Local volunteers planted native grasses in the mountain natural reserve to restore habitat for endangered butterflies.

The university's new curriculum included a seminar on natural philosophy to explore the historical roots of modern science.

The villagers whispered that the abandoned cottage was a freak of nature, its twisted silhouette unsettling anyone who passed by.

She spent the afternoon photographing rare birds in the nature reserve near her town.

We spent the afternoon hiking through the nature preserve, spotting deer and rare wildflowers along the way.

We spent the weekend volunteering to clear invasive species from the natural preserve near our town.

Scholars compared several natural histories to trace how species descriptions changed over time.

At the outdoor concert, several people had to leave early to answer calls of nature.

During the long meeting, I was distracted by a sudden call of nature and quietly slipped out to use the restroom.

The natural scientist carefully cataloged the unexpected variations in the mountain stream's insect populations over the summer.