The Big Yard: Notes from a Pajama Birdwatcher

The Dark-eyed Junco of the Gray Head.

December 13, 2023

Tis the season of juncos.  Trios of gray-heads with their black eyes and flared tails, sputter to the fountain pool with a sound like burning sapwood.  Others watch.  The pink-sides keep to the naked chokecherry thicket, uncertainty written in their dark gaze.  The boldest of all are the Oregons, which genuflect at the top of the fountain to dip their bills into a trickle of water.  They don’t even look like juncos in their soot-colored hoods.

Along with the Gray-headed, the Pink-sided form is the most common in the yard in winter.

The Oregon Dark-eyed Junco is the smallest of the six forms.

Of the six races of dark-eyed juncos, five visit the yard.  The slate-colored and red-backed being the other two.  I’m still waiting for the largest dark-eyed junco, the rare white-winged.  The ID of which could be problematic since a variant of the slate-colored—like 1 in 200—shows prominent white wingbars. 

So, I scrutinize each bird’s wings.  And bills—whether they’re pale or pink or gray or bi-colored pale and gray.  Or bi-colored pale and gray at just the upper bill because, among all these flashy winter denizens of the dark-eyed kind, there be hybrids.

The slate-colored Dark-eyed Junco is the most widespread of the forms, reaching across the US and Canada.

Rare in southern Arizona, the Red-backed form is more common along the Mogollon Rim and northern Arizona. Notice the bi-colored bill.

A rare hybrid Gray-headed X Red-backed, Dark-eyed Junco. Notice the bi-colored upper bill.

I’m reading Lixing Sun’s new book, The Liars of Nature and the Nature of Liars: Cheating and Deception in the Living World, a humous take on how life on our planet—from genes to cells to possums playing possum and crows crying wolf—is rife with creative impostors.  Like the singing toadfish, which constructs its nest and woos females with loud monotonous humming until he gets thousands of eggs from multiple suitresses. What’s creative are the “Type II” toadfish males, which don’t waste effort on singing or building nests.  Instead, they put their energy into masquerading as females in both looks and behavior to gain access to the nests of Type I males and surreptitiously fertilize any unfertilized eggs. Apparently, they also grow very large testes...

Then there are those sneaky dark-eyed juncos.  Female dark-eyed juncos.  Both sexes tend to have only one mate with which they nest and defend a territory.  They are “socially monogamous.”  However, females frequently copulate with other males and as a result, males raise young that are not necessarily their own.  “In the socially monogamous dark-eyed junco,” Lixing Sun writes, “birds born out of ‘wedlock’ can rack up 85% more offspring than those produced by the monogamous pair.”  Females, in this way, are rewarded for straying by producing more grandchildren.

Could this be why there are so many different-looking juncos in my yard?

Hybrid-colored beaks are easy to miss...and dismiss.  But I wonder if somewhere during summer a daddy gray-head questions all the sooty-heads in his nest.

There’s something to be said about the simplicity of the one-basic-patterned, yellow-eyed junco, which is also monogamous—but only for a single breeding season.

The Yellow-eyed Junco, whose range barely reaches into Arizona from Mexico, is such a stunner.

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