Eared Grebe - Podiceps nigricollis

Lots of Eared Grebes right now at the Las Gallinas ponds right now, most of them busy feeding on insects at the water's surface, almost like phalaropes. This shot shows an eye that is more orange than red, perhaps indicating a sub-adult. 

Next shot is a crop to show eye and bill better. Juvenile Eared Grebes have a tan or brown-orange iris, and adults a brighter red. The BNA account (#433) has one photo of similar bird, with a similar eye.The grebe here is not in full basic plumage, as the neck still looks pretty dark, but the dingy neck appearance helps separate it from the similar Eared Grebe, which has a whiter neck in winter. Right now most of the birds are in transition, so it can be confusing. But note the steep forehead with the peak above the eye, definitely "eared". The bill looks more Eared than Horned, but it's not as flat on top as on the average Eared Grebe.

This shot of a juvenile Eared Grebe, taken a few years ago at Bodega Bay, shows the lighter iris and a wash of brown on the grays of the head and back.

Eared Grebes are said to be the most numerous of all grebe species in the world, with a North America population of something like 4 million. They love saline lakes, and stage in huge numbers at the Great Salt Lake and Mono Lake (September to Dec). When gorging on brine shrimp and brine flies at staging areas they are flightless (see below).

I found the account in Birds of North America Online, #433, by Cullen et. al. to be of particular interest in regard to the longs periods of flightlessness in this species, and the dramatic fluctuations in the birds weight and organ sizes, to whit:

"While at fall molting/staging lakes, adults more than double their arrival mass and allow the pectoral muscles to atrophy below a size that allows flight. Then, during a hyperphagic period, they greatly increase the size of the organs involved in digestion and food storage. These changes in size and proportions—the most extreme yet known for any bird—are then reversed during a brief predeparture period, when the birds catabolize much of their just-deposited fat, increase heart size, and reduce digestive organ mass to perhaps 25% of peak in preparation for a nonstop flight to wintering areas. The function of the predeparture events is to reduce wing-loading while maximizing flight range and performance. Migration occurs shortly after food supplies run out, typically in December–January. As a result, the Eared Grebe is the latest of the North American migrants to move to its winter stations. Because a similar atrophy/hypertrophy cycle is repeated 3–6 times each year, the Eared Grebe has the longest flightless period of any volant bird in the world, perhaps totaling 9–10 months over the course of a year. At fall staging areas alone, flightless periods average 3–4 months for adults and may reach 8 months or more in nonbreeders."     (volant = "flying", or capable of flying or gliding)

For an excellent article on sorting out confusing fall Podiceps grebes see:  

Kaufman, K. 1992. The practiced eye: Identifying monochrome Eared Grebes. Am. Birds 46:1187-1190.

Sora - Porzana carolina

Birders who visit fresh water marshes will often hear the strange descending whinny call of the Sora, a small secretive rail that is usually tough to spot. An adult and a juvenile Sora were reported recently at Ellis Creek, Petaluma, at a location where they could be easily found and observed. The adult gave a loud whistled call as it foraged on the west side of pond "D".

Check out those large toes!

First shot shows the large toes typical of many marsh denizens. The yellow bill, is distinctive for the adult Sora. In this case the yellow bill is a bit dusky, which along with the minimal black in the face near the bill suggests it may be a female.

 Second shot gives a better look at the bill, as well as the pretty brown eye. Note the cocked-up tail, a frequent posture. You can just about see the white undertail coverts

Third shot shows it in the grass along the bank of the pond, where is foraged actively for seeds the entire time we watched. Often it was too close for me to frame a shot! By far our best ever look at this shy species.

The Sora is said to be our mostly common and widely distributed member of the rail family (around here I would bet on the Coot to win that distinction). They breed all across Canada in fresh water marshes that have cattails and other emergent vegetation. Most are migratory, despite their not being strong fliers. The genus Porzana has 14 species world-wide, with the other 13 sharing the common name "Crake".

Cardinal Meadowhawk

As the fall birding season heats up the days are cooler and the dragonflies have mostly mated and laid eggs, while some are migrating south. Last week I watched a male Cardinal Meadowhawk at the pond in Tiburon, and got 2 shots of the same individual in a similar pose, but on 2 slightly different perches. 

I think I like a bit of color in the background. Note how these shots illustrate one of the limitations of digiscoping, which is the very narrow depth of field. Here The head, feet and abdomen are in reasonably sharp focus but the wings are clearly blurred. Here's the same ode on a nearby perch, which allowed a different background:

The bright red color helps with the ID, but the key feature is the 2 white spots on the side of the thorax. The wings have amber along the leading edges, the eyes are red, and the face is….well you'll just have to see it:

Note how the front legs are kept ready to hold or manipulate prey, and are not needed when perching.

Mute Swan - Cygnus olor

An adult Mute Swan, Cygnus olor, and a large "dirty gray" juvenile have been lingering in the first pond at Las Gallinas ponds, San Rafael, for a week or so. Mutes Swans are big birds indeed, a large male can rival the native Trumpeter Swan in size. Length of up to 63", wingspan to 94" and a weight of 25 pounds! This makes the Mute Swan one the largest birds capable of flight, up there is the American White Pelican.

Juvenile Mute Swan, Las Gallinas water treatment ponds

Mute Swan adult in a common swimming "display" - Ellis Creek, Petaluma 

The Mute Swan is a Eurasian Species, with 2/3's of the estimated population of 500,000 found in Russia (or what used to be the USSR). They are protected in some countries, eaten in others, and considered pests by some in many areas where they have been introduced, including northeast US and now California. Lots of people think their beauty outweighs the possible negatvie impacts. Good numbers of Mute Swans of can be seen in Sonoma (Shollenberger, Ellis Creek and Chileno Valley). Fortunately their numbers seem to have stabilized, wheras back east they increase by up to 10% per year. They are aggressive to other birds near their nesting sites, and to humans who get too close. The chicks, or cygnets, are gray, and remain gray through September, just now starting to get white plumage, as in the first photo. White gygnets are known to occur (photo, May 2013, Ellis Creek), presumably from a leucistic gene, and will become white juveniles.

The fully grown juvenile has a gray bill which lacks the knob seen on the adult. The bill here  (below) is starting to show some pink color, and will become orange by winter. Other swans native to our ABA area (Tundra and Trumpeter) have some yellow on the bill.

Taxonmy: 

Order: Anseriformes - Ducks, Geese, Swans, and Screamers

Family: Anatidae - Ducks, Geese Swans

Subfamily: Anseriinae - Swans and Geese

Tribe: Cygnini - Swans - Only 7 species in the world, in 3 genera. Our Tundra Swan (aka Whistling Swan) and Trumpeter Swan, along with the Whooper Swan, are in the genus Olor.The 3rd genus of swans is Coscoroba, with a single species, the Coscoroba Swan of southern South America.

Genus: Cygnus - 3 species, including the Black Swan of Australia/New Zealand, Black-necked Swan of southern South America and the Falkland Islands, and the Mute Swan.

Species: Cygnus olor - Mute Swan. From the above you will note that it is closer to the Black Swan than it is to the Tundra Swan.

Sources: Waterfowl, Madge and Burn, 1988, and Wiki-pedia.

Variegated Meadowhawk - Sympetrum corruptum

After I sent the recent photos of the Common Green Darner, May Chen reminded me that I could have mentioned that this is one of the few dragonfly species that migrates. Another migratory species that we see locally is the Variegated Meadowhawk, Sympetrum corruptum. We saw this one at Ellis Creek the same day we watched the Green Darner.

The Variegated Meadowhawk is very common, and although the colors can vary (duh…), several features make it easy to identify. On the sides of the thorax you can usually see 2 diagonal white stripes, each ending in a bright yellow dot. On the wings you may be able to see that the small stigma on each wing near the end is bicolored, darker in the center and lighter at the ends.  Red veins near the leading edge can be seen in some photos. On the abdomen there is row of white spots, or "portholes" (Manolis), and two dark spots on the top of the 2 segments near the end (8-9). Red/coral rings on the abdominal segments add color and interest, and he has a pretty face as well!

Another view:

May Chen sent this great link to a remarkable TED talk of how a scientist discovered the migration patterns of the Wandering Glider in Asia (from India to Africa!) - it is well worth your time, providing a great example of how a scientist gradually put observations together to paint a full picture:

Charles Anderson: Dragonflies that fly across oceans | Video on TED.com

The Xerces Society has initiated a project for gathering data on 5 species of migratory dragonflies, including the Common Green Darner and the Variegated Meadowhawk. If you'd like to learn about how you can help gather data for the project:

http://www.xerces.org/dragonfly-migration/migration-monitoring/

Brief Taxonomy-

Family Libellulidae is huge, with over 1,000 species wordwide. These are the Skimmers and allies.

Genus Sympetrum is big too, with over 50 species.

Species Sympetrum corruptum, the Variegated Meadowhawk. Seen widely across much of Canada and the US and south into Central America.