June 2007. The question of risk associated with importation of birdseed was raised by Palau. In response, Guam mentioned that sometime ago the University bought a range of birdseed products from a local pet store and found that most of the seed germinated and did very well under local conditions. Needless to say, none of the seed was indigenous and it is still readily available in bulk to anyone who wants to buy it. Another store routinely imports suet blocks impregnated with bird seed of various types, despite the fact that there are no birds on the island that would use it!
It was pointed out that these products contain a wide variety of weed seeds too. New Zealand requires that bird seed contain no viable seeds. Importers can heat treat the product or as is more usual, have it irradiated at 25 kGy to devitalise the seed. In the case of relatively simple mixtures of seed, the importer may elect not to process the product, but then must go through all the steps needed to gain entry as if it were grain for planting. Most importers find it easier to devitalise the seed.
Vietnam told of a company that wished to import birdseed from the USA, but the birdseed was tested by quarantine and found to be viable, and the request was refused.
In Australia, it is illegal to import mixed seed, so all birdseed is mixed within the country. Birdseed is notoriously bad for carrying numerous contaminants. The list of ingredients will not cover the lits of contaminants. In Western Australia, birdseed is only allowed in from the eastern states after it has been irradiated as it contains so many weed seeds its not possible to clean it.
The seed used is usually the lowest grade reject seed with contaminants; these don’t bother the birds!
An email copy of the regulations from Norway, New Zealand, Australia and Canada was sent by the IUCN SSC Invasive Species Specialist Group.
Hanson CG, Mason JL (1985) Bird seed aliens in Britain. Watsonia 15, 237-252.