Tuesday, May 17, 2016

Django and Junco

Sometimes our cat Django gives us the slip and darts outside, even though I have lectured him many times about why it's important that cats be kept indoors. He dives under the deck before I can grab him, shouting over his shoulder that he doesn't care if I want to keep birds safe. He just wants to go eat grass and drink filthy water out of a flowerpot.

Male junco on feeder pole in our yard.
But payback comes in the form of a fierce pair of juncos nesting somewhere in the yard. As soon as Django creeps out from under the deck, the two little birds perch above him and denounce him loudly. Chip! Chit! Chit! they scold, and he flattens to the ground, as much as an 18-pound cat can flatten himself. His ears stick out sideways. His gratitude, when I slide open the door, is immense, and he flees from the tirade to the safety of the back of the sofa.

Juncos are such exceedingly common birds that most people who pay scant attention to birds tend to lump them in with all the other little brown or gray things with wings that flit about the yard. They aren't really far off the mark in so doing--juncos are, after all, a kind of sparrow, and it's hard to get more common than a sparrow. (Well, depending on what sparrow you're talking about, that is.)

But I'd never seen one before I moved to the Northwest from the east coast more than 25 years ago. I quickly learned that this little gray and brown bird with the black executioner's hood was an Oregon junco--one of the many races of the species known as the Dark-eyed Junco, Junco hyemalis.

Actually, it would have been remarkable if I'd seen an Oregon junco on Long Island in New York; it's a western bird, found only casually in the East. What I would've seen back east was another race, the slate-colored junco. ("Casual" in birding doesn't mean that the bird is found in jeans and a tee-shirt leaning nonchalantly against a wall. It means "Species not recorded annually in the ABA [American Birding Association] Checklist Area, but with six or more total records—including three or more in the past 30 years—reflecting some pattern of occurrence." In other words, slim pickins.)

Dark-eyed juncos live year-round in many parts of the West, the Appalachians, and some northern states. In winter, they spill out to fill the rest of the country. This migratory habit earned them the common name of "snowbird." In warm states, the term would imply they're escaping winter's cold, but people in chillier states think of them as sticking around or arriving with the snow.

Juncos "drift into our gardens when snowy weather comes and when days are dark with rain, and winds blow cold," writes Francis Staver Twining in her book Bird-Watching in the West (1931). "I am always glad when the juncos come dancing in."

Male Oregon Junco, USFWS photo

The juncos in our winter garden join finches, sparrows, towhees, and chickadees at our feeder. Though they're ground birds, they will also struggle to snatch seeds directly from the feeder, flapping furiously as they try to cling to its sides with one foot and grab something before they lose their balance.

A junco's crisp markings stand out nicely in a snowy scene. The Oregon junco male's head is jet black, and his gray-brown wings fold neatly to form lapels on his russet sides. The female has much the same coloring but in paler shades. Both have white feathers on either side of their tails.

These white tail feathers serve many purposes. If threatened, juncos flare their tails as they fly away so the white feathers can signal an alarm to other juncos, in the same way that a raised white tail signals alarm in a fleeing deer. At the same time, the flash of white tells a predator, "I see you, you missed your chance, you've been spotted, hunt something else." Observers have also seen juncos flaring their tails to threaten other birds, including other species, in crowded feeding conditions on the ground.

Female junco, Marymoor State Park
In courtship, male juncos flare their tails to show off the white feathers as they seek to win over a female. Scientists have found that birds receiving better nourishment grow feathers with bigger white patches than birds eating merely a subsistence diet. If so, it may be that bigger white patches = more pugnacious bird = female selection pressure on male juncos to have hunky white tail feathers.

Another study seems to show that suburban juncos have less white in their tails than rural birds; the speculation is that there is less predation and competition in suburbia, and so female selection pressure is leaning more toward having a mellow dad around to help with household chores than an aggressive warrior.

Just recently, when Django the Cat made an escape and I responded to the junco's angry cheeps by stepping outside to fetch him, I nearly trod on a male junco apparently leading him up the steps by scrabbling along the deck with his tail flared, much like a killdeer feigning a broken wing. I'd heard that the white tail feathers might also entice a predator into going after the junco's tail instead of its vital head and body, so it's not such a leap to imagine the junco might likewise use its white feathers to lure a predator away from its young.

The white tail feathers, the variety in coloration, and much more make the humble junco "a rockstar study organism" for scientists. These scrappy little birds have been used in studies focusing on evolution, speciation, migration, ecology, and other topics. There's even a movie about them that can be downloaded or ordered and used in schools, museums, and other venues (find it here).

I poked around in a few old bird books to see if I could find some fascinating tidbit about these backyard birds, but without much luck.

My old reliable Birds of California by William Dawson devotes much of its account to the parsing of junco species and races. The Audubon Society Encyclopedia of North American Birds gives workmanlike accounts of each race (with an odd note in the Oregon's write-up: "Juncos attracted to warmth of caves in Yellowstone have died there from gases").

John James Audubon, however, had lots to say about juncos, which he was glad to see in winter when they migrated into Louisiana.

According to him, the junco was apparently quite well known among people in the mid-1800s:
So gentle and tame does it become on the least approach of hard weather, that it forms, as it were, a companion to every child. Indeed, there is not an individual in the Union who does not know the little Snow-bird, which, in America, is cherished as the Robin is in Europe. 
And his description of its behavior tells you exactly why a junco can put the fear of God into a fat housecat:
Although the Snow-Birds live in little families, consisting of twenty, thirty, or more individuals, they seem always inclined to keep up a certain degree of etiquette among themselves, and will not suffer one of their kind, or indeed any other bird, to come into immediate contact with them. To prevent intrusions of this kind, when a stranger comes too near, their little bills are instantly opened, their wings are extended, their eyes are seen to sparkle, and they emit a repelling sound peculiar to themselves on such occasions.
Our resident juncos are currently spending a lot of time emitting repelling sounds, because they even shout at the cat when he's indoors if they spy him through the glass sliding doors. Meanwhile, the rufous hummingbird will divebomb the male junco if he happens to be sitting too close to the nectar feeder. Which makes the other cat, Pebble, utter that weird chittering noise cats make when they gaze at birds from a window. Which  makes the dog come in to see what's going on. It's a busy season, springtime is.