would agree that in view of what appears to be a mechanical finish to the underside of the foot, then almost certainly a modern piece - nice find though from a charity shop - and the intaglio one side step to the cut is easy to see - think you're probably correct about the black grouse.
It's probably fair to say that when compared to a piece of bog standard C19 pteridomania copper wheel engraving, then this is superior - some of those ferns are ultra basic and very two dimensional. So, in addition to Northwood's 'intaglio' process improving the realism of an image, improvement must also be due to the overall quality of art and skill level of the engraver - with this black grouse the entire image remains un-polished, so might we assume less skill required than had a part mirror-finish been produced?
I don't think we should be too dismissive of a lot of late C19 copper wheel engraving - again, if you look in Hajdamach (1800 - 1914), he shows images from that process that are to die for, and even some of the grape and vine images can show amazing minute detail, and some of the acid engraving is amazing.
I have some pieces where both methods have been used (intaglio and copper wheel), and they look v.g., and I'd suggest that a skilled intaglio engraver uses the step cut to give perspective to what might otherwise be a lacklustre image.
In some ways, this perspective appearance can be seen in Kny's cut work for Stuart, where he creates a fine mitre around the shape of leaves, and though only a small addition it brings the image of his leaves to life.
Sorry, no idea as to origin - Scotland perhaps ?
Pheasants were a fairly common C18 and first half C19 subject to include in their engravings - I believe they shoot both birds at one time or another - images of rural life I suppose.
the more we tick on about Northwood's 'intaglio' cut with the 'step', the more I'm irritated - what a tragedy that a different description wasn't used.