Bird needs a week in reproducing litter (4,9)

'bird' is the definition.
I don't know anything about this answer so I can't tell whether it can be defined by this definition.

'a week in reproducing litter' is the wordplay.
I cannot quite see how this works, but
'a' is found in the answer.
'week' could be 'w' (abbreviation) and 'w' is located in the answer.
an anagram of 'reproducing' is 'piedcurrong' which is within the remaining letters.
No letters remain.
This explanation may well be incorrect...

'needs' acts as a link.

Can you help me to learn more?