Peter Slater (1932-2020) was author and illustrator of one of the main Australian field guides (The Slater Field Guide to Australian Birds). He died on 28 May 2020. I own most of the field guides for Australia, but the Slater guide is the one I always take with me when I go to Australia because it is the most convenient for travelling with (it is small enough to fit in the leg-pocket of cargo pants).