Perhaps it was a bird dog fee?
It may be a mistake, but do the words bird & fee together mean anithing?
It was something like "... the payment must be done on February 23rd bird fee..."
The dictionaries give no answers.
Without any context, my (wild) guess is that it's something to do with paying for shooting game birds; you might pay £X per day, and an extra 'bird fee' per bird shot.