The most common and most likely answer to this crossword clue is the 4 letter word JIZZ
J
I
Z
Z
Buddy explains!
The straight part
We know that "Characteristic features" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case characteristic features = jizz.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 JIZZ mean?
JIZZ noun- The physical and behavioural characteristics of a bird that enable it to be immediately recognised by an experienced birder as a certain type of bird, especially to family or genus level.
- Male ejaculate; sperm, semen.
- To ejaculate; to eject semen.
- To ejaculate on, over, or into; to cover in semen.