Monday, August 30, 2010

Black-headed Grosbeak

Black-headed GrosbeakBlack-headed Grosbeak, Forest Grove, Oregon on 15 May 2009 by Greg Gillson.

 

Black-headed Grosbeaks are common migrants and summer residents throughout the Pacific NW. They arrive in May and are quite common in towns at bird feeders and in riparian areas and deciduous and mixed woods through September.

The male, pictured above, is rusty-orange on the breast and rump, yellow on the body, black on the back. It has a black head and black wings and tail with large white patches and spots. Males sing a clear, rapid, robin-like warble. Both sexes give a sharp pik call.

Females and young during the first year are duller overall (brownish and pale orange) with striped head ("chipmunk bird").

These songbirds take 2 years to reach full adult plumage. The immature male plumages have a more striped head and back than adults.

Wednesday, August 25, 2010

Do the Shuffle!

Pied-billed GrebeJuvenile Pied-billed Grebes, Fernhill Wetlands, Forest Grove, Oregon on 19 August 2010 by Greg Gillson.

 

Last month I photographed the sinking dives of a Pied-billed Grebe at Fernhill Wetlands, in Forest Grove, Oregon. This week I photographed two birds there, one of which is probably the same individual.

These two birds have been hanging around the ponds there. From a distance I noted that they were regularly holding out their wings. So I walked closer to investigate, obtaining the photo above.

I observed that the grebe (the bird farthest back) holds its wings out about 3 seconds, fluffs its back feathers and shakes its back and tail, as in the next photo below, taken 6 seconds after the top photo. [Click photo for larger view.]



This behavior is called "feather settling." It is one of a number of maintenance behaviors that presumably gives the bird comfort. Other comfort movements are yawning, stretching, and resting. Many behaviors in birds are innate--they are instinctively performed following a constant pattern. Feather settling is often performed by raising the feathers, shaking the body, flapping the wings, and finally depressing the feathers down into proper position.

This reshuffling of the feathers was performed several times alternately by both birds. In the photo below the other bird takes its turn (6 more seconds after the second photo above). [Click photo for larger view.]



I realized that I had seen this before, without really thinking about it. Rich Ditch recently photographed a Pied-billed Grebe with its wings out. Now I know what it was doing!

This also explains the bizarre "fuzzy gull" I photographed last week at the coast. The adult California Gull fluffed itself all up as you can see in the photo below. [Click photo for larger view.]



Then it shook itself and flapped its wings. [Click photo for larger view.]



This gull was very worn. The feathers of the tail has lost most of the vanes and the tips are just bare feather shafts. This bird needs to start its fall molt and replace its old feathers very soon!

Perhaps this gull is getting new feathers and they itch? That would explain a reason for feather settling, too. As a matter of fact, the juvenile Pied-billed Grebes are also going through body molt. Itchiness might explain the repeated feather settling they are doing.

Monday, August 23, 2010

In the backyard... Rufous Hummingbird

Rufous HummingbirdRufous Hummingbird, Forest Grove, Oregon on 21 April 2010 by Greg Gillson.

 

The Rufous Hummingbird is common throughout the Pacific NW. Males first arrive along the southern Oregon coast in early February and reach Portland and the northern Oregon coast about the first of March. From then on through April reports increase northward, east of the Cascades, and into the mountains. Males arrive about two weeks earlier than females and set up a feeding territory that they defend vigorously against all other hummingbirds.

When the females arrive, they mate and then set up a separate nesting territory. Females take care of all nesting, incubation, and feeding duties.

Interestingly, Rufous Hummingbirds breed as far south as SW Oregon, but apparently not (or rarely) into northern California. Brookings, on the southern Oregon coast, seems to be the dividing line between breeding Rufous Hummingbirds to the north and Allen's Hummingbirds to the south.

Male Rufous Hummingbirds are cinnamon-colored with bright reddish-orange throats (see photo above). Some males also have green backs--thus appearing as Allen's Hummingbirds. Female Rufous Hummingbirds have green backs and lack the colorful throat, and are nearly identical to female Allen's Hummingbirds. In both cases, narrower tail feathers in the Allen's can separate them in-hand or with close-up photos at just the right angle.

Rufous Hummingbirds are most common in moist Coast Range forests and the west slope of the Cascades. They are found in other moist forests , riparian areas, and in towns throughout the Pacific NW. They feed on flower nectar and insects.

After mating, males generally depart into the mountains and start heading south to Mexico for the "winter." It is unusual to see adult male Rufous Hummingbirds in the breeding areas much beyond the first half of July. Females start migrating south in August and it is mostly immatures that are present in the Pacific NW from mid summer to the first week of October.

For instructions on making hummingbird nectar to attract them to your yard, and debunk some myths, see: Bird feeding... Hummingbirds that appeared here back in April 2009.

West of the Cascades, and in some towns just east of the Cascade crest, from Vancouver, British Columbia, southward, the Anna's Hummingbirds are found year-round.

Friday, August 20, 2010

Birdfest & Bluegrass Festival: October 9-10

RIDGEFIELD NATIONAL WILDLIFE REFUGE
HOLDS 11th ANNUAL BIRDFEST & BLUEGRASS FESTIVAL
Thousands of birders gather to celebrate the fall migration

WHAT:
Birders from around the country will be gathering at the Ridgefield National Wildlife Refuge for the annual BirdFest & Bluegrass Festival. Now in its eleventh year, the Festival celebrates the natural beauty and rich culture of the Refuge as well as the beginning of the fall migration and the return of the Sandhill cranes. The Refuge provides habitat to more than 200 species of birds and is an amazing showcase of birds in the Pacific Flyway. The mild winter climate and wetlands along the Columbia River create ideal resting and feeding areas for Canada Geese, Sandhill Cranes, Great Blue Herons, swans, shore and song birds, and a variety of waterfowl.

The two-day event offers activities for both avid and novice bird watchers. Scheduled organized activities include:

· Sandhill crane tours
· Raptor shows
· Audubon-guided family bird walks and bus tours
· Kayak and canoe tours
· Guided photography walks

In addition to the birding activities, there will be:
· Bluegrass bands providing entertainment
· A Birders’ Marketplace with great local food and bird related crafts and art
· Guided tours of the historic Cathlapotle village archaeological site

The annual festival is hosted by the Friends of Ridgefield National Wildlife Refuge, a nonprofit organization dedicated to supporting the Refuge through the sponsorship of programs that connect people with nature and restore important wildlife habitat.

WHERE:
Ridgefield National Wildlife Refuge is located approximately 20 miles north of Vancouver, Wash. Visitors should take the Ridgefield exit off Interstate 5 and drive three miles west to Ridgefield, where there are signs directing you to the Refuge.

WHEN:
Saturday, October 9 and Sunday, October 10, 2010.

For more information and a schedule of activities, visit www.ridgefieldfriends.org

Sunday, August 15, 2010

Cliff Swallow

Cliff SwallowCliff Swallow, Malheur NWR, Oregon on 29 May 2010 by Greg Gillson.

 

Cliff Swallows are rather common throughout the Pacific Northwest, especially near water east of the Cascades. In agreement with their name they do nest in colonies on cliffs, bridges, highway overpasses, under the eaves of barns, and in smaller numbers on porches and out buildings, especially in rural settings. They are not usually found in forest habitats or urban areas.

They need water nearby, as they build their nests of mud. Those nests are gourd-shaped structures--a mud ball usually with a protruding side entrance. The bird in the photo above is collecting one bill-full of mud at a time to build its nest on a cliff near the Buena Vista Station at Malheur National Wildlife Refuge in SE Oregon.

Field marks for this swallow include the compact shape with short square tail, creamy-tan rump, dark rusty throat, and pale forehead. It is the only swallow in the Pacific NW with a buffy rump. The call is rather grating.

As with all swallows, they primarily feed on insects on the wing. They often feed over water. Their bills are short, but very wide.

Cliff Swallows winter in South America. They first arrive in the Pacific Northwest by the first of April. Fall migratory flocks form in July and most birds are gone by the end of September, though some stragglers may remain, rarely to November.

Thursday, August 12, 2010

Nature Journal: Sunbathing Cliff Swallows

Cliff Swallows sunbathing on a roof, Jackson Bottom Wetlands Preserve, Hillsboro, Oregon on 7 July 2010 by Greg Gillson.

 

We had a rather cool and wet spring. Thus, when it finally warmed up just after Independence Day [Editor's note to visitors: it always rains on all holidays in western Oregon.], I went out on the trails at Jackson Bottom one hot morning and found these Cliff Swallows sprawled out and panting on the roof of this wildlife viewing stand.

Why?

I got out my trusty reference guide, The Audubon Encyclopedia of North American Birds (1980) by John Terres.

It turns out all sorts of birds sunbathe, fluffing up their feathers and panting. Some take it to the extreme by flopping their wings forward wildly, gasping for air, while lying prostrate.

That seemed to be the case for the birds observed here, many of which were in a dusky juvenal plumage.

Why do they do it?

Terres' sources indicate that sunbathing benefits birds in several possible ways. Heat is absorbed (they were just cold and wanted to warm up); Vitamin D is produced; skin and feather parasites may move off the back and to a place where the birds can remove them. Some birds apparently sunbathe during the time of molt--perhaps it stops the skin from itching?

Monday, August 9, 2010

Not just any trash bird: Brewer's Blackbird in molt

Chipping SparrowJuvenile male Brewer's Blackbird, Fernhill Wetlands, Forest Grove, Oregon on 28 July 2010 by Greg Gillson.

 

I think that I am like a majority birders in that my understanding of molt was never really very strong. I could, though, recognize the four annual plumages of the larger gulls leading from chick to adult. And I recognized breeding and non-breeding plumages of many birds that changed dramatically from summer and winter. And I recognized that juvenile shorebirds have plumages unlike the adults.

But until recently, and perhaps now still, I don't have as good a handle on plumages and molts as I could have, or that I would like.

David Irons, on the BirdFellow blog recently posted a 3-part article on an introduction to molt limits. David didn't specifically define the term "molt limits," but it is simply the contrast between different ages ("generations") of feathers on the bird, especially wing and tail. Perhaps this is most obvious on blackbirds, as the above photo demonstrates.

If we know the state of molt we can know the age of the bird--at least for the first two years for most species. Knowing the age of the bird helps in the identification of shorebirds, gulls, fall Empidonax flycatchers, and some others. It also tells us about things such as survivorship of first year birds, where birds go after breeding, whether adults or first year birds wander more widely, winter in different areas, etc.

In a personal extreme example, an immature albatross was discovered off Oregon in September 2008. It was in the Wandering Albatross group, only seen in North America once before. The taxonomy of albatrosses is in flux. While right now the North American scientists in the A.O.U. (American Ornithologists' Union) treat several populations as one species--Wandering Albatross--such is not the case in other countries. In the future, the A.O.U. may well split this complex into 3-5 species. Only by looking at the exact sequence of old and new feather generations in the wings were we able to determine that the bird was likely 5 years old and pin down the breeding island (Antipodes). In the future, I may have Antipodean Albatross on my list, rather than Wandering Albatross or "unknown Wandering-type Albatross," a highly undersireable thing for any birder, I can tell you.

Even without knowing too much about molt, most birders would be able to tell you that this Brewer's Blackbird (above) is a young bird (hatched perhaps only a month or two ago). It is obviously molting into adult plumage. And, with that black plumage and tell-tale pale eye, it is a male.

In this case, we can look at the molt and tell more. Using the Humphrey and Parkes terminology (and, please, if I have this wrong someone please tell me!) The fluffy brown feathers are the juvenal plumage--the very first feathers birds get after their downy chick state.

The next plumage after juvenal is the first basic plumage. It is acquired by the prebasic molt. And that is the state of the Brewer's Blackbird above. The first prebasic molt is not a complete molt. Some juvenal wing and tail feathers will not be replaced. Thereafter, every subsequent prebasic molt will be complete.

In this bird that doesn't have a more colorful alternate (or breeding) plumage, it molts once per year, in the late summer/early fall. It molts from basic plumage to basic plumage in an endless cycle.

Other birds (for instance, Yellow-rumped Warbler) have two molts per year and switch between the brighter alternate plumage (breeding) and duller basic plumage (non-breeding). Alternate plumage is often only a partial molt--just the body feathers, not wing and tail.

OK, this has gone longer than I intended. The blackbird above has new black, shiny feathers on the greater secondary coverts, old juvenal feathers on (most of) the median secondary coverts, and new feathers on the lesser and marginal coverts on the shoulder. Some body feathers near the sides are new. There is one new tertial feather and 3 black primary feathers mixed in with the "old" brown juvenal feathers. If I blow up the photo I can see at least 3 black greater primary coverts. This molt is not yet over and will undoubtedly include more feathers in the coming weeks.

For more information online see the Ontario Field Ornithologists' web site and print out and study Ron Pittaway's April 2000 article: Plumage and molt terminology. This article discusses older and newer plumage terms, calendar year terminology, molts, banding codes, Humphrey and Parkes terminology, and the two main molt and plumage sequences.

[The title of this article alludes to "trash birds," a facetious term applied to any bird considered common or uninteresting, especially to those birders seeking new species to add to their list. Obviously, for the purpose of learning molt and plumages, this bird is not a trash bird.]

Friday, August 6, 2010

Dragonflies

SkimmerEight-spotted Skimmer, Fernhill Wetlands, Forest Grove, Oregon on 5 August 2010 by Greg Gillson.

 

Yesterday the birding was rather slow, but I noticed several dragonflies. I should have a macro lens for close-ups, but since I don't, I stood with my 100-400 mm telephoto lens back about 7 feet from the insects.

Everything I know about dragonflies I learned 30 minutes ago from local fellow birder and blogger Stefan Schlick in a recent post to his Birdmeister blog.

The odonates of Emma Jones Natural Preserve in Hillsboro, OR (08/04/10, part1)

The odonates of Emma Jones Natural Preserve in Hillsboro, OR (08/04/10, part2)

I knew, or thought I knew, that the fat-bodied ones were dragonflies, and the thin-bodied ones were damselflies. Beyond that I knew nothing about these "bugs," except that some birders also liked identifying these and butterflies, as well as birds.

Photographing them yesterday I didn't know if the different-colored flies were males and females (seems they probably were) or whether I needed more than the abdomen color and wing pattern (probably do).

So, even though Stefan calls himself "quite a rookie" I used his photos and ID's of local dragonflies as the basis for my identifications.

So, here goes. The beautiful creature pictured above is likely Eight-spotted Skimmer.

Next are the two damselflies, probably a blue male and green female (or do I have this backwards?). Stefan's photo of a mating pair has me confused about dragonfly anatomy... (hey, no rude comments there!). Tule Bluet? Is that some kind of inside bug joke?





OK, on to the big blue and green dragonflies. Again, the blue is male and female green? These, I guess, are Western Pondhawks?





I found a nice website of dragonfly photos at Greg Lasely's Dragonflies and Damselflies.

Monday, August 2, 2010

Nature Journal: Separating Cedar Waxwings from European Starlings in flight

European StarlingEuropean Starling, Charleston, Oregon on 30 August 2008 by Greg Gillson.

 

Cedar Waxwings and European Starlings are one of the common summer birds from the mid-latitudes of Canada to the mid-latitudes of the US. In summer both species frequently fly around in smaller flocks, often flycatching on the wing.

In size, shape, flight style, and flocking behavior these two species are very similar. If one does not note the yellow band at the end of the tail, the pale undertail coverts, or the crest on the waxwing, there is not much to separate them. They are very similar in flight as a silhouette against the bright sky. Under the entry for Cedar Waxwing, Sibley simply says, "Compare European Starling in flight."

Yet even though they are so similar, somehow for years I've been able to accurately determine whether the chubby pointed-winged bird flying by was a waxwing or starling in about 3 seconds. How did I do it? I wasn't sure.

The human mind has a great ability to evaluate and recognize patterns. Thus, you can identify a relative when she is quite distant and you can't see any details of her face. Unfortunately, our pattern recognition ability works so well that we don't usually know how we're doing it! We're obviously using something, some field mark (or set of field marks) even if we don't know exactly how we know what we know.

So I've been spending time lately, really observing waxwings and starlings in flight, taking notes in the field. In a minute I'll tell you how to tell them apart in flight. But first I will describe the "flight style field marks," those non-plumage characters that identify silhouetted birds in flight.


Field sketch showing silhouette and wing shape of European Starling and Cedar Waxwing. July 5, 2010. Greg Gillson. Click for larger view.



Flight silhouette - We're looking for the overall structure and proportions and how the bird holds its head, neck, body, wings, and tail. For instance, though cranes and herons are superficially similar in their long neck and pointed beaks, they hold their necks much differently.

Wing shape - Differences in wing bones, feather tracts, and feather length account for the differences in wing shape. Birders would do well to study an ornithology manual to better appreciate wing shape. As an example, albatrosses and swifts both have pointed wings, but the albatross may have 25-40 secondary feathers and the swift only 6-7, while both have exactly 10 primaries.

Flapping - How many beats per second? What is the angle the wings travel above and below the plane of the body? Is there a pattern of flaps and pauses? How stiff are the wings?

Flight path - Is the flight progression undulating, swooping, erratic, or straight? What is the general height above ground and speed?

Flocking flight characteristics - Geese may fly in 'V' formation. Other birds fly in flocks that are disorganized and constantly changing. Many birds don't fly in flocks at all.

Flight type (or purpose) - Birds fly differently depending upon what they are doing (or even how fast the wind is blowing). If they are fleeing, then they will flap more deeply and quickly than if in standard commuting flight. Other birds soar and glide, or even hover.


Notes and field sketch of Cedar Waxwing flight path. July 7, 2010. Greg Gillson. Click for larger view.



So how do starlings and waxwings differ in flight?

Both species have pointed wings. The arm (inner portion of the wing between body and wrist) of the waxwing is relatively longer than the starling. The wrist is held straighter on the waxwing, creating a straighter leading edge than on the starling (see my top sketch).

The actual measurements of the ratio of tail length to body length is nearly identical between the two species. However, the waxwing tail appears slightly relatively longer than the starling. This may be caused by a thinner wing, wing set farther forward, or optical illusion caused by pale vent on the waxwing.

In flight characters, both species flap several times and fold their wings. The starling flies relatively straight and level. The final flap or two of the waxwing, before the folded pause, propels the bird upward slightly, so that the flight is slightly undulating.

The starling head (crown) appears quite flat. The waxwing has a rounder head, accentuated by the much shorter bill. The head of the waxwing is often raised slightly above the plane of the neck.

The identification of birds in flight is not well-covered in the field guides. But it is worth the effort to observe and learn. After all, one of the unique features of birds is that they have wings, and most can fly. It only makes sense to be able to identify them when they are flying.