The book we picked for FFF is the Immortalists. According to our kindle
Line 8 - out
Line 12 - shift
Line 16 - annual
We saw movement out the window and went down stairs to see,
What our friend might be doing when outside it was so gusty.
She watched her for a moment as she sniffed all around,
Then the little red fox, marked up the snowy ground.
Quickly her attention did shift and she was on her way,
She stopped to do some sniffing on this winter like day.
It's the annual time of year, when spring begins to bloom,
And our little friend may be on the hunt for a groom.
Note: I did some research and both male and female foxes mark. They can mark up to 70 times per hour when looking for food!