Big Atlas Weekend—June 25–27

By Gabriel Foley May 28, 2021

Photo Credit: Gabriel Foley

If this year’s “Big Day” didn’t fit into your busy spring schedule, here’s another chance to make your birding count! How about a Big Atlas Weekend? This exciting new event is a fun way for birders from across the state to document breeding birds and come together as a birding community. For many birds in our area, breeding peaks in late June. It’s a great time to Confirm breeding and fill gaps in the Atlas data.
This event is being coordinated across four states that are currently conducting breeding bird atlases—New York, Maine, Maryland and DC, and North Carolina.


  • June 23 @ 7 pm – Kickoff. Introduction by the four Atlas coordinators followed by guest speakers Purbita Saha and Stephanie Beilke from the Galbatross Project talking about female bird song and identification and female bird days. (pre-registration required)
  • June 24 @ 7 pm – Training for new atlasers in Maryland and DC. New atlasers will be walked through what an Atlas is, learn about the essentials needed to participate, and receive general atlasing tips. (Google Meeting details)
  • June 25-27 – Big Atlas Weekend! Go atlasing in any of the four participating regions from 6 pm on Friday to 11:59 pm on Sunday.
  • June 30 @ 7 pm – Awards ceremony. Enjoy highlights from the weekend, share your stories in small groups with atlasers from all states, and find out who won the individual and state champion awards. (pre-registration required)

All event details are posted on Facebook.

How to Participate

Go atlasing between 6:00 pm Friday, June 25 and 11:59 pm Sunday, June 27 and submit your checklist through the MD-DC Atlas portal in eBird.
If you are new to atlasing, check out our 3 Atlas Essentials and don’t forget to also attend the special training offered on June 24th!

Challenges and Prizes

The Big Atlas Weekend will have prize opportunities for atlasers of all skill levels, ranging from first-timers to veterans. One prize winner will be selected in each of the following categories to win a Cornell Lab of Ornithology Bird Academy course of their choosing.

  • Complete Atlas checklist for the first time ever
  • Complete Atlas checklist with at least one coded species
  • Complete Atlas checklist with at least one Confirmed species
  • Complete Atlas checklist with nocturnal effort
    • Learn about atlasing at night. A nocturnal checklist is considered to be a checklist submitted between 20 minutes after sunset and 40 minutes before sunrise.
  • Complete Atlas checklist with at least one Confirmed priority species (MD-DC only)
  • Complete Atlas checklist in a block with <20 hours of diurnal effort
  • Complete Atlas checklist in a block with no visits

Interstate Competition

Just to make this event even more exciting, the Atlas team has set up a friendly competition between the four participating states—New York, Maine, Maryland-DC, and North Carolina.
An overall state champion will be selected based on a point system. The ranking of each state in three categories that are comparable across atlases in various stages of data collection will be used to award points. The top placing state in each category receives 23 points, second place 13 pts, and third place 7 pts. The state with the most points wins. The odd point values are chosen to help prevent ties. The number of checklists in each category will be standardized before determining rank. The categories and standardization adjustments are:

  • Nocturnal hours in priority blocks
    • Hours from complete nocturnal lists with duration
    • Adjusted for number of participants (# nocturnal hours / # participants)
  • Confirmed codes in priority blocks
    • Number of complete checklists in priority blocks that have at least one species with a confirmed code
    • Adjusted for number of blocks (# eligible checklists / # eligible blocks)
  • Atlas checklists
    • Any complete atlas checklist with at least one coded species
    • Adjusted for number of atlasers (# eligible checklists / # participants)


Who doesn’t love a bit of swag?! We’ve designed a logo for this year’s event that features the birds on each of the participating state’s Atlas logos. Order a t-shirt and other items from TeePublic. Proceeds go towards next year’s event.

Let’s all get out atlasing between June 25 and June 27 so that Maryland and DC can claim bragging rights for the inaugural Big Atlas Weekend!