Shooting and Fishing: The last thing you need is a smartarse crawling through the heather, spooking deer

I know only one person who has managed a Macnab – a brace of grouse, a stag and a salmon, all in one day, and not necessarily in that order. But there will be hundreds of men and women out there in the hills this summer and autumn attempting to pull off the same feat.

(They say you need to catch the salmon first as that's the hardest of the three. From there on, it's uphill all the way). The odd thing about "doing a Macnab" is that it bears almost no resemblance to the plot of John Macnab; the novel by John Buchan, other than that the action takes place in the Highlands and involves shooting a stag or catching a salmon. Note: OR catching a salmon. Grouse don't get a look in.

Now you might say this is all rather splitting hairs. Scotland, stag, salmon; what more do you need? But what you need is a challenge. Not the challenge of killing three species in 24 hours, which I accept is hard enough, but the challenge of not being caught doing it.

That was the whole point of the John Macnab story. It was a dare; three respectable but disenchanted men issue a challenge to three Highland estates that they will shoot a stag or catch a salmon between certain dates. The challenge is issued under the nom de guerre of John Macnab. (Macnab, nab, to pinch or poach. Geddit?) In other words it's not about shooting three species, but an invitation to "catch us if you can" – a test of field craft.

The added frisson is that as respectable gents in politics and business, their careers and reputations will be done for if they are caught doing anything quite so criminal, not to say common, as poaching.

The Field magazine, which runs an annual Macnab competition of the standard three-species sort, suggests that ambitious readers might want to try a "real Macnab", poaching a stag or salmon having first warned the landowner when they will do it.

I should imagine this would be even more unpopular than it was in Buchan's day. The last thing you need is some smart arse crawling through the heather spooking your deer and shifting the grouse just when you have a lodge full of paying guests. As one does.

The fallback would be to challenge a friend who was up for it, which is how the plot for John Macnab originated – with the exploits of Capt James Brander-Dunbar. Dunbar, a swaggering 22-year-old from Moray, had announced to the 3rd Cameron Highlanders officers mess that he could poach a deer off any estate in Scotland. His fellow officer, Lord Abinger, took him up on it. It took Dunbar three days to get his beast, chased at the last by Abinger's men as he dragged the stag's head through the River Spean to safety. Abinger wrote the 20 cheque out to JB Dunbar "poacher".

And that is the real "real Macnab."

This article was first published in The Scotsman on Saturday, August 28