Lewis's Woodpecker - Melanerpes lewis

At Lake Solano Park, near the end of Pleasants Valley Road, 10-15 Lewis's Woodpeckers were busy sallying out from the tops of the trees to catch flying insects. Others carrying acorns, some so large the bird would lose it in flight.

Birds at the tops of trees are a challenge for the photographer, and the Lewis's rarely stayed for any length of time before launching for another insect:

The above photo shows the adult Lewis's WP, with red face, gray chest and collar, rose belly and green back. Note the bill, shape, which is rather broad at the gape to facilitate capture of flying prey. The bill is less sturdy than that of many woodpeckers, so Lewis's has to find a dead tree to excavate a nest hole, often choosing a burned Ponderosa Pine forest in the foothills, or further north.

Turns out that Lewis's Woodpeckers cache food much like their Acorn Woodpecker cousins, using a tree as a granary to sustain them when other food sources are diminished during the winter. Rather than using carefully constructed holes to hold each morsel, the Lewis's will break the acorns and stash the mast in nooks and crannies of tree bark, or in a cavity. The cache is aggressively defended, as there is a lot of poaching by Acorns Woodpeckers, and vice versa.

We saw a number of Lewis's there that were darker and more monochromatic, indicating a juvenile bird, and some like in the second photo that were just replacing their juvenal plumage with adult type feathers, with red in the face, green sheen on the back and rose underparts. No problem confusing this species with any other woodpecker, for sure.

Lewis's Woodpecker is an bird of western U.S., with a breeding range that includes southern Canada and a wintering range that includes Baja California. Their numbers have declined, and they are rarely seen in large numbers at any location. Some of them don't migrate at all, or form small flocks to search for productive foraging areas. Such nomadic behavior makes finding them unpredictable, kind of like looking for a roving flock of Pinyon Jays. In some years Lake Solano park becomes a destination for the winter, as there is a good supply of acorns, flying insects, and one of their favorite berries, that of the Oak Mistletoe. Which brings us to another great reason to visit Lake Solano Park, as the mistletoe attracts a small population of Phainopepla each year. Other goodies there includes a good selection of river ducks and dabblers, along with Wood Ducks. Best go on a weekday if possible, as it is a popular area for picnics, fishing, etc.

Here's an older shot of an adult Lewis's Woodpecker, from a trip to the Central Valley:

Merlin - Falco columbarius

On today's "First Thursday" walk at Las Gallinas (San Rafael, CA) we ventured out to find the Tropical Kingbird, which has been flycatching from the snags at the end of the open field, just before the path swings left to go north. No Kingbird today, as the same snag was adopted by a Merlin,Falco columbarius. If I were that Kingbird I wouldn't be returning any time soon, as the Merlin is a fearsome predator of birds.

Note the streaks on the chest, and the very weak mustachial stripe.

The shot above shows the white superciliary line better.

Merlins are fast powerful predators. At about 12" they are a bit larger than the American Kestrel, but as we read in Hawks in Flight (Dunne, Sibley, Sutton): "A Merlin is to a Kestrel as a Harley Davidson  motorcycle is to a scooter."

Western Scrub Jay - Aphelacoma californica

A recent Marin Audubon outing at Bodega Bay with Peter Colasanti produced a good variety of birds, including Western Scrub-Jays along the west side. At Owl Canyon a cluster of sparrows were feeding actively at the base of a tree near the road and this Western Scrub Jay came in to check out what had attracted them. Scrub-Jays eat a variety of foods, including acorns and pine nuts, and just about anything else. It puts some people off because the "anything else" can include eggs and nestlings of smaller songbirds. Nevertheless, everyone's gotta make a living, so we might as well admire the Scrub-Jay for its adaptability and cleverness, not to mention its rather striking blue plumage. The black bandit's mask is perhaps a fitting field mark. The bill is more robust than the interior race.

Check out the long tail, and the aggressive "attitude".

Another shot after it hopped up to the tree nearby:

Western Scrub Jays were once part of a larger complex complex, which was split to elevate the Island Scrub Jay (Santa Cruz Is.) and the Florida Scrub-Jay to full species status. Currently under consideration are further splits within the genus Aphelocoma, with the Western Scrub Jay split into 3 separate species. The shy interior (inland) race, A. c. woodhouseii, would become Woodhouse's Jay, and a race in southern Mexico, A. c. sumicrasti, would be known as Sumichrast's Jay.

For dedicated taxonomy fans, check out:

Genus Aphelocoma

Western Scrub Jay complex

Hybrid Dabbling Ducks

During the past week a lot of ducks have been passing through the bay area. At fresh water sites the dabblers have been well represented, although many seem to just stop for a while to refuel before heading further south or to the central valley. Today at the Las Gallinas water treatment ponds (San Rafael, CA) we spotted an unusual Cinnamon Teal along the shore, partly obscured by the cattails.

The shot above shows the typical blue wing patch of the Cinnamon Teal, as well as the dark spatulate bill and orange feet, but the gray-blue ptch above and behind the eye, as well as the  black spots on the breast and flanks seemed to indicate the presence of other dabbling duck DNA. One possible explanation would be a hybrid bird, Cinnamon Teal x Blue-winged Teal, which are said to be common, and I have seen a few internet photos of such a hybrid that resemble this bird.

Above we get a different view of the gray patch on the head, partially outlined by a white white line as we sometimes see on Green-winged Teal, especially on the Eurasian Green-winged. The color of the iris seemed to be a deep brownish red.

Shot above better highlights the similarity of the head strip on the hybrid Cinnamon drake, with that of the male Green-wined Teal sleeping nearby. Similar shot below, with a probable female Cinnamon Teal on the left. I'm favoring Cinnamon Teal x Green-wined Teal as the ID for this bird, but of course that is speculative.

Last week at Corte Madera's "Shorebird Marsh" I spotted a hybrid Northern Pintail, with a pretty buffy patch on his cheek. Distance precluded a sharp shot, but the green iridescence on the side of the head suggested some Green-winged Teal DNA at work. The scapulars and tertials strongly suggested Pintail, as did the bill.

Here's another shot, showing the buffy cheek and bill somewhat better:

And lastly:

Eclipse Dabbling Ducks

In September and October each year we see a confusing array of atypical-looking ducks as they molt from eclipse (basic) plumage into the more familiar breeding plumage of winter and spring. I've found that as with passerines it helps a lot to focus first on the bill and face of the bird before checking out the rest of the bird. These photos, from Las Galinas ponds in San Rafael, are not as sharp as I would have liked, but since I learned something from each one I figured they are worth sharing.

The eclipse Cinnamon Teal drake looks a lot like the female, but the red eye gives him away. Note the Shoveler-like bill and "plain" face, i.e. no dark line through the eye.

The Eurasian Widgeon was puzzler, as its color was almost like a Cinnamon Teal, but the bill clearly said "wigeon", and it was much too red to be an American Wigeon. The female Eurasian Wigeon can often be warm in color, but never quite so warm as this drake. There is no real black border where the bill meets the face, as seen on American Wigeon. Same bird viewed 10 days later began to show some buffy color on the forecrown, and a hint of gray on the shoulder.

At times there have been up to 3,000 Northern Pintails at the ponds, but numbers down to perhaps 600. Very instructive to seem the males in every stage of molt from eclipse to breeding. The male here has the plain brown face we see in the female Pintail, but his beautifully trimmed steel blue bill gives him away. We can also see the beginning of fine vermiculations on the side of the body.

Here's another Pintail that is a bit further along in the pre-alternate molt:

The eclipse Gadwall looks a lot like the breeding male, save for the lack of vermiculation on the body. Here he's showing the cinnamon wing patch, formed by secondary coverts on the top of the wing, best seen in flight. Female and juvenile Gadwalls have some orange on the bill.

Lastly, here's a male Northern Shoveler from early September. I suppose it could be a juvenile, but the bright yellow eye is more consistent with an adult eclipse male.

Anna's Hummingbird - Subadult male - Calypte anna

Ducks have been returning to the San Francisco Bay Area for about a month, many of them in the confusing molt between eclipse plumage and the alternate or "bright" plumage of winter and spring. Of course all birds molt, but I don't remember seeing this take place in such vivid detail as on this subadult male Anna's Hummingbird seen this morning along Strawberry Point during a waterbird survey for the Richardson Bay Audubon Center.

These 3 shots were taken in succession. It was amazing to see the array of colors shown by this individual, with a palette that changed with very small changes in his posture. 

Iridescent colors in birds colors produced by the structure of the feather, akin to how colors produced by a thin film of oil on water (interference pattern). Blue colors in birds are also created by feather structure, but by a process that involves the selective scattering of reflected light, based on short wave length.

Those interested in the physical base for these phenomena may want to check these sources:

Why Are Hummingbirds Iridescent? (from Johnsgard book on N.A. Hummingbirds)

The Color of Birds (Stanford)

Structural Color in bird feathers (Wiki, somewhat technical)

Eared Grebe - Podiceps nigricollis

Right now (October 7, 2014) Eared Grebes are present in pretty good numbers, so I couldn't resist taking some shots of this one as it navigated around the Canada Geese and dabbling ducks at Las Gallinas ponds. When I got home I realized that the shots were interesting shots, as the 2 photos, taken 6 seconds apart, show how the features of a bird change with posture and activity.

First shot is a typical Eared Grebe posture, with a steeply sloped forehead, a peak of the crown above the eye, and the high-riding stern. 

Soon thereafter it began to swim faster, anticipating a dive, and the feathers became more streamlined. The forehead slope is now more shallow, like a Horned Grebe's, the peak of the crown a bit behind the eye, and the butt end is sleeker and low-riding.

I think this is young bird, molting into its "first basic" plumage. Note the amber/orange iris, as opposed to the redder iris characteristic of the adult Eared Grebe. The typical "first fall" birds are browner, but I imagine there is a fair amount of variation.