WASHINGTON (AP) — Researchers and citizen scientists will observe how animals’ routines at several zoos are disrupted during the April 8 total solar eclipse.

The moon’s shadow will sweep across North America including from Texas to Maine.

In 2017, a team noticed strange animal behavior at a South Carolina zoo in the path of total darkness.

This time, scientists will stand by to track how tortoises, giraffes and apes at the Fort Worth Zoo in Texas react when day transforms into dusk.

It’s only in recent years that scientists have started to rigorously study the altered behaviors of wild, domestic and zoo animals during a full solar eclipse.