On 14th August this year, the Sunday Times ( uk) correspondent, Lois Rogers, reported on an unexpected consequence of climate change.
Monitoring projects have shown that over thirty species of native wild birds in this country are dying from avian malaria. Laszlo Garamszegi is a world expert on avian malaria, and his study has looked at infection data in over 3,000 species of wild birds worldwide since 1944.
In Britain, whole populations are showing massively increased mortality rates from the disease as avian malaria reaches epidemic proportions. The house sparrow, for example, has recently shown an infection rate of 31%, as against a figure of just 9.4% in 1960. In this one species alone, the overall population, currently calculated as approximately 13.4million, has declined since 1970 by a staggering 67%. Other wild species known to be suffering similar rises in infection rates include the tawny owl and the song thrush. A survey by the British Trust for Ornithology found that numbers of nightingales have fallen by 90% over the past 40??? and concerns have been raised that the species may face extinction.
A one-degree Celsius rise in global temperatures has been sufficient to favour the rapid growth of infection-carrying mosquito populations and the consequent huge increase in the incidence of the parasitic disease that attacks oxygen-carrying red blood cells.
To put this in the context of implications for breeders: It seems very recent indeed that threat of H5N1 variant avian flu put breeders on their guard against opportunities for the transmission of pathogens to budgerigars. Shows were cancelled at the peak of the concern, there was much greater emphasis on bio-security, and the government imposed sanctions that restricted the movement of birds. While there is no evidence to suggest that avian malaria can mutate into a form that can infect humans, the risks posed to budgerigar studs, particularly those where birds have access to outdoor flights, are as great. Ben Sheldon, professor of Ornithology at Oxford University is concerned because, as he says, “Malaria is a significant cause of mortality, but how it is transmitted is not straightforward. “
And his concern is echoed by Matt Wood, a bio scientist at the University of Gloucester, who has tracked malaria amongst blue ****. He believes that there is no way of knowing how virulent a new strain of the disease could become, because, as he says, “ Things are changing very fast and we need to understand much more about which mosquito species can transmit the disease.”
Until more is known about this killer and effective, targeted strategies can be identified to limit its contagion rate, it probably makes sense to budgerigar breeders to adopt the same rigorous regimes to protect their birds as were used when H5N1 avian flu threatened.
At that time, the Government department DEFRA advised that breeders should cover open flights and outdoor aviaries to avoid contamination from the droppings of wild birds passing overhead. In fact, this is regarded by many as good practice since birds, like other species, can carry and transmit many infections by this means. In order to avoid contamination by the transference, into the birdroom, of droppings and other materials, DEFRA further advised that anyone entering should first thoroughly wash their hands outside in a disinfectant solution, (e.g. Virkon S or F10,)and step into a trough containing the disinfectant to remove any possible contaminants. Visitors to the birdroom must also comply with this practice.
Since this article was published in the Sunday Times, and similar coverage appeared in other newspapers, it is possible that there could be an “alarmist” reaction among the general population, sparked by tabloids with hysterical headlines of the “Budgie-with-malaria-killed-our-kitten” variety. As with the avian flu outbreak, neighbours should be made aware of the precautions that have been taken in order to reassure them that your birds do not constitute any kind of threat.