Words and photography by Leo Fremonti
The first time I saw an Anna’s Hummingbird buzzing around in the snow, my jaw dropped. I was so surprised that such a small, delicate species could survive in such harsh conditions. I used to think of hummingbirds as frail specimens that would drop dead if they had to go without nectar for even a single hour, and I doubt I am alone in this. Even as a lifelong bird nerd, I just assumed that all hummingbirds in the Pacific Northwest were obligate migrators, and had to head south as soon as winter reared its big, cold, sopping wet head. From October to June, this part of the world just doesn’t seem like a place where a bird that weighs about as much as a penny can survive. But they can. And they do.
How are they pulling this off?
Well, it hasn’t always been this way. In fact, in the first half of the 20th century, this species only bred in southern California and northern Baja, but since the 1990s, Anna’s Hummingbirds have gradually been able to expand their range northward with the help of another species: Homo sapiens. You guessed it; us human beings have unintentionally allowed Anna’s hummingbirds to expand their breeding range as far north as British Columbia and their non-breeding range all the way up to southeast Alaska (1).
I wouldn’t blame you for thinking that this might be the result of human-influenced climate change or some other nefarious or destructive activities, but the answer is much more wholesome. These hummers have been able to make a home in northern latitudes due to the planting of exotic species of flowering plants that provide nectar and the presence of artificial nectar feeders (1, 2). That’s right; human beings’ affinity for landscaping, combined with our love of feeding birds has allowed these guys to drastically expand the edge of where they can exist and thrive, even through the harsh winter months.
A Positive Feedback Loop
A study undertaken in 2017 found that human behavior has also likely changed in response to the range expansion of Anna’s hummingbirds. People in areas newly inhabited by the hummingbirds are more likely to hang nectar feeders than people living in the historic range. Furthermore, people in these areas tend to leave feeders up well past the summer months if they notice hummingbirds hanging around, which is one reason they are now able to exist in cold climates year-round (2). So, more hummingbirds means more people hanging feeders, which results in more hummingbirds, which leads to more feeders… I think you get it.
You might be thinking to yourself. Is more hummingbirds really a good thing? I say absolutely! Hummingbirds are efficient pollinators, which means that they play an extremely important role in the food web, including our own food supply. Some plant species are specifically adapted to hummingbird pollination, and they can actually increase diversity of flowing trees and plants in a landscape! (6).
What if they can’t find food?
In order to maintain their fast wing beats, all hummingbirds have very high metabolic rates, and the Anna’s are no exception. These birds maintain a resting heart rate between 420 and 460 beats per minute, and increase it to as much as 1,260 beats per minute while in flight! If that wasn’t extreme enough, they also maintain a body temperature of 107 degrees Fahrenheit, which could be a deadly fever to a human.
To maintain these extremes, they need a lot of high sugar food, and they need it often. When the going gets tough, they are able to enter a state of torpor, where they lower both their heart rate and body temperature dramatically. If food is in short supply or they are unable to feed through a cold night, these birds are able to drop their heart rate to as low as 40 beats per minute, and their body temperature to as low as 48 degrees Fahrenheit (also certain death for a human) (3, 4). This useful adaptation is likely one of the keys to surviving harsh winters in northern latitudes.
How can you help?
If you have been paying attention so far, you may already have an idea of what your local Anna’s hummingbirds might ask of you if they could talk. Here are three things you can do to help these birds to continue to increase their populations and survive chilly winters.
1. Get creative with your landscaping.
The body of research on Anna’s hummingbirds indicates that habitat modification by humans is one of the main factors in their range expansion since the 1990s (1,2). Just by planting nectar-rich flowering plants in your yard can increase the presence of Anna’s (and other hummingbirds), and allow them to thrive and grow their numbers. So this spring, head to your local garden store and pick up some flowering plants for your garden. Bonus points for natives! Some great ones to plant are Oregon Grape, Red Flowering Currant, Western Bleeding Heart, Western Columbine, Pink Alumroot, Orange Honeysuckle, Cascade Penstemon and many more!
2. Put out hummingbird feeders.
As mentioned before, hummingbird feeders with man-made nectar are one of the main reasons why Anna’s hummingbirds are able to remain in northern latitudes through the winter. Head to your local garden store, pick up some feeders and fill them with a solution of 4 parts water, and 1 part white sugar. Do not add any dyes or honey!
TIP: to prevent the nectar from freezing in the coldest temperatures, I recommend investing in a hummingbird feeder heater like the one pictured below. It will prevent freezing, and I like to believe the birds like a warm spot to sit and eat.
3. Citizen Science!
Much of what we know about populations of Anna’s hummingbirds and many other bird species comes from data collected by ordinary citizens. You can easily get involved in one of the multitude of citizen science initiatives such as Project FeederWatch, eBird, and Audubon’s Christmas Bird Counts.
Why do anything?
Data gathered through scientific studies and citizen science efforts shows that Anna’s hummingbird populations are growing (5). So that means they are doing fine, right?
Well, yes, but I see this as an opportunity to do good while we are ahead, and to not take a positive trend for granted. While these winter warriors are doing well and increasing their populations, history shows that this can all be taken away in short order. In the mid 1800s, the passenger pigeon was the most abundant bird species on Earth, with a total population of 3-5 billion (with a b). They were so abundant that flocks were said to darken the skies during migrations. In 1914, the last passenger pigeon died in captivity, rendering the species extinct. The most abundant bird species on Earth was completely wiped out by humans in just a few decades.
I bring up this sad and extreme story to illustrate how easily ecosystems can be knocked out of balance when we humans act irresponsibly. So, head on over to your local garden store to pick up some feeders, and plant as many native flowering plants as you can stand next Spring! And, when the Anna’s hummingbirds begin to call your yard home, count them. It could make a world of difference.
P.S. Somehow I only have photos of females. If I manage to capture a shot of a male, I will update this article!
References
- Battey, C. J. (2019, September). Ecological release of the anna’s hummingbird during a Northern Range expansion | the American naturalist: Vol 194, no 3. The University of Chicago Press Journals. https://www.journals.uchicago.edu/doi/full/10.1086/704249
- Greig, E. I., Wood, E. M., & Bonter, D. N. (2017, April 5). Winter range expansion of a hummingbird is associated with urbanization and supplementary feeding. The Royal Society Publishing. https://royalsocietypublishing.org/doi/full/10.1098/rspb.2017.0256
- Anna’s Hummingbird Overview. Cornell Lab of Ornithology All About Birds. (n.d.). https://www.allaboutbirds.org/guide/Annas_Hummingbird/overview
- Lasiewski, R. C. (1963, April). Oxygen consumption of torpid, resting, active, and flying hummingbirds. The University of Chicago Press Journals. https://www.journals.uchicago.edu/doi/abs/10.1086/physzool.36.2.30155436
- English, S. G., Bishop, C. A., Wilson, S., & Smith, A. C. (2021, September 15). Current contrasting population trends among North American hummingbirds. Nature. https://www.nature.com/articles/s41598-021-97889-x
