How will scientists use your observations?

Common Redpoll reports from the Great Backyard Bird Count in 2001 and 2002.

Note the increase in the number of redpolls reported along the Canadian - U.S. border in 2002 when compared with one year earlier. Using data from Project FeederWatcha nd the Great Backyard Bird Count, scientists have found a two-year cycle in Common Redpoll irruptions. Scientists will be able to use your information in the eBird database to uncover movement patterns in all species, and from time periods throughout the year.

Documenting Bird Distribution

Your checklists document the presence (and ideally absence) of species at a specific time and geographic location. Plotting all of the observations of that species over days, weeks, months, or years allows us to determine the species' range, including movement patterns and changes in distribution.

Each species' seasonal movements become evident when comparing its distribution from various times throughout the year. We can discover the precise migratory paths followed by Neotropical migrants, we can look for patterns in the post-breeding wanderings of Wood Storks, or we can watch the movements of nomadic species during the winter months.

By comparing a bird's range among different years, scientists can keep track of changes in distribution. Where will Eurasian Collared-Doves colonize next? Where do Lawrence's Goldfinches winter each year? Are breeding and wintering ranges of different species expanding, shrinking, or staying the same? Do migratory paths change between years? Answering these questions will help us understand birds more completely and aid in their conservation.

From a scientist's perspective, knowing if a bird species is absent is equally important as knowing if it is present. For this reason, it is important that you report all of the birds you saw or heard whenever possible, so researchers analyzing your observations will know not only which species you saw, but also which species you didn't see. If birders only report the birds they went out looking for, the resulting distribution map ends up only showing where birders like to go to see various species and not where the birds are distributed. Accurate distribution maps need to reflect where birds are and where they are not.

Abundance Trends

Whether you submit actual counts or only presence/absence information for each species, you help scientists to estimate how common a species is at various locations across its range. Actual counts are more informative (there's a big difference between 1 and 10,000 Snow Geese!), but researchers at the Lab of Ornithology have successfully used presence/absence data to explore such topics as the habitat preferences of forest songbirds. Comparing how birds' numbers change over time is especially important in conservation biology. Your counts will be instrumental in helping scientists to determine whether population sizes are increasing, decreasing, or remaining the same.

It's actually quite easy to collect data that are useful for mapping distributions and determining an index to a species' abundance. To make sure your observations are included in these analyses, pay particular attention to these pieces of information:

• Keep track of when you started, how long you were birding, how far you traveled, or the size of the area you covered. Knowing these variables will allow you to make and submit a more valuable observation to eBird.
• Record and report all of the birds you observe, not just the highlights. Knowing which birds are not present is just as valuable to scientists as knowing which species are present.
• Whenever possible, count the number of individuals for each species.