It's only greed that causes mad cow disease: greed that makes a cow eat parts of other dead cows instead of grazing on grass, as cows were meant to do (why aren't religious fanatics objecting to meddling with this intelligent design?). Now a study by the non-governmental organization GRAIN Fowl play: The poultry industry's central role in the bird flu crisis blames the spread of avian flu on the intense confinement of factory poultry farms that allowed the virus to mutate and spread.

The study casts doubt on the theory that the disease travels along migratory bird routes. Instead, it found that avian influenza is spread along poultry trade routes, where meat, eggs, poultry, manure and other chicken products pass through.

Avian flu has not yet spread to Hawaii. We seem poised to blame it on the poor kolea, which will mingle with other migratory birds during its summer in Alaska (see, for example, Bob Krauss' April 9 column Migratory kolea face avian flu challenge). When I read that article I was wondering how the little sick birds would be able to fly back here over the vast distance. But what do I know about these things.

The study challenges the popular wisdom, though. It won't be kokea transmitting the disease to the rooster pecking around your yard, if the study is correct.

Still, it's wise to take precautions. A March 20 story Hawai'i in bird flu's path also picked on the kolea (plover):

If avian influenza spreads to Hawai'i, it likely will arrive on the wings of a Pacific golden plover or some other migratory bird returning from arctic nesting grounds.

Once here, the disease could spread to backyard pens, poultry farms and the clusters of feral chickens that roam many communities. It could impact operations at the Honolulu Zoo and wildlife refuges, threatening native birds already teetering on the brink of extinction.

Certainly, if factory farm conditions favor not only the spread and mutation of the disease, we should be looking at closing any factory farms that might breed the microbe. But will we? Probably not, that's where the greed kicks in.

I don't know what chicken farming is like in Hawaii. If there are intensive factory farms here, now may be the time to let the birds loose.