Spotted Owls, to themselves no more upsetting than robins, have become a focal point of human controversy in the Pacific Northwest. Most recently, the Barred Owl invasion is negatively impacting them. Stephanie Houtman, Environmental Planner/Biologist for Caltrans, will present an in-depth history and natural history of Northern Spotted Owls. Her discussion will include the owl’s decline and the impacts of Barred Owls as well as forestry, regulation, and fire. This is an opportunity to learn of this substantial interface of conflicting demands and conditions in our own backyard.
This is the link to the zoom meeting:
Topic: Wintu Audubon Presentation: Spotted Owls and Barred Owls
Time: Sep 9, 2020 07:00 PM Pacific Time (US and Canada)
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.
The spotted owl, to itself no more upsetting than a robin, has become a focal point of human controversy in the Pacific Northwest. Stephanie Houtman, Environmental Planner/Biologist for Caltrans, will present an in-depth history and natural history of Northern Spotted Owls. Her discussion will include the owl’s decline and the impacts of forestry, regulation, the barred owl invasion, and fire. This is an opportunity to learn of this substantial interface of conflicting demands and conditions in our back yard.
What do you know about Saw-whet Owls? If you’re like most of us, probably not much. But these little birds are all around us, year round, fighting out their fierce lives in our forests and woodlands. Come learn about these neighbors from Ken Sobon, director of the Northern Saw-whet Owl Research Project in Northern California.
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.
