In fact, Marc Choisy and Pejman Rohani at the University of Georgia at Athens in the US have shown that killing wild animals with a disease like flu could actually lead to more infected animals, not fewer.
This is due to a classic principle of ecology, called compensation. Many wild species produce more offspring than can survive. Hunting removes animals which would otherwise have competed with these excess young, especially as hunters often target bigger, older beasts. So in a hunted population, more young usually survive which compensates – or sometimes even over-compensates – for the loss due to hunting.
But when a disease causes lifelong immunity in its host, most of the older animals in a population have survived it and are therefore immune, leaving only the young susceptible.
A raised death rate of older birds due to hunting would increase food available to younger birds. Therefore more younger birds would survive early youth. These younger birds would be immunologically more immature and at greater risk of getting infected by H5N1 influenza.
The net effect if hunting would depend on the percentage of birds killed and whether the killing of birds was sustained. In the extreme the extinction of a bird species would eliminate it as a bird flu carrier.
In any case, if bird flu becomes pandemic in humans you'll at orders of magnitude greater risk from getting it from humans than from birds.
|Share |||Randall Parker, 2006 May 31 09:34 PM Pandemic Signs|