It's been done in New York's Central Park. Last year it was done right here in Balboa Park and this weekend it's taking over Mission Trails Park on and around Cowles Mountain. It's BioBlitz 2009 hosted and organized by the San Diego Natural History Museum.
The first BioBlitz was conducted 13 years ago in Washington DC and since then has been held in various cities around the country.
A year ago, scientists, researchers and volunteers counted more than 1,000 species living in Balboa Park. Starting at 3 p.m. Friday, more than 50 experts will hit the hills and canyons of Mission Trails to see what kind of animal and plant life they can document there.
That's the goal of a Bioblitz: to count and identify as many species as possible in a 24 hour period. The answer will be announced on Saturday at 3 p.m at the park's visitor center.
The public is invited to attend on Saturday but a word to the wise: there's a chance of showers so dress for cool and possibly wet weather.