Re. Canada Geese
The River Thames is close to Heathrow Airport. A few years ago the river had been taken over by Canada geese to the extent that the geese were a threat to the river's ecology. Canadas are attractive looking, tame birds, so there is an uninformed but strong resistance to culling them. Driving along the riverbank very early one morning I spotted a group of people from the Environment Agency, who manage the Thames, conducting a scientific experiment. They were finding out how many geese you can herd into a panel van. The answer in layman's terms is lots. Since then the goose population has stabilised at an acceptable figure, at least from an ecological point of view. No doubt by repeating the experiment more frequently I see no reason why the population could not be further reduced if necessary. The underlying difficulty of course is that airports are usually sited in places that are equally attractive to small feathered birds and big aluminium ones.
Congratulations to Halfnut. The advertising world's loss has been aviation's gain.