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Author Archive | Dan Greaney

Birds Get Down, and More, for Winter

By on February 7, 2017 in BirdWords
Ruby-crowned Kinglet Male

Ruby-crowned Kinglet Male

On frosty winter mornings when just a few minutes outside has your cold fingers complaining and refusing nimbleness, think of the hummingbird. This creature no bigger than your pinky has perched outside all through the starry night, and before the frost is gone will be darting about lapping up nectar and snapping up insects. How do they do it?

Birds are wonderfully well adapted to dealing with cold. Most creatures become inactive when the temperature drops low. Insects may survive as hidden eggs or cocoons. Lizards lie motionless under a log. But like us mammals, birds are warm-blooded, and warm-bloodedness allows activity even in the cold. Of course, like any furnace, warm-bloodedness requires energy. Birds must eat!

Little birds especially, with their limited capacity for fat storage and the greater exposure of small things to the elements, seem almost constantly ravenous throughout the daylight hours. Tiny hummingbirds can devour up to three times their weight in a day. Kinglets flitter nonstop in their almost frantic hunt for winter insects. Rolling packs of chickadees glean over fir needles, green in their snowy mountain homes. A robin may be the size of your pet boa, but it must dine more, and more often.

Warm-bloodedness also needs insulation to be effective. Naked scales might work for our cold-blooded relatives, but mammals have fur and birds have feathers, nature’s finest insulation. Beneath their outer contour feathers, birds wear the thin but dense layer of down that traps still air, keeping their bodies at a comfortable 104 degrees even as winter chases less robust creatures, like grizzly bears, into protected hideaways. When the cold bites especially hard, birds can fluff their feathers to increase insulation, and pull their heads down on their shoulders, or tuck them under a wing.

Of course, their feathers must be kept dry. Like us, most birds have natural body oil. They spread this oil from a gland at the base of their tails, keeping their feathers glistening, both beautiful and waterproof.

Double-crested Cormorant

Double-crested Cormorant Wings Spread

Most water birds produce plenty of this preening oil, but oddly one of our diving birds produces hardly any. Apparently the advantage of pursuing fish without the buoyancy of dry feathers can compensate for getting wet. Instead of preening, however, cormorants stand in the sun with their wings held out to dry, a performance visible all along the Sacramento River.

Birds are also vulnerable to cold through their unfeathered feet. Long-legged herons and egrets are particularly exposed. Handily, the birds have a built-in heat-exchanger. Arteries carrying warm blood from the feathered body are intertwined in the legs with veins carrying chilled blood from the feet. Heat naturally dissipates, warming the veins and cooling the arteries. The result is that some heat is quickly returned to the warm core, and, especially in icy habitats, the feet just live at much colder temperatures than the rest of the body. Birds handle this by keeping their heat-loving muscles in their warm bodies, with little more than bones and tendons nakedly exposed. Also, watch a heron or egret. They frequently stand on just one leg, tucking the other up into their feathers, warming their toes and reducing heat loss.

Great Blue Heron

Great Blue Heron

Different birds undertake a variety of other strategies to survive the cold. Watch a robin face the morning sun, catching that warmth full on. Little nuthatches huddle together in tree cavities. Hummingbirds can actually go into overnight torpor, a mini-hibernation in which their body temperature drops as much as 50 degrees and their heart-rate slows from 500 to 50 beats per minute, saving precious energy. Poorwills, the western cousins of the whip-poor-will, can enter that state of torpor for weeks at a time.

Migration, of course, is perhaps the grandest adaptation to cold. But with birds, so well suited to handling Earth’s normal chills, migration may reflect the pursuit of food more immediately than the temperature change. Birds cannot survive when seeds are covered by snow, or fish by ice, or when fruits are picked clean or insects have ceased to crawl and flutter. Without food, it’s time to go. But a chill morning? Pah! Put on your coat and watch them!

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Quail Live the Good Life

By on December 31, 2016 in BirdWords

California Quail Male

If your True Love went local, and instead of offering an Old World “partridge in a pear tree” gave you their California native counterparts, be glad! A quail in a crab apple brings much to enjoy!

Quail, after all, are a lesson in living the good life!

For starters, they enjoy music. They sing to one another, a hello call that is usually rendered Chi-CA-go, although the North State dialect sounds more like Lake-SHAS-ta. Pairs sing together, duets in which the female maintains the hello refrain and the male fits high grace notes into the spaces of her song.

Quail are dedicated parents, too. They have large families, 10-16 eggs in a clutch, or more if a neighbor contributes. They help their children explore the world, watching dutifully as the young leave the nest within a day of hatching to start poking at the world, beak first. The parents are, of course, unable to produce milk, but their chicks, no more discerning than human infants, pick through the adults’ feces and, just as humans acquire valuable antibodies through nursing, they swallow protozoans that help in digestion.

Families of quail typically neighbor up to form a covey, a community for living and child-rearing that unsurprisingly increases adult life expectancy. The covey keeps together with an ongoing low pit-pit chatter: I’m right here – Don’t go away – We’re OK.

Sometimes a male will perch prominently on a bush, boulder, or fencepost , but he is not alone. He is watching for danger, and if he becomes alerted his calls grow louder and more urgent. Other males in the covey may join him to peck at a small predator, or the quail may all flee. Once the chicks can fly, which begins at about day ten, the covey’s wings create a burst of thunderous flutter as the birds explode into their short flights from peril.

The high-perched male is certainly watching for predators, but he might also be showing off a bit. Quail are stylish, and, while the female wears the muted tones common to avian patterns of nest camouflage, the male sports a striking attire of scaled grays, chestnut, cream, black and white, all under a burgundy crown decorated with a black plume that might inspire royalty, or punk rockers, or a praetorian guard.

Beyond sharing the cultural pleasures of music, family, community, and flair, quail take care of their individual physical needs, too. They eat a healthy diet, up to 30% lean meat, but mostly vegetables—seeds and such. They also get enough sleep. Particularly in winter, while hordes of daybreak sparrows flitter through yards and under feeders, quail become scarce, seeming content to sleep late through the cold hours of the season. Their coveys, numbering scores or hundreds of birds, provide plenty of eyes and ears to attend to safety in their brushy hideaways and protective trees.

This good life seems to be serving the quail well. In a time when many species are declining, California quail have slightly increased their population, even while sustaining a statewide shotgun harvest of a million birds per year.

If you have brush close by, California quail may troop to your backyard bird feeder. And if they pass an old crab apple tree that still struggles along the fenceline, perhaps you’ll hear them chuckle a low song of satisfaction.

Something for the Canaries to Sing About

By on October 29, 2016 in BirdWords, Conservation
Rufus Hummingbird at Sunflower

As this hummingbird refuels on sunflower nectar, her heart beats over 615 times a minute, and she take 110 breaths

Fortunately for old miners, clean air may be even more immediately important to our feathered friends than it is to us.

Like us, birds are warm-blooded. That pretty much guarantees a high rate of metabolism, the routine internal processing done by a healthy body. Cold-blooded bodies generally work slowly–the heart rate of a resting one-pound snake is about 16 beats/minute—and these animals usually become inactive in cold seasons. But warm-blooded creatures burn their food to keep active even in cold weather. Their bodies must work faster. The heart rate of a one-pound crow is 345 beats/minute, five times ours and over twenty times as much as the snake’s!

Heart beats, of course, are pushing blood to every cell in the body, carrying food and, more urgently, the oxygen that can unlock food energy and keep each cell functioning. So along with their fast heartbeats, birds breathe rapidly. That puts a premium on clean air.

As birds process the air they breathe, any toxins present can take a toll. As I drive to work I create a whole cloud of trouble. Over time, ozone and nitrogen oxides can rupture blood vessels in the lungs. Polycyclic aromatic hydrocarbons can cause DNA mutations, decrease body weight, and probably reduce egg-laying and hatching. Inhaled particulates damage lung tissue. Together, pollutants reduce red blood cells, effectively cutting the birds’ ability to process food. Further, extra carbon dioxide in the air creates climate change, altering habitats the birds need to live.

Some 20-50% of these pollutants are from vehicle emissions. Hence, the problem with me driving to work.

So what’s a person in intelligent consideration to do? One solution would be to quit work. Sometimes tempting, but fortunately there are less drastic fixes.

Not long ago it seemed reasonable to think that buying a cleaner emission car was reserved to Hollywood glitterati and Silicon Valley CEO’s. But it’s not that way now. An MIT study of ten-year costs, including purchase, fuel, and maintenance, of America’s 125 most popular vehicles showed that low-emission vehicles are often less expensive than their guzzling counterparts. Clustered at the least-expensive/least-polluting corner of the data are electric, battery-powered vehicles such as the Chevrolet Spark, Nissan Leaf, Ford Focus, Smart Fortwo, and Fiat 500E. Many of these vehicles have internal combustion versions, but with reduced fuel consumption and federal and state refunds the electric versions cost comparably or less.

And their emissions are cleaner—better already than 2030 Paris Accord goals.

Now a small car that needs recharging rather than refueling might not meet everybody’s needs. But it will meet some needs, and apparently can do so without requiring a second mortgage. The increasing options in affordable, cleaner cars may give the canaries something to sing about!

Bird Migration Fueled by Fall Bounty

By on September 28, 2016 in BirdWords
Yellow Warbler

Yellow Warblers surge down local riversides in September feeding on abundant insects from streamside vegetation

Salmon will be arriving soon, and the birds will know it. Turkey vultures know the smells, and will congregate in bare trees at fish-rich creeksites. Experienced eagles will displace the vultures at sand-spit carcasses. Mergansers and cormorants will swallow salmon fragments in the water. Herons and egrets will ply the shorelines where carcasses wash up. Sandpipers may join them. Insects will quickly colonize the dead fish, and their swarming hordes will feed the thrushes, warblers, and flycatchers who come to share in the salmon bounty.

The fall run of Chinook salmon to north state rivers and creeks delivers a huge, valuable load of Pacific Ocean protein and calories that benefit a wide range of wildlife—bears, foxes, otters, fishers, raccoons, skunks, coyotes, bobcats, and a variety of insects that in turn feed more mammals, reptiles, amphibians, and fish. For many birds, the salmon calories are especially important.

Birds that migrate long distances can as much as double their weight in preparation for the trip. In the weeks before flight, they go into hyperphagia, a profound over-eating binge that can see their weight increase as much as 10% per day. They store the energy as fat, which concentrates their necessary fuel in a form lighter than carbohydrates or muscle. The birds then burn this fuel in flight, arriving at their wintering grounds once again slim and hungry.

Of local birds that eat salmon, perhaps the most fish tonnage goes into turkey vultures. Some vultures spend winters in the north state, but most still migrate to Mexico or throughout South America, up to 6000 miles from Redding. Even soaring most of the way, as vultures do, the calorie requirement is high.

Smaller birds cannot soar their way south, but must flap almost nonstop. For numerous songbirds, riversides are highways full of calories. Right now they are hungrily devouring insects, from salmon, from oak trees, from cottonwoods; they are not particular. In addition to insects many songbirds devour the grapes, blackberries, and pokeberries scattered along autumn shorelines. Thrushes, waxwings, tanagers, orioles, vireos, and flycatchers all wolf down this wealth of food to enable their flights south.

Some of our most numerous gems flocking downriver right now are yellow warblers. Relying on insects, they are swarming through Shasta County streamside woodlands, bulking up their little third-of-an-ounce bodies for a flight of two to three thousand miles. They are on the move, and may appear just as flashes of yellow through the pale September foliage, but scores of them can sometimes be seen in a brief streamside stroll.

Fortunately our departing birds do not exhaust the food supplies. Many birds that summered in Canada’s prairies or forests, or in the high arctic will soon flock hungrily into Shasta County, and they should find plenty to eat. Ducks and gulls will feed on salmon that still wash to the riverbanks. Robins and hermit thrushes will eat grapes hanging high in cottonwood trees. Little bushtits, who nested here, will now stay the winter, finding sustenance in the insect larvae and eggs tucked into crevices of leaves and twigs. The bounty of autumn rivers keeps on giving.

Western Kingbirds on Field Patrol

By on June 25, 2016 in BirdWords

Western Kingbird

Most birds are more sensible. They gather their food from the ground, or leaves, or something solid, or at least liquid! But flycatchers make a living on the wing, plucking insects—not necessarily flies—right out of the air.

The flycatchers are a large group of birds that thrive in many habitats. Some are small, greenish, and tucked in close to riparian brush. Some hunt in woodlands or forest canopies. Some flash brightly along open fields.

But all of them share their hunting behavior. They scan from a perch, fly out in pursuit of an aerial insect, and, with any luck, snatch the bug with their beak and return to a perch to dine. If you see a bird fly out, squiggle in the air, and return to a post or prominent branch, you are almost certainly watching flycatching.

Our largest flycatcher, the western kingbird, is frequently seen on roadside fence-wires. The fences make perfect perches from which to hunt over the fields they prefer. A nearby oak or telephone pole will provide a nesting site, and the kingbirds are good to go!

Not shy at all, western kingbirds decorate their neighborhoods with bright flashes of color from their lemon-yellow bellies, and loud, rubber-ducky chattering. They will tolerate nearby nests of what they judge as gentler birds, such as robins and doves, but aggressively harass hawks, owls, and nest predators such as ravens, crows, and magpies. While defending their nesting territories, kingbirds may become aroused, causing their head feathers to stand erect and revealing the crimson crown that is normally completely hidden but earns the kingbird its name.

Like other flycatchers, kingbirds must be strong flyers. To support their aerobatics, they have a keeled breastbone—picture a fin of bone extending out from your breastbone. This structure allows the strong muscles that move the wings to anchor farther forward, giving them better leverage for power and agility. A less pronounced version of the keeled breastbone may be seen in your chicken dinner.

Unlike chickens, kingbirds migrate a long way. Most western kingbirds winter in Central America. In March and April they flap a couple thousand miles into the western US or Canada. There they build a nest of soft plant material, usually high in a tree or human construction, and incubate a handful of camo-blotched eggs. The number of eggs per clutch and the number of clutches attempted vary with the abundance of food.

The hatchlings emerge naked in about eighteen days, and set about gaping for food and growing their muscle, bone, and feathers—gray head and back, yellow belly, and black tail with fine white edgings. If all goes well and the nest predators are kept at bay, in just three more weeks a new generation of western kingbirds is ready to try its skill at hunting the bugs that buzz our fields.