Why Have Geese Stopped Migrating?

To finish up this four-part series, we’re going to look at the poster-birds for migration: Canada Geese, who’s V-formations as they fly south are an iconic autumn sight. So the big question is: why can you still see these ‘iconic migrators’ staying put in the dead of winter? Why have the poster-birds for migration stopped migrating?
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TRANSCRIPT:
Canada geese are like the poster birds for migration. Their iconic V formations are a harbinger of autumn as colder weather sets in and they start their journey south.
So with all that said… what’s up with this? Why is it you can see Canada geese staying put through the dead of winter? Why have the poster birds for migration… stopped migrating?
Last time we explored all the biological tricks that Northern Cardinals have evolved to withstand winter without retreating south.
Canada geese do have some similar adaptations. They have a down undercoat to keep them warm, and a counter-current circulation system that reduces heat loss as blood flows out to their extremities and back.
That all helps. But one of the biggest reasons Canada geese are able to forego migration has to do with us.
Canada geese are one of those species that took extremely well to human habitation. They’re surprisingly at home in urban environments, taking advantage of bird feeders, hand-feeding… our crab apple trees that hold onto their fruit late into the season, and aerators that give them access to open water year-round.
But of all the things we do for them, the most significant might be our obsession with grass.
It seems like our default response to any environment we don’t pave over is to flatten it and cover it in grass. We love our lawns, parks and, god help us, golf courses.
Meanwhile geese are some of the only birds who can live on a diet of grass. We may have thought we were just making green spaces for our cities but we were actually terraforming for their benefit, giving them expanses of ideal grazing territory - even in winter.
Plus, the lack of predators has a big effect. A three-year study by the University of Illinois tagged geese to track their survival rates. For the geese who stayed in the urban areas? 100% survival.
For the geese who ventured out into rural areas with hunters and other predators? 48% survival.
The urban, or resident, geese, are so entrenched now that they can have entirely separate breeding ranges from migratory geese, creating distinct and diverging populations.
And the resident geese seem to have all the advantages. Not only do they avoid a dangerous trip twice a year, they start nesting younger and produce more offspring than migratory geese.
Just 55 years ago, they were considered almost extirpated. But efforts to protect them let the geese gain a foothold that has become an explosion in urban population.
Now, we’ve got the opposite problem, to the dismay of our resident human population. Geese can be obnoxious, aggressive, and poop machines. It’s gotten to the point where serious effort - and money - are being spent to try and curb their population growth.
For example, Vancouver’s last goose control proposal was estimated at up to $375,000 and included this, which is literally called ‘The Goosinator’.
I also have to mention that on the web site for the Goosinator is just a big button that says ‘Contact Randy’, which is the icing on the cake.
Anyway, how are all those control measures going? I think this quote sums it up pretty well:
“Remedial measures have been attempted in several large cities to reduce the number of resident Canada geese, including repellents, balloons, flagging, frightening devices, landscape modification, pyrotechnics and nest-destruction. All have failed.”
The fact is, we may have accidentally made our cities just too darn comfy for geese. Enough for them to give up their ‘poster bird for migration’ status… and maybe, enough that there’s no going back.

[@tornadosirenwednesday]

Wow