Adaptive radiation is a fascinating aspect of evolutionary biology where a common ancestral species develops into a wide variety of different others, each one adapted to the niche parameters of their specific environment.
The famous Darwin’s finches in the Galapagos Islands are a classic example, with the individuals in each island having evolved their own unique features. It happens in Scotland, too – for example, on St Kilda where the wrens and field mice have formed their own separate sub-species, featuring slightly different morphological traits from their mainland cousins. The freshwater sticklebacks in North Uist show differences depending on which body of water they inhabit, and there are numerous other examples of such diversity.
A recent visit to the Canary Islands brought home to me this wondrous facet of nature. On the island of Gran Canaria, I was lucky enough to stumble upon a giant lizard, a magnificent reptile that is unique to the island, and which can grow up to 80cm long (including the tail), although most specimens are smaller. The one I found was about 50cm long, and was taking things easy by basking in the morning sun on a steep embankment close to the shore.
The neighbouring islands of La Gomera, Tenerife and Hierro also have their own endemic giant lizard species, the isolation brought by the islands spurring distinct differences in form. Tenerife and Gran Canaria also host the globally unique blue chaffinch, which have diverged further, so that each island has its own species.
The Canary Islands are a wonderful holiday destination for those with an interest in nature, with the flora being especially fascinating. Around 40 per cent of the islands’ plants are endemic, many of which are endangered.
The mountains of Gran Canaria are truly spectacular, and my wife Lynda and I spent much of our time hiking the high trails, whilst at sunrise I would slip into the sea with snorkel and mask to explore the underwater life. Dawn is my favourite time to go snorkelling – the rising sun delivers a magical soft-lit aura and many nocturnal marine creatures are still out and about.
One early morning snorkel brought my first ever encounter with a flaming reef lobster, a stunning bright orange crustacean with white spirals and other intricate patterning on its shell. Another intriguing discovery was a cylindrical shaped gelatinous and pink-flecked object that drifted just below the water surface, which transpired to be the egg mass of a diamondback squid.
As well as birds, reptiles and plants, the uniqueness of life in the Canaries extends to fish, and one type I encountered was the island grouper. Classified as vulnerable on the ‘red list’ of endangered species, it is only found around the Canary Islands, Madeira, the Azores and Cape Verde.
This was a charismatic fish with striking blotches and stripes on the body, and a confiding demeanour that allowed a close approach. Its beauty and brashness perfectly encapsulated the compelling nature of the Canary Islands and its boundless capacity to create new life from within.