The most common and most likely answer to this crossword clue is the 8 letter word BUNTINGS
I've seen this crossword clue in The Daily Telegraph
B
U
N
T
I
N
G
S
Buddy explains!
The straight part
We know that "birds" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case birds = buntings.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 BUNTINGS mean?
BUNTINGS noun- Strips of material used as festive decoration, especially in the colours of the national flag.
- A thin cloth of woven wool from which flags are made; it is light enough to spread in a gentle wind but resistant to fraying in a strong wind.
- Flags considered as a group.
- Any of various songbirds, mostly of the genus Emberiza, having short bills and brown or gray plumage.
- A warm, hooded infant garment, as outerwear or sleepwear, similar to a sleeper or sleepsack; especially as baby bunting or bunting bag.
- A pushing action.
- A strong timber; a stout prop.
- An old boys' game, played with sticks and a small piece of wood.