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Robins Grace our Days

By on February 27, 2016 in BirdWords
American Robin

American Robin

John James Audubon reports that when at the age of eighteen he emigrated from France to the New World, “The first land-bird seen by me, when I stepped upon the rugged shores of Labrador, was the Robin, and its joyful notes were the first that saluted my ear… I could scarcely refrain from shedding tears when I heard the song of the Thrush, sent there as if to reconcile me to…the barren aspect of all around.”

While the age of birdsong eliciting tears has largely been buried by hastier technologies, Audubon’s raw experience is something most of us can still find in our own backyards and parks. Reported to be the second most numerous land bird living in North America today, the robin remains a soulful beauty, so common as to be almost overlooked.

As Audubon noted, the robin is a thrush, a family that includes bluebirds and several speckle-breasted singers of deep forests. More than any other thrushes the robin has accommodated human civilization. It thrives wherever there is moist earth, trees and shrubs, and a supply of fruit, berries, and insects. From those places it seems to greet us vigorously. Its song, often the first in the morning and the last at night, is not the haunting flute of its thrush cousins but rather a lengthy and cheerful burbling punctuated with lively chirps. Nor does the robin confine itself to woodsy shadows. Most of us see it out in the open, pulling worms from a rain-wet lawn, or gracing the day from a skyward perch.

Robins range over most of the continent, wintering across the US and well into Mexico, and extending their nesting range high into Canadian forests. Redding often hosts large flocks in winter. Sometimes thousands of them will roost together high in cottonwood trees along the river, joining in avian lullabies at dusk—a treat for Turtle Bay visitors. As spring comes, the winter migrants will fan back northward. The flocks disappear. The locals pair up.

Alert observers may notice clear differences among different robins. All adults have yellow bills, and in some birds the white around the eye is striking. Their breast feathers may show a deep chestnut color, or brick red, or pale orange. Some birds will flash a glimpse of white at the corners of their tails. In general, female birds are paler, which serves well as they tend the nest. Other differences occur geographically. Robins are grouped into seven subspecies, but they interbreed, so their differences are not abrupt but rather blend from one to the other.

Females build the nest, mostly of grass and mud. She incubates 3-5 blue eggs for twelve to fourteen days. She will leave the eggs briefly to find food, but the male feeding his mate on the nest has been observed. Both parents care for the young through their fledging in another two weeks. Then the male may continue to look after the fledglings while the female, if weather and the insect supply permit, starts a second or even third nest.

BirdWords: Wood Ducks

By on January 23, 2016 in BirdWords
Wood Duck Female

Wood Duck Female photo courtesy of David Bogener

For those who observe them, it’s small wonder that six of the new gifts offered in The Twelve Days of Christmas are birds! Not mentioned, however, are some of our most stunning winter birds, the ducks.

Wood ducks are the kings of color— green, blue, chestnut, and goldenrod, their beaks and eyes in two shades of vermilion, all set off with bold blacks and whites and decorative plumes and pony tails. The hen ducks are less outlandish, dressed mostly in their camouflage grays, but still sporting a splash of dark aquamarine and a delicate white eye-ring that thins into a teardrop behind the eye.

As their name suggests, wood ducks favor wooded byways. They spend the winter in small flocks, often with just a few friends, resting and feeding in quiet water. They eat mostly plant material—seeds, acorns, berries, and weeds—gathered either in the water or on land. Along about January they pair up. Courting involves mutual preening, and shrill whistles and stretched wing-and-tail dance moves from the male.

Then in early spring the hen wood duck, like only a handful of other duck species, chooses a cavity in a tree to make her nest. She is far too big for woodpecker holes, so she will often lay her 10-15 eggs in the rotted out scar of a fallen branch, usually 30-65 feet up. She will prefer to reuse successful nest sites from prior years. Other passing hens may dump more eggs into her nest, and she will incubate and raise them all.

Once hatched, day-old ducklings face immediate challenges. If their nest-hole is deep in a tree trunk, they might need to climb vertically many feet, up to fifteen, to reach their nest entrance. But they have clawed toes and instinct to help them out. Once reaching the entrance they blithely drop to the ground outside. It’s a long fall but doesn’t seem to faze them. They pop right up and begin to follow their mother to the nearest water, a hike that may be over a mile on their little duckling legs.

In truth, things have gotten easier for wood ducklings. With extensive tree-clearing in the late 1800’s wood duck numbers plummeted. But the ducks readily accepted human-made nesting boxes, and now they are thriving. Most nesting boxes are close to the ground, so ducklings might drop eight feet instead of their historical fifty.

Wood ducks live year-round in wet woodlands along the West Coast and throughout the Eastern US, and will winter in Mexico and nest all along the US/Canada border. Here in the North State look for them in quiet woodland waterways such as those of Battle Creek Wildlife Refuge, Anderson River Park, and Turtle Bay.

Our Education chair Dan Greaney writes for the Wintu Audubon Society and wrote this post.

The Hoarders: Birds That Store Food

By on November 7, 2015 in BirdWords
Acorn Woodpecker Granary

Acorn Woodpecker Granary

Last month in the Birdwords column we heard about the yellow-billed magpie and its relatives in the crow (or corvid) family. Birds in that group store food away for later, also known as caching. That trait also shows up in many other species that are not related to the corvids – or to each other either.

You may see several of our common backyard birds visiting your feeders too frequently to be eating all that bounty on the spot. Both the perky little gray birds with the jaunty crest – the oak titmouse; and the sleek white, gray and black tree-clinger – the white-breasted nuthatch – can be observed doing this. In both species, a bird will carefully select a seed – often discarding ones that don’t meet its standards – and dart off to lodge the seed firmly in a crevice in the bark of a nearby tree. Studies have shown that they have remarkable memories as to where their stashes are located. In the black-capped chickadee, a close cousin of our oak titmouse, it has been found that the structures in the brain involved in memory are more highly developed than in non-caching species – although I don’t think the question has been answered as to which came first: the behavior or the brain modification.

Among the woodpeckers, there are several species that hoard food – most notably, the acorn woodpecker. If you look around, you are bound to see trees with many small holes excavated by acorn woodpeckers. Each hole was made to accommodate a single acorn. These are called granary trees. To the chagrin of ranchers, these birds don’t limit themselves to trees but will also puncture fence posts and barn walls. I’ve even seen power poles used as granaries.

Acorn woodpeckers are togetherness birds – they form a colony of a number of individuals to fill and use their granaries. They even nest communally – a behavior not seen in other woodpeckers, in which a pair will nest alone. The granaries are vigorously defended. Acorn woodpeckers go on red alert if a western scrub jay comes near. The jay is definitely not above conducting a raid if a granary is left unguarded, so the potential thief must be chased away.
The acorn woodpeckers’ acorns are strictly for their own benefit. However, various species of jays inadvertently aid the oak trees as well. They hide acorns by burying them in the ground. A certain percentage of the seeds don’t get retrieved and eaten before they have germinated and sprouted into baby trees. Young oak trees can’t grow in the shade of a parent tree, so by” planting” them elsewhere, the jays help regenerate and spread the oak forest.

A botanist noticed this connection and did some mapping. If he superimposed the areas of the world where various species of jays live over a map of the occurrence of all the oak forests of the world a remarkable pattern emerged. There were some places that had jays but no oaks – but there were no oaks where there were no jays. So, our familiar pesky western scrub jay is actually a forester!

You may have noticed this year’s acorn crop has been a good one. Keep your eyes open as the cooler days of autumn spur our avian friends to lay in their supplies for winter!

The Plight of Cavity Nesting Birds

By on July 1, 2015 in BirdWords
Western Bluebird Nestlings

Western Bluebird Nestlings Day 1

Some eighty-five species of North American birds excavate nesting holes (primary cavity nesters), use cavities resulting from decay, or use holes created by other species (secondary cavity nesters) in dead or deteriorating trees. Over half of those species may be encountered here in Northern California.

These deteriorating trees, commonly called snags, have often been considered undesirable by forest and recreation managers because they are not esthetically pleasing, conflict with other forest management practices, may harbor forest insect pests, or may be fire or safety hazards. In the past such dead trees were often eliminated from the forest during a timber harvest. As a result, in some areas few nesting sites were left for cavity-nesting birds.

Purple Martin Pair

Purple Martin Pair at Nest Cavity

Many species of cavity-nesting birds have declined because of habitat reduction. In the eastern United States, where primeval forests are gone, Purple Martins depend almost entirely on man-made nesting structures. In the southeast the Red-cockaded Woodpecker is currently listed as near threatened (NT), primarily as a result of habitat destruction, and the Ivory-billed Woodpecker is listed as critically endangered (CR) and thought by many to be extinct. The wood duck was also very scarce in many portions of its range – at least in part for the same reason – and probably owes its present status to provision of nest boxes and protection from overhunting.

As early as the 1930’s people noticed that the Eastern Bluebird was fast disappearing from their fields, their backyards and their lives. Dwindling sightings of these most endearing of North American birds encouraged several bluebird enthusiasts to sound the alarm concerning their plight. In addition to nesting sites for bluebirds being lost to deforestation and snag removal, competition for the remaining sites was brought about by the increasing populations of two non-native species, the English (House) Sparrow

House Sparrow Male

House Sparrow Male

and the European Starling.

European Starling at Nest Cavity

European Starling at Nest Cavity

After decades of alerting people to the plummeting bluebird problem, Dr. Lawrence Zeleny, a retired agricultural biochemist living in Maryland, with the help of several supporters from National Audubon Society chapters and the Audubon Naturalist Society, founded the North American Bluebird Society (NABS) in 1978.

The North American Bluebird Society is a non-profit education, conservation and research organization that promotes the recovery of bluebirds and other native cavity-nesting bird species in North America. An affiliate of the NABS here in California is the California Bluebird Recovery Program (CBRP). Both of these groups promote placing and monitoring nest boxes (birdhouses) in optimal locations for cavity nesting birds. Because of these programs and hundreds of thousands of nest boxes put up across North America, cavity nesting birds are on the rebound!

If you have birdhouses in your yard and want to learn how to monitor them and add your nesting statistics to the CBRP database, or you are interested in information on how to build, place and monitor nest boxes, our Wintu Audubon webmaster, Larry Jordan can help. He is the Shasta County coordinator for the CBRP and you can contact him by email at webmaster@WintuAudubon.org

You can also find lots of information about birdhouses and attracting birds on our “Attracting Birds” page.

Climate Change is Beginning to Take Its Toll on Bird Populations

By on June 3, 2015 in BirdWords, Conservation, In the News
Western Meadowlark

Western Meadowlark

Last month I wrote about insect-eating birds swarming into Shasta County to raise their young. Unfortunately, I was indulging in a bit of optimistic nostalgia. The migration itself is as real as ever, but our nesting numbers are dismally down.

It can’t really be a surprise. Everything needs its habitat, and in actions that seemed reasonable, we have converted much wildland to more prosaic purposes. But the yellow-headed blackbird can’t nest where the marsh is drained, nor can the meadowlark make a home where grasslands are converted to row crops. The thrasher can’t sing where the chaparral is cut for houses, or the pet cat kills its young. The kestrel can’t nest where old woodpecker holes have been cut down to reduce hazards, and the pygmy owl can’t stalk grasshoppers where the woodland is paved into yet another retail center.

Driving up the valley as a kid it seemed there was a hawk on every telephone pole. But we reasonably want produce, and farmers pragmatically maximize their production. So after forty years of our plowing through the lairs of fieldmice, gophers, and snakes, of course the hawk numbers are down; after forty years of pesticides to kill hungry insects, of course the songbirds are reduced; after more recent advances to mow right to the fenceline, of course the hedgerow birds are gone.

Unfortunately, our personal perceptions of too-quiet treetops, empty telephone poles, and vacant fencelines are confirmed by research around the globe. Complementing the 115 year old Christmas Bird Count, the North American Breeding Bird Survey has run each May since 1966. It documents declines of 40-60% in a quarter of our birds, and up to 96%, depending on the species and region.

And that’s what has happened already. Now farm produce is being bio-engineered to withstand yet more pesticides, and their application has begun. Climate change is beginning to take its toll. At current carbon emission projections, 314 of 588 species studied by Audubon will lose at least half their seasonal habitat within the lifetime of this year’s graduates.

Many birds will face challenges as seasons unsynchronize: hummingbirds can’t sip on flowers that have already fruited, and fields gone dry offer fewer insects to bring to the nest. Some birds will be unable to shift northward as quickly as this climate change is demanding—especially if they need vegetation that moves north more slowly. Those who successfully shift will encroach on existing nesting grounds; ravens, which eat eggs and nestlings, are already increasing in the arctic, and invaded tundra birds have no Farther North to flee to.

As in most places, in Shasta County we have not, to my knowledge, lost any entire bird species in recent history. But the music is fainter, the voices fewer. Not so long ago, when the canaries started dying we recognized a problem and acted on it. We should be so wise and disciplined today.