This video from Scotland says about itself:
Grey Mare’s Tail Nature Reserve
Ravens nest early, and are usually sitting on eggs by late February or mid-March at the latest. The onset of laying tends to be related to distance north and/or an increase in altitude. As the Grey Mare’s Tail Ravens nest at 650 metres altitude they usually start laying around the middle of March; so late for Ravens but still very early compared to most British bird species.
This footage was shot on March 10th 2014 as our pair of Ravens completed their annual nest renovation, and just days away from the female laying her first egg.
All footage was filmed and edited by the Grey Mare’s Tail Ranger Service.