Probably confused by changing climate patterns, hedgehog mothers gave birth relatively late in the year.
British Dictionary definitions for hedgehog
any small nocturnal Old World mammal of the genus Erinaceus, such as E. europaeus, and related genera, having a protective covering of spines on the back: family Erinaceidae, order Insectivora (insectivores) related adjective erinaceous
any other insectivore of the family Erinaceidae, such as the moon rat
(US) any of various other spiny animals, esp the porcupine