The story of the increasing numbers of non-migrating, resident Canada Geese is more interesting than just “bird slothfulness”, and may be an example of the unintended consequences of human intervention, bird adaptation, and evolution in action. These year-round birds also generate strong human emotions and responses, similar to when a house guest overstays their welcome.
My first childhood memory of Canada Geese was when my father pointed out the honking V’s, high overhead as we made our cottage ready for winter in Upstate New York. When I moved to the Chesapeake 33 years ago they took center stage each fall, and all exited stage left each spring, leaving us with fond memories and anxious for their autumn return. Back then they were very welcome, but things have started to change. The Branta canadensis PR department must re-examine their new behavior before it’s too late.
There are about 5 or 6 million Canada Geese in North America with the resident non-migratory population now greater than 50% of the total. In 1900 however, Branta canadensis was in serious jeopardy, mainly from hunting pressures. By 1950 the “Giant” subspecies, occidentals, was thought to be extinct. Luckily a small surviving group was located and allowed to breed in captivity, and were eventually released back to nature, but now as non-migrating birds. Interbreeding with other subspecies led in part to this growing population of geese that no longer heeds the call of the north each spring.
And how can you blame them? 1500 miles is a long way to fly if you don’t need to. When you get there, tired and hungry, you must immediately mate, build your nest, and fight off predators, only to make the return flight south in 6 months. The resident geese however can enjoy a year-long stable climate and breeding conditions, beautiful grassy lawns for feeding and ponds for swimming, few predators, and only have to take short, low-altitude flights. They’ve boldly adapted to lawn mowers, dogs, picnickers, golfers–no problem for them.
The problem is for humans. Denuded lawns, goose droppings on the putting surface and elsewhere, polluted ponds and pools, health concerns, and airplane collisions are some of the issues. The birds are protected by the Migratory Bird Act but some efforts to reduce the population have been tried without significant success. Many states have an early hunting season, before the migrating geese arrive. Nest and egg destruction, harassment, habitat management, etc. have all been tried to little avail.
It interesting to note that while the migratory geese are only breeding after they arrive in Canada, the resident geese breed down here–they don’t interbreed and their gene pools do not mix. I suspect someday we will begin to see morphologic differences such as smaller migratory birds with stronger flight muscles, as well as genetic differences when mutations occur and are passed on only along the isolated lines. I think I can already detect the fatter and bolder resident birds when the flocks mix here in the winter. Someday, in perhaps several million years, we’ll see a distinct separation of two species.
This spring we had two families of resident Canada Geese raised along our shoreline. I must admit it was enjoyable watching the growing families parading across the lawn each evening. One day I found several small chicks had entered our pool but could not climb out–the parents were nearby honking loud instructions but were unable to save their young. Here was my chance to cull the population–but I just could not do it. I spent a long time catching the downy youngsters in my leaf net–those little buggers can really swim and dive even if that can’t fly. I finally released them to their concerned and squawking parents, with nary a thank you I must add. I guess I’ll just leave the culling to someone else.