But frogs worldwide are in an accelerating decline, with some species disappearing even before scientists can document their existence.

By the mid-1900s, scientists had documented deception in cases where one species fooled another.

In camp, the scientists would process and document their findings while preparing them for shipment to the Smithsonian Institution at the next available opportunity.

It's true that scientists have documented psychological and physiological differences between male and female brains.

These mahogany populations vanished before scientists could document them and little is known about them.

Also, scientists should make precise, detailed observations, and document them carefully.

In recent years, scientists have documented a marked seasonal decline in ozone over Antarctica.

To the unguided eye, it is astonishing that the wildlife that scientists have now documented has ever been present.

This is the first time that scientists have documented the deaths of birds from the Usutu virus.

Now, scientists have also documented remarkable variety of another sort, in courtship songs.