Painted lady butterflies are world travelers. The ones we encounter in Europe fly from Africa to Sweden, ultimately returning to areas north and south of the Sahara. But what determines whether some ...

This winter, volunteers from the Xerces Society, a nonprofit environmental group, tallied just 9,119 western monarchs — a ...

The number of monarch butterflies spending winter in the western U.S. dropped dramatically this year, despite moves to extend ...

Painted lady butterflies are world travelers. The ones we encounter in Europe fly from Africa to Sweden, ultimately returning ...

Painted lady butterflies are world travelers. The ones we encounter in Europe fly from Africa to Sweden, ultimately returning ...