www.ukbutterflies.co.uk

These calculations are not definitive but based on guesses and very rough estimates. However, the result might be in the right range.

Scotland has 40,000 hectares of gardens. My own garden approx 1/100 of a hectare (30 x 30 metres) and is currently home to 10+ Peacocks.
Amendment 17th Septemeber. 12 just now on a white buddleia.
So that suggests very approximately 40 million garden Peacocks in Scotland.

Let's put some realism in that number and say that the total number of Peacocks in Scotland is probably in the range 4 million to 400 million. The human population of Scotland is approx 5.5 million. So it is more than likely that each human has his/her own Peacock.

Perhaps I should name ours 'Jack2' and 'Stella2'

Jack

I'm sure countrywide there must be multi-millions of Peacocks, Jack, although this is a butterfly that is ubiquitous in summer for just a short period when they are all busy feeding up for hibernation (which, like Brimstones, they undergo rather earlier than Comma & Small Tortoiseshell).

It's one of the few species that has done well in this most awful of years, with Small Whites enjoying a spectacularly good Indian summer too.