The Big Yard: Notes from a Pajama Birdwatcher

Feeding Cassin’s and House Finches among a few Pine Siskins.

January 15, 2023

Birds frenzy at the fountain and feeders this gusty, bruised-sky morning as another Pacific cold front shoulders in, carrying the promise of rain and snow to add to the year’s already impressive 1.59 inches of moisture.  Clouds of tawny pine siskins descend in waves, scores of the nomadic and energetic finches mingling with the lesser goldfinches and even the occasional and rare American and Lawrence’s goldfinches among a dozen, lingering Cassin’s finches.  It’s finches galore, and my efforts to count them fall short somewhere in the 60s.  I’ve never seen so many in the yard all at one time, especially this “irruption” of siskins hailing from the boreal forests of Canada and Alaska.

Wrapped in a blanket, I watch these champions of the cold flit between the fountain and thistle feeder.  When nighttime temperatures plunge into negative numbers, pine siskins can fire up their metabolism five times greater than other songbirds their size.  To fuel this metabolism, they stuff their crops with seeds equaling ten percent of their body weight. 

When I get cold, I eat a sandwich.  But not one weighing 17 pounds.

A cold-loving Pine Siskin refueling on scattered sunflower seeds.

The ever-present (when there’s thistle seed to be had) Lesser Goldfinch, which really should be called the Mexican Goldfinch since most of its range is south of the border.

This Lawrence’s Goldfinch and the American Goldfinch (below) are both uncommon visitors in Winter.

This male Anna’s Hummingbird doesn’t even feel the cold.

The real masters of metabolism are the hummingbirds.  This morning, like most mornings this time of year, three Anna’s chase each other around the feeders, which I keep filled with a higher concentration of sugar water for them all winter.  Flapping 40 to 50 times each second, their wings make a distinct sound that draws my attention (a sound distinct even among other hummingbirds).  The sound of hovering flight.  No other kind of locomotion among animals consumes more energy.     

To accomplish this, hummingbirds quickly process sugar—fructose as efficiently as glucose (unlike humans).  Recently, the journal Science published a study about researchers in Germany who, by screening bird genomes, discovered that the absence of a certain enzyme in flight muscles leads to better sugar metabolism.  Michael Hiller, the study’s lead author, says that the loss of this gene in the hummingbird ancestor was likely a key step in the evolution of hovering flight 48 to 30 million years ago.

The research illustrates how, with evolution, loss can be gain.

Something I point out to the wife in defense of my shrinking Y chromosome and the probable extinction of the male species.

Our second largest hummingbird, a magnificent male Rivoli’s Hummingbird, whose powerful flight muscles create a unique-sounding wingbeat at 22 flaps per second.

Thanks for subscribing! More birds on the way!