Maybe one flying header from Silva, as well as Haaland (10)

I believe the answer is:

sanderling

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

'maybe one flying' is the definition.
Although both the answer and definition are singular nouns, I can't understand how they can define each other.

'header from silva as well as haaland' is the wordplay.
'header from' says to take the initial letters.
'as well as' becomes 'and' (I've seen this in other clues).
'haaland' becomes 'erling' (I am not sure about this - if you are sure you should believe this answer much more).
The first letter of 'silva' is 's'.
's'+'and'+'erling'='SANDERLING'

Can you help me to learn more?

(Another definition for sanderling that I've seen is " wading bird".)

I've seen this clue in The Guardian.

Want a hint initially instead of a full solution? Install my app