Sunday, August 14, 2011

Malaria affecting British birds?

Also in today's Times are claims that the decline that has been seen in British Song Birds in recent years might be due to infection with avian malaria.

British birds, claims the article in the Times, including sparrows, chaffinches and nightingales are dying from malaria. At least 30 common types of bird are now infected. In some species the disease was unknown as recently as the mid-1990s but is now being regularly diagnosed by monitoring projects. Only 20 years ago less than 10% of house sparrows in Britain were infected. That figure has now reached 30% and is rising rapidly. The screening of birds such as blue tits, great tits and owls has shown even greater proportionate increases since the mid-1990s, when almost none were infected.

The bird form of malaria cannot be transmitted to humans but, just like human malaria, it kills by destroying oxygen-carrying red blood cells and is transmitted by mosquito bites. The study that identified this new epidemic was carried out by Laszlo Garamszegi, a world expert on avian malaria who is attached to the Spanish government’s DoƱana biological station near Seville.

In the largest analysis carried out so far, Garamszegi compared malaria infection data from more than 3,000 species around the world, dating back to 1944. The findings follow disturbing studies from the Royal Society for the Protection of Birds that reveal a fall of up to 68% in the British house sparrow population since the mid-1990s. A survey of nightingales by the British Trust for Ornithology found a 90% decline in the past 40 years.

No comments: