Keep an ear out for Great Horned Owls calling at night from now (actually having begun ~1 month ago) and throughout the winter. You will often hear the male and female of a pair calling back-and-forth to each other, where you can tell the male as his call is deeper than the female’s. A mnemonic you can use to identify their call is: “Who’s awake? Me too.” They lay their eggs as early as December and January, mainly because their young take so long to fully develop at the nest compared to most other birds.