What aspect of Red's provision of shelter is unprecedented the year that is depicted in the narrative?

Red tells the reader that while every spring brings lots of new babies, the spring depicted in the novel is "unprecedented" (25) in this regard. Red names this spring's inhabitants as "owl nestlings, baby opossums, and tiny raccoons" (25) before adding that often the skunk kits come out from their home under the porch in order to visit Red as well.