The most common and most likely answer to this crossword clue is the 8 letter word DOVECOTE
I've seen this crossword clue in The Times
D
O
V
E
C
O
T
E
Buddy explains!
The straight part
We know that "Its occupants may be collared pinching grain" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case its occupants may be collared pinching grain = dovecote.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 DOVECOTE mean?
DOVECOTE noun- A small house or box, raised to a considerable height above the ground, and having compartments, in which domestic pigeons breed; a dove house.
- In medieval Europe, a round or square structure of stone or wood, free-standing or built into a tower, in which pigeons were kept.