Urban Bioblitz 2D: Species Accumulation Curve

Volunteer citizen scientists are one of the main ways cities actually measure urban biodiversity — a "bioblitz" sends a handful of observers wandering through a park for a few hours to log every species they can find. This simulator renders that survey as a pannable, zoomable 2D map: a patchy habitat holds a hidden pool of species at realistically uneven abundances, small dots represent individual organisms that stay grey until a wandering surveyor passes close enough to record them, and a live species-accumulation curve tracks cumulative richness against accumulated observer-hours. Because the true richness is never fully known mid-survey, the panel also computes the bias-corrected Chao1 estimator from how many species have been seen only once or twice, showing how ecologists extrapolate "how much more is still out there" from an incomplete sample — and how surveyor count, species rarity skew and habitat patchiness each change how fast and how reliably that estimate converges.