A grassroots bioblitz is an event where local volunteers organize and conduct an intensive survey of the biological diversity of a park or other natural area. Participants record observations of as many different organisms as possible – everything from algae to alligators. The event typically lasts for a few hours to a day, and observations are recorded through a smartphone application.
In 2014, Nerds for Nature held eight grassroots bioblitzes where 221 iNaturalist users logged 7,155 observations. Those observations fell into 1,536 unique identification assignments (anywhere from no taxa down to subspecies). More than half, 3,601 observations, were "research grade," which means that multiple people confirmed the ID and those observations are useful for science and fed into state, national, and global biodiversity databases.
The map below shows the locations of all eight bioblitzes in 2014 and then overlays those with a timelapse of observations throughout the year. You can use the "Visible Layers" picker in the upper right to turn off the timelapse and turn on other views, like observations by animal type or by quality.