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Listen for a Nasal Beeping in Your Neighborhood Trees

By Dan Greaney on August 10, 2019 in BirdWords

White-breasted Nuthatch

In the bird world of the North State, there’s little that’s more common than a nuthatch. You’ll find more avian tonnage in winter refuges and flooded fields, and you’ll find brighter plumages and louder songsters. But nuthatches are year-round decorations in our native trees.

Red-breasted Nuthatch

You can scarcely go for a walk up in the fir belt without hearing the tiny red-breasted nuthatches. These little cuties may be tough to see as they pick small insects from high-up in the conifers, but their quick, nasal ankh-ankh-ankh-ankh-ankh calls can be relentless and ubiquitous as they keep in touch with one another.

Down in the oak woodlands, the larger, teacup-sized white-breasted nuthatches fill the woods with calls that are similar but a touch more mellow, slower and lower.

White-breasted Nuthatch

The white-breasteds are often easily viewable, as they usually forage not in twig-tip foliage but on the open expanse of exposed trunks and large limbs. Also helpful for viewing, the oaks are shorter than firs, and many will later lose their leaves. With their regular calling and white faces that stand out against dark trunks, white-breasted nuthatches are one of the most visible little birds in the trees. When flying away, they may flash more white at the corners of their tails. You may be able to see their blue-gray backs, and, in the males, their nape and crown darkened to a rich blue-black.

White-breasted Nuthatch

But it is nuthatch behavior that really stands out. Most birds are like us–our feet are down and our heads are up. But nuthatches give the world a different look. Their regular habit is to fly high and work their way down a trunk. They pick for insects in bark fissures, and the down-trunk approach gives them a view into crevices that woodpeckers and other gleaners miss. Perhaps that less common world view helps lead to their success. These nuthatches are widespread across North America.

Pygmy Nuthatch

Their visibility can be enhanced in your own yard, especially if nearby you have some of the big old oaks they favor. Nuthatches will frequent feeders, especially those offering sunflower seeds. Unlike finches and sparrows, they dine take-out style. They will select a seed and fly away with it. If you can follow their flight, you may see them wedge the seed into some bark, either for later consumption or to hold it there as they bang at it with their bills to “hatch the nut” out! They will nest in cavities of old limbs or in nesting boxes that you can place in your yard.

White-breasted Nuthatch Nestlings in Nest Box

Nuthatches lay a half dozen or more eggs each spring, and their populations have increased over the last fifty years. They are expected to remain regular winter residents of the North State, but are likely to move north for breeding as they deal with climate change.

Swift and Secret

By Dan Greaney on June 29, 2019 in BirdWords

Black Swift

Black swifts are birds of mystery. We know they’re fast, probably powering to over 100 mph. We know they’re fliers, apparently spending up to ten months a year in flight. But much that is known or speculated about them is based on only a few observations, so uncertainty is also part of our understanding.

Black Swift at Burney Falls photo courtesy Glen Tepke

Like the Redding eagles, black swifts seem comfortable, or at least unconcerned, with having people around; but unlike the eagles, their “around” doesn’t include downtown. They do their living in out-of-the-way places, and even there they are unobtrusive neighbors. They nest in dark crevices of waterfall or oceanside cliffs; they forage high above us, and never perch on wires or trees where we can see them; and they utterly neglect to announce themselves with colorful displays or loud songs. They are small, black-brown birds that flit by with the speed of their name, and their light chittering song is often lost to our ears in the roar of nearby water. They are variously reported as having stable local populations and as having declined 94% over the last fifty years.

Burney Falls

But here in the North State they give us this much: they nest at Burney Falls. Each spring, for longer than our history can testify, black swifts make their way to the torrent, where they build and repair nests in the protected nooks among braids of tumbling water. Working with mud and moss, they fashion a hand-sized crib, palm up to cradle their single egg. In the soggy damp of the falls, the egg will take four weeks to hatch, twice as long as most birds their size. Then, with continuing slow development, the chick will not fledge for another month and a half.

Black Swift on Nest photo courtesy of Julie Price

It is at nest-sites that we can best observe these wide-ranging birds. Both parents incubate and tend the young. There are reports of adults roosting near the nest while their mates warm the baby. But those are the only documented reports of these birds landing at all.

Swifts are in the family Apodidae, meaning those without feet. In fact, their feet and legs are reduced, capable of catching cliffside toeholds, but incapable of standing, perching upright, or walking. It is said that if they ever landed on the ground they would not be able to take off again. They go into flight by dropping from their cliff-hold.

Black Swifts at Burney Falls photo courtesy Glen Tepke

Once airborne, however, they are in their element. They zip through the air, often in loose flocks, catching and eating insects on the wing, often higher up than we can see them. They drink water by skimming open-billed at the surface of a lake or pool. They apparently mate on the wing, and almost certainly sleep in the air. Studies on oceanic frigatebirds show that some birds can sleep one hemisphere of the brain at a time–a sleep schedule that seems unappealing, but beats staying awake for ten months!

When young black swifts fledge, they have no trial flights. Most songbird fledglings flutter weakly and hide and rest, gradually building their flight muscles. But swifts are immediately on their way, catching insects and winging–where?

They will fledge in July. By September they are out of Shasta County. By mid-October they are out of the country. Until 2012 we could only guess where they went. That year researchers using ultra-light geolocators studied black swifts from Colorado. They learned that those swifts winter in the lowland rainforest of western Brazil, a land rich in vegetation and the flying insects these birds need.

Maybe our Burney Falls black swifts winter there, too. But we don’t know. They haven’t told us yet.

…because they don’t know the words?

By Dan Greaney on May 25, 2019 in BirdWords

Anna’s Hummingbird Female Feeding from Peruvian Lily

When Columbus arrived in the Americas thinking he’d found a new route to India, he marveled at another new discovery, too. He wrote in his diary of little flying gems, the ones that we call hummingbirds. Of course, the locals had loved hummingbirds long before Columbus. Aztec kings wore whole cloaks made of their shimmering skins. In what became New England, Native Americans wore hummingbird earrings. After Columbus, the pope and then fashionistas throughout Europe soon included hummingbird skins in their décor.

Rufous Hummingbird Male

The fascination is understandable. Smaller than any other bird, more brilliant, and, for those who saw them alive, capable of flying in one place, these creatures were magical! But they are even stranger than the rapt observers of old could appreciate.

Anna’s Hummingbird Male

Being so small, and warm-blooded, requires a high metabolism. Variably among their three hundred plus species, hummingbirds live at 10 heartbeats and two breaths per second, conditions that would kill a human. At such high rates, they burn their energy fast, and can begin to starve in as little as fifteen minutes. To survive through the night, some species routinely go into torpor, a sort of mini-hibernation, to internal temperatures as low as 48 degrees, slowing their body processes and conserving energy until the next day of frenetic feeding.

The feeding itself includes catching small insects from the air—they do need protein, after all—and famously, drinking the high-energy nectar of flowers. Plants, of course, benefit from hummingbird visits because, just like bees, the hummingbirds pick up pollen and spread it about, fertilizing other flowers. These bird-loving, or “ornithophilous,” flowers often co-evolve with certain hummingbird species, matching, say, curved bills with curved corollas, to maximize nectar-gathering and pollination for just those birds and flowers.

Green Hermit Female, Costa Rica, photo courtesy Michael M. Baird

To be able to gather nectar, hummingbirds have a unique hovering capacity. Most birds flap their wings up and down and the physics of the Bernoulli principle keeps them afloat as they go forward. But to hover, hummingbirds have an extra capacity. After their down and forward wingbeat, they can flip their wings over to arc down and backward, creating a figure-eight motion that holds them in place. Of course, all of this happens at some seventy wingbeats per second, so it wasn’t discovered until high speed filming allowed researchers to slow the blur to a visible level.

Hummingbird coloring includes pigments like that of most living things. But with a rare level of expertise, their feathers also create color with refraction. Sunlight bouncing off the birds is bent by minuscule feather cells that act like prisms. Depending on the species, male hummingbirds’ throat feathers, called a gorget, shine with particularly iridescent brilliance. No fools, males orient themselves opposite the sun to flash most brightly to females they are courting.

Calliope Hummingbird Male

The old joke—that hummingbirds hum because they don’t know the words—really isn’t right. They do know the words—and their languages are as bizarre as so many things about them. Many talk with their feathers, with particular feather-hums unique to different species. Many talk with flight patterns. A male Anna’s hummingbird, the only hummer species to stay in our area through winter, dances high into the air near a female he is courting, then dives down into a j-curve in front of her. In case that alone is not enough to impress his heart-throb, at the bottom of his dive he pops the air with his outer tail-feathers, creating a loud, staccato explosion that we unfeathered humans have trouble recognizing as sound from very small quills.

Alas, as far as we know, his ardor does not extend to caring for the young. The female builds her tiny nest of plant parts and spiderwebs, and tends her two eggs and hatchlings for over a month. Gardens with the tubular flowers that hummingbirds love can help her succeed in raising her little ones.

Anna’s Hummingbird Female on Nest

Chaparral Homes

By Dan Greaney on April 27, 2019 in BirdWords

Blue-gray Gnatcatcher photo courtesy David Bogener

We just might live in one of the world’s most under-appreciated plant communities. Although so many of us make our homes in the chaparral, people often look past this native brushland to sigh at the forests above us or the spreading fields below. They are missing a lively world right here.

Chaparral is a community of living creatures uniquely adapted to the Mediterranean climate at about our latitude on the west coasts of continents around the globe. It’s not desert because of winter rains. It’s not forest because of regular summer heat and drought. It’s not grassland because, historically, its fires were too infrequent.

How do the plants survive, here where we huddle indoors with AC? They minimize water loss. With leaves that are tiny or vertically oriented, they cut their exposure to the withering sun. With waxy surfaces or whitish colors they reflect sunlight. With thick, resinous leaves they resist wilting, and with hairy surfaces they catch water vapor that cools the plant as it re-evaporates.

The success of these plants creates a thick bramble, a perfect hideaway for numerous animals wherever it grows. The tale of Br’er Rabbit and his safe briar patch has origins that include the fynbos, the African version of what we call chaparral. Here in California many birds find the brush a safe and welcome home.

Wrentit

Wrentits are tightly tied to their shrubby habitat. The size of a tangerine with a long, cocked-up tail, these hideaway gray-brown birds weave their way through the brush picking insects and making up for their near invisibility with a common chaparral song, described as a bouncing ball accelerating and ending in a trill. Strictly local, wrentits mate for life shortly after fledging and stay their whole lives in the brush within a quarter mile of their native nest.

Black-chined Sparrow photo courtesy David Bogener

Black-chinned sparrows also hug the scrub, but they vacation in Mexico each winter after the work of raising their kids here. These pink-billed beauties are reclusive, rarely seen even by avid birdwatchers except when a spring male perches on a low shrub to sing his heart out. They seem particularly rain-sensitive. Too much or too little precipitation reduces their nesting success.

California Thrasher photo courtesy David Bogener

California thrashers are another timid-seeming bird of the chaparral. They like to remain under brush when they scrape for insects, and their long, curved bills allow them to keep an eye up and out for predators even while foraging. They will, however, perch high and exposed in the tallest shrub around to sing loud and long for a mate! Some things seem even more important than safety!

Blue-gray gnatcatchers break the mold of “secretive” chaparral birds. These plucky little balls of fire energetically twitch their tails sideways and chase scrub-jays at least ten times their size. As a species, they range broadly, nesting in scrublands and forests across the US, and annually migrating as far south as Central America. Their habit of sprinkling other birds’ songs into their own buzzy trills has earned them the title “Little Mockingbird.”

The chaparral where these birds prosper is often misunderstood regarding fire. While many chaparral plants do bounce back from burns, either by crown sprouting or with seed germination, they cannot endure frequent fires. Their historic burn rate seems to have been on the order of 30-150 years. More frequent burns kill off the chaparral and turn it into grassland.

That has been happening recently. The longer, hotter summers of our time have joined with development to diminish chaparral for both people and birds. The Carr fire alone burned over a thousand homes and over 200,000 acres of habitat. In the last fifty years, wrentits and California thrashers have declined by a third, and black-chinned sparrows by a catastrophic 72%.

Fortunately, however, we can live here and still have a “here.” With thoughtful siting, landscaping, and construction material choices, and by steering away from fuels that create the longer, hotter seasons of our fires, we can continue the rhythms of the chaparral and coexist with the wild beauties that also make it home.

Good Things Come in Small Flocks

By Dan Greaney on March 30, 2019 in BirdWords

Bushtit Male photo by David Bogener

In the list of things cute, bushtits belong right up there with babies and buttons. They’re tiny and fluffy, sociable, soft-voiced, and soft-toned. They’re the downy little twittering things, the size of a mouse, the weight of a hummingbird, and the color of a country road. They fly severally from one tree to another—three of them together, then four more, oh, ten of them, and another seven, and sometimes on up to several dozen. They gently tweet among themselves—“I’m here,” “I’m here,” “I’m right here with you”—keeping loosely together as they scour leaves and twigs from every angle to find their miniscule insect meals.

Bushtit Male

Up close, their gray-brown feathers seem softer than an Easter chick’s. The males look gentle, doe-eyed. The females sport a modest adornment. Their eyes are amber.

Bushtit Female

But the great extravagance in the bushtit world is their nest. Both parents and sometimes additional helpers, too, work for up to a month to weave their hanging crèche. It might be in weeds just off the ground, or it might be a hundred feet up in a tree. It is often at a handy viewing level. Imagine a hanging tube sock, a foot long, woven of soft plant fibers meshed with strong spider webs. In that mossy pouch the young will hatch and grow. The upper part of the sock, stitched closed against its supporting leaves and branchlets, holds a single half-inch peep-hole, the nest’s only doorway.

Bushtit Nest

The extensive work required for their elaborate homes seems to structure much of bushtit life, but they face the challenge with a pragmatism that would make a yankee proud. First, they do not migrate. Staying put allows them to start building their homes early, as early as mid-winter, when mild spells begin to break winter’s chill. Second, mated pairs stay together for several years, a level of commitment normally seen only in large birds like swans and eagles. Their mating fidelity spares bushtits from hitting the dating scene every year, and leaves more time and energy for nesting. Third, once they build a nest, a pair will usually reuse it for a second clutch of eggs. Building a new architectural masterpiece would take time and energy away from that second batch of young.

Bushtit Female Emerging From Nest

Fourth—ah, being tiny does not make life less complicated. Bushtits live in flocks of about 10-40 birds. They travel together when foraging, they huddle together when it is cold; they sometimes intersect with other flocks, but then reform their own. And in nesting season, when there are unmated birds or when flock-mates lose a nest, they often undertake what is called plural cooperative breeding.

Adults without their own nest will often help their flock-mates at all stages of nesting—construction, incubating, feeding young, and shepherding fledglings. Up to six adults may help at some nests, all sharing in the warmth of the home. Helpers often continue to feed fledglings while the breeding pair starts a second clutch. Sometimes two or more females will lay their eggs in the cooperative nest. The DNA studies to determine paternity in shared nests have not been done.

Close views are often possible with little birds. When my daughter was a child a flock approached us in the back yard, twittering through twigs just a yard away with their peeping and soft feathers. We watched, and she scrunched her nose over a smile as if in recognition that Oh, there’s beauty in the world. It’s a view I’d wish for every child, and every parent, too.

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