Archive | BirdWords

Rock Pigeons are both Wild Birds and Human Associates

By Dan Greaney on August 29, 2021 in BirdWords

Rock Pigeon

For better and for worse, many species have cast their lot with humans. Dogs, cats, barnyard and feedlot animals, plants that feed and house us, many bacteria that make us their home, and of course many viruses, too, all prosper or fail in accord with our disposition. Among birds, rock pigeons have closely associated with us for some five thousand years.

Living with people for that long has created changes in the species. These birds, familiarly known as “city pigeons,” have expanded their range from the Mediterranean to temperate regions around the world, following the proliferation of granaries that concentrate the grains they eat and architectural ledges that mimic the rocky cliffs where they historically roosted and nested. Of course, human reaction to them has varied. The birds are sometimes reviled for soiling revered monuments, and sometimes loved for the same action. They are both disparaged as “winged rats” and honored as beauties that invite our kindness for just “tuppence a bag.”

Rock Pigeon

When we take time to observe them, the beauty of their smooth, rainbow iridescence is evident. Living in and out of domestication for five millenia, they have been bred into many forms–rusty browns, ivory whites, sooty blacks, and endless mixes of those hues. Some variation of the historic wild form seems most prevalent: an orange eye in a slate-colored head that blends into a lustrous green neck, lavender shoulders, pale ashen wings with two black bars, perhaps a white rump, and a dark tail tipped in black. To an attentive viewer, their feet in good light stand out like their eyes: pink, sometimes with eye-popping brilliance.

Rock Pigeon

Some domestic rock pigeon strains, notably the homing pigeon and the carrier pigeon, have been bred for specialized uses. Rock pigeons navigate effectively by sensing the Earth’s magnetic field and noting the position of the sun. With that navigational prowess, these birds have been bred into service for the sport of pigeon racing.

For that same skill they have been pressed into military service. Smaller pigeons are usually called doves, symbols of peace, so making rock pigeons into tools of war is a curious case of beating ploughshares into swords. Julius Caesar used them to carry military messages, a practice that continued through WWII. The birds then were also trained as suicide missile guidance systems. Riding in the missile, they would peck at their target through a window; the location of their pecks would guide the missile to the target.

Rock Pigeon

For themselves, rock pigeons are prolific breeders. Males select a nest site on a ledge and coo to woo a female to it. He subsequently delivers twigs to her, which she arranges into a flimsy nest. She lays one to three eggs. Like other pigeons, both parents feed the young “pigeon milk,” a high protein, high fat secretion from their crops. The young grow so quickly on this fare that the pair can repeat the nesting process as many as six times a year if conditions of food, water, and security are right.

Despite their fertility, abundance, and widespread range, rock pigeons have not avoided the worldwide decline of living things. Their North American population has fallen by about half in the last fifty-five years.

The Gifts of the Oaks

By Dan Greaney on August 1, 2021 in BirdWords

Oak Tree

The earliest oak tree fossils, found in what is now the eastern US, are dated from twenty-five million years ago. Since then oaks have diversified around the globe, where they provide a wealth of food and shelter in support of a variety of rich, diverse ecosystems.

Western Bluebird Male

Several types of oaks make the North State home. Valley oaks deck our waterways with the majestic art of massive trunks and branches. Live oaks provide green foliage year round. Black oaks finger into conifers, painting our lower mountains with streaks and fields of autumn golds. But in the bathtub ring around the Central Valley, the foothills below the cooling mountain altitudes but above historic waterways, in the land of summer heat and drought, it is the blue oaks that dominate and define much of the landscape.

Female Lesser Goldfinch Feeding Nestlings

As one of the few trees that can populate this seasonally harsh environment, blue oaks are home to a vast variety of life forms. Their summer leaves, gone bluish and leathery to protect from water loss, are often studded with starbursts of galls, the nests of tiny wasps and flies. Studies on the blue oak’s Midwest cousins have shown as many as five hundred fifty-seven species of caterpillars on a single tree. As larvae and pupae these insects are life-sustaining for the birds that pick them from leaf and twig and trunk, variably to raise their young, fuel migration, and survive the winter–nuthatches, titmice, wrens, kinglets, warblers, vireos, and orioles. When the insects morph into adults with wings, they similarly feed flycatchers, hummingbirds, bluebirds, swallows, and waxwings.

Oak Titmouse Approaches Nest with Grub for Nestlings

Oak Titmouse Approaches Nest with Insect for Nestlings

Downy woodpeckers join oak tree specialists–the theatrical acorn woodpeckers, beautiful Lewis’s woodpeckers, and trilling Nuttall’s woodpeckers–in picking beetle larvae, ants, and termites from the trees, and in making homes in the long-standing soft wood of dying oak branches–homes that are used for nesting by most of the birds already feeding on the oaks, plus a variety of owls and a falcon.

Great Horned Owl with Owlets Nesting in an Oak Tree

But none of this vitality even mentions the defining characteristic of oaks: acorns! Acorns are packed with proteins and fats and calories in general. Woodpeckers, band-tailed pigeons, scrub-jays, and turkeys are only some of their gourmands. Deer and bears feast on them. Gophers, mice, and ground squirrels chomp on fallen acorns, and in turn are eaten by bobcats, foxes, coyotes, and hawks. Yet more insects infest the acorns, and are eaten by reptiles, amphibians, and ground-feeding birds–sparrows, towhees, and quail.

California Scrub-Jay Atop an Oak with an Acorn

Acorns are also devoured by cattle, who prefer grazing and resting near and under the oaks, and gain weight faster in oak-rich grasslands.

As a foundation for so much life, oaks truly are Giving Trees, and the blue oaks have a particularly special place for us in the North State.

Osprey are Awesome!

By Larry Jordan on June 26, 2021 in BirdWords

Osprey Adult with Nestlings Underwing

The Osprey, aka fish hawk, is a bird of prey with some very special adaptations giving them their own taxonomic genus, Pandion and family, Pandionidae. Their outer toes, like those of owls, are reversible, allowing them to grasp their prey with two toes in front and two behind. Osprey toes also have sharp spicules on their lower surface allowing them to grasp slippery fish. They are the only raptor that plunge-dives feet first for live fish, which account for over 99% of their diet.

Osprey Diving For Fish courtesy of Teddy Llovet, Flickr Creative Commons

Like the Bald Eagle, Osprey populations suffered major declines largely due to the use of DDT in the 1950s and 60s. Osprey studies provided key evidence in court to block continued use of persistent pesticides, and Osprey populations recovered rapidly thereafter. Although small pockets of contamination remain, their historic range has greatly expanded and many populations in Canada and the United States now exceed historical numbers, owing to a cleaner environment, increasingly available artificial nest sites, and this bird’s ability to tolerate human activity near its nests. Now Osprey are the second most widely distributed raptor species, after the Peregrine Falcon, found in temperate and tropical regions of all continents, except Antarctica.

Osprey Building Nest at Shasta Dam

Being a predominately fish eating raptor, they nest near fresh or salt water, building large stick nests historically atop trees, rocky cliffs, and promontories. However, predation, loss of trees, and development of shorelines have been driving forces of Osprey shifting their nesting preferences to an array of artificial sites like channel markers in harbors and busy waterways; towers for radio, cell phone, and utility lines; and platforms erected exclusively for the species.

Osprey On Nest Platform

Shasta County is blessed, having many nesting locations for Osprey, several of them being man-made platforms. There was a pair of Osprey that built a nest atop the soccer field lights at Anderson River Park for many years. Unfortunately, the lamps in that light array had to be replaced every so often which usually caused damage to the nest. Wintu Audubon Society and the late Karen Scheuermann, wildlife rehabber of Tehama Wild Care, coordinated with the City of Anderson to install a permanent nesting platform atop that light stand to allow the Osprey to nest there in the future without being disturbed.

Osprey are usually monogamous and mate for life. They also show high fidelity to successful nest sights. We are pleased to announce that a pair of Osprey have indeed accepted our nest platform at the Anderson River Park soccer field and are currently raising two young! In the coming weeks we will be mounting a plague on the light pole to commemorate this coordinated and successful effort to advance the continued breeding success of this beautiful raptor.

Osprey Adult with Nestling at Anderson River Park, June 17, 2021

Buntings: a tale of time, song, and brilliance

By Dan Greaney on June 2, 2021 in BirdWords

Lazuli Bunting Male

This season last year we had a torrent of reports of lazuli buntings scouring through the Whiskeytown brush and in the chaparral all around the North State. These little birds attract attention because they are visually stunning.

Western Bluebird Male

A superficial description of a male lazuli bunting makes it sound like a western bluebird: blue on the head and topside, pale belly, and a rusty-colored breast. But there’s no room for confusion in daylight viewing. The bluebird is darker, almost cobalt, its breast a burnt brick. The lazuli bunting, in contrast, looks like plugged-in high wattage gemstones–turquoise lapis up top, a moonstone belly, and red jasper on the breast. The bird doesn’t actually glow in the dark, but it has that look to it.

Lazuli Bunting Male

Each spring the females, with the same feather pattern as their mates but browner over all, follow up from Mexico a few days behind the males, who arrive first on the breeding grounds–Great Basin oases or brushy thickets throughout the West. The females will build their nests low to the ground, but first the males establish nesting territories by chasing and singing other males away.

Lazuli Bunting Female

Their music is vital. Buntings are like most songbirds in the way males stake out their breeding grounds by singing. But the song means so much more, too.

Yearling males arrive on breeding grounds with no song of their own. But like young people developing their place, they assimilate snippets from their older kith and kin, and piece those musical fragments into a pattern that becomes their own. In this way, they develop distinctive individual songs that share the phrasing of their community. The neighborhood recognizes and tolerates some encroachment from birds that share their song. Other buntings with unfamiliar music are vigorously chased off.

In evolutionary terms, buntings’ vocal cues serve to support perpetuation of a localized gene pool, a condition that can develop both distinctive beauties and destructive in-breeding. But change, for better and worse, is written into the laws of nature.

The tropics, so rich in the conditions for abundant life, churn out an amazing variety of species. It seems that buntings of yore expanded northward from South America, likely sometime well after our continents joined perhaps fifteen million years ago. But the birds became separated east and west when they hit the Great Plains, the vast grassland of North America that sported bison but not the brushy thickets where buntings make their homes. Divided, the western birds developed into what we call lazuli buntings, and the eastern group became indigo buntings.

Indigo Bunting Male By Kenneth Cole Schneider

More recently, however, the Plains have been breached; agriculture and other development introduced brushland where buntings from both east and west could live; and both could sing there, and hear each other’s songs. Apparently the young of both species readily adopt songs from either. They become musically bilingual, and then, as often happens when the same language is spoken, the two groups begin to court and nest together. Their young are proving to be fertile, so the hybridizing and rejoining of the two bunting species is ongoing in mid-America.

Whether that reunion will reach the west coast, and what new beauties it may produce, remains to be seen. Conditions change, and so then do nature’s children.

Lazuli Bunting Male

For now, though, we can enjoy the treat of our time. Lazuli buntings are striking compatriots. You might not recognize the nuances of their warbler-like trill as well as they do, but look for their blazing color in our North State brushlands!

Lawrence’s Goldfinch: Feathered Wealth

By Dan Greaney on April 24, 2021 in BirdWords

Male Lawrence’s Goldfinch

Gold comes in many forms–in nuggets, flakes, and veins. It also comes in birds.

One of the cutest little finches has got to be the Lawrence’s goldfinch. It’s gold is not the brilliant blaze of an American goldfinch, an almost neon beauty, but rather more subdued, with just wing and breast patches of yellow in its mostly-gray feathering. Not much longer than your longest finger, this little lemon freshet of song exuberantly trills, buzzes, chirps, and tweets wherever it is; and right now, it is here.

Core Lawrence’s goldfinch country is along coastal California for about 150 miles north and south of San Diego. In winter some will explore across the arid southwest as far east as El Paso. In spring some will flutter north as far as Redding.

Here they feast on the bounty of spring wildflower seeds, packed with proteins and solar energy locked in by the plants. A goldfinch favorite is fiddlenecks, whose golden blooms deck our oak savannah meadows. The lucky observer will see a goldfinch perched right on the flimsy flower stalk, riding it tipsily as she reaches into the flower cup for breakfast.

Fiddleneck

Wherever they roam, Lawrence’s goldfinches customarily travel in flocks and, like many finches, often wander nomadically. When settling down to nest, they invariably select a building site near a water source. Along a spring rivulet through a flowered meadow is perfect. There the flock begins to break up as nesting pairs form, although they often choose to nest in a sort of neighborhood.

Lawrence’s Goldfinch Female

Courtship includes perching close to each other, calling, and then beak-touching, wing-fluttering, singing, and feeding. Mated pairs continue much of their courting behavior. She builds a nest of soft plant parts, fur, and feathers, typically about ten feet above ground, and there lays her handful of eggs. She tends them assiduously, hiding them beneath her subdued coloring, keeping them close to her warmth, almost never leaving. Her little mate defends the area close around the nest, and brings her food, supporting her dedicated incubation. When she does leave the nest, he assumes incubation duties.

Lawrence’s Goldfinch Nest

Both parents gather insects to feed their helpless young, and then, if all goes well, reform their flocks to roam the meadows of their west-coast world. As home to these little finches, California is indeed the Golden State.

← Previous 1 … 4 5 6 … 19 Next →

Navigation

Archive | BirdWords