About

The Green Big Day is an international birding event for birders who want to support greenbirding in their local communities.  The object is to count as many bird species as possible in a 24 hour period in a designated geographic area without using motorized vehicles.

How to Participate

  • Choose a date and birding route in your home county.
  • Assemble a hiking or biking team of two or more.
  • Go birding during any 24 hour period April-May.
  • Submit your results through the website by June 15.

Green Big Day Rules conform to the ABA Recording Rules with the following additions:

Count can start anytime after midnight and end anytime before midnight within a single 24 hour period. Once count has started, competitors must refrain from using any motorized vehicle until counting has ended.  Approved human-powered or natural methods include walking, skiing, biking, kayaking, sailing, etc.  Heard only birds are acceptable subject to confirmation by all members of the team.

Competition is for teams of 2 or more, and only species seen or heard by all members of the team may be counted.  Single person records will be accepted and posted with the designation “single”.  Records will be recorded for the following geographic areas: County, State and Country.