The Case of the Sentinel Chickens
In 1999, the first North American cases of West Nile Virus were observed
in crows and other wild birds in the northeastern United States.
The next year, knowing that the disease was carried by birds but transmitted by certain species of mosquitoes, authorities in Canada’s Maritime Provinces took steps to establish an early warning system that would detect the virus if it spread into the region. They contracted the Atlantic Wildlife Institute to conduct monitoring activities.
The monitoring consisted of:
- Exposing a flock of chickens to the resident mosquitoes, taking weekly blood samples from the birds, and forwarding the samples to a lab to be tested for the virus.
Trapping mosquitoes every week and forwarding them to the lab for identification, in order to determine whether any of the carrier species were present.
In later years, this method of gathering data was abandoned. Ever since, however, sick wild birds have been referred to the Atlantic Wildlife Institute. AWI receives and cares for these cases until the birds recover. If they die, the remains are forwarded to the New Brunswick agricultural pathology lab for a necropsy to determine whether West Nile was the cause of death.
The project is well suited to the AWI mission. Data gathering allows us to develop collaborative research relationships with other science-based agencies. And the direct, hands-on experience of participating in a public health project provides a rich supply of educational material for use in demonstrating the links between wildlife and the human experience.
As for the chickens? They’re now lifetime residents at AWI. An honourable retirement seemed only fair after all they did in the cause of public health.