Brown-headed Cowbird: "North America's most reviled native bird"

Brown-headed Cowbird, Hines, Oregon, 24 May 2009 by Greg Gillson.

 

Brood parasite: "Organisms that use the strategy... involving the... use of host individuals... to raise the young of the brood-parasite." -- Wikipedia.

The Brown-headed Cowbird does not build its own nest. Instead, it lays its eggs in nests of other birds. In fact, at least 221 known bird species have been hosts to Brown-headed Cowbirds. They usually only lay one egg per host nest. The host parent, often a much smaller species of bird, raises the cowbirds' young, usually to the detriment of its own young.

In "Brown-headed Cowbird: Villain or Scapegoat?" Birding 31:448–451, August 2004, author Stephen I. Rothstein argues that widespread population declines of host species by cowbirds is not scientifically supported. He believes that "North America's most reviled native bird" is unfairly blamed for declines in bird populations largely caused by habitat loss. Of course, we know who is responsible for altering and destroying the established natural landscape, now don't we?

So let's take a step back for a moment and view this bird without prejudice.

The Brown-headed Cowbird is a migratory blackbird. It arrives in the Pacific NW in April and remains into October. A few birds may be found in winter mixed in flocks with other blackbirds at cattle feedlots and similar concentration points.

The male has a black body and brown head; the female is slate-colored gray-brown. The young birds are brownish-gray with paler feather edgings. The bill is pointed and rather thick. Thus, as with female Red-winged Blackbirds, this combination causes some confusion with beginners in thinking juvenile cowbirds might be a sparrow or bunting.

 

Juvenile Brown-headed Cowbird, Hillsboro, Oregon, 13 July 2010 by Greg Gillson.

 

Two hundred years ago, this bird was restricted to the Great Plains. They followed great herds of American bison as they traveled, eating the insects kicked up as the huge mammals walked through the grass. Because of the nomadic lifestyle of the bison, cowbirds couldn't stay in one place to raise their young. Thus, the strategy formed of laying its eggs in other bird's nests.

With the subsequent cutting of forests, both in the East and West, the cowbird substantially increased its range. Cowbirds became common west of the Cascades only in the 1960's. In the past 50 years they have increased tremendously in the Pacific Northwest.

Male cowbirds give a rising squeaking call (starling-like) as they chase females in courtship. They also give a bubbly rattle call, similar to Bullock's Oriole.

Besides insects, cowbirds eat seeds. So, you may host cowbirds at your bird feeder--especially, it seems, east of the Cascades.

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Note: I write some of my "natural history" articles weeks in advance and have them published on a schedule. As sometimes happens in blogging about birds, another blogger posted an article on cowbirds while mine was in the queue (in news parlance, I was scooped!). Please read Dave Iron's account on Brown-headed Cowbirds that appeared on the BirdFellow blog on June 18.

Friday Foto: Black-throated Gray Warbler

Black-throated Gray Warbler, Beaverton, Oregon, 18 May 2011 by Greg Gillson.

 

Black-throated Gray Warblers are abundant migrants through the lowlands west of the Cascades and nest there and quite locally in juniper woodlands east of the Cascades.

We have discussed Black-throated Gray Warbler previously.

The bird that shouldn't be

If there really is such a thing, you should be able to call these crows in Victoria, British Columbia, Northwestern Crows. 16 September 2007 by Greg Gillson.

 

Regular readers of this blog know that on occasion I like to discuss field identifiable forms, or subspecies, of our Pacific Northwest birds. Such forms look and sound different than the "same" species elsewhere, and might be raised to full species status in the future.

However, this time, I'd like to discuss a species that is in your field guide that probably should not be there.

No, I'm not talking about the Pacific-slope/Cordilleran Flycatcher mess, or the 10 types of Red Crossbills proposed by call. I'm going to discuss the elephant in the room--the bird problem no one wants to acknowledge--the supposed "Northwestern Crow."

The range of Northwestern Crow (Corvus caurinus) is usually defined as along the immediate coastline from SE Alaska through British Columbia. Then its range is less well-defined, but into the Puget Sound region and northwestern Olympic Peninsula of Washington. You may find reference of birds to Long Beach and Vancouver, Washington, and even along the Columbia River from Astoria to Portland in Oregon.

As far as identification, it is supposed to be smaller than American Crow (Corvus brachyrhynchos) with faster wing beats and a deeper, raspier voice.

But guess what? There are pockets of crows along the Oregon coast, and even along the northern California coast, that are smaller than their counterparts 20 miles inland, and some are within the measurement range of Northwestern Crows (Measurements of Possible Northwestern Crows from Oregon. 1989. Range D. Bayer. Oregon Birds 15(4):281). They have more rapid wing beats and deeper calls. Are these, then, Northwestern Crows? This question has been asked for decades, with the usually accepted answer being "no."

The question of the status of Northwestern Crow in Oregon is somewhat of a template for discussing whether Northwestern Crow exists at all.

Northwestern Crows have been reported in Oregon since the time of Lewis and Clark. But Gabrielson and Jewett in their 1940 book Birds of Oregon had this to say: "Lewis and Clark... found crows abundant on November 30, 1805, at the mouth of the Columbia and listed them as Northwestern Crows, but unless the distribution of the two species has radically changed since that time, the Western Crow... was the more abundant species." Gabrielson and Jewett considered only 4 of the numerous crow skins taken in Oregon prior to 1936, and labeled Northwestern Crow, to actually be that species.

Subsequent evaluation of crow specimens from Oregon found none that could be clearly assigned to Northwestern Crow, and many were definitely female and juvenile American Crows. The book, Birds of Oregon: a general reference (2003, page 620-621, Marshall, Hunter, Contreras, editors) summed it up: "Given the lack of reliable specimen evidence, it cannot be shown that the Northwestern Crow has ever occurred in Oregon."

A study by D. W. Johnston in 1961 (The biosystematics of American Crows) found that Northwestern and American Crows were very closely related and may be conspecific (the same species).

The National Geographic book, Complete Birds of North America (2006, Jonathan Alderfer, editor) has this to say about the ID of Northwestern Crow: "Unfortunately, [C. b.] hesperis [Western American Crow] found in the Pacific Northwest is identical." That's pretty damning. As is: "Field identification within the suspected range of overlap in WA is probably impossible."

Thus, it is apparently only range that separates American Crows and Northwestern Crows. If you are in SE Alaska or the coastal slope of British Columbia and Queen Charlotte and Vancouver Islands, the crows are Northwestern. Inland in British Columbia and the rest of the West, including Oregon and California, they are American Crows. If you are in Puget Sound or on the Olympic Peninsula of Washington, well, then, I guess you can call them whatever you want.

That doesn't sound like a "good" species to me. Does it to you?

Pacific NW specialty... Varied Thrush

Varied Thrush, Beaverton, Oregon, 27 March 2011 by Greg Gillson.

 

Visiting birders to the Pacific Northwest often have Varied Thrush on their "target list" of bird species to see. Fortunately, this species is not rare, and are not difficult to find, if one knows where to look.

When I think of Varied Thrush habitat, my search image is of damp, dark, moss-covered Sitka spruce forests on steep, foggy hillsides overlooking the ocean in the Pacific Northwest. I know! My search image is something like this photo I took at Cape Perpetua on the central Oregon coast way back in August 2003:



Likewise, Varied Thrushes find their home in similar dense, damp high-elevation old-growth forests in mountains from Alaska to extreme NW California. Periodically, in winter, vagrant birds will be found far to the south, and even to the East Coast.

In winter, birds from the north or higher elevations move into the lowlands west of the Cascades. A winter snow storm will bring these birds out of cover and into backyard feeders and landscaping, where they favor fallen apples. As soon as the snow melts they disappear back into the dense brush. The bird photographed above spent the winter in my backyard in Beaverton, Oregon. But it never ventured out far from cover.

These birds eat berries, seeds, acorns, insects, and invertebrates that they forage from on or near the ground.

Their eerie songs are single hummed whistled notes, each given with a pause of about 3 seconds between them. Each note is a different pitch, first higher, then lower, but each far apart from each other. For instance, if they give a note in the middle of their frequency range, the next will be at the extreme end. This is very typical of thrush songs, even though this song is nothing like the flutelike, ethereal and very complex songs of that master singer, the Hermit Thrush.

Varied Thrushes appear similar to American Robins, also a thrush. They differ in the orange eyestripe and orange patterning in the wings, and black necklace across the chest. Males, such as the one in the photo, are darker gray-black above and deeper orange below than females.

Friday Foto: Common Yellowthroat

Common Yellowthroat, Forest Grove, Oregon, 2 June 2011 by Greg Gillson.

 

We have discussed Common Yellowthroats previously.

New eBird data entry page released!

eBird today released their new data entry page. I've been testing the beta version for a few weeks and appreciate the new layout and changes.



Some of the new tweaks that I appreciate are...

-- Two pages instead of 3 to submit a list: This makes adding a new checklist even quicker and easier. A checklist with 35 species in an area you've birded before only takes a minute or two to enter.

-- Single column species entry: I didn't mind the 3-column species entry, because I didn't have to scroll down as much. However, it seems most people do like the single column format. It eliminates problems accidentally entering data in the wrong species box. It will be easier for using smart phone and hand-held computer eBird apps.

-- Customizable species entry list: This is exceptionally nifty. You can choose to show the full checklist, including subspecies and rare birds, or just a portion. You can also choose to show just the most likely species for each location! I think this will help newer birders know what to expect in season--teaching status and distribution!

-- Easy species comments information: As eBird is a scientific tool, as well as a public list keeping program, it is very important that species entered are correctly identified. eBird is used by scientists, birders, and school children. Thus, an army of volunteers examine data for possible errors.

In the previous version, if you saw something unexpected, the eBird program would tell you and ask if you were sure. Then, a Reviewer would look at your report and send an email to you asking for more details.

Now, this is more automatic. When you see an unusual bird, add comments about what plumage or behavior you saw to make the ID, who else saw it, or anything else that you think the Reviewer needs to know about your unusual sighting. Then the Reviewer can read your comments without the need to contact you further!

-- Breeding bird codes: This feature was not enabled on the beta version. It's been a dozen years since Oregon finished its 5-year breeding bird atlas project. I must say, searching for breeding birds was a very fun thing to do in late spring and summer (right now). So I'm anxious to see how this feature is used.

In the backyard... Western Wood-Pewee

Western Wood-Pewee, Trout Creek, Deschutes Co., Oregon, 5 August 2005 by Greg Gillson.

 

The Western Wood-Pewee is widespread throughout the West.

As with most flycatchers, it sits upright and motionless on an exposed twig. When an insect flies by, the bird sallies out and chases it, often clicking its bill several times during the chase. Once it catches its prey, it often returns back to the same or nearby perch.

It has the prototypical flycatcher shape--the head is large and slightly crested. The bill is quite wide and flat, but this is only obvious when viewed from directly below.

On a perched pewee the primaries are very long and pointed. The tail also looks quite long. This flycatcher has wide buffy wing bars, but lacks an eye ring. Smaller Empidonax flycatchers (Willow, Dusky, etc.) have both eye rings and wing bars. Even though larger than these other flycatchers, it is only 6-1/4 inches long--the length of a junco. It is much smaller than than some other flycatchers, such as Say's Phoebes and Western Kingbirds, for instance.

These birds arrive in the Pacific NW in mid-May, after there are many larger flying insects to eat. They remain into late September before migrating south. They winter farther south than most Neotropical migrants in the West, to Colombia and Venezuela.

These flycatchers are found in open woods, preferably deciduous trees, thus most likely to be found in mature trees in residential areas. They avoid breeding in sage, grasslands, and dense conifers.

Their voice is loud: a plaintive, drawn out, slightly buzzy descending pee-year and a similarly burry rising weep.

Friday Foto: Red-winged Blackbird

Red-winged Blackbird in red elderberry tree, Forest Grove, Oregon, 2 June 2011 by Greg Gillson.

 

Visit any wetlands in North America right now and you'll likely see (and hear!) this bird!

We have discussed Red-winged Blackbirds in the past.

Oregon Shorebird Festival: August 26-28, 2011

The Oregon Shorebird Festival Celebrates 25 years - August 26-28, 2011

Experience the wonder of shorebird migration along the scenic Oregon coast at the 25th Oregon Shorebird Festival to be held August 26-28, 2011. The U.S. Fish & Wildlife Service, Cape Arago Audubon Society, South Slough National Estuarine Research Reserve and many other sponsors will have a full weekend of activities planned for birders of all skill levels. The festival is headquartered at the Oregon Institute of Marine Biology in Charleston, OR. Activities include expertly guided land based field trips to Bandon Marsh National Wildlife Refuge, Millicoma Marsh and the greater Coos Bay area. And for those who want to experience birding on the water, The Bird Guide, Inc. will offer a five hour pelagic trip on Saturday. Expected seabirds include Black-footed Albatross, Parasitic Jaeger, Fork-tailed Storm-Petrel, Sooty & Pink-footed Shearwater, Pomarine Jaeger, Red-necked Phalarope, Cassin's Auklets, and more. The Friday evening program will feature a live bird of prey from exhibit by staff and volunteers from the Free Flight Wildlife Rehabilitation Center. The keynote speaker on Saturday will be Samantha Franks from the Centre for Wildlife Ecology at Simon Fraser University. Her presentation is titled "Have Feathers, Will Travel: The Migration Strategies of Shorebirds."

Bring your best pair of binoculars as Bandon Marsh and Coos Bay are renowned for shorebird watching and each year a few rarities have delighted festival attendees. Regular migrants include Black-bellied plover, Semipalmated plover, Western sandpiper, Least sandpiper, Dunlin, Whimbrel, Long-billed dowitcher, and Red-necked phalarope. Please join us on the southern coast of Oregon for a weekend of birding fun and challenges. To register for the festival or for more information please visit our website at www.fws.gov/oregoncoast/shorebirdfestival.htm or contact Dawn Grafe at 541-867-4550.

Bird songs and calls

Singing Marsh Wren, Forest Grove, Oregon 2 June 2011 by Greg Gillson.

 

Listen. Do you hear it?

No, because this is a photo without sound. But I hear it in my mind.

Here's a link to a sample song of Marsh Wren.

O, what a quiet world this would be without birds! Well, quiet except for human-made sounds. When we think of the sounds of nature, we usually include the calls of birds.

Many birders have trouble identifying bird songs and calls. No wonder; it takes just as much (or more) work than learning to identify birds by sight. And there isn't a workable "field guide" to bird songs and calls.

However, Nathan Pieplow, on the EarBirding blog, wrote this brief guide to
describing what you hear. He writes "How to identify bird sounds in six easy steps." Great stuff.

This gives a framework for describing bird sounds. Even playing a recording of a bird song doesn't help you remember it, if you can't describe it to yourself--if you can't hear it in your own mind when the bird is no longer singing.

Michele, at Northwest Nature Nut recently recorded 50 seconds of audio at the Ridgefield wildlife refuge, in her post:Ridgefield bird songs of May. How many different bird songs and calls can you pick out? I heard 11 species and in the post's comment field recorded the first time I heard each species and the second count of the recording when it calls, so you can compare. Try it!

Bird trip: Fossil, Oregon: June 19, 2011

Here's another birding opportunity.

This is in the very interesting John Day Fossil Beds of north central Oregon.

Greg

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Paula Fontenot
Volunteer
Oregon Paleo Lands Institute
333 4th Street, Fossil, Oregon 97830
541.763.4480
www.paleolands.org

OPLI Adventure Trip ~ Bluebirds and Other Avian Wonders of the Fossil Area

Sunday, June 19, 2011 6 a.m. to 9 a.m.
Meet at the OPLI Field Center at 6:00 a.m.

Join naturalist Char Corkran as we peek into nest boxes to see how Western Bluebirds, Mountain Bluebirds, Mountain Chickadees, and House Wrens are faring. Then it’s off to look for American Kestrels and other raptors. Songbirds will be singing, and other avian species of the grasslands, junipers, ponds, and riparian areas will add to our enjoyment of the bird nesting season in this rich and beautiful region. We will end the examining bird skulls and skeletons, and discussing adoptions to varied habitats and lifestyles. Char Corkran, has studied bluebirds in the Fossil, OR area since 1988. Round Trip Transportation available from Portland to Fossil via I-84 (Hood River, The Dalles).

Trip Fee: $85 Adults/ $50 kids under 12
Pre-registration is required. For more information and registration call OPLI at (541)763-4480 or email explore@paleolands.org

Woodpecker weekend: Sisters, Oregon: June 24-26, 2011

Here's an announcement for a fun birding excursion.

My wife and I went 2 years ago and head a wonderful time... and saw lots of woodpeckers and other birds!

Here are posts from my visit to the Woodpecker Wonderland Festival 2 years ago.

I recommend this fun weekend.

Greg

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Birders,
Drumming up some attention for the upcoming 2011 Woodpecker Weekend! !

East Cascades Audubon Society (ECAS) is bringing a low cost, casual and fun birding weekend to you on June 24, 25, and 26. It will be based in Sisters.

The weekend will be of interest to birders with any level of experience and interest in birds. We will specialize in woodpeckers and 11 are possible here. But we will have a variety of trips to focus on much more than woodpeckers … a Friday trip to Summer lake, Saturday and Sunday trips to a variety of burns, forests and lakes … and early morning trips for dawn chorus and other specialties. All trips will be led by 2 to 3 local birders who are eager to share their enthusiasm for the Central Oregon birds and who have a real knowledge of the local areas and wildlife. Any profits will go to ECAS to fund cool projects to help birds. We are keeping the costs down so anyone can afford to participate. We will car pool on field trips and will have a pizza pot luck instead of a banquet on Saturday p.m. Note that we are limiting registration and use of playback to avoid excessive disturbance to the birds and to fulfill the requirements of our special use permit from the USFS.

So register soon! See the link for more details and for the registration form, found on the ECAS website: http://ecaudubon.org/Projects/WoodpeckerWeekend/tabid/246/Default.aspx

Judy Meredith
jmeredit@bendnet.com

In the woods: Golden-crowned Kinglet

Golden-crowned Kinglet, Cooper Mountain Nature Park, Beaverton, Oregon, 19 March 2011 by Greg Gillson.

 

Tiny little balls of fluff, moving nervously through the forest branches.

Sibilant, soft, high-pitched notes from birds unseen in the tree-tops.

Golden-crowned Kinglets.

Was that a haiku? It wasn't meant to be. Just some brief notes I put down to include in my post, to be finished later. But those sentence fragments capture the impression of these common, yet unfamiliar (to many) birds.

I feel privileged that my "over 50" ears can still hear the high frequency songs and calls of Golden-crowned Kinglets. The National Geographic field guide describes the song as an "almost inaudibly high... series of tsee notes accelerating into a trill."

And they are truly tiny. At only 4 inches long, they are the same length, bill tip to tail tip, as Anna's Hummingbird, though the kinglet has a larger body and shorter bill and is about 50% heavier, overall. Still, it is 1-1/2 inches shorter than a Black-capped Chickadee.

These little sprites are tough little birds, though, living on bark beetles, scale insects, aphids and their eggs, year-round in the conifer-covered mountains of the West. Some birds move into the lowland woods in winter. Eastern birds breed in the taiga forests across Canada and barely into northern US, including northern Appalachians, and winter throughout the US.

 

Golden-crowned Kinglet, Cooper Mountain Nature Park, Beaverton, Oregon, 26 January 2011 by Greg Gillson.

 

Sexes are similar, though the male has a bit of orange on the crown that is best seen when the crown feathers are raised in agitation.

Those long claws and strong feet are perfect for gleaning insects from the tips of branches. They often hang upside down from branch tips as they search for insects. They may hover-glean, flying in place as they pick at insects.

Constantly on the move in small flocks, they are handsome little birds--a fact only appreciated in these larger-than-life-sized photos of frozen time.

Friday Foto: Black-footed Albatross

Black-footed Albatross, 25 miles off Newport, Oregon, 15 May 2011 by Greg Gillson.

 

Found in the Pacific NW only far offshore where they eat squid, the Black-footed Albatross has a 7 foot wingspan. This actually makes them one of the smallest albatrosses in the world!

I organize guided birding boat trips offshore specifically to see these and other seabirds that cannot usually be seen from land in the Pacific NW.

We have discussed Black-footed Albatrosses previously.