The most common and most likely answer to this crossword clue is the 4 letter word ERNE
I've seen this crossword clue in The Guardian
E
R
N
E
More clues leading to the result ERNE
- Wise, perhaps, to release one bird
- Reportedly bring in large bird of prey
- Bird caught in bigger net
- What was long vessel in the sound
- Eagle sailors found in middle of Greece
- Reportedly bring in bird of prey
- Bird found in better neighbourhood
- High flyer in European capital wanting opening
- From what we hear, deserve to get the bird
- Concerned to trap seabird
Buddy explains!

The straight part
We know that "seabird" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case seabird = erne.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does ERNE mean?
ERNE noun- A sea eagle (Haliaeetus), especially the white-tailed eagle (Haliaeetus albicilla)
- An eagle.
- To long; to yearn.