They weren't "missing": GPS-tagged red-footed falcons revealed that they migrate to a tiny communal roost in central Angola (“Falcopolis”) each February–March.
There, saved you a click (disappointed on National Geographic for that clickbaity headline).
There, saved you a click (disappointed on National Geographic for that clickbaity headline).
That’s why the article is titled “ A Million Falcons Went Missing. Here’s How They Were Found”.
Something was unknown, then we used sensors to solve the mystery. Wild, isn’t it?