Mike Tomkies 1984. A Last Wild Place. London: Jonathan Cape, 250 pp.

I must have first read this at least 20 years ago, and several times since - for the simple pleasure of the nature writing, based on wild animals, plants and places, closely observed over many decades by Mike Tomkies. Mike Tomkies removed himself from a completely different life in Hollywood after a relationship with an actress didn’t work out. He went on to spend most of the rest of his life in wilderness locations in Canada, Scotland and Spain, writing about and photographing wildlife. A Last Wild Place is based on 19 years living alone in an abandoned croft at Gaskan (he called it ‘Wildernesse’) on Loch Schiel in western Scotland. Much of Mike Tomkies’ field activities and writing in this and other books revolved around studying Golden Eagles nesting on cliffs above his croft. However his interests and knowledge were diverse with many observations of other birds and mammals. Ebird has few lists posted from Loch Shiel so it is not clear if this is still a good location for birds and other wildlife. On this re-reading I’m drawn to his short chapter on Black-throated Divers nesting on a nearby island on the loch.

Divers (= loons in North America) are notable for their exquisite breeding plumage and because they are an ancient lineage of birds (evidence for that conclusion includes a Cretaceous fossil from Chile, and deep genetic divergence from other birds). They are diving birds most closely related to grebes (Livezey & Zusi, 2007) and hunt fish by sight. Divers thus prefer clear waters (Scottish lochs, for example) and are capable of swimming submerged for at least a minute and, according to Mike Tomkies, to nearly 20 m depth. And they look smashing—who wouldn’t want to see one?

Black-throated Divers (Gavia arctica) were observed by Tomkies nesting on Loch Shiel in the 1970s and 1980s but there are no recent ebird sightings from there. But they are widely seen in western Scotland and all around the UK as far south as Cornwall. The RSPB map shows Loch Shiel to be close to the southern limit of the summer (breeding) range of this species, which as of 2017 is estimated to number at most 250 breeding pairs.

Black-throated Diver (Gavia arctica). Photograph: Steve Garvie / Wikimedia commons / CC-BY-SA-2.0

Red-throated Divers (Gavia stella) are the most primitive of the divers. Mike Tomkies saw Red-throated Divers visiting Loch Shiel in the 1970s and 1980s and they are still observed there (although small highland lochs are preferred for breeding). The RSPB map shows the summer range of this species extends further south than does the Black-throated Diver, and includes northern Ireland. The Red-throated Diver is much more numerous in the United Kingdom with about 1,600 breeding pairs in 2017.

Red-throated Diver (Gavia stella). Photograph: Ómar Runólfsson / Wikimedia commons / CC-BY-SA-2.0

There are three other species of divers, two of which, the Great Northern Diver and the Yellow-billed Diver (both larger birds), are also seen in the United Kingdom but are less common. The first phylogeny of the family, based on morphological data (Boertman, 1990) had Gavia arctica and Gavia pacifica as sister taxa but that was rejected by a mitochondrial DNA study (Lindsay, 2002). A recent study using next generation sequence data (Sprengelmeyer, 2014) showed that the morphological study had been correct after all.

• Boertman, D. (1990). Phylogeny of the divers, family Gaviidae (Aves). Steenstrupia 16, 21–36.

• Lindsay, A. R. (2002). Molecular and Vocal Evolution in Loons (Aves: Gaviiformes). Doctoral dissertation, University of Michigan.

• Livezey, B. C., and Zusi, R. L. (2007). Higher-order phylogeny of modern birds (Theropoda, Aves: Neornithes) based on comparative anatomy. II. Analysis and discussion. Zoological Journal of the Linnean Society 149, 1–95.

• Sprengelmeyer, Q. D. (2014). A phylogenetic reevaluation of the genus Gavia (Aves: Gaviiformes) using next-generation sequencing. Masters dissertation, Northern Michigan University.