Monday, January 31, 2011

Dabbling duck silhouette quiz



 

The identification of hen ducks deserves more consideration than what is given in the field guides. Many birders identify hen ducks only by noting what drakes they are hanging out with.

The "Peterson System," where birds are identified primarily by field marks, is heavily weighted toward color and pattern. Yet the end plates in Peterson's field guides contain, not colorful birds with field marks pointed out, but silhouettes--in other words, shapes.

No one would mistake a wren for a sparrow if they birded by shape. Starlings and blackbirds are shaped nothing alike. A heron or crane? Please; they're nothing alike--just look at the shape!

Yet no field guides tell you how to bird by shape. Not that it can't be done, just that no one has sat down and created the vocabulary that would identify and explain the shapes. Well, actually, that's not entirely true. An ornithology manual would describe and define such bill shapes as spatulate, acute, pointed, recurved, etc. And then it would explain the terms long and short as it relates to bill length. Nevertheless, shape is used as an identification tool far too infrequently in field guides.

Dabbling, or puddle, ducks are those that tip up to feed and rarely dive. The males are colorful, but the females are camouflage patterned with various shades of brown. Nearly all ducks can be identified by shape alone, there are very few exceptions in the dabbling ducks or in the diving ducks--especially in the Pacific Northwest.

Here I present some hen dabbling duck silhouettes. They are created from photos I have taken, adjusted so they are all about the same size, and then turned to black.

So "forget" the patterns of buffs and browns, the color of the speculum, or the markings on the bill. Concentrate only on shape. Primarily look at the overall length--whether compact or long, the neck length and thickness, head shape, and bill shape.

Make your guesses in the comments section below. I'll give you the answers next week, with the silhouettes replaced with color photos. Sound fun?

Too hard? Then to help you get started here are your choices for the 7 dabbling ducks: American Wigeon, Cinnamon Teal, Gadwall, Green-winged Teal, Mallard, Northern Pintail, and Northern Shovleler.

Answers

Friday, January 28, 2011

Friday Foto: Dark-eyed Junco

Dark-eyed JuncoDark-eyed Junco, Dawson Creek Corporate Park, Hillsboro, Oregon, 31 December 2010 by Greg Gillson.

 

I thought I would start a new feature for a while, sharing my recent photos, without much commentary.

This female Dark-eyed Junco of the "Oregon" form is common throughout the Pacific NW.

We discussed Dark-eyed Juncos previously. In fact, it was the very first post!

Monday, January 24, 2011

Proposed split: Gambel's and Bailey's Chickadees

Mountain ChickadeeProposed Gambel's Chickadee, spp. grinnelli, King Mountain, Harney Co., Oregon, 26 May 2009 by Greg Gillson.

 

There is a recent proposal before the A.O.U. (American Ornithologists' Union, Committee on Classification and Nomenclature, North & Middle America) to split Mountain Chickadee, Poecile gambeli into two species. The new species would tentatively be called Gambel's Chickadee Poecile gambeli and Bailey's Chickadee Poecile baileyae.

Both of these forms of Mountain Chickadees are common in the Pacific Northwest.

As is the case for several recent splits of North American birds (Winter and Pacific Wren is a recent example), published research showing differences in songs and calls, together with supporting DNA evidence, were the primary deciding factors for recommending separation. They don't really look that much different.

Not all recommendations to the committee are passed. But if accepted, the A.O.U. could update its checklist in July 2011, making this split official.

Mountain Chickadees are found from the Rocky Mountains westward in drier pine forests to timberline.

The proposed Gambel’s Chickadee is found in the Great Basin and Rocky Mountains. In the Pacific NW it is found in mountain forests and juniper woodlands in interior British Columbia, northern Idaho, SE Washington, and NE Oregon (to the Ochoco Mountains in north central Oregon).

The proposed Bailey’s Chickadee is found in coastal California, Sierra Nevada, and the Cascades of Oregon and Washington. In the Pacific NW it is found in the Klamath Mountains of SW Oregon and northward primarily on the east slope of the Cascades to Mt. Rainier but, apparently, not in British Columbia (Birds of Canada. 1979. Godfrey).

There may be some areas in the Pacific NW where the two forms come together.

In the field, the primary separation of these forms is range (they are non-migratory) and breeding song. In-hand measurements can be used to identify captured birds or specimens. On average Gambel's is tinged buffier below with a wider white eyestripe and perhaps more white on the lores. But a comparison of the two photos here shows how difficult this identification would be based only on plumage. Both the Sibley and the National Geographic guides illustrate the two forms of Mountain Chickadees.

Gambel's Chickadee reportedly has a wider range of pitch between song notes than Bailey's Chickadee. If this split goes forward birders will need to really listen to the songs. Listen to Mountain Chickadee songs.

 

Mountain ChickadeeProposed Bailey's Chickadee, spp. abbreviatus, Sunriver, Deschutes Co., Oregon, 3 February 2008 by Greg Gillson.

 

Monday, January 17, 2011

The secret to my birding success

Red-breasted NuthatchRed-breasted Nuthatch, Hagg Lake, Washington Co., Oregon on 17 December, 2010 by Greg Gillson.

 

The photos in my blog postings in recent weeks were all from one 10-minute photo session in mid-December.

The Ruby-crowned Kinglets and Hutton's Vireo in ID: Little green bird: Kinglet or Vireo? and Wing-flicking: Ruby-crowned Kinglet, the Hermit Thrush in Hermit Thrush in Winter and The old hermit that lives in the woods, and the Red-breasted Nuthatch above were all photographed together at the same time.

Would it surprise you that these were just the tip of the iceberg as to the birds present? Would it surprise you that they appeared at my bidding--that I didn't just luck into this active flock? In fact, I was unaware that these birds were there at all. I'll tell you about it in a moment.

What is the secret to my birding success? It is more important than having the best birding optics. It doesn't matter what you wear or even where or when you go birding. It is simply the most-effective birding fieldcraft technique for seeing birds at close range--by getting them to come to you:

Pishing.

Pishing is the art of making of hissing, squeaking, kissing, whistling, and chattering sounds to attract birds. In many ways pishing appears to mimic the scold notes of a flock of chickadees, causing other birds to investigate.

Pishing may be a funny word, but it has its own Wiki page. If you think the word itself is funny, think how you'll feel getting "caught" doing this in your local birding patch!

After too many posts on this subject on the Oregon bird discussion list, OBOL, in early December, Mike Patterson wrote a nice blog post on pishing. It included a recording of some of his repertoire of sounds.

Birding author Pete Dunne actually wrote a book called "The Art of Pishing."

On December 11, 2010 David Fix posted interesting comments on pishing to the OBOL (Oregon Birders OnLine) list. He calls it "spishing" so it sounds less like a certain vulgar word.

Some of his observations:

Spish LOUDLY. This teensy, soft, underbreath stuff some birders do isn't even worth it. Make a real racket, a huge fuss. The point is to make a bizarre sonic scene that no small bird will want to miss out on.

VARY the sounds: make all sorts of creative, squeaky, kissy, upslurred and downslurred sounds.

Intersperse half-minute bouts of Pygmy-Owl tooting.


Birds have one of three reactions to pishing: they come close, they do nothing, or they flee. Usually they come excitedly to investigate.

I've noted, too, that various sounds have different effects on different birds. While most sparrows are highly attracted to pishing, high-pitched "seee" hisses will scare them away (it sounds like the alarm call of Song Sparrow, I think). However, the same loud-as-possible hiss will pull Golden-crowned Kinglets out of the crown of the tree right down into your face.

And the same pishing that works in winter may scare some birds during the nesting season.

Next lower in pitch is a gentle "shhh..." sound similar to chickadee calls. A lower harsh chatter may be like some notes of wrens. Imitating the "tchut" of Common Yellowthroat or the husky "chep" of Fox Sparrow will bring them out when "normal" pishing seems ineffective.

The pygmy-owl whistles are especially effective on forest birds. A pygmy-owl imitation will stop a flock of Red Crossbills in their tracks as they fly over the forest, though they usually remain in the tree tops. I actually tend to use a similar Gray Jay whistle imitation, which is about like the pygmy-owl but more quickly-paced and downslurred. Often a real owl or jay comes in to liven up the party.

And keep it up. Sometimes the most interesting birds are the last to respond. Five to 10 minutes is not too long to pish if new birds are still arriving.

Now for my story of the photo above and the past few posts...

This was at Hagg Lake on the foothills of the Coast Range in NW Oregon. I was at a location along the shore with some openings at the edge of the Douglas-fir and big leaf maple forest. There didn't appear to be many birds about on this cold winter day, but I saw a couple of silhouettes of Varied Thrushes moving in the trees and wanted to get a better look at them. So I started pishing.

Soon I was surrounded by about 15 each of Black-capped and Chestnut-backed Chickadees. A dozen Ruby-crowned (photo) and 20 Golden-crowned Kinglets mobbed me. A pair of Bewick's Wrens worked their way over to me. A Pacific Wren or two snuck up to me through the ferns. Several Red-breasted Nuthatches (photo) called from deep in the forest and flew close. A Hermit Thrush (photo) left the safety of the deep shadows and came out in the open to see me. And the Hutton's Vireo (photo) investigated me at close range for several minutes. A Yellow-rumped Warbler flitted about. A Sooty Fox Sparrow (photo) and a Spotted Towhee called from the blackberries, along with a pair of Song Sparrows and a dozen Dark-eyed Juncos flitted about on the ground.

All told, over 100 individual birds of 14 species responded to my pishing! They came very close, and stayed close, out in the open where I could photograph them.

Remember, this isn't a weird one-time event. This is how birding is every day for birders who know how to pish. This is the secret to my birding success.

Oh, and the Varied Thrushes that started it all? I never saw them again.

Monday, January 10, 2011

The old hermit that lives in the woods

Hermit ThrushHermit Thrush, Hagg Lake, Washington Co., Oregon on 17 December, 2010 by Greg Gillson.

 

Here is another photo of the Hermit Thrush from last week's post.

This bird has more to tell us.

If you click on last week's photo and bring up the largest version from the pBase photo gallery, you can see a dark spot on the lower eyelid. I believe this is probably a tick. Birds can host numerous insect ectoparasites, including feather lice, fleas, mites, and ticks.

But I want to concentrate now on the opposite end of the bird--its tail.

Below I have created a larger view of just the tail. What do you notice? There are two things to see. Look close.

 



 

Did you notice that the tips of the tail feathers are very sharp-pointed, not blunt?

Did you notice that there are light and dark bars on the tail?

Both of these features indicate that this bird is less than about 15 months old. Due to the December date, we can say this bird is 5 or 6 months old. Why can we say this?

The pointed tips on the juvenile tail (and wing) feathers are common to many birds. Juvenile feathers are the first real (non-down) feathers a bird grows. The wing and tail of most smaller birds are kept for a year and molted in the fall. Adults have blunt ends to the wing and tail feathers. To have juvenile tail feathers in winter, this bird has to be about 6 months old.

Those light and dark bars on the tail? They are growth bars. Most adult birds molt their wing and tail feathers a few at a time, in sequence, symmetrically. Besides allowing the bird to keep flying through molt, it is less stressful to molt a few feathers than many. [Ducks are an example of birds that molt all their wing and tail feathers at the same time. They become flightless for several weeks after the breeding season.]

These growth bars are present on juvenile wing and tail feathers and not adult feathers, likely because of the nutritional stress incurred growing all those feathers at once.

According to Steve N. G. Howell in the 2010 book "Molt in North American Birds":
The dark bands represent feather material grown during the day, whereas the light bands indicate nocturnal growth. Thus, one pair of bands represents a day's growth and the total number of pairs indicates the number of days taken for the feather to grow. This phenomenon, which is analogous to that of growth rings in trees, is termed "ptilochronology."


There is your vocabulary word for the day. Remember to use "ptilochronology" several times today as you carry on conversations! And for extra credit, use "ectoparasites" and "ptilochronology" in the same sentence. I just did--and you can too!

Monday, January 3, 2011

Hermit Thrush in winter

Hermit ThrushHermit Thrush, Hagg Lake, Washington Co., Oregon on 17 December, 2010 by Greg Gillson.

 

The Hermit Thrush is the only spotted thrush expected in the Pacific NW in winter. They are one of the winter birds termed "half-hardy," such as the Lesser Goldfinch discussed a few weeks ago. They don't survive well if water stays frozen for more than a couple of days. Thus, their winter range in the Pacific NW is primarily west of the Cascades from southern British Columbia southward.

Hermit Thrushes in winter can be found in dense shrubbery in backyards and, especially, foothills. In this, they are found in similar winter habitats to Varied Thrushes. Both are shy birds, generally sticking to the shadows and brushy cover of conifer saplings.

The spotted thrushes are all very similar in appearance, with only slight differences.

In contrast to their plain plumage, most spotted thrushes (genus Catharis) have very complex and beautiful breeding songs. The name, Catharis, means "pure" and refers to the lovely melodius songs of this group. In fact, the Hermit Thrush is arguably the most beautiful singer of all North American birds. In winter, however, Hermit Thrushes are very quiet, giving only a blackbird-like "chuck" note that belies their extensive spring repertoire.

The difference between the calls of Hermit Thrushes and Varied Thrushes is slight. As mentioned, Hermit Thrush gives a "chuck" or "djuck" call. The call of Varied Thrush is slightly more mellow, "tchook" (with a long U sound, like "duke," not "book"). These soft calls are often the only indication that these birds are hiding nearby as you walk along the trail through the woods.

I am not the only one to have photographed and written about Hermit Thushes this winter. See the article by Dave Ingram on his Nature Island blog: Hello Hermit!.