Grand Junction Audubon Society birders

Follow local birders in pursuit of their life lists. For more visit audubongv.org.

Page 9 of 11


AS BLUE AS I CAN BE

By Nic.Korte
Tuesday, July 16, 2013

   Where would you go to see brightly colored birds? Somewhere in the tropics, right? Generally, yes—but here in Western Colorado we can claim some of the most beautiful blue birds in the Americas. Those who know Central and South America might be saying: “Wait a minute. What about turquoise cotingas and some of the honeycreepers?” Well, yes, they are beautiful and blue but just try to find one of those cotingas. I’ve been bird-watching in the tropics many times and I’ve only seen the usually-rare cotingas three times and only briefly. The honeycreepers are easier to find, but they are small and often bouncing around high in the forest canopy permitting only brief glimpses.
   If you want to see beautiful blue birds, Western Colorado is a great location. If I remember correctly, it was the pioneer author Mary Austin who referred to mountain bluebirds as ’’flecks of fallen sky.” It is easy to be poetic about this common bird which can be seen almost all year on any drive to Grand Mesa, up Unaweep Canyon, even along interstate 70. Typically, we have a few around our valley all year. This is the male of a pair that nested in one of my birdhouses near Collbran this summer.   

 

In our pinyon-juniper forests, especially where they transition to some oaks and aspen, the Western Bluebird is easy-to-see. It is a deeper blue than its cousin, the mountain bluebird, and sports chestnut-colored shoulders.

 

A smaller, strikingly-colored bird that is mostly blue is the lazuli bunting which might even visit your backyard bird feeder. Here is a photo of the beautiful male. These are also fairly easy to see in the oak/pinyon/juniper complex. Females of all three of these species are less brightly colored—especially the bunting—so for your fix of “blue,” you need to see the male.

   Other blue birds that live and breed locally, and topic for a future blog, are three of our jays. And, in case you missed it, check out Jackson Trappett’s excellent photo of a blue grosbeak in a previous entry (http://www.gjsentinel.com/blogs/birds_and_more/entry/floatin-down-the-old-green-river).

  Being blue has interested scientists for some time because red and orange pigments in feathers come from diet, but blue pigments that are eaten are destroyed with digestion. It turns out that blue is a structural color (as opposed to a pigmented color) because it’s generated by light interacting with a feather’s 3-dimensional arrangement. Different shapes and sizes of these arrangements create different shades of blue. You can read all the details here: http://www.smithsonianmag.com/science-nature/Why-Are-Some-Feathers-Blue.html#ixzz2Z8BN2buc . This post provided by Nic Korte, Grand Valley Audubon Society. Western Bluebird and Lazuli Bunting photos by Jackson Trappett. Send questions/comments to nkorte1@hotmail.com]To learn more and to participate in the activities of Grand Valley Audubon, please see our website at audubongv.org and “like” us on Facebook!]
 

0 comments

Here Come the Orange Hummingbirds (Good News and Bad News)

By Nic.Korte
Thursday, July 4, 2013

   Most folks have seen a bright orange flash around their hummingbird feeder or maybe out hiking.  These are rufous hummingbirds.  Before getting to the good news/bad news; consider their strange life history.  Have you ever thought it unusual that they show up about the first of July?  They don’t nest in Colorado.  Indeed, they are on their way back from as far north as southeastern Alaska. They breed further north than any other hummingbird.  Their US breeding range is essentially confined to Oregon, Washington, Idaho and Montana.
   This story so far should strike you as very odd.  If they are on their way back, why didn’t we see them on their way north as we do with the sandhill cranes and many shorebirds that show up in the spring and again in the fall?  Rufous hummingbirds migrate north up the Pacific coast shunning the intermountain West. Only on their return trip do they pass through Colorado.   And, why are we only seeing bright adult males? 
   As with all hummingbirds, males have only one role in breeding—impregnating the females.  That done, they head for home but somewhere in their evolutionary history have developed the unusual practice of migrating in a circuit.  All of this is why the first birds you’ll see, showing up in very late June or early July, are only adult males.  The females are still busy with their domestic duties but the males are headed back to Mexico where the species spend most of their lives. Females and juveniles will be coming through later in July and in August.
   The good news is they are a beautiful little bird.  I’ve been lucky enough to see 60 or 70 species of hummingbirds (which, by the way, are only found in the Americas—more about that in an upcoming blog.)  So, I’ve seen hummers with names like mountain gem and jewelfront, and coquette.  As striking as many of these are, the male rufous is a contender for most handsome.

   My photo doesn’t it do it justice.  The gorget, if seen perfectly in the sun, is a scintillant orange-red while the body is a shiny rufous-orange—although some are green-backed.  So, that’s the good news.  This beautiful bird is back again to brighten our yards and feeders.  They are also endearing to many people because of their fierce reputation.  Often they will successfully chase the local hummers (bad news for them) away and take command of a feeder. 
   The bad news, for me, takes two forms. On a personal level, they are a sign of summer waning.  It may only be July, but here’s a Northern migrant headed home. Can this much-anticipated summer season be slipping away already?  Can fall be far behind?
   The worse news is that National Audubon Society scientists estimate that the global population of these amazing flyers (1000 miles without food or rest has been recorded) has declined nearly 60 percent in the past three decades.  My first encounter with them was in Northern Arizona about 30 years ago.  There were dozens among a field of pink beeplant—a sight I’ll never forget.
   I will probably see them in my yard this year, but my memory tells me that formerly I saw two or three and had one every day for several weeks.  Not so anymore.  A couple of years ago, I didn’t’ see any in my yard.  
We have some mountain property where up to 30 hummingbirds may show up at our feeders. I can count on the rufous being there again this year—but not so many as ten years ago. 
  What’s causing the population decline? According to the National Audubon Society: “A deadly combination of habitat destruction, toxic pollution and the spread of invasive plants. And now a new threat may overshadow them all: ecological chaos caused by a warming climate. Warmer weather prompts earlier flowering of nectar-bearing plants that hummingbirds rely on during their epic migrations. If the flowers are gone before the birds arrive, they may starve.”  (This post provided by Nic Korte, Grand Valley Audubon Society.  Send questions/comments to nkorte1@hotmail.com]To learn more and to participate in the activities of Grand Valley Audubon, please see our website at audubongv.org and “like” us on Facebook!])

 

2 comments

SWALLOW TALES (TAILS)—A LESSON IN JIZZ

By Nic.Korte
Saturday, June 22, 2013

This butterfly is called a pale swallowtail—a common species in Western Colorado. (Yes, many birders can identify a few butterflies—more on that in a later blog.)   I have seen these in the mountains and in my yard this year.  But, this essay is a tale about swallows and their tails.

   Did you realize there are seven species of swallows that are relatively easy to see in Western Colorado?  With a little planning, I could probably find them all in a long morning.  Cliff swallows nest under bridges and nearby cliffs and are common near the Colorado National Monument.  Barn swallows, perhaps the most widespread, can be found over most fields and lowland ponds.  Rough-winged swallows can be found along streams too—such as Plateau Creek.  Bank swallows and purple martins are a little more local, but I know some nesting locations.  We’ll get to the other two—tree swallows and violet-green swallows, below. 
    In contrast to swallows, if someone asked me to show them all the thrushes that live here, or all the owls, even though we could be certain of being in the right habitat—those birds might not show themselves.   Swallows make it easy because they feed 100% on flying insects which means they are out over open areas making them easy to spot—but not always so easy to identify. 
Two species very easy-to-see in mountain meadows—but also, at times, anywhere in the valleys, are violet-green swallows and tree swallows.  Both have green iridescence and the typical swallow wings that seem longish and pointed. 

   When adult males are perched, their differences are easy to note.  See the dark face of the tree swallow on the left and the white face of the violet-green on the right?  The violet-green swallow is a little smaller and often it is possible to see its white rump patch when in flight.  Unfortunately, they don’t always perch close by and in good light.  Even worse, the females are drab and juvenile violet-green swallows may have a dark face.  Now how can you tell them apart?  Especially in flight?  Why by their jizz, of course!
   According to Wikipedia, “there is a theory that [jizz] comes from the World War II acronym GISS for ‘General Impression of Size and Shape (of an aircraft).’  More likely, jizz is a corruption of gestalt, a German word that roughly means form or shape, or more obviously of the word gist which has the same meaning.”  But you get the idea.  The clue is in the photos.  Look at the tails.  Notice that the tree swallow has a tail as long as its wings.  Not so for the violet-green swallow which has a short tail--and almost a bullet-like appearance in flight. 
   For many years, all birding field guides emphasized field “marks” such as the white face or the rump patch of the violet-green.  That only works for a perched, fresh-plumaged adult male so the newer generation of field guides puts more emphasis on a bird’s structure or in birding lingo—jizz.  Now you know how an experienced birder can make a quick glance at greenish, dark swallows flying into the sun and confidently identify them.  It isn’t so difficult after all.  This post provided by Nic Korte, Grand Valley Audubon Society.  Send questions/comments to nkorte1@hotmail.com]To learn more and to participate in the activities of Grand Valley Audubon, please see our website at audubongv.org and “like” us on Facebook!]

 

0 comments

BIRDS DO IT!

By Nic.Korte
Wednesday, June 12, 2013

How can I talk about spring when its 100 degrees in the valley? It’s because I have the opportunity for frequent visits to a mountain meadow at 8400 feet where spring is still happening in mid-June.  Just this week the serviceberries and chokecherries were in full bloom covering the hillsides and roadsides with a white mantle.  The aspen leaves may have turned dark, summer, green but the oaks haven’t—still showing the light sea green of new growth. 
Wildlife watchers have been observing young great-horned owls down in the valley for many months but mountain birds are just now getting around to it.  Over several weeks, I’ve seen relatively elusive birds such as green-tailed towhees and MacGillivray’s warblers singing from exposed perches. They were difficult to see this week. There is little need for them to announce their presence as nesting has begun. 
Several of our nest boxes attract tree swallows, violet-green swallows, mountain bluebirds and house wrens.  The tree swallows, in fact, were really going at it this week.

They were flying in and out of nest boxes and, yes, copulating.  Over and over again.

 

Encounters were brief—but frequent.  We watched this pair on our seed feeders complete the act ten or more times over the course of a few minutes—immodestly in full view of a flock of pine siskins and Cassin’s finches. 
Tree swallows spend much of their days airborne, but not so much as the white-throated swift which can be seen copulating in mid-air near cliff faces in locations such as the Colorado National Monument.   I recall the first time I saw a pair of swifts seem to collide and then tumble earthward before resuming their flights.  Recounting this to a friend, his comment was, “well, that behavior gives new meaning to the concept of performance anxiety!”  
Tree swallows spend their winters in Southern Mexico although some populations can be found in Southern Arizona, Southern California and the Gulf Coast.  They are a common summer resident in Colorado mountain meadows where they co-exist with violet-green swallows and mountain bluebirds—all of which may share the same next boxes.  Here, a female mountain bluebird surveys the meadow from the box she and her mate selected last week.

Nesting behavior raises a lot of questions that are still being studied.  Some mountain bluebirds have already nested at lower elevations.  Why do some nest so much later and higher?   What was the pair in this nest box doing a month ago when their cousins were nesting in the valley?  Why do so many birds fly north to breed when very closely related species, with whom they spend most of the year, do not?
Studies have shown that tropical birds tend to have very low nest success (often <20%) because of the high rate of predation. Adult birds, however, tend to be long-lived and usually lay only two or three eggs so they can try again when the nest, eggs, or fledglings are lost. In contrast, most birds nesting in North America have larger clutch sizes—even to five or six.   Apparently, the idea is both to overwhelm the system and to take advantage of everything else that is growing all of a sudden.  Here, everything occurs at once.  The flowers bloom. The insects hatch. All the eggs are laid.  That’s why June in a mountain meadow is so fascinating for its remarkable fecundity.  Insects abound.  Butterflies flit in mating pairs. The birds are calling, chasing each other, and mating.  Too soon, it is all over.  Better go out and take a look before you have to wait until next year. (This post provided by Nic Korte, Grand Valley Audubon Society.  Send questions/comments to nkorte1@hotmail.com]To learn more and to participate in the activities of Grand Valley Audubon, please see our website at audubongv.org and “like” us on Facebook!]
 

 


 

0 comments

FLOATIN’ DOWN THE OLD GREEN RIVER

By Nic.Korte
Thursday, June 6, 2013

  Maybe you aren’t familiar with the old Dixieland tune which is the title of this blog.   The song salutes a particular alcoholic beverage with a few obvious double entendres.  I learned the song off an old record as a youth growing up near the St Louis Riverfront where Dixieland music still hangs on.  When I’m on a river, to the dismay of my family, I sing it to them.  Fortunately, better music is made by all of the birdlife along the riverbanks.  And, no matter that the river water might be brown; this interface of land and water, the riparian zone, is truly green and is the most important wildlife habitat in our area.   Estimates are that 90% of all bird species, 72% of all reptiles, 77% of all amphibian species, and 80% of all mammals, which occur regularly in the Colorado Plateau region, routinely use riparian areas for food, water, cover or migration routes (http://cpluhna.nau.edu/Biota/riparian_communities.htm).  Even if you are in an inner tube, listen and watch because there is much more to see than the great blue heron (not a crane!) flying ahead or the many ravens croaking nearby. 
  While floating rivers, I’ve been surprised that some experienced river runners were unaware of the Say’s Phoebe—a common flycatcher which may appear as frequently as every 50 to 100 yards. 

Say’s phoebes are a good bird to learn because one of the first skills needed if you are going to learn birds is to be able to classify them to a family.  Say’s phoebes are flycatchers and, as with most of their family, sit in the open and sally out to grab flying insects before returning to a conspicuous perch.  These habits and their upright posture are a sign that says “flycatcher.”   Say’s phoebes are not musical but they are very vocal.   Listen for “pweeeer,” and watch for them as they frequently fly across the river.
  As common as Say’s phoebe near our desert rivers are Ash-throated flycatchers—a little bigger and duller gray than the phoebe.  These usually stay in the dry stuff—and not so close to the river bank.  Not many minutes pass as you float without the sound of its calls, which can be described as “kabrik” and “breer”—the latter being a shorter version of the Say’s Phoebe.   
  More difficult to see, but easy to hear are two members of the warbler family.  One night on a recent rafting trip, a song (?) began in the middle of the night and continued for hours. There were melodious whistles, interspersed with a variety of toots and squawks.  As the song continued into the morning, one of the trip members asked, “What the heck is that?”  Identifying it was easy—seeing it—not so much.   The bird was a yellow-breasted chat.  They are common wherever there is a tangled grouping of large tamarisk and willows.  They will sit deep within thick vegetation while keeping up constant chatter…hence, their name.   Away from the dry tangles, wherever there is a group of cattails, lives the common yellowthroat whose more musical “whichity-whichity-whichity” followed us down the river.  
  Both the chat and the yellowthroat (the male at least) are very striking birds, not always sitting up and easy to see, but if you listen for them—and watch, they’ll pop up eventually. The chat has a bright yellow throat and belly with a grayish green back and head with white spectacles.  The male common yellowthroat has a striking black mask and also a bright yellow throat. The female is much duller and lacks the mask.
  More surprising to my companions on a recent trip were blue grosbeaks.  The male is deep blue with cinnamon-colored wing bars.  These too are common residents of desert riparian areas but are often overlooked.  Females are buffy-brown but retain the cinnamon wing bars.

So, the next time you are “Floatin’ Down the Old Green River,” pay attention to the "thin green lifeline" provided by flowing water.  This post provided by Nic Korte, with photos by Jackson Trappett, Grand Valley Audubon Society.  Send questions/comments to nkorte1@hotmail.com]To learn more and to participate in the activities of Grand Valley Audubon, please see our website at audubongv.org and “like” us on Facebook!]

 

0 comments
Page 9 of 11




TOP JOBS




THE DAILY SENTINEL
734 S. Seventh St.
Grand Junction, CO 81501
970-242-5050
Editions
Subscribe to print edition
E-edition
Advertisers
Sign in to your account
Information

© 2014 Grand Junction Media, Inc.
By using this site you agree to the Visitor Agreement and the Privacy Policy