Navigation

Archive | BirdWords

Eclipse of the Ducks

By on August 25, 2018 in BirdWords
Mallard Drake in Eclipse Plumage

Mallard Drake in Eclipse Plumage

When most people hear the term “eclipse” they think lunar or solar. But those familiar with waterfowl understand the term might refer to the feathers, or plumage, of a duck or goose.

Mallard Female

Mallard Female

All birds molt, a process of dropping old feathers and growing new ones. The new feathers keep the birds in good shape for flying, keeping warm, and sometimes for breeding showiness. By the end of summer the bright feathers of spring might be difficult to recognize. Many birds molt in the fall to replace worn plumage, and then again in spring to acquire their most alluring outfits.

Mallard Pair

Mallard Pair in Breeding Plumage

But waterfowl—ducks and geese—choose their mates earlier than songbirds. Ducks usually pair up by late fall, and cannot wait until spring to dress up. Male ducks, in particular, have gorgeous plumage, but in late summer all the males seem to disappear. The Sacramento River gains a steady supply of feathers floating downstream, and no male ducks are to be seen. The beautiful shining green heads of mallards vanish. The ornate wood ducks and brilliant male mergansers can’t be seen anywhere. Suddenly there seem to be many female ducks along the river, but no colorful males of these common year-round species.

Mallard Drakes in Eclipse Plumage

Mallard Drakes in Eclipse Plumage

There’s a scientific reason. Most birds lose a few feathers at a time, replacing them piecemeal without seriously disrupting their lifestyle. But ducks shed all of their outer feathers when they molt, including their wing feathers. For a few weeks, they become flightless. Males acquire the same camouflage as the females, a useful protection while they cannot fly. An observer can distinguish a male mallard at this time only by his slightly larger body and large, yellow bill, in contrast to her orange and black bill. Males at this hapless stage tend to gather in small groups and skulk along shores with reeds and grasses, laying low until new flight feathers develop. After those new wing feathers grow back the males enter a second molt into their bright breeding plumage. The second molt is less severe, and the ducks retain their ability to fly and escape from predators. All of this happens in timely fashion—in the fall, just before the duck dating season opens.

Wood Duck Pair

Wood Duck Pair in Breeding Plumage

Female mallards, wood ducks, and mergansers are always attired in camouflage, so they only molt once—but again, it is in time to have fresh feathers for understated attractiveness when the males come looking.

Geese also molt in the fall, but they usually mate for life, and seem to dress for long-term health and beauty rather than for just a brief courting period. They do not molt all their wing feathers at once, so, although briefly disheveled, they retain the ability to fly.

Wood Duck Drake Preening

Wood Duck Drake Preening

Ducks and geese can often be seen preening their new feathers. They have oil glands on their rumps, which supply the waterproofing that they spread over their sleek contour feathers. The feathers have small barbs that lock their parts together, and combing them helps keep the birds smooth, warm, and attractive. Waterfowl instinctively know how important their feathers are, and do the work to maintain them.

Wood Duck Pair in Eclipse Plumage

Wood Duck Pair in Eclipse Plumage

Webster defines “eclipse” as to obscure, leave out or fail. He discusses the partial or total obscuring of one celestial body by another, making one seem less brilliant, but he makes no mention of the less brilliant plumage of male ducks in the fall. Ornithologists, however, have studied the annual phenomenon extensively. Eclipse plumage allows ducks to quickly molt into fresh breeding feathers. Understanding it solves the mystery of the disappearance of the male ducks.

0

Redding’s Miracle of the Swallows

By on July 28, 2018 in Birds, BirdWords
Cliff Swallow

Cliff Swallow photo courtesy David Bogener

Late July, and you may see no more of Cliff Swallows than their orange rumps, heading south.

For a couple of months they have eddied around North State bridges like summer snowflakes. But now nesting is done. Roomfuls of flying insects have been caught and turned into feathers and warm heartbeats. Winter remains distant, so young birds and vagrant souls may roam with no sense of urgency.

Cliff Swallows In Flight

But the flocks will tend south, to the clime that history tells them is home. For cliff swallows this is deep into South America, a 6000 mile flight to where they may be seen hawking insects over Argentinian grasslands.

Cliff Swallow In Flight

Throughout most of North America, these are the swallows that build their gourd-shaped nests of mud, cemented under eaves, sills, and bridges. In Redding, they have long colonized the old Monolith at Turtle Bay. With recent developments, house sparrows have taken over those nests, and the swallows have moved to both the Sundial and Highway 44 bridges.

Cliff Swallow at Nest

Architecture like the Sundial Bridge is a boon to cliff swallows. The bridge provides the ceilings and cornices where the birds can construct their nests beyond reach of terrestrial predators. The shoreline provides mud that the swallows can carry, one beakload at a time, to form their crèches. The river also hosts its salmon-fest of insects, which the swirling clouds of swallows catch in flight to feed their young.

Similar conditions made them and the Mission of San Juan Capistrano famous a century ago through the legend created by Fr. O’Sullivan, and recorded in his book Capistrano Nights:

One day, while walking through town, Father O’Sullivan saw a shopkeeper, broomstick in hand, knocking down the conically shaped mud swallow nests that were under the eaves of his shop. The birds were darting back and forth through the air squealing over the destruction of their homes.

“What in the world are you doing?” O’Sullivan asked.

“Why, these dirty birds are a nuisance and I am getting rid of them!” the shopkeeper responded.

“But where can they go?”

“I don’t know and I don’t care,” he replied, slashing away with his pole. “But they’ve no business here, destroying my property.”

Father O’Sullivan then said, “Come on swallows, I’ll give you shelter. Come to the Mission. There’s room enough there for all.”

The very next morning, Father O’Sullivan discovered the swallows busy building their nests outside Father Junípero Serra’s Church.

Since then, generations of tourists have marveled at the annual “Miracle of the Swallows.” Indeed, when 1990’s renovation cleaned out the nests and chased the swallows off, Capistrano undertook substantial efforts to coax the birds back.

Here in the North State our development has created our own “Miracle of the Swallows.” Their nesting success allows the hope that we will see them swirling here again each spring!

0

Cowbirds Pose a Challenge

By on July 3, 2018 in BirdWords
Brown-headed Cowbird

Brown-headed Cowbird Male photo courtesy David Bogener

Some folks have difficulty maintaining a charitable attitude toward cowbirds, and it’s an understandable challenge.

The birds aren’t especially ugly or messy or anything like that. You can see them herding with other blackbirds. They’re the slightly smaller ones—the females a muted mouse-gray, the males a glossy black with the brown heads that give them their name: brown-headed cowbirds.

Flapping overhead they cry a distinctive zeet-zeet-zeeet, rising on the third syllable. Or you may see several males at a treetop, chortling in the morning sun, or on a park lawn bowing to the females in spread-winged courtship.

Brown-headed Cowbirds in Courtship by Jan Malik CC

Formerly they followed bison, feeding on grains and insects that the grazers stirred up. Now they often associate with cattle, where they are joined by other blackbirds.

But bison were ramblers, and cowbirds wandered with them; and wandering is not conducive to child-rearing. Cowbirds adapted.

They learned to watch for available homes where they could leave their eggs for stable fostering. In as little as an open minute, a mother cowbird can lay her egg in another’s nest, preferably one where incubation has not yet begun. She may quickly devour an existing egg there, or, if some nestlings have already hatched, toss them out to die, promoting a new nesting attempt by the host with her own egg as the oldest. The cowbird story grows no less brutish from there.

House Finch nest with Brown-headed Cowbird Egg and Hatched Cowbird Chick

Often laid into nests with smaller eggs, cowbirds usually hatch first and bigger than their foster siblings. Scarcely functional themselves, they may, like their mothers, overtly push or yank their unfeathered nestmates over the edge to certain death. This behavior, however, is rare; cowbirds grow most quickly along with a couple nestmates. Their collective begging seems to motivate parental food deliveries, and the cowbird then uses its dominating bulk and gaping red mouth to gather the lion’s share. Its out-sized appetite can leave the smaller nestlings undernourished and weakling.

Brown-headed Cowbird being fed by Red-eyed Vireo

Brown-headed Cowbird chick being fed by Red-eyed Vireo

It’s a problem in the nest, and becomes a problem in whole bird communities. Today’s cattle and deforested land are more widespread than bison and prairies were, and cowbirds have expanded their range accordingly. In new lands they have found new species to raise their young. Many of the new hosts end up raising just a cowbird. The nest parasites survive; the hosts decline.

Brown-headed Cowbird chick being fed by Chickadee

Brown-headed Cowbird chick being fed by Chickadee

Freed of the work of child-rearing, a cowbird can lay three dozen eggs or more every year, each in a separate nest. Some host species do not distinguish the cowbird egg from their own. Indeed, many cowbirds seem to specialize in particular hosts, mimicking the coloring of exactly those eggs.

Song Sparrow nest with Cowbird egg

Many species do, however, recognize the parasite egg. Larger birds are sometimes able to discard or puncture cowbird eggs and successfully raise their own. But this resistance is discouraged by cowbirds’ “mafia” behavior. Adult cowbirds are known to pillage nests from which their eggs have been removed.

Smaller birds avoid such bullying by being too small to throw the foreign egg out. Warblers often abandon their invaded nest and build a new one over it. But even if this second attempt is successful, it wastes springtime and reduces the number of clutches of their own that the warblers can hatch.

This apparent cowbird thuggery is, of course, not truly cruel, or rational or immoral at all; it is instinctive, and students of life can respect nature’s blind cleverness in devising its different ways to survive. However, overly successful parasitism is fatal, and although cowbirds have extended their range, their numbers have begun to follow the declines of their host species.

0

If Birds Could Vote

By on May 26, 2018 in BirdWords

Greater White-fronted Goose with Ducks

Birds can’t vote, and they shouldn’t. They don’t study the issues.

If they could, however, they probably wouldn’t get too worked up over much of it. They mostly embrace the migrant lifestyle, so immigration isn’t a concern. Cutting Medicare and Social Security to fund tax cuts wouldn’t bother them; after all, they’re not slated to get Medicare or Social Security anyway. As for civil rights in general—well, people may aspire to things like kindness and decency, but birds, honestly, are more known for things like hen-pecking than human compassion or civility.

But if they could understand the issues rather than only suffer them, there’s one area in which birds would likely vote as a fairly united bloc. They’d vote for a healthy environment.

Birds would vote to test chemicals for toxicity. Like humans, birds start gathering toxins in utero. Adults in the US contain over 250 synthetic chemicals, new to the world, in our tissues and fluids, entering us from food, furniture, carpet, clothing, and environmental effluent, through our mouths, lungs, and skin; 70,000 more synthetics are on the market, and we imbibe them in ever-increasing dosages. Current law requires testing for carcinogenic effects only if there is evidence of potential harm, and the EPA is given only 90 days to find that harm. Cancer doesn’t work that fast. But if birds could understand the issue, they would object to this bird-brained process and the 80 million of their feathered kin killed by poisons each year. They would likely vote for synthetic chemicals to be held off the market until there was reasonable assurance that they were safe.

Birds would vote for clean water, too. They need it for healthy food supplies, drinking, and for places to swim. But government powers are reverting to Cleveland-River-on-Fire policies, trying to allow more toxic discharges into water supplies, redefining pesticides as nonpollutants, discontinuing monitoring of toxic discharges so that voters are less aware of the poisoning, and suppressing existing studies that, as the White House recently noted, would be a “public relations nightmare.” Birds with understanding would recognize that gutters run to creeks, to rivers, to all of us, and would want to protect all the waters of the US. They would know that we—birds, people, and trees, now and for our children—rely on clean water.

Clean air would also be a priority. Birds process oxygen even more rapidly than incumbent congressmen do, and those incumbents’ efforts to allow vehicles and industry to dump more mercury, benzene, and nitrous oxides into the air will most emphatically harm the lungs of fast breathers like birds and children.

Birds would also seek to protect grasslands and forests from development and destructive extraction practices. In the last 50 years, American forests have lost a quarter of their birds, and grasslands half. Past Farm Bill provisions have shown promise in curtailing habitat loss, but the current bill in congress allows increased toxic dumping.

And perhaps most emphatically, birds would vote to curb the craziness of climate change. They would recognize that the problems are devastating, with most of their kin expected to lose most of their seasonal range within the lifetime of today’s children; and that there is no good reason to exacerbate droughts, fires, and floods when clean fuels are available if people choose them.

The birds might recognize that they cannot make lifestyle changes or government changes, but they might hope that their more intelligent North American companions will.

0

It’s Parenting Season

By on April 28, 2018 in BirdWords
Black-headed Grosbeak Male

Black-headed Grosbeak Male

It’s spring, and the busier the birds and bees are, the better it is for all of us. Part of that busy-ness has to be raising offspring.

Birds take on rearing their children with all the variety and flair of feathers. Many young birds are brought up in two-parent nests; others just by mom, some just by dad; some are raised by foster parents; still others are grouped into “it takes a village” scenarios. There are numerous child-rearing styles. But no young bird prospers without substantial parenting in some form.

Black-headed Grosbeak Male Feeding Young

Black-headed Grosbeak Male Feeding Young

Billions of aspiring avian moms and dads are in this child-raising season right now. Most songbird pairs share their nesting duties. Typically, the female incubates and turns the eggs, and quietly chirps to the young, who learn her voice before they hatch. Males in some species spell their mates on the nest, but more often do guard duty, dive-bombing or distracting predators. Both parents feed the hatchlings, hunting down hundreds of insects and making scores of feeding visits to the nest every day. When the fledglings take wing, the male often shepherds them, while mom perhaps begins a second or even third nest.

Black-headed Grosbeak Female

Black-headed Grosbeak Female

Black-headed grosbeaks, colorful, big-billed birds, take the sharing of nest duties a notch or two farther than most species. When a dangerous jay or neighborhood cat approaches, the female readily joins her mate in harassing the predator, attempting to drive it from their vulnerable young. On his part, the male, with rare egalitarianism, undertakes an even share of egg incubation and nestling-warming. More noisily than his mate, he nests with what seems foolhardy flair; he sings loudly right from the nest, as if he can’t contain his proud papa-hood.

Black-headed Grosbeak Juvenile

Black-headed Grosbeak Juvenile

Unike the precocial ready-to-go chicks of turkeys, ducks and quail, hatchling grosbeaks are altricial—blind, naked, and helpless. Within two weeks, however, under their parents’ relentless feeding and guardianship, the babies are full grown and feathered, ready to try their wings.

Like so many of our nesting birds, grosbeaks are travelers, wintering in Mexico and nesting as far north as British Columbia. Like robins, they have adapted effectively to suburbs and parks. They prefer to nest near water where both trees and brush offer cover. The females weave loose nests, usually on outer branches no higher than a second story window. Both the male and female sing profusely, a tune and tone frequently likened to that of a tipsy robin. His song is especially loud and clear, waltzing through the woods any time of day.

These singers of the American West dine on seeds, insects, and fruit, happily foraging high above us mere walklings. They are, however, happy to descend to our level to empty our feeders of sunflower seeds. There we can enjoy their burnt orange plumage and oddly hefty bills.

0