High on the wanted list of most first-time visitors to Iberia is Azure-winged Magpie, a species which, fortunately, is very easy to see here. And what an attractive and elegant bird it is with its blue tail as well as azure wings.
However, it is a species that provokes both argument and debate. To start with, should we really still be calling it Azure-winged Magpie? Or should we now refer to it as Iberian Magpie?
The long-held view has been that Azure-winged Magpie Cyanopica cyanus is a species with a remarkable disjunct distribution with populations in the Far East (China, Japan, Korea, etc) and also in Spain and Portugal. That does seem very strange but it has been suggested that it results from birds being introduced into Iberia by Portuguese sailors returning from the Far East something like 500 years ago. That makes sense and it has certainly been a widely accepted explanation. Others have suggested the less likely scenario which had those same sailors taking birds from here and introducing them into China or Japan! Another theory is that the species originally had a much wider and continuous distribution and that the two current, separated populations are simply what remains after the loss of birds from the central part of the range as a result of the Pleistocene glaciations.
Towards the end of the last century the discovery in cave deposits in Gibraltar of fossilised Azure-winged Magpie bones that were said to be more than 44,000 years old seemed to provide pretty convincing evidence that the species is native to Western Europe and not a recent introduction.
Genetic and morphometric analyses followed (read them here and here if you’re so inclined) which showed a clear distinction between the two populations and so it is that the list of the world’s birds produced for the International Ornithological Congress includes two species, Azure-winged Magpie Cyanopica cyanus, the Far East birds, and Iberian Magpie Cyanopica cooki , the much smaller population in Spain and Portugal. Incidentally, the stated purpose of producing this list was “to facilitate worldwide communication in ornithology and conservation through the consistent use of English names linked to current species taxonomy.”
So that, you might think, has settled the debate. The species has been split into two and we all know where we stand. Well, not quite! Switch now to Birdlife International, another respected authority in the world of ornithology and you will find that their Taxonomic Working Group are having none of this! They do not accept the proposed split into two species and continue to treat Cyanopica cyanus as a species with two separate populations roughly 9,000km apart. In other words, as far as they are concerned, we’re back where we started. Apparently they don’t regard the genetic and morphological differences that have been documented to be sufficient to treat the two populations as separate species. Also, there does seem to be some lingering doubt about the identification of those bones in Gibraltar!
So here in Portugal (and in Spain), what do we have, an endemic species that we should appreciate and protect or an introduced species that is on a par here with Common Waxbill and Black-headed Weaver? Does it matter? Well it does start to be an issue as the number of birds and their range increases. Just as with Common Magpie in the UK, there are now people ready to blame the predations of Azure-winged Magpies for perceived reductions in the numbers of breeding and wintering songbirds. If it were true (and that’s a huge IF) that Azure-winged Magpies are having a serious effect on the populations of small passerines, what should our attitude towards them be? Will they, like Common Magpies in the UK, become demonised and blamed for all the world’s ills or will they remain the attractive, restricted-range species (or perhaps sub-species) that all of our visitors enjoy?
1 week ago