Let's look at your sentence carefully and fix the grammar so it sounds better!
Your sentence: Most of the time, seabirds glide over the water following schools of fish. On land, where they come together in groups to find food and keep their little ones safe.
Problems:
- The first part is a complete sentence, but the second part starting with "On land" is a sentence fragment (it doesn’t finish the idea).
- Also, the phrase "On land, where they come together in groups to find food and keep their little ones safe" needs to connect better.
Here’s a corrected version:
Most of the time, seabirds glide over the water following schools of fish. On land, they come together in groups to find food and keep their little ones safe.
Or you can join both ideas into one sentence:
Most of the time, seabirds glide over the water following schools of fish, but on land, they come together in groups to find food and keep their little ones safe.
This way, the sentence is complete and easy to understand!