We prescreened and classified airports based on this initial
contact. We defined airports as eligible and included them in the
target population even if their initial emails were returned due to
email delivery failure or there was no readily available contact
information. Airports with less than 12 flights per year, used solely
for training activities, or private airports, were defined as ineligible
and excluded from the target population. The final sample consisted
of 76 British Columbia, 31 Alberta, and 17 Saskatchewan
airports.
From January 14 to 28, 2008, we phoned or emailed each airport
and asked the contact person to identify the staff expert in animal
management issues. We advised the staff expert of our research
project on airport animal management practices and invited them
to participate in an online survey. If the person agreed to participate,
we defined the airport as eligible, and asked the animal expert
to complete the survey online via a link. If the person we were
speaking to was not the animal expert, then we asked them to
forward the survey to the person in their organization who was
most knowledgeable in animal control at airports. If the contact
person declined to participate, we still defined the airport as
eligible and it remained in the sample population. We sent one
follow-up email on February 22, 2008 and the online site closed on
February 29, 2008.