Some years ago, two penguins were seen swimming off the north end of Vancouver Island. Since that particular species occurs only off the coast of southern Chile, and since penguins don’t fly, it was logically assumed the birds had been “ship assisted.” From time to time, Cockatiels are seen flying around Vancouver. These birds are native to Australia but are frequently kept as cage birds, it is assumed that free flying birds are escapees. A little closer to home, I have twice seen Scarlet Macaws flying around near Salmo. A few enquiries told me that these were pet birds that were permitted to fly free periodically, (apparently they always returned home). In these instances it was fairly easy to conclude that the birds did not arrive at these locations on their own.
In other instances, however, it is not that clear. Three examples are a Whooper Swan on Vancouver Island, a Xantus’s Hummingbird in Gibsons and a Blue Rock Thrush in the Fraser Canyon. These are all fairly old records but make good examples. The Whooper Swan is a Eurasian species that sometimes occurs in Alaska, but it is also kept by some waterfowl collectors. Did it fly down from Alaska or did it escape? B.C. and Washington collectors were consulted and reported no such escapes, but could it have escaped from California and flown up to B.C? The Xantus’s Hummingbird belongs in Mexico and has almost no history of vagrancy. Is it possible that such a small bird, never previously seen north of Los Angeles, could fly unassisted to B.C? The Blue Rock Thrush is also a Eurasian resident with no history of visits to North America, although it has occurred in Australia! A thorough check of bird collectors and of import permits was conducted and turned up nothing, but can we ever be sure that this bird flew here on its own?
These example give some idea of the difficulty faced by authorities trying to monitor bird movements. Clearly there are some instances when a decision simply cannot be made. I formerly served as chairperson of the B.C. Field Ornithologist Bird Records Committee. The committee was responsible for examining reports of rare and unusual birds. There were essentially two things to be considered: has the bird described been correctly identified and did it arrive on its own. The latter was clearly the committee’s most difficult task!