Great Horned Owl Fledglings

It's spring, and the marshes, grasslands and woodlands of California are brimming with life as young birds of all description hatch, grow and begin to fledge.  I've mentioned before that when I can't get out into a proper patch of wilderness, I enjoy birding at CSU Stanislaus.  This year, there is something particularly exciting on the college campus: a family of Great Horned Owls (Bubo virginianus).


Great Horned Owls begin breeding very early (or late) in the year, with courtship beginning in the late fall and early winter.  While out for a walk last December, Eric and I heard a pair of Great Horned Owls on campus.  Noting the presence of tall pine trees (potential nesting habitat) and an abundance of prey (gophers and waterfowl), I dared to hope they might choose to stay.  And it turns out, they did!


Great Horned Owls lay their eggs as early as January or February in California.  Eggs are incubated by the female for about four weeks, while the male keeps her supplied with food.  Baby owls are called owlets.  Great Horned Owl owlets are nearly naked, and their eyes are closed at the time of hatching.  At about one week of age, the owlets' fluffy white down is replaced by grayish down; at ten days old, their eyes open.  The female continues to brood the young owlets for a couple of weeks.


Three-week old owlets begin to practice hunting skills by pouncing on sticks in the nest.  At about six weeks of age, they become "branchers," venturing out of the nest onto surrounding tree branches.  Their main mode of transport at this time is climbing, using their talons to grip tree trunks and branches, as their wings have not yet fully developed.  Awkward test flights begin at seven weeks.


The owl couple at CSU Stanislaus has produced two owlets, which is typical for Great Horned Owls.  These fledglings most likely hatched around the beginning of March, and are probably around eight weeks old.  They already have some of their primary wing feathers as well as tail feathers (called rectrices) and are flying short distances between trees (which is fun to watch in the evenings!)


The young owls will stay together through the summer, fed sporadically by their parents as they learn to hunt.  As the juvenile owls grow larger, the parents will begin to roost separately from their offspring.  In the fall, the young will likely disperse to either find their own territory, or become "nonnesting floaters" until suitable territories become available. 

Testing his wings (just after sundown, hence the blurry photo)

Great Horned Owls are fairly common and abundant around the Great Valley, and I see them fairly often.  (I wrote more about their breeding habits earlier this year.)  But it is still a special experience every time I see a Great Horned Owl.  They are adaptable and can be found in a wide variety of habitats, from deserts to mountains, provided there is an availability of ample cover, nesting sites and prey.  In a world of rampant habitat destruction, it's comforting to know that a few stalwart species are still able to carve out a place for themselves in the midst of our human habitat.

Comments

Post a Comment

You Might Also Like:

Birds of the Desert: Residents & Spring Migrants

Image
Nearly everyone knows the desert as a barren, desolate land of extremes: high heat, low precipitation; little available food and water; prickly, spiny, unfriendly plants growing in a sea of rocks and sand as far as the eye can see.  But for those who stop and look closer, the desert reveals itself as the beautiful, incredible, mesmerizing place it truly is, teeming with unexpected life. Juvenile male Costa's Hummingbird visiting chuparosa blooms next to our campsite in Anza-Borrego Desert State Park. I particularly love the desert in the spring, when the annual wildflowers, cacti, flowering trees and shrubs are all in bloom.  (I've experienced the desert in the searing 120 degree heat of summer, and the rainy, even snowy cold of winter... and spring wins every time!)  Eric and I just returned from a week in the Colorado desert, exploring the imperiled, accidental Salton Sea (more on that coming soon), the vital wetlands of the Sonny Bono Salton ...
Read more

Joshua Tree Woodlands: A Tale of Sloths, Moths and the Trees that Need Them

Image
In 1844, early California explorer John C. Fremont gave a somewhat scathing review of Joshua trees when he wrote, "...their stiff and ungraceful form makes them to the traveler the most repulsive tree in the vegetable kingdom."  Rather unkind, don't you think?  But when Joshua trees were formally described by scientist William Trelease in the 1890's, he noted that Joshua Trees are "the most attractive of all the Yuccas."  I am inclined to agree with this sentiment, and must disagree most heartily with Lieutenant Fremont! I, for one, adore Joshua Trees, with their whimsical shapes and great ecological significance!  If you struggle with plant identification, the iconic Joshua tree, hallmark of the Mojave Desert, is a good place to start.  With densely spiked tufts protruding from the ends of gangly arms stretched towards the heavens, this looks like a plant straight from a Dr. Seuss book....
Read more

A Shorebird Primer: Godwits, Curlews, Willets and Whimbrels

Image
For those of us living in the Great Central Valley, autumn is the time to head to the coast.  Of course, there is no bad time to visit California's magnificent coastline.  But as the heat and haze of summer drag on in the Valley, the sea becomes increasingly tantalizing: September and the onset of autumn bring sunny weather and an abundance of migratory seabirds and shorebirds to our coast. A new birder visiting California's Central Coast will undoubtedly be met with a splendid array of very confusing birds.  Among these are small shorebirds like  "peeps" (sandpipers), Sanderlings and various  plovers .  But the larger birds can be just as confusing, until you learn a few distinguishing features.  Four large shorebirds that are commonly seen (and commonly confused) along California's Central Coast are Godwits, Curlews, Willets and Whimbrels. Marbled Godwit (upper left), Whimbrel (upper right), Long-billed Cu...
Read more

All The Ducks!

Image
On a recent birding trip to Merced National Wildlife Refuge, I tallied up a list of sixteen different species of ducks.  Only a few more species, around twenty in total, are expected in the Central Valley of California's freshwater marshes during the winter, so I consider that to be an excellent day for ducks! North American ducks are broadly separated into two categories, largely based on their methods of foraging for food.   Dabbling ducks , also known as "puddle ducks," tend to frequent shallow water, where they are commonly seen tipping bottoms-up to feed on plant matter and invertebrates in the water and on the muddy bottom.  They are most at home in water, but walk easily on land as well, as their legs are positioned near the center of their bodies.  The wings of dabbling ducks are relatively large, which allows them to take off from the surface of the water, straight up into their air.  Dabbling ducks almost all nest on the ground, near water....
Read more

Birding in Adverse Weather Conditions: Wind and Rain

Image
Though I often extol the virtues and merits of winter in the Central Valley , especially when it comes to birding, the whole truth is that we experience "bad" weather also, just like anywhere else.  But even when the winter weather rolls in, the birds are still out there!  And sometimes, despite our best planning efforts, a birding day happens to coincide with crummy weather.   In that case, what's a birder to do?  Usually, we go birding anyway!   Birders far more intrepid than I regularly brave the ice and snow of northern winters to see their favorite birds, so perhaps you should look to them for real tips on winter birding!  For those of us in the valleys of California, the worst weather we see - wind and rain - is really comparatively mild.  Birding on an extremely windy day! I don't know of anyone who actually likes birding in the rain.  But I would argue that birding in the wind is just as aggravating as trying to bird in the rai...
Read more

Winter Gulls: The Great I.D. Challenge

Image
Gulls are a fun challenge for birders, from beginners to experts.  A few things make gulls an interesting study: they are large and conspicuous in their open habitats, so they are easy to see, easy to put a scope on, and easy to watch and study for long periods of time.  Furthermore, gulls are almost always identifiable as gulls; none of this confusing warbler/vireo/kinglet nonsense! And yet, gulls are almost impossibly difficult!  (Though perhaps not nearly as difficult as Empidonax flycatchers!) An intimidating scene to many a birder: a mixed flock of gulls.  I see five different species of gull here. Oh, and one American Coot in the background. One of the reasons they are so complicated is most gull species take two or three years to achieve adult plumage, and go through multiple molts in a year.  So, you may be looking at three or four gulls together that look like four completely different species, when they are actually just different ages (...
Read more