The most common and most likely answer to this crossword clue is the 10 letter word KOOKABURRA
I've seen this crossword clue in The Times
K
O
O
K
A
B
U
R
R
A
More clues leading to the result KOOKABURRA
Buddy explains!

The straight part
We know that "cackling bird" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case cackling bird = kookaburra.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 KOOKABURRA mean?
KOOKABURRA noun- Any of several species of kingfishers in the genus Dacelo, known for their laugh-like call.