Hi Rex & Val (from northwest Queensland, this time!),
I've checked through some of the RSPB info on this story, and it seems that the Daily Mail (DM) is once again sensationalising and oversimplifying matters for a good story.
Various (and very different) strains of avian malaria exist in most migratory and some (many?) resident populations of birds in the temperate zones, Each strain (like 'bird flu') mutates and evolves differently, but for UK/European birds, these mutations may or may not be significant in their effects. The doubt arises from the interplay of many other factors; for example, habitat changes in the temperate zone are ongoing, yet sub-Saharan wintering migrants are exposed regularly to the prevalent strains in the Sahel or further south, and so these strains, should they mutate faster than expected, mght have an unexpected impact on resident UK/European species.
However, it is in the nature of things that resistance to avian flu strains develops: in Hawa'ii, where the resident species had never been exposed to avian flu until mosquito larvae were accidentally imported in freshwater casks filled in South America in the early 19th century, no resistance had developed at all, which has led to species extinction there on a large scale. A few Hawa'iian species have begun to show signs of resistance, but as mean temperatures increase with altitude, it may be too late for them, as refuges diminish.
UK/European species may well be affected by avian malarian strains being spread due to mean temperature increase at such latitudes, but it is likely that many such species, having developed some kind of resistance, will cope n the long term, even if declines occur in the short term. That said, it may be true that avian malaria's spread is one pressure too man for a few species in Europe.
As an aside, it's interesting that the Daily Mail is quite content to blame global warming for this problem, while in other mainstream articles is quite content to suggest global warming is not occurring. Do you vote for the DM or for the scientific general consensus?
MJB
