October Big Day 2021: a world united by birds

By Team eBird October 13, 2021
Dunlin Calidris alpina

Last Saturday, nearly 33,000 birders around the world enjoyed birds for October Big Day. October Big Day contributors joined from a record-setting 195 countries and reported 7,269 species, making 9 October the biggest day in October birding history! This year’s global team consisted of more than 800 eBirders in Africa, 2,000 in Asia, 2,500 in Europe, and 5,300 in Central and South America. These tremendous efforts showcase the power of birds to bring people together.

October Big Day wouldn’t be the global phenomenon it is without the incredible birding community. The eBird portal collaborator network continues to inspire and motivate communities around the world and we’re grateful to work with every one of these groups. Huge thanks also to Carl Zeiss Sports Optics for their sponsorship of eBirder of the Month challenge, including an opportunity to win Zeiss Conquest binoculars by participating in October Big Day.

In addition, this year’s October Big Day celebrated World Migratory Bird Day and the second annual Global Bird Weekend. Tremendous thanks to the World Migratory Bird Day team, and also Global Birding, Birdlife International, and Swarovski Optik for making Global Bird Weekend possible.

Listen to Michael Ramsey’s recording of a Scarlet Robin, one of the first audio recordings uploaded on October Big Day:

October Big Day by the numbers

  • 32,670 people went birding
  • 78,024 checklists submitted
  • 7,269 species recorded
  • 43,153 photos submitted to the Macaulay Library
  • 1,170 audio recordings submitted to the Macaulay Library
  • 108,000 Merlin users saved nearly 15,000 bird identifications

Explore more October Big Day results

For thousands, this year’s October Big Day was their first big day. More than 2,800 contributors submitted their first eBird checklist on 9 October. Welcome to the fun!


Below we’ve highlighted some fun themes and stories shared by you, the global birding team.

Birds connect us to nature

This year, October Big Day coincided with World Migratory Bird Day—an opportunity to recognize and celebrate migratory bird species. Hundreds of millions of migratory birds were on the wing during October Big Day, and from every continent, eBirders observed the movements of songbirds, cranes, raptors, and more.

Observers in Mexico and Taiwan were treated to large flocks of migrating raptors:

Sandhill Cranes took flight in North America, while Common Cranes passed through Spain:



“Welcome, little migrating zebra” tweets Esteban Ortiz from Colombia, where this Black-and-White Warbler recently arrived for the winter:

The amazing, continent-spanning journeys of migratory birds connect us to the natural world, and to each other.

Birds connect us to each other

Each community celebrates October Big Day in a unique way, and it’s inspiring seeing October Big Day supporting existing groups and initiatives. This year, eBird Taiwan put their own “spin” on October Big Day with a Low-carbon Birding Challenge. Participants were asked to spend the day birding by foot, bike, public transportation, or rideshare. A team of eBird Taiwan members even completed a long-distance cycling and birding adventure!

The Festival of Birds on San Cristóbal, Galapagos celebrated October Big Day with games and a presentation on local birds that was fun for the whole family:

Birding on October Big Day is a chance to connect with others. In a Big Day tradition, people who protect nature professionally count birds alongside students, researchers, birding clubs, and tourists to raise awareness for local biodiversity and promote conservation initiatives.




Big Days are also an opportunity to enjoy birds with friends and loved ones. In Venezuela, a group of 45 scouts went birding together in a local park.

While in Honduras, Nhering Lobo spent the day birding with the Club de Observación de Aves Los Alzacuanes (coALA) and found four lifers. Check out the Club’s great October Big Day sign!


For young people, October Big Day can spark a lifelong passion for birds. Young birders in Colombia were inspired by toucans and other colorful birds. Their smiling faces brought joy to the rest of the group.

Matías Garrido shared baby-birder Lautaro’s excitement over new species at the London Wetland Centre. We all know that lifer feeling!


Every bird counts

There’s no right or wrong way to contribute to October Big Day. As the examples below demonstrate, you can be a part of October Big Day from home:

Or very far from home. Teams on the islands of St. Kilda and Gough added unique endemics to the October Big Day species list from opposite sides of the planet:

You can spend the entire day birding, a few hours, or just a few minutes!

On October Big Day, every bird and every list counts. A single bird may not seem like much, but submitting even one checklist means you’re a part of the global team.


Another huge thanks to everyone who contributed. We couldn’t do it without you!

Communities connected by birds

Every year, we are blown away by volunteer efforts to rally communities around the world in support of birds. Thanks again to the tremendous network of eBird collaborators for making October Big Day possible, we can’t appreciate you enough.


Thank you!

A massive and heartfelt THANK YOU to everyone who submitted checklists on October Big Day. eBird contains more than 1 billion observations of birds from over 710,000 eBirders, all thanks to your efforts. Your observations provide valuable insights into the lives of birds that help us to better understand and protect bird populations.

At eBird, every day can be a big day, a reason to step outside even for just 10 minutes to enjoy birds and share observations for science. Together we can help better understand, conserve, and enjoy birds for many years to come. Thank you for being a part of it.

More Results

TOTAL species by country

  1. Colombia—1,335
  2. Peru—1,213
  3. Ecuador—1,084
  4. Brazil—1,059
  5. Bolivia—820
  6. Kenya—792
  7. India—790
  8. Argentina—780
  9. Costa Rica—731
  10. Mexico—709

TOTAL checklists by country

  1. United States—39,832
  2. Canada—7,222
  3. Colombia—3,489
  4. Argentina— 3,217
  5. Costa Rica— 3,181
  6. India—3,084
  7. Australia—2,450
  8. Spain—2,201
  9. Chile—2,127
  10. Brazil–1,688

INCREASE in number of checklists over 2019

  1. Thailand—322%
  2. Iran—179%
  3. Cayman Islands—150%
  4. Zimbabwe—138%
  5. Zambia—111%
  6. Japan—109%
  7. Chile—82%
  8. Iceland—57%
  9. Finland—48%
  10. Bolivia—45%


TOTAL eBirders by country

  1. United States—17,146
  2. Canada—3,015
  3. Colombia—1,053
  4. India—912
  5. Australia—897
  6. Costa Rica—793
  7. Argentina—694
  8. Spain—657
  9. United Kingdom—645
  10. Brazil—606

NEW eBirders by country

  1. United States—1241
  2. Canada—173
  3. Colombia—129
  4. Costa Rica—100
  5. Brazil—95
  6. India—94
  7. Australia—92
  8. Chile—88
  9. Peru—82
  10. United Kingdom—60

INCREASE in number of eBirders over 2019

  1. Zimbabwe—210%
  2. Thailand—136%
  3. Czech Republic—117%
  4. Cayman Islands—114%
  5. Malaysia—47%
  6. Uganda—35%
  7. Iran—31%
  8. Tanzania—28%
  9. Australia—28%
  10. Chile—27%