A Tale of Two Nests

Nesting cormorants--upper left Double-crested; lower right Brandt's.
Photographed at Newport, Oregon on July 21, 2012 by Greg Gillson

Take a close look at the cormorant's nests. Do you note that they are constructed differently?

According to The Audubon Encyclopedia of North American Birds, the Brandt's Cormorant (lower right in front) builds a nest of marine plants, mosses, and grasses in a circular nest. On the right hand side of the upper piling are two fuzzy brown Brandt's Cormorant chicks.

On the left side of the upper piling is a nest of Double-crested Cormorant. Notice that is is built of "sticks and weed stems, lined with leafy twigs and grass."

There is actually a third species, Pelagic Cormorant in this photo. See the dark form up on the bridge just above the upper right hand Brandt's Cormorant? That's where they build their nests. On natural substrates they build nests on "remote and precipitous cliffs" of seaweed, grass, and rubbish.

Xantus, Scripps, and Guadalupe

Scripps's Murrelet. 2007 off Newport, Oregon by Greg Gillson.

The American Ornithologists' Union this month split Xantus's Murrelet into two species (see my Oregon Seabirds blog article: Guadalupe and Scripps's Murrelet).

The origins of these names are not all that familiar to birders. Who were Xantus and Scripps? And where is Guadalupe?

John Xantus (1825-1894) fled to the United States from Hungary in 1851, escaping the unsuccessful war of independence from Austria. Soon he joined the US army, stationed in Riley, Kansas. There he developed an interest in natural history (in that age this evidently meant shooting mammals and birds, and collecting eggs and plants for museums). In California he collected "massive amounts of materials," including many fishes, for Spencer F. Baird at the Smithsonian. He made an expedition to Baja California, Mexico, in 1859, using Cabo San Lucas at the very tip of the peninsula as his base for collecting. (See also this biography of John Xantus). Xantus's described to science the murrelet that came to be named for him. Xantus also collected the hummingbird named for him by George Newbold Lawrence. Fifty-two species of plants, molluscs, lizards, insects, birds, and fishes were named for him. Xantus described to science many birds including Hammond's Flycatcher, Spotted Owl, and Cassin's Vireo (The Audubon Encyclopedia of North American Birds. 1980. John K. Terres.). Xantus eventually returned to Budapest, Hungary as a naturalist.

The murrelet type that Xantus originally described breeds primarily on Guadalupe Island, or Isla Guadalupe, about 150 miles west of Baja California, Mexico, and about 250 miles SW of Ensenada. (See Biology and conservation of Xantus's Murrelet in Marine Ornithology. 2006. Carter et al.).

In 1939 Green and Arnold described two forms of Xantus's Murrelets, including one breeding on Anacapa Island, California. They named the type specimen for Robert P. Scripps, on whose yacht they traveled to visit Anacapa. The Scripps family made their fortune in the newspaper industry in the Midwest, and most retired to San Diego. In 1903 E.W. Scripps and his older half sister, noted philanthropist Ellen Browning Scripps, provided funds to help create the Scripps Institution of Oceanography in La Jolla, California.

Recent research has discovered that both the Guadalupe and Scripps's Murrelets breed on the San Benito Islands without significant interbreeding. They have different calls and different facial markings. And now they are considered separate species.

Field-friendly bird sequenceRaptors

Barn Owl, Hillsboro, Oregon, 22 October 2009 by Greg Gillson.

 

The 13 categories of North American birds listed in the Field-friendly bird sequence: Part II are:

Swimming Waterbirds
Flying Waterbirds
Wading Waterbirds
Chicken-like Birds
Raptors
Miscellaneous Landbirds
Aerial Landbirds
Flycatcher-like Birds
Thrush-like Songbirds
Chickadee and Wren-like Songbirds
Warbler-like Songbirds
Sparrow and Finch-like Songbirds
Blackbird-like Songbirds

A beginner should be able to quickly place a bird they see into one of these categories.

Raptors are birds of prey that hunt other birds and animals. They have strong beaks and claws. Many can be seen soaring high overhead, while others hunt low from a concealed perch.

Raptors include vultures, hawks and eagles, falcons, and owls.

Bald Eagle, Tualatin River NWR, Sherwood, Oregon, 6 July 2010 by Greg Gillson.

 

Peregrine Falcon, Hillsboro, Oregon, 29 April 2010 by Greg Gillson.

 

Turkey Vulture, Newport, Oregon, 12 September 2008 by Greg Gillson.

 

Red-tailed Hawk, Hillsboro, Oregon, 6 December 2008 by Greg Gillson.

Where should I go birding in August?

 Hot and dry. That is August in the Pacific Northwest. Thus, birding in late summer is often concentrated around finding water where birds concentrate.

Even more than July, birding in August revolves around shorebirds at quickly-drying inland marshes and high tide roosts along the coast.

Another cool location is the high mountains. Access to alpine areas in August may provide you with views of many birds moving upslope to cooler wetter areas. It has been several years now, but I love camping in the park-like pondersoa forests on the east slope of the Cascades and making day trips to various surrounding areas to find wonderful birds amid snow-capped mountains and blue skies. Use the Oregon Cascades Birding Trail brochure as your guide.

If you want to get away from the heat, a pelagic trip at this time of year is often cool and frequently misty--at least in the mornings. Trips offshore at this time of year feature Long-tailed Jaegers, Sabine's Gulls, Arctic Terns, and Fork-tailed Storm-Petrels, along with the regulars like Black-footed Albatross, Pink-footed Shearwater, and Rhinoceros Auklets.

I'll be attending the 26th annual Oregon Shorebird Festival, August 24-26. The Bird Guide, Inc. will be hosting the pelagic trip for the Shorebird Festival, something we've been doing for several years now (sorry; no more spaces available!). The Friday and Saturday night presentations are top notch. Friday's speaker is Noah Strycker, speaking about his Antarctic adventures: "Among Penguins." Noah has subsequently completed walking the Pacific Crest Trail from Mexico to Canada. He's been busy! The field trips are led by knowledgeable and friendly local birders. Dawn Grafe, with the US Fish & Wildlife Service, has ably and cheerfully organized this Festival for several years. Attendance is only 60-100 persons. You shouldn't miss it!

Where are you planning on watching birds in the coming month and what species do you hope to see there? Are you a field trip organizer? We want to hear what you offer (fee or free). Leave your response in the Comments section as ideas for others.

Birding festivals:

Southwest Wings Birding and Nature Festival
August 1-4, 2012
Sierra Vista, Arizona

Oregon Shorebird Festival
August 24-26, 2012
Charleston, Oregon

Wrentits in northern Willamette Valley

This spring and summer there have been several scattered reports of Wrentits in NW Oregon outside their historic range. Could the sightings and heard-only reports be correct? Possibly. On the other hand some might just be weather balloons.

Reports have come from North Portland, Sauvie Island Wildlife Management Area, Hagg Lake, and Tualatin River National Wildlife Refuge. Thus far, all these reports from well-birded areas are unverified--descriptions are incomplete and others can't find them the same or next day. That's a problem for me. I'll tell you why.

Wrentits are sedentary to the extreme. Their home ranges are a tiny 2-1/2 acres--a few hundred feet across. Pairs of birds mate for life and are never far apart (Terres, 1980. The Audubon Encyclopedia of North American Birds). Both sexes sing throughout the year--a very loud and unique bouncing ball whistled trill. On the rare occasions when birds have been found pioneering new areas they are rather easily and repeatably detected.

The range of Wrentit in Oregon hasn't changed all that much in 200 years. Historically, they were found along the immediate coastline in salal bushes under the scrubby shore (lodgepole) pine, from California to the Columbia River. They have never crossed the Columbia into the state of Washington, even though regular on the Oregon side of the mouth of the river. In winter they sometimes can be found a few miles inland into clearcuts. They also occur in the SW area of the state near Medford in low-elevation chaparral of the Rogue Valley, and in low numbers into the Klamath Basin.

Recently (the past 50 years or so), their inland population has inched northward through the Umpqua Valley to the eastern edges of the southern Willamette Valley in Lane County. A population has also crawled northward on the western edge of the Willamette Valley, from Finely NWR near Corvallis in the 1970's to Grand Ronde of Yamhill County.

There are three known isolated outposts north and east of this range. Birds were detected in the late 1990's near Lebanon. Birds this century colonized the Sandy River delta near Gresham. Birds recently arrived at Minto Browns Island Park in Salem. Especially is this last location hard to fathom. Birds either hopped across miles of city streets or somehow crossed the Willamette River. This from a species that refuses to come out of cover and is loathe to cross a single lane dirt road!

Of course, birds had to get to these new outposts by crossing miles of unsuitable and even dangerous (for a Wrentit) habitat. Thus it is possible that some of this year's out-of-range reports may be correct. I take comfort in my present skepticism, knowing that if birds really are present at these new locations they won't stay undetected for long.