Hummingbird Math

Being in coastal Oregon, in the middle of nowhere, we get to see a lot of hummingbirds. We were doing some necessarily “fuzzy” (or maybe it was “feathery”) math the other day based on how much one hummingbird can eat in a day, and how much sugar-water nectar we are feeding them.

two female Rufous Hummingbirds

(I took the photo of the two female Rufous Humminbgirds pictured above a few minutes ago during a quiet period.)

The math goes something like this:

Depending on which website you read, an adult flighted hummingbird (not sick or injured and able to fly), such as our local Anna’s Hummingbirds and Rufous Hummingbirds, will eat about half an ounce of nectar per day. So one ounce of nectar would support two hummingbirds, if that’s all they were eating.

But it’s not cut and dried math, because maybe the hummers only come by to “tank up” in the morning after a long cold night, or before heading off at twilight to their nests.

We have flowers everywhere now; foxglove and blackberries are blooming, as well as camas, irises, columbine and uncountable numbers of buttercups and daisies. And hundreds of other nameless little wildflowers. The rhododendron are also in full bloom right now.


Blue Boy Iris

Blue Boy Iris

Foxglove

Foxglove

Camas flower

Camas flower

Rhododendrons

Rhododendron

So there are plenty of flowers blooming, from which a huge number of hummingbirds could take sustenance.

Back to the Fuzzy Math

We have four hummingbird feeders, each holding one quart of nectar. Each feeder has to be cleaned and refilled twice a day. So we are putting up two gallons of nectar per day. One gallon = 128 ounces. Two gallons = 256 ounces.

Two hummingbirds per ounce per day x 256 ounces = 512 hummingbirds. More or less. This assumes no external source of food, which is patently untrue. They drink even more when it is cold and rainy.

However, using fuzzy math, by one calculation we could be supporting as many as 1500 hummingbirds with our four feeders. At dusk when they come to “top off” before the cool nights (down in the 40’s, most nights) we can sort of count about 150 hummers at any one time. It’s hard to be accurate, because they are moving so fast and only a small percentage are actually at the feeder. Many more are usually perched in the nearby trees, or flying to and from the feeder from their nests. It gets quite loud, with all the chittering and thrumming of wings. If, God forbid, we let some of the feeders go empty, they will congregate around the remaining feeders in a swarm we call a “hummernado”. We can hear the change in background noise when this is going on – it is my alarm that the feeders have run dry.

Hummingbirds, though pretty, are nasty little birds. They are often aggressive to each other, and they are constantly attempting to knock one another off of the feeders. They remind me of indignant little fighter jocks, always looking to pick a fight at the bar.

Several of my clients have suggested we put up a webcam. Leave a comment if you’d be interested in viewing The Hummer Cam.

2 Responses to Hummingbird Math

  1. Donald Mitchell December 9, 2015 at 5:54 pm #

    Sure, I’d like to see a hummer-cam. Do you get your big numbers primarily during the northbound migration in March or so? Are you far enough south and west in Oregon to get Allen’s Hummingbirds in addition to Anna’s and Rufous?

  2. Jere Matlock December 9, 2015 at 6:56 pm #

    Donald – we did get some Allen’s Hummingbirds as well as the Rufous and Anna’s. I think our big numbers came from the annual migration, as you say. Hard to tell, because we don’t know of any other stations around to compare with that also got big numbers at that time.

    We’ve moved out of our house on the timber ranch and gone mobile – living in an RV since August, traveling around the whole country. We’ve gone from one form of paradise to another; sadly the hummingbirds will have to make do without our many gallons of sugar on their next migration. There are plenty of flowers, however, so they’ll just have to give up their lazy ways and go back to gathering nectar. We left a bunch of honeysuckle growing on the ranch, and a ton of everlasting peas, which have great flowers and a long growing season (for Oregon, anyway).

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