Sunday, December 16, 2007

Field Notes: Scarlet Tanager

Scarlet Tanager (Piranga olivacea)
Allan Hancock College campus, Santa Maria, California
December 15, 2007

First-year female Scarlet Tanager in Santa Maria, CA on December 15, 2007

While attempting to locate a reported Eastern Phoebe (Sayornis phoebe) at Allan Hancock College campus in Santa Maria, I discovered this first-year SCARLET TANAGER flycatching from low pines around an open lawn area near the college administration buildings.


Account:
At approximately 9:15 a.m. while looking and listening for phoebes, I spotted a large passerine lazily fly down from the lower branches of a pine into a thick hedge of junipers near the southeast corner of the college administration buildings. My initial reaction upon viewing through binoculars was that I have found a late Western Tanager (Piranga ludoviciana) since the bird was facing me and I could not see the upperparts. When the bird returned to perch in a pine then I could clearly identify it to species. I watched it for approximately 50 minutes. The following account is from memory and review of photos.

Description:

This was a fairly large passerine, clearly larger than a wood-warbler and approximately the size of a Western Tanager, but smaller than American Robin (Turdus migratorius). The plumage was overall greenish from head to tail, darker on the mantle and wings, and brighter yellow on the underparts, especially on the undertail coverts. The sides and flanks were paler gray. The first identifying character I looked for was the presence or lack of any wing bars. Any tanager in California in December is a potentially "good" bird, and could theoretically be almost any North American species. A tanager without wing bars effectively rules out Western Tanager, the most likely species to occur in December. When viewing from the back I could clearly see there were no wing bars and the wing coloration was a darker gray and olive-green, not the dull glossy black of a young male. The ends of the tertials were light gray, and the greater coverts and tertials were greenish edged. The upper surface of the tail was also gray-green, while the under surface appeared pale or whitish. This bird also lacked the dark gray mantle of a female Western Tanager. The back was concolorous with the head and nape. The bill was short, thick and flesh colored. It was smaller billed than Summer Tanager (Piranga rubra). The culmen was curved to the tip and dark along the upper edge. Legs and feet were blackish. It would perch still for periods of time only flying into other nearby trees after flying insects.

Note green-edged greater coverts

Addendum:
On December 16, 2007 the tanager remained where previously seen. The photographs above and below were taken on that date. It was also heard calling on this occasion; a thick warbler-like "chip" or "chep" note which it repeated for about one minute.


Note short, flesh-colored bill, lack of wing bars. Photographed December 16, 2007


Status:

In Santa Barbara County Lehman (1994) lists Scarlet Tanager as a casual fall vagrant along the coast. Garrett & Dunn (1981) also describe this species as casual in southern California. It is seldom encountered in December. In the recently published Rare Birds of California by the California Bird Records Committee (Western Field Ornithologists 2007), coastal records account for nine out of every ten found in the state, the great majority of them found from Santa Barbara County southward. As of this publication, two records in California (San Diego) accounted each for a December 30 and January 2 date. Photos © J. Chavez

Tuesday, December 4, 2007

Field Notes: Glaucous Gull

Glaucous Gull (Larus hyperboreus)
Goleta Beach County Park, Goleta, California
December 4, 2007

First cycle Glaucous Gull (center) at Goleta Beach Park

Recently reported through the Santa Barbara County listserve was a first cycle GLAUCOUS GULL found by Kyle Braunger in the estuary at Goleta Beach Park on November 27, 2007. This gull has been intermittently seen by others, most often at the end of the day as the gulls come to the estuary before sundown. Returning from Ventura County I decided to stop at the estuary to see if I could locate it. The following notes are from memory and review of photographs.

Account:
At approximately 4:45 p.m. while sorting through gulls just up-river of the estuary I saw the Glaucous Gull fly in and land in the water where there were several other gulls swimming and feeding. It was quite noticeable flying in; a large, very pale gull with mostly white primaries. The gulls eventually flushed from the water and the Glaucous Gull flew to an adjacent sandbar where it could be studied out of the water.

Description:
It appeared larger than nearby Western Gulls (Larus occidentalis) and California Gulls (Larus californicus). Overall plumage pattern and coloration appeared consistent with a first cycle bird. It's plumage was mostly pale creamy-white with soft tan markings over much of the face and neck, upper breast, while the undertail coverts were patterned with tan bars. The scapulars were only slightly darker tan than the other tan bar markings, but obviously darker than the mantle. The wings looked nearly white as it swam in the water. It had a fairly large and long bicolored bill- pinkish at the base with a dark tip (approximately 1/3) and a dark edge on the lower mandible. Seen out of the water the lower belly was also patterned with tan barring. Legs and feet were pink in color, and the eye appeared small on the face. When standing the gull had a fairly erect posture, somewhat large chested, with relatively short primary projection beyond the tip of the tail. Other gull species noted nearby for comparison were Ring-billed Gull (Larus delawarensis) and two Thayer's Gulls (Larus thayeri).


Note bicolored bill and short primary projection

Status:
In Santa Barbara County Lehman (1994) treats this species as a very rare winter visitor being found most often along the coast. Garrett and Dunn (1981) also list this as a very rare winter visitor to southern California, mainly from late December through March. Almost all records have involved first-year birds in Santa Barbara County. The earliest arrival date was November 26, 1989. Photos © J. Chavez

Addendum:
I was reminded of this gull which I photographed on May 14, 2005 at the Santa Maria River estuary in Santa Barbara County. While it looks superficially like a Glaucous Gull- large bill, very pale plumage, apparent short primary projection, pink legs, barred undertail coverts- I was unable to determine its identity. An extremely bleached or worn individual, a hybrid with American Herring Gull (Larus smithsonianus) or a leucistic gull are all possibilities. One prominent feature lacking on this bird is the bicolored bill of a Glaucous Gull.

Mystery gull at Santa Maria River Estuary May 14, 2005

Thursday, November 29, 2007

The Hunt for Collared-Doves

Recently an acquaintance of mine where I work handed me the 2007 California Hunting Regulations booklet for Waterfowl and Upland Game. I'm not sure why- I don't hunt and neither does he- but he said I might find it interesting reading. Okay... so I looked through it. I must admit I was surprised to find among the expected list of bird species approved for hunting in California (waterfowl, quail, pheasant, etc.), the addition in 2007 of Eurasian Collared-Dove (Streptopelia decaocto). This somewhat recent addition to the avifauna of California is certainly expanding at an incredible rate and they seem to be everywhere now, but where exactly can one hunt for Collared-Doves in the wild? Where I live they seem only to be a denizen of the urban jungle where hunting is generally frowned upon. I digiscoped this Eurasian Collared-Dove in a local city park in January 2006. Photo © J. Chavez

Eurasian Collared-Dove

Sunday, November 25, 2007

White Geese: Snow vs. Ross's

You might think large white geese really can't be that difficult to identify. This is reasonably true until you find a solitary Snow Goose (Chen caerulescens) grazing in some far off pasture, or spot a lone Ross's Goose (Chen rossii) swimming in a reservoir. Their identifying features only a haze in the distance. Occasionally you might find a mixed flock and the differences become clear since one is obviously larger than the other. When the two are conveniently found together, such as the two in these photos, you tell yourself you will never make the mistake of confusing these geese again.

Both look very much the same from a distance- white geese with black primaries in their common "white morph" phase. A closer look reveals the structural difference between them. Snow Goose (or "Lesser Snow Goose" representing the interior west, and C.c. atlantica or "Greater Snow Goose" being found in the east) is a larger bird- longer necked, longer legged with a bigger head. Superficially similar, Ross's Goose, the smallest white goose, looks like a smaller, dumpier version of it's larger relative. Comparisons of overall body size, neck length, bill size and shape all help to distinguish the two species. Each has a "blue morph" phase, but Snow Goose maintains a white head while Ross's Goose looks somewhat like a Barnacle Goose (Branta leucopsis) in this form.

At close range one of the best field marks for separating these two is the shape of the head and bill. Snow Goose shows a longer wedge-shaped head. It has a larger reddish-pink bill with black cutting edges that form "lips", or what is commonly referred to as a "grin patch." Ross's Goose by contrast lacks this feature. These black "lips" on the sides of the mandibles of Snow Goose can be seen from quite some distance away with binoculars or a spotting scope and help to identify this goose to species. In comparison Ross's Goose has a smaller rounded head, and a stubby pinkish bill. It lacks the grin patch of its larger counterpart.


Snow Goose illustrating the larger bill and black "grin patch"

Ross's Goose illustrating the short, stubby bill. Note warty area at base

Another helpful feature at close range in separating Ross's from Snow is the warty area at the base of the upper mandible. This warty area is occasionally bluish-gray in color and is most apparent in older males. Madge and Burn (1988) note such warty protuberances are considered to be a useful isolation character that prevents extensive hybridization where the two species breed alongside each other.

Speaking of hybrids, this helpful little exercise wouldn't be complete without a cautionary note on hybrid geese. These two are known to hybridize where their breeding territories overlap in the Arctic north. A particular goose showing characters of both species may in fact be a hybrid. Such birds are probably best left as unidentified, but do make for interesting study.

So who was Ross and why is a goose named after him? Ross's Goose is named in honor of Bernard Rogan Ross (1827-1874) by John Cassin, curator of birds at the Philadelphia Academy of Natural Sciences. Ross was the chief trader for the Hudson Bay Company in the MacKenzie River District in northwest Canada during the 1860's. Ross's primary significance is in the field of natural history rather than the fur trade. Like many company men he contributed much to the early scientific knowledge of the northwest. While at Fort Simpson he made valuable collections of mammals, insects, and birds, forwarding specimens to the Smithsonian Institution in Washington, the Royal Scottish Museum in Edinburgh, and the British Museum in London. Ross's Goose was named in his honor in 1861.

These photographs were taken on November 24, 2007 at Waller County Park in Santa Maria, Santa Barbara County, California. Photos © J. Chavez