East Pilgrim wren, an unexpected guest

Right in our own backyard, this adorable little bird took up residence and delighted us much of April throughout May, but seems to have left.

In January?

Was surprised to find these birds nested on top of a robin’s nest–not so much because of this, but because this was in early January and it was freezing cold! Temperature was in the teens, and I have never seen any birds nest around here other than in the spring. What are they? From my research, looking in my books, I think they might be winter wrens? These were ALMOST ready to fly…the mother flew off when I came out (this was right on our porch), and the babies hopped out of the nest to the very edge, but went no further. Next morning they were gone!