Presumed to house birds from the east? (4)

I believe the answer is:

emus

I'm a little stuck... Click here to teach me more about this clue!

'birds from the east?' is the definition.
'emus' can be an answer for 'birds' (emu is a kind of bird). I am unsure of the 'from the east?' bit.

I can't explain the remainder of the clue.

Can you help me to learn more?

(Other definitions for emus that I've seen before include "Muse about flightless Australian birds" , "Running birds" , "Largest native Australian birds" , "Aussie birds" , "Large flightless birds of Australia" .)

I've seen this clue in The Mirror.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.