It used to be that sightings of robins were relatively rare, at least, spotting the first one in spring was welcomed as a genuine sign of spring, and even the rest of the summer, you might spot one or two robins as you go about your life.
Now? Well, it’s a rare morning that I don’t open my front door to see at least four male robins hopping around in my really not very large front lawn. And I swear I see a robin, maybe two, in the yards of all the houses I pass on the way to work.
(I’m in Eastern MA.)
Now, okay, this can just be confirmation bias or whatever, but the change in population seems very real to me. So I was wondering –
Do other people see this happening?
If so, is it just a part of global warming? Like, a whole bunch of robins that used to hang out south of here have shifted northward?
I have an alternative theory. Dogs used to be allowed to run free in this town. 12-15 years ago the law was changed to require dogs to be on leashes/runs/fenced at all times.
Very soon after that, chipmunks shifted from rarely seem to common – every stone wall around here (and we have lots of old stone walls) seems home to a family or two.
Not very long after that, the fox population increased greatly. Again, from something super rare to being seen maybe every week or two in our neighborhood, at least.
About the same time, coyotes moved into the area.
Not long after that, a lot of people began keeping their cats indoors to keep them from becoming coyote chow.
So…maybe its a chain of cause and effect? Leashed dogs kill fewer small rodents things = more rodents. More rodents = more food for foxes & coyotes. More coyotes = more cats killed. More cats killed = cats kept indoors.
Cats kept indoors = fewer robins killed?
Could house cats really have been killing enough robins to make such a big swing in their population?
Hmm. Will more robins = fewer worms? Fewer worms = less fertile soil? Less fertile soil = less success in gardening?
Weird to think that something like adding a leash law could shift the local ecology in such a way.