Just had one doing that blood curdling "murder in progress" mating call in the back field - is it me or is it a bit late in the season for that now?
Mating is normally earlier, but it might be the harsh winter putting it off a bit. Birthing should be starting around or after this time.
Vixens that have given birth won't leave the den and will call to the dog Fox for more food, so it could also be that.
When he wrote that poam, he did so on or about the 5th April, 1804 for his sister who had noticed an early "belt of Daffodils" Climate changing even thenAye, most things are a bit behind this year, even Wordsworth's Daffies.