The Many Faces of Long-eared Owls
Category: Birding at the Chico
Although unseen unless looked for, Long-eared Owls roost in the winter in dense trees and sometimes in dense colonies on the Chico.  In abundant rodent years.  a couple of pairs might stay to nest.  Looking clockwise from the upper left, a recently fledged Long-eared Owl that was able to crawl around on branches but could not yet fly.  When owls are this age they are called branchlings.  In the second photograph notice how Long-eared Owls are notorious for elongating their body, attempting  to become less visible and to look more like a tree trunk.  The third image is of an adult on a winter roost only six feet off the ground.  The next photographs shows hundreds of Long-eared pellets just below a favorite winter roost branch.  The next photograph shows an adult sitting on a nest, here an abandoned squirrel's nest.  This bird was observed by hundreds of school children over a few weeks at a distance and through a spotting scope.  Next, the head of a relaxed adult Long-eared Owl.  The last photo shows a juvenile bird after a rainstorm and still trying to consume the kangaroo rat that it was fed just before dawn.  The whole swallowing process took about 10 minutes.  I took all of these images on Chico Basin Ranch during a three year period.
Posted by Bill M. on 02/21/2009

Waterfowl Migration
Category: Birding at the Chico
If you live near a body of water, you have a great opportunity to observe the spring waterfowl migration that is in progress, first hand.  It is like magic, as soon as the ice moves out at HQ Pond, the ducks move in.  

There are two species of goldeneye and both are on the Chico Bird List, as the name implies, only Common Goldeneye (lower photo) is a regular migrant.  Examine the photos to see if you can see the differences in plumage between the two goldeneye species.  As in the majority of ducks, goldeneyes exibit sexual dimorphism where the female's dull coloration will be less easily detected by predators when she is tending to her young. 

Can you see the different head shape in Barrow's Goldeneye, with the steep-angled forehead and did you notice the all-yellow tip to the female Barrow's Goldeneye bill (above photo)? Male Barrow's Goldeneyes have a white crescent in front of their eyes on a purplish head, while the white is oval-shaped on a green head in Commons.

Both species are tree cavity nesters and both species are strong divers, often staying below the water surface for as many as 20 seconds where they search for insect larvae such as those of dragonflies and damselflies.  Barrow's Goldenye is primarily found west of the Continental Divide, but in the winter some are reported along the Front Range Reservoirs.  

Both species start to form pair bonds in the winter, if you are at Chico watch for the spectacluar courtship displays in the male Common Goldeneyes that include, head-throw, head-throw-kick, bowsprit, head-throw-bowsprit, nodding,  masthead, ticking, head-flicks, head-up-pumping, and other displays.  The most distinctive courtship display is the head-throw-kicks, where males thrust thier head straight forward, then lowers it to his rump with his bill pointed back past the vertical, at which point he utters a single, loud call, thrusting his head rapidly forward while kicking water out with his feet.  Lots of fun to watch!
Posted by Bill M. on 02/19/2009

New Chico Bird
Category: Birding at the Chico
In spite of the strong winds, I ventured out to see if the northbound waterfowl numbers were increasing.  There were over 200 Redheads (the duck) along with about 10 Canvasbacks at Rose Pond and a few dozen Ring-necked Ducks at HQ Pond.  I was hoping for an early Cinnamon Teal, but I didn't find any yet.

The biggest surprise was the first ranch record of Greater White-fronted Goose or Specklebelly to most hunters.  This species is common in winter and migration in the eastern part of the state, but much less common along the Front Range although this species was overdue on the Chico.  The Ranch list now stands at 320 species.

Unlike the highly social Snow Geese nesting in tightly packed colonies, Greater White-fronted Geese prefer solitary nesting.  The white "front" in the name refers to the white forehead and is reflected in the species name, albifrons, meaning white forehead. 

Like many goose species, this one has many regional names such as: gray wavey; tiger brant, laughing goose; marble belly; prairie brant.

Thank you to Bill Schmoker for providing the very nice photo that compares a Colorado Greater White-fronted Goose (foreground) with a Canada Goose.
Posted by Bill M. on 02/17/2009

Winter Juncos
Category: Birding at the Chico
Junco is a word that describes both the common name and scientific name of a group of sparrows, all currently one species.  The origin of the word junco is uncertain.  What is certain is that juncos descend upon Colorado in the winter.  Once considered as different species, they are currently all lumped together and named Dark-eyed Junco, descriptively distinguishing these wintering birds from their southern yellow-eyed relatives.  There are many junco subspecies recognized and, both subspecies and  males and females are distinct in appearance.  Juncos feed mostly on the ground where they scratch with their toes for seeds. 

Moving clockwise and starting in the upper left, the subspecies of Dark-eyed Junco portrayed here are Oregon Junco with the dark hooded appearance, Slate-colored Junco, uniformly dark slate gray in males, the light gray White-winged Junco (first discribed to science by Charles Aiken of Aiken Canyon fame), an unusual white-winged form of Slate-colored Junco, the red-backed Gray-headed Junco (the only subspecies that breeds in CO), and the very common wintering subspecies, Pink-sided Junco. 

Because White-winged Juncos breed isolated from the other subspecies in the area surrounding  the Black Hills of South Dakota, this taxon might turn out to be a good species. There is much hybridization among juncos and it is commonl to see many individuals that combine characters of two subspecies.
Posted by Bill M. on 02/11/2009

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