One parrot species that feeds on large seeds nests is in the same tree as a parakeet that feeds on small seeds. how are the birds able to coexist?

They are able to coexist because they eat different things. The parrot eats the big seeds, while the parakeet eats the small ones. There is enough food for both of them because they eat different things.

They occupy different niches.

Step-by-step explanation:

They live in the same habitats, ecosystems, and communities, but what makes the difference is that they occupy different niches and thus eat different things.