National picture

What thousands of volunteer surveys across the country show, and the expected-score model trained on them that the chapter's sites are judged against.

Where volunteers monitor19,960 sites across the lower 48 states have usable surveys; most are in IA, NJ, VA. Context Paved watersheds lose sensitive animalsNationally, sensitive animals fall from 40% of groups found in near-natural watersheds to 22% where a quarter or more is paved. Context How the expected-score model worksTrained on 7,332 surveys at 1,162 sites, it explains 39% of the variation at sites it never saw. Context Volunteer monitoring took off after 2017The Hub holds 83,297 usable surveys; 7,414 are biological, enough to train a national model. Context