Day 169: Next newsletter goes out tomorrow; meanwhile, a ruckus

Issue 13 of The 10,000 Days Newsletter goes out tomorrow. Here is the essay from the last one. Thank you for reading.

Photo by Faye Cornish

Ruckus at the feeder

They announce themselves before they swoop. From up in the trees, one or two or three trumpet a piercing fanfare that sounds like an angry hawk, which some ornithologists believe is no accident. Then they dive to ground around the feeder. Blue jays go in a straight line like a bullet, flaring wing feathers as they land. They seem never alone. The first one appears and in an instant there are five, six, eight; the most I have counted under the feeder at one time is 12. They have large vocabularies and a gift for mimicry, which I suppose is handy when dinner for ten convenes. Captive jays have been known to torment the cat by learning how to meow.

The pigment in the feathers of blue jays is melanin, and melanin is brown. So…then…. Quite the optical trick, it turns out. Their feathers have barbs and the barbs have cells on their surface that scatter light; we see the scatter as blue. Jays have crested heads. Drawings and sports mascots always show the crests at full flare, but as the birds hop about picking seeds out of the grass, they wear their crests flat against their heads, creating blue tonsures that, in some light, are the same blue as the headscarf worn by Vermeer’s girl with a pearl earring. Naturalists regard a flattened crest as a sign of low aggression, and I notice that if there are doves or cardinals or squirrels already on the ground, the jays leave them alone. Plenty for all. Despite their reputation for pushiness, jays are frequently bullied off feeding trays by woodpeckers and grackles.

They usually partner for life. About 20 percent migrate, the rest stay home, where they work as foresters. Ornithologists once tracked a half-dozen with radio collars and observed that in a single autumn each cached 3,000 to 5,000 acorns. They did not remember all those caches, so a lot of oak trees got their start from those half-dozen jays. They carry acorns in their upper throats, as many as five at a time, which seems to me like a human coming home with five oranges stuffed in his mouth. Don’t try that—use a hemp bag instead.

They come in varieties: Steller’s jays, pinyon jays, Mexican jays, Canada jays, and various scrub jays labeled Florida, California, and Woodhouse. The extended family includes magpies, Clark’s nutcrackers, and green jays, which look like someone grafted a blue jay’s head on a canary’s body.

Suburban folklore casts them as thieves and predators. They will raid nests for eggs and nestlings, but one study of 530 jays found traces of either in just six. Still, one summer evening when I was a boy, my father pointed out a jay in our apple tree that had pinned a sparrow to a branch and was stabbing it over and over again. Sparrowcide. After the jay fled, we examined the crime scene and found the sparrow’s body minus its head.

Before they eat ants, jays will rub the insects on their feathers. This may be to rub off formic acid and improve the gustatory experience.

They may have problems being fully in the moment. In 2000, Dukas and Kamil published a paper, “The Cost of Limited Attention in Blue Jays,” in Behavioral Ecology. I quote: “Consider a blue jay perching on a tree trunk and directing its gaze toward the bark in search for cryptic insects. The blue jay has the visual ability to simultaneously detect approaching predators while foraging, but such detection may be hindered due to limited attention, at least when the foraging task is difficult and attention-demanding.” To me, this is obvious. What else commands attention like a cryptic insect?

The term of venery for larks is widely known, for some reason: an exaltation of larks. Generic birds flock, but a flock of doves is a dole, of crows is a murder, and of goldfinches is a charm. (That’s lovely, isn’t it? A charm of goldfinches.) The term of venery for blue jays is a scold, and that’s good, but I propose something better—a ruckus. A ruckus of jays.

Out back, a spring rain has eased. From the trees sounds the clarion and they come again, their feathers scattering light as their beaks unscatter sunflower seeds.

Day 93: Quantum birds

Reading an issue of the science magazine Nautilus from a few years back, I came across this in a story on animal navigation by Sally Davies, pertaining to migratory birds:

Other studies point to the presence of a quantum mechanism in the eyes of avian migrants that enables them, perhaps literally, to see magnetic fields. An optical protein known as cryptochrome is thought to change into a quantum state when light strikes it, with two unpaired electrons zipping around two molecules in a configuration known as a radical pair. If these electrons spin in parallel, the system exists in what’s known as a triplet state; if they spin against each other, it’s known as a singlet. Running a magnetic field through this delicate biochemical web of subatomic particles will push the system towards either a singlet or a triplet state, depending on the direction of the field lines. The theory is that sensitivity to the balance of these states in the eye would allow the bird to perceive magnetic field lines, like a thread running through three-dimensional space, and use it to set their compasses for flight.

That's staggering. Birds might have quantum magnetic field detectors in their eyes? What would it be like to have that as part of your vision?

Animal navigation gets my attention because I am a man who can barely navigate his own house. GPS units and smartphone nav apps keep me from wandering for days trying to remember my way home. More on this topic coming soon.