January-to-February is mating time for red foxes in Pennsylvania and the Mid-Atlantic region.
Red foxes pair for life. They remain together from midwinter through summer. In autumn the foxes are solitary but reunite in winter for mating in January or February. Following a period of about 51 days, four to six young are born in late March or early April.— Guide to the Mammals of Pennsylvania, p. 252 — Joseph F. Merritt
People usually don’t see foxes mating but Carly Lesser & Art Drauglis came upon this pair in January 2013 at Hain’s Point Golf Course in Washington, DC. Click here for another photo and scroll down to read the description.
If foxes mate in January, they have kits in March.
(photo by Carly Lesser & Art Drauglis at Wikimedia Commons; click on the caption to see the original)