The National center for Biosecurity and Infectious Disease will survey backyard poultry flocks and their owners in two North Island areas.

Both are areas where wild birds congregate, with farms nearby providing opportunities for inter-species mingling.

Researchers said the aim is to find out whether backyard poultry, such as hens, ducks, geese and turkeys, can catch avian influenza from wild bird populations and whether people can be infected as well, under New Zealand conditions.

New Zealand does not have the deadly H5N1 strain of bird flu that has spread from Asia into Europe and Africa, but more than 30 mild forms have been identified in wild bird populations here. They are regarded as harmless to birds and humans.

Dr. Bruce Adlam from the Environmental Science and Research Institute said there is no evidence that any of the bird flu viruses found here have infected people, but no one has done any research to establish whether there is a risk.

Dr. Adlam said the two-year study will initially survey 10 properties in each area and that will be expanded later to 50 farms in total.

The manager of Biosecurity New Zealand's animal health laboratory Joseph O'Keefe said the backyard poultry survey will also complement other bird flu monitoring programs in New Zealand.