Both birds build the large nest, which can take several weeks to complete, from small branches and twigs, and line it with mud and vegetation. The nest is usually in a large tree and domed to prevent predation by other crows.
The hen lays and incubates eggs that are smooth, glossy, pale blue with olive-brown - grey spots. The eggs are about 35 mm by 24 mm. During the breeding season, the hen can often be identified by having bent or damaged tail feathers.
Incubation = 21-23 days, - Young Fledge after 22-28 days.
I became aware of this nest building a few week ago.... a single Magpie flew overhead with a small twig in its beak.... within the day a platform was built... and over the last three weeks the nest as steadily grown. If I look out of my front window this nest is in view...... and another can be seen from my back door.
More signs of spring tomorrow