No wonder he looks so smug—this male rufous hummingbird can eat what is to us the rough equivalent of a few hundred cheeseburgers a day, and never gain an ounce.
I hadn’t realized how much I usually do in a day until we moved to town in fall, after the big flood that chased us out of our house.
Six months of town life made me pack on pounds so fast I actually googled “rapid weight gain,” absolutely convinced that I must have some weird metabolic disorder.
Turns out, I did.
Couch potato-itis.
Day after day after day, all I did was sit around.
The only exercise I got was walking the dogs once a day, a ten-minute stroll, half hour tops, in the neighboring field.
Other problem—food.
When we’re living at home, we go down to town about every week and a half to stock up on mostly basics.
In town, we could run to the grocery store (mmm, olives, mmm, good cheeses, mmm, candy, mmm, ice cream) whenever we got a craving.
Or order delivery pizza and yummy greasy sandwiches.
Sure, just take a seat right at the feeding trough! Works great for high-metabolism hummingbirds. No so great for human chowhounds.
Looking back, I figure my daily intake zoomed from around 1,000 calories to more like 2,500.
And compared to our usual regimen at home—hauling wood and water, walking the mountains, working outside, going up and down flights of steps 20 times a day—well, yep. Couch potato disease.
Every 3500 calories that are taken in but not burned off equals a pound of weight.
No wonder I was gaining a pound or two a week.
Call me dumb, or maybe just preoccupied, but it took a good three or four months before I realized why even my baggiest jeans were getting tight.
And by then it was Christmas cookie time.
No, I can’t say no.
But now that we’re back home, I’m slowly getting back to my normal routine. And the pounds are gradually—very, very gradually—starting to disappear.
I’d love to speed up the process.
Which is why I envy our hummingbirds.
Boy, if our metabolism was like theirs, we’d all be size 6 without even trying.
Hummingbirds weigh only about as much as a penny.
Still, it’s not only overall weight of their bodies compared to ours that makes the difference.
Their heart rate is proportionately way, way higher than ours, as is their respiration and digestion. Not to mention excretory processes.
And by “way, way faster,” we’re talking more than 70 times faster for digestion, and more than 1,000 beats a minute for a hummer’s heart rate.
If you’ve ever held a hummingbird, you know how fast that tiny heart beats. (We don’t have screens (no skeeters!), so capturing a hummer in the house and releasing it outside is almost a daily occurrence.)
How do all those incredible numbers translate to real life?
Try this on for size: We’d need to be eating more than 150,000 calories a day to keep up, gram for gram of body weight.
That’s close to 300 McDonald’s Quarter Pounders with Cheese. Every single day.
I don’t think even I could eat that much. But, mmm, just think of all those triple-thick milkshakes….
And, thanks to that super-fast digestion, a hummingbird’s food gets digested practically instantly. A sip of nectar? Consider it gone a few minutes after it’s swallowed.
A shame that my favorite Reese’s peanut butter cups don’t work that way with me.
Maybe it’s time I add a new workout to my daily routine: Flapping my arms like a hummingbird’s wings.
Or maybe not. That’d be about 50 flaps a second. 3,000 flaps every minute.
Watch your hummingbirds for a while, and you’ll see they don’t spend all day flying or hovering. Those activities burn fuel incredibly fast.
So hummers spend nearly three-quarters of their time sitting and resting, as they “leisurely” digest their food. Couch potato, you say?
Hummers can hover while at your feeder, but they’ll quickly take advantage of a perch—keeping their wings still saves precious calories that would otherwise be used as hovering fuel.
Sugars, in flower nectar and at feeders, get used up fast by flight. Nearly 100% of those calories are burned almost as fast as they go down the hatch.
But protein lasts a little longer in a hummingbird’s body.
Protein in your nectar feeder?
Nope. In bugs. Which hummers eat plenty of, though most of us don’t even notice.
An insect the size of a fruit fly—that’d be like a rib-eye steak, to us—is nothing but nutrients in only 10 minutes. A bigger spider—Chateaubriand for one, please—around an hour.
How do these incredible birds eat enough to survive the night?
Those insects are stored as fat in a hummer’s body, for longterm fuel. The birds manage to maintain their weight, just barely, thanks to insects, and at the crack of dawn, they’re back to eating sweets for flying fuel.
Spiderwebs are a convenient source of food for hummingbirds, who pick trapped insects right out of the web. Our most common species, the broad-tailed hummingbird, eats more insects than most other hummers, so that it can better survive the cold mountain nights.
If a cold night requires more calories than they’ve stored to keep their tiny bodies warm, hummers go into a state of “torpor,” slowing down their metabolic processes so they can survive.
And when migration time nears, hummers spend a much larger part of their day eating. Even sugar water gets turned to fat if you drink enough of it and don’t exercise enough to burn it off. (Coca Cola, anyone?)
Yep. Hummingbird metabolism can make me mighty envious. Though, on the other hand, I don’t really want to spend all day at the trough.
Fine. Guess I’m stuck with human metabolism.
No thanks, no cheeseburger today. Not even one. I’m liking this looser waistband 
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