Darwin stuck snails on ducks' feet and submerged them in seawater and found them to die quickly on exposure. |
I think because they live in trees and are particularly sticky, they're prone to being carried by birds. |
It must have gotten there, we think, on some sort of migrating bird. |
Land snails, which we normally think of as being rather slow moving, can actually disperse enormous distances by hitching rides on birds. |
One of the species on the Azores returned to Europe. It seems that having got there in the first instance a very long time ago, it relatively recently migrated back to Europe. |
This clearly has nothing to do with human agency. These dispersal events happened long before humans were around. |
Traveling to the South Atlantic is quite problematic for a very pedestrian snail. |
Trying to get one of those birds and the snails together is problematic. So I suspect that some type of wading bird, with a cargo of stowaway snails tucked into its feathers, was blown off course by a storm and deposited the snails on these islands. |