They are a large bulky construction of twigs lined with sheep wool and by now, female ravens will each be sitting on five or six blueish-green eggs spotted with brown.
This follows elaborate courtship displays earlier in the year involving pairs circling in opposite directions, diving with closed wings or turning over and flying on their backs.
How can you tell if you are watching a raven?
They are much larger than crows, about two feet from beak to tail tip but at a distance, it is hard to judge the size difference.
One giveaway is if the raven calls – a deep honking croak which makes the crow sound like a soprano in comparison.
In flight, the raven’s head, neck and massive beak protrude in front of the wings more noticeably than a crow’s, and the raven’s tail is long and has a wedge-shaped end compared with the fan-shaped tail of the crow.
Until fairly recently, the raven was largely confined to the uplands of North Wales, the Scottish highlands and islands and Lake District but, along with the common buzzard, the raven has expanded eastwards, although not in such a dramatic fashion.
A few pairs have colonised the high chalk cliffs of the Sussex coast while, where there are no cliffs available, they will nest in woodland or even on electricity pylons.
They are also chosen some city centre nest sites. A pair first nested on Chester Cathedral in 1996, the first ravens to do so in an English city centre since the 15th century, and they have returned to raise three or four youngsters most years since then, choosing either the cathedral or town hall. A pair now nest regularly on the Civic Centre, in Cardiff, while ravens have also nested in Edinburgh.
In Yorkshire, ravens are found mainly in the western half of the Yorkshire Dales National Park and in the Peak District National Park, but that unmistakable call has also been reported from a number of places in the North York Moors National Park.
A glance through Yorkshire place names, such as Raven Crag and Raven Scar in the Dales, or Ravenscar, the rock or place inhabited by ravens, on the North Yorkshire coast, indicates that the raven must have once been much more widespread across the county and, although I am sure some would disagree, it would be nice to see this impressive bird return to more of its former haunts.
A few waders have been moving through the region on spring passage, with 20 black-tailed godwits at Wheldrake Ings and a bar-tailed godwit inland at Great Heck, North Yorkshire.
Three avocets can be seen at the Saltholme RSPB reserve, Teesside, and more of these elegant waders should soon be back at breeding sites in the region any time now.
A Mediterranean gull was seen on the mere at the Old Moor reserve, South Yorkshire, where a pair bred successfully last year.
A shore lark was seen with 60-plus linnets at the Nosterfield Nature Reserve, North Yorkshire, where a drake smew was also present.
Great grey shrikes have been seen again at Storiths, North Yorkshire, and from the viewing platform in the middle of Thorne Moors, South Yorkshire – a rough-legged buzzard was also seen from there this week.
Up to three long-eared owls continue to give good views at the Blacktoft Sands reserve, near Goole, while some of the 17 marsh harriers on the reserve are starting to display.
Along the Yorkshire coast, up to 100 Lapland buntings have been seen near the North Cliff Marsh, at Flamborough.