29/01/2026
The unintended evolution happening in our backyards.
Anna’s hummingbirds were once confined to Southern California and Baja. Their beaks were perfectly sculpted over millennia to match the native flowers they fed from. But in less than a century, something remarkable and a bit unsettling has happened.
Since the 1930s, these birds have exploded northward, now reaching as far as Alaska. That’s a range expansion of over 1,000 miles. The culprits? Exotic plants, and the explosion of backyard feeders after World War II. So, in other words, humans are responsible.
But here’s where it gets interesting: their bodies are changing too. Museum specimens reveal that in just 10 generations, Anna’s hummingbird beaks have become longer and more tapered. They’ve evolved to exploit the endless sugar-water flowing from our feeders rather than the flowers they co-evolved with for millions of years.
We didn’t set out to reshape a species. We just wanted to watch hummingbirds from our kitchen windows. But evolution doesn’t care about our intentions. It responds to selection pressure. And we’ve become one of the most powerful evolutionary forces on the planet.
Are they visiting fewer native flowers, potentially disrupting pollination networks that have existed for millennia? What happens when they become too specialized for the world we’ve built them, rather than the world that built them?
This becomes more complex when you think about the fact that the birds that overwinter in colder climates rely heavily on feeders to make it through the winter. But we can’t just take this food source away now…can we? Just food for thought. Ps. I maintain a feeder 🐦
