October 13, so by Monday, October 12.
There's no minimum. eBird's announcement says you don't need to be an expert or go out all day: even 10 minutes of birding from home counts. Last year more than 870,000 people took part, and eBird is hoping to pass a million this time.
Key facts
- eBird's announcement and its October Big Day page both give the date as October 10, 2026. The day runs from midnight to midnight in your own time zone.
- It's free. You need a free account, and the same account works in eBird and in Merlin.
- On October 11, 2025, eBird's official results counted 113,510 checklists from 48,830 eBirders, 7,834 species and 196 countries. More than 870,000 people went birding with eBird or Merlin that day.
- The United States sent the most checklists in 2025 (40,204) and had the most eBirders (22,937). Colombia found the most species (1,382).
- The first October Big Day was October 6, 2018. Its first results counted more than 17,000 birders in 146 countries and 6,136 species.
Facts checked: October 4, 2026.
October Big Day 2026 at a glance
| Question | Answer |
|---|---|
| Date | Saturday, October 10, 2026 |
| Hours | Midnight to midnight, your local time |
| Where | Anywhere in the world, including from home |
| How long | As long as you like. Ten minutes counts |
| Cost | Free, with a free eBird account (Merlin uses the same one) |
| How you report | eBird checklists, or birds you save in Merlin |
| Deadline | Before October 13, for the official results |
| Run by | eBird, at the Cornell Lab of Ornithology |
| Sister event | Global Big Day in May (May 9 in 2026) |
How do you take part?
These steps follow eBird's own announcement, as it read on October 4, 2026.
- Get a free account. One account works for both the eBird and Merlin apps. Set it up before Saturday so you're not doing it on the day.
- Go birding on October 10. Any time between midnight and midnight where you are. A window, a backyard, a city park or a full day out all count.
- Keep a list for each outing. Note where you were, when you started, how long you watched, and every species you saw or heard, with a count of each if you can.
- Share it. Enter each list as a checklist on the eBird website or in the free eBird Mobile app. If you use Merlin, tap "This is my bird" for each bird you identify. If you use both apps, Merlin's settings can save your identifications to eBird, so they're added to the day's totals.
- Submit before October 13. Checklists in by then are counted in the official results announcement.
- Watch the totals come in. During the day, eBird's October Big Day page shows sightings arriving from more than 200 countries.
eBird's announcement also asks for one extra thing this year: if you can, add at least one bird sound recording to a checklist. And it notes that taking part also celebrates World Migratory Bird Day and Global Bird Weekend.
What counts on October Big Day?
Any bird you see or hear on October 10, in your local time, wherever you are. You can make as many checklists as you like through the day, in as many places as you like.
eBird's tips ask for three things that make your lists more useful to scientists:
- Complete checklists, meaning you report every species you identified, not only the highlights.
- Counts, how many of each species you saw.
- Several checklists through the day, one for each place or outing, rather than one long list.
Here's how a day might go, made up for this guide. Twenty minutes at the kitchen window before breakfast: a checklist with six species. A lunchtime loop around a pond: a second checklist. An hour at a hawk watch in the afternoon: a third. All three count, and together they're your Big Day.
How is October Big Day different from Global Big Day?
They're the same idea at two times of year, both run by eBird. Global Big Day is in May (Saturday, May 9 in 2026), during spring migration in North America. October Big Day falls in fall migration, when many birds are on their way south.
October Big Day is the younger of the two. The first one was on October 6, 2018. By 2025 it had grown to 7,834 species from 196 countries, and eBird says it was the first October day ever with more than 100,000 checklists.
The 2025 numbers above are eBird's official results. Its live stats page keeps adding checklists sent in later, so the totals there for the same day run a little higher.
Is it the same weekend as The Big Sit!?
Yes, in 2026. The Big Sit! runs on Saturday, October 10 and Sunday, October 11, so the two events share a Saturday. They're different events with different rules.
| October Big Day | The Big Sit! | |
|---|---|---|
| Date in 2026 | Saturday, October 10 | Saturday, October 10 or Sunday, October 11 |
| Where you bird | Anywhere, moving as much as you like | From inside one circle, 17 feet (5.2 m) across |
| Run by | eBird, at the Cornell Lab of Ornithology | The New Haven Bird Club |
| How you report | eBird checklists or Merlin, before October 13 | An eBird checklist shared with the organizers |
You can join both at once. The Big Sit! organizers ask each circle to report its count as an eBird checklist, and October Big Day's totals are built from the eBird checklists people send in that day. So a circle that sits on Saturday and submits its checklist in time is part of both. eBird's 2025 results post features one such day: the Queens County Bird Club in New York held an October Big Day Big Sit from the platform at Fort Tilden.
What is a "Big Day," exactly?
Among birders, a Big Day traditionally means trying to see as many species as you can in one day, often as a team that drives across a state from before dawn until after dark. The biggest counts ever made are in our guide to birding records.
October Big Day borrows the name but drops the race. There's no target and no minimum, and a short look from your doorstep counts as much as a dawn-to-dusk marathon.
Keep a record of your day
Your checklists stay in your eBird account. Your own notes are worth keeping too: who came along, the bird of the day, and your final count. If you see a species for the first time, it belongs on your life list with the date and place. And if one count a season isn't enough, the Christmas Bird Count runs from December 14 to January 5.
Over the years, Big Days add up to a long list. Birdfolio prints a birder's life list as a hardcover book, each species beside a classic painting.
Questions people ask
When is October Big Day 2026?
Saturday, October 10, 2026, from midnight to midnight in your local time zone.
Do I have to bird all day?
No. eBird says even 10 minutes of birding from home counts.
Is it free?
Yes. You need a free account, which works for both eBird and Merlin.
What's the deadline for checklists?
eBird asks for them before October 13 to include them in the official results.
Can I take part outside the United States?
Yes. It's worldwide: in 2025, checklists came in from 196 countries.
Is it the same as Global Big Day?
No. Global Big Day is the spring event in May. October Big Day is its fall counterpart.
October Big Day is run by eBird at the Cornell Lab of Ornithology. We have no connection with it.
Birdfolio is not affiliated with eBird, the Cornell Lab of Ornithology or iNaturalist.