Author Archive | Dan Greaney

The Little All-over Invisible Owl

By Dan Greaney on February 29, 2020 in BirdWords

Northern Saw-whet Owl courtesy Ken Sobon

We all have our blind spots, but when the spots are small and secretive we might be forgiven them. At Wintu Audubon’s general meeting last month, Ken Sobon, director of the Northern Saw-whet Owl Project, introduced attendees to a much overlooked little predator that could well be the most numerous owl in North America.

It’s not exactly invisible, but even avid bird watchers are unlikely to have seen this puffball. Daytimes it hides away, roosting quietly in thick foliage, remaining still even as you pass right by. At night you might hear it, especially if you get out into our local coniferous forests. This time of year males begin their long-running nocturnal too-too-too calls, which can beckon a female from half a mile or more away. If interested, she carols back with her own songs–high squeaks or a rising wail that is music to his ears. He may then sing and circle her many times before alighting at her side.

The male often shows her a cavity that he thinks will make a good nest–perhaps a hole carved in a snag by a large woodpecker, with a nearby meadow for hunting. Of course, she seems to make the final decision on just where she will lay her half-dozen eggs. That nest will be her station for the roughly forty-five days of incubation and early child care.

Like raptors around the world, she begins incubating as soon as the first egg is laid, so her young hatch not all at once, as chickens do, but over a period of a week or more. If food is plentiful, all the young may survive; the male may even support two mates and two nests. If food is scarce, however, only the older siblings are apt to successfully fledge.

He hunts every night. From a low perch in the quiet of the forest, he listens for the rustling of small rodents, and then swoops down. He kills with the piercing clutch of his talons. He is scarcely the size of a man’s fist, and the mice and voles he captures can easily weigh half as much as he does. But he ferries the load to the nest where, if the eggs have not yet hatched, the delivery may serve as both a hot meal and left-overs for later.

After her youngest is two and a half weeks old, and the oldest is almost ready to start exploring nearby branches, the female will leave the nest and either assist in hunting for the young, or she may move on to find a new mate and nest a second time. The male continues to feed the nestlings for at least another month.

Saw-whets span North America coast to coast. Our locals appear to migrate along the west coast, but they freely travel east-west, too. They nest in our forests and parts north, well into Canada, where they are apt to retreat if American forests continue to suffer as expected from climate disruption.

As for their name, it is another of their mysteries. It supposedly recognizes a similarity in the sound of saw-sharpening and the owl’s vocalization, but that match eludes most of us.

Gold Rush Into Shasta County

By Dan Greaney on November 30, 2019 in BirdWords

Common Goldeneye Pair

Goldeneyes grow up in Canada, but you don’t need to fly to Great Slave Lake to see them. They’ll fly here instead!

Common Goldeneye Drake

After a long summer of little more than mallards on our waterways, now is the season of ducks returning like rain to the North State. To the delight of Thanksgiving hunters, bird-watchers, and children at Kutras Pond, the colors, quacks, and squeals of many duck species are returning to the North State. The goldeneyes, like so many ducks that nest in the vast Canadian forests or in the midcontinent prairie potholes, are heading south from their nesting grounds to what they need–open water that won’t freeze over.

Common Goldeneye Drake

In our area they can be seen on the river, readily identifiable by–well, you can guess their eye color! The males, or drakes, have black backs, white sides, dark heads with a green cast, and, between their black bill and bright eye, a bold white spot. The hens forego that white beauty mark, but wear a tip of yellow on their bill; they replace bright white flanks with nest-camo gray, and the sheen of their head feathers is cinnamon-burgundy.

Common Goldeneye Female courtesy Corine Bliek

Goldeneyes are cavity nesters, making homes in trees near boreal waters, using the large holes formed by pileated woodpeckers or by limbs ripped from their trunks by wind or time and decay. As in several duck species, new hatchlings tumble two or more stories from nest to ground, pop up no worse for wear next to their waiting mother, and follow her to the local lake or river.

That walk can be a long one. Unlike mallards, goldeneyes are diving ducks. Their legs, situated farther back on their bodies, facilitate power and agility under water, but make land travel a stilted, more unsteady endeavor. Still, both the young ones and their mothers do what they must to accommodate reality, and make the trek from nest to water.

There they are all at home. The day-old ducklings begin to feed themselves, starting a lifestyle of diving for underwater invertebrates and small fish in both calm and rippling waters. The hen goldeneye may protect her babies, but the ducklings readily attach to a foster-mom for oversight, too.

In their first fall they will fly south to winter in the US, and the next spring will wing back to their boreal home. Apparently they are starting to fly farther north than they used to, following the forests that around the globe are retreating northward due to logging, mining, and climate change.

Boreal Bird Migration Map

Logging for paper products opens the land to further warming as exposed permafrost melts. Turning trees into toilet paper has become a widespread concern. Among locally available products Seventh Generation, Green Forest, Trader Joe’s regular (not SuperSoft), and Natural Value–generally the less gentle product lines–get high marks for using recycled content rather than virgin forest in their toilet paper.

Mining for fossil fuels also exposes permafrost, and its intended product is the source of 76% of our climate change emissions.

And climate change itself kills boreal forests by supporting beetle infestations, drying the forest, increasing fire susceptibility, and reducing the winter chill needed for new tree growth.

Goldeneyes are part of the circumpolar constriction toward the North Pole that the whole boreal forest is undergoing. In the coming decades of unrestrained climate change, they are expected to winter farther north and their gold will become rarer in the Lower Forty-eight.

Enjoying Red-shouldered Hawks

By Dan Greaney on October 29, 2019 in BirdWords

Red-shouldered Hawk

Red-shouldered Hawks have the loudest calls of any hawk species, and are probably the noisiest of all the birds of prey. One immediately knows of their presence when hearing their loud, high-pitched “Kee-yah, Kee-yah” calls while they are perched somewhere close or are flying overhead.

They are very beautiful and colorful members of the genus Buteo, with red shoulders and breasts. The black barring on their tails and wings give those body parts a checkered look. They may circle overhead with wings and tails spread out or fly in the open in their distinctive “Flap-flap-glide” flight pattern.

Red-shouldered Hawk in Flight

They feed on a variety of creatures: lizards, snakes, frogs, small mammals, crayfish and sometimes small birds. They often perch hunched over, looking for their prey to appear below, peering down so it seems they are looking at their toenails. They sit quietly until they sight their prey, then drop quickly, seizing the unsuspecting rodent or amphibian in their strong talons. A crayfish dinner requires a different approach. The hawk apparently sights the crayfish from the air and if unable to drop directly on its prey, it must wade into the shallow water. Fortunately the Red-shouldered hawk has fairly long legs for a raptor, which enables it to wade successfully to grasp the crayfish in its very strong talons.

Red-shouldered Hawk Hunting

The breeding habitat of monogamous red-shouldered hawks is usually among deciduous trees or mixed wooded areas, most often very near water. Our yard along the Sacramento River attracts this hawk species since it has tall trees and water all year long. April 2019 found a pair of these hawks beginning to build a nest in the forked branches of a very tall sycamore tree in our side yard. The female red-shouldered is noticeably larger than the male, which is true of most birds of prey. The female is built to lay eggs and brood the young and the male must be quick enough to capture food. Both sexes share the nest-building duties, bringing sticks and moss to the chosen nesting site. The female usually lays from 3 to 4 eggs in the nest and begins sitting on the eggs after the first egg is laid, so hatching is “asynchronous.” The first chick may hatch a week before the last.

Red-shouldered Hawk Pair

Hatchlings may be brooded almost constantly by the female for several weeks with the male providing most of the food for her and the young. Our red-shouldered hawk nest was so high in the tree that we did not know when the chicks hatched, and it was a while before we saw the fuzzy, fluffy young peering over the edge of their nest. We saw only two young with their curved and large bills. We kept our spotting scope on the nest constantly but it was 50 feet+ up in the sycamore tree. The late afternoon sun made the hawklets pant so we were glad when they declared their independence on July 4th and began exercising their wings by flying high up from tree to tree. We could tell when Mom and Dad fed them as they approached with their loud “Kee-aah kee-aah” cries.

Red-shouldered Hawk Nestling courtesy of Frank Kratofil

Under the hawk nest and around our yard we began finding “hawk pellets”. We knew owls regurgitated undigested parts of their diet such as feathers, bones and fur but we learned something new when hawk pellets began showing up. Almost every pellet contained some undigested part of a crayfish such as a small pincher or reddish colored shell.

Researchers find that hawk pairs use the same nest year after year simply by adding more nesting material and making it ready for another family. We hope this happens with our red-shouldered pair.

Birds – Variety and Extremes

By Dan Greaney on September 28, 2019 in BirdWords

Somali Ostrich

The ten thousand species of birds in the world come with tremendous variety. The ostrich can stand nine feet tall, tip the scales at 280 pounds, and run at over forty miles per hour. The bee hummingbird is less than two and a half inches long, weighs one twentieth of an ounce, and can’t run at all, or even walk.

Bee Hummingbird

A red-breasted merganser flew even with a plane at an air speed of over 80 mph, ground speed over a hundred. Peregrine falcons stooping on prey have sped to at least 186 mph. Hummingbirds can hover in place, a flight achievement of zero mph.

The engine of a plane in Africa sucked in a Ruppell’s griffon vulture–at an altitude of 36,100 feet! Penguins “fly” only under water. New Zealand’s kiwi has stubby little wings, perhaps as useful as a T-rex’s hands; it cannot fly.

Killdeer nest in open flats, maybe gathering just a couple pebbles to mark the site. Orioles weave hanging baskets of plant fiber or other debris. Cliff swallows build with mud, swiftlets use saliva, and hummingbirds gather and form lichen and spider webs. Kingfishers nest in tunnels they dig, as much as eight feet into the ground. Emperor penguins’ feet serve as nests. Eagles build with sticks, adding more as they re-use the nest over years and generations; a nest in Florida was 9.5 feet across, 20 feet deep, and estimated to weigh over two tons. Gyrfalcons in Greenland use a cliff nest that is 2500 years old.

Chimney Swift on Nest

Osprey flap over water looking for fish to catch. The thick-billed murre has been found swimming 690 feet under water.

Goatsuckers and owls wear camouflage feathers that blend into the gray-brown bark they press against. Tanagers, orioles, and honeycreepers blaze brilliant colors with stunning richness and iridescence.

Western Screech-Owl

All this variety of behavior and physical features is the result of the distinctive habitats that grace our planet. The diverse opportunities, requirements, and happenstance of survival hone the qualities of plumage, flight, size, color, and nest building, as well as the shape and strength of feet and bills, flocking behavior, and everything else about the birds.

The thing about these adaptations is that they do not just permit living a certain way in a certain habitat; they require it. An eagle can’t catch flies from the air to have its dinner. A woodpecker can’t paddle like a duck and skim algae off the water. Like all living things, birds need the habitat they are designed for.

Amazon Fires

But now the world is changing. The Amazon is burning, the ice caps are melting, and the reefs are dying. What are the birds to do?

Many have begun the spiral toward extinction. Depending on how fast and how extremely the changes come, some will adapt, as they always have on the changing Earth.

The uneven pattern of evolution is normal. The biologist Stephen Jay Gould termed it punctuated equilibrium, long periods of relative stability “punctuated” by brief periods of rapid evolutionary change.

Generally speaking, when change comes fast, creatures with short generations do well. Bacteria, for instance, can “grow up” and reproduce–which in their case means divide in two–in as little as twenty minutes. The quick regeneration allows for more mutation and more rapid genetic development of adaptations to the new environment. We humans reproduce more slowly, so don’t do well by this measure. However, we are capable of considerable non-biological adaptation–say, build and operate an AC unit.

As for birds? So much depends.

Aw, nuts! -A Pine Forest and a Bird

By Dan Greaney on August 31, 2019 in BirdWords

Clark’s Nutcracker photo courtesy David Bogener

When Thomas Jefferson commissioned Lewis and Clark to explore the West, the president, a man with informed intelligence and curiosity, hoped the explorers might find new animals in that wild land. Of course they did not find the mastodon, mammoth, or “large lion-like creature” that Jefferson imagined from the new science of fossil research. But they did find numerous animals previously unknown to science, including grizzly bears, mountain goats, pronghorn antelopes, prairie dogs, and two bird species that now bear the explorers’ names.

Both of those birds live in our area, but to see one of them we’re best to hustle to the mountains now, before the snow flies and bars our way.

White Pine Lassen Volcanic National Park

Clark’s nutcrackers live near timberline, and even their winter retreat downslope usually keeps them well above snowline. They’ve got the chops for that wintry life.

These birds are seed-eaters. Throughout the summer and fall they gather high-calorie pine nuts, tens of thousands of them, that they hide hither and yon over their miles of range. The energy-loaded seeds allow nutcrackers to survive winter conditions that send other birds to Baja.

But of course they can’t just choose to live on pine nuts at timberline. They have to have the right adaptations.

Clark's Nutcracker

Let’s start with the bill. When William Clark first described the bird in 1805 he noted its robust bill and called it a “Bird of the woodpecker kind.” But the nutcracker is actually a corvid, closely related to jays and crows, not a woodpecker. Its powerful bill is used not for pounding through wood but for hacking into pine cones and the nuts inside them.

After extracting the seeds, the nutcrackers need to hide them for later consumption. Like ground squirrels, they have pouches in their mouths to hold the seeds for transport. Ground squirrels’ pouches are in their cheeks. Nutcrackers’ are under their tongues. They tuck scores of pine nuts into this pouch and then hide them over many square miles across their mountain homes.

Of course, if they are going to make a living by hiding seeds, the birds have to be able to find them. Nutcrackers routinely cache 30,000 pine nuts a year. They are able to find the vast majority of them, with their memory only starting to fail after six or seven months–that is, after winter is past and spring begins to bring a new supply of food to their homes.

Clark’s Nutcracker Adult Feeding Young

Their favorite nut, a high-nutrition preference they share with grizzly bears, comes from tree-line whitebark pines. These pine nuts have a higher concentration of calories than chocolate. With such a rich supply of energy, nutcrackers are able to give their young a head start on life. Rather than waiting for spring thaws to bring green shoots and the food source of buzzing bugs, nutcrackers begin to nest in the heart of winter, while mountain storms still howl. The energy locked into pine nuts keeps them going strong. But that energy must be passed on to the young. In most corvids, only the female tends the nest. But to successfully warm their eggs in the chill mountain world, male nutcrackers also help. They develop what typically only females do– a brood patch, an unfeathered area on their breast, that allows their warm skin to nestle right against their precious eggs. Once the eggs hatch, the young are fed the pine nuts directly.

Clark’s Nutcracker Juvenile

Of course the effect of nutcrackers’ success at high-altitude living doesn’t stop at the tips of their bills or their black and white tails. Whitebark pines have co-evolved with the birds and become highly dependent on them for seed dispersal. Unlike many common pine seeds, whitebark nuts don’t grow “wings” to help spread them on the wind. They count on nutcracker wings, and it is estimated that nearly all tree-line whitebark pines are planted by nutcrackers.

Unfortunately, whitebark pines are declining throughout the west. Their cones are typically opened only by nutcrackers, squirrels, and fire, so fire suppression has inhibited their reproduction. Also, warmer temperatures are spreading pinebark beetles, which are turning expanses of pine forests into matchsticks–a rather unpleasant solution to overzealous fire suppression. Most powerfully for the whitebark pines, blister rust, a fungus imported from Europe, is killing five-needled pines on a massive scale.

Fortunately, we are successfully addressing some attacks on this subalpine ecosystem. Some trees show blister rust resistance, and foresters are working to get their seeds dispersed. In Germany, foresters are putting out acorn buckets for jays to plant, and similar efforts are contemplated for whitebark pines and nutcrackers. So far the nutcrackers in most of our mountains are maintaining their populations despite the whitebark pine decline, so they may well be of service in sustaining the high-elevation ecosystems.

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