ML626834901

Věk a pohlaví

Juvenilní, neznámé pohlaví - 1

Chování

Letící

Poznámky

Possible juvenile Herring (Vega) Gull initially reported on 17 November 2024 by Mark Wilson, here photographed in flight by Curtis A. Marantz on 21 November 2024 along the Los Angeles River channel above Downey Street in Vernon, Los Angeles County, California.

Podrobnosti k pozorování

This was a conspicuously large gull that appeared somewhat larger and stockier than nearby Western Gulls, but its structure was generally similar overall. The bill was relatively short and moderately stout as it tapered from a base of medium depth to a blunt, if not weakly hooked, tip along a culmen that was straight for most of its length before curving smoothly downward near the tip. I also noted a moderate angle at the gonys, but the bill overall was slimmer than those of the Western Gulls and it did not have a blob-tipped appearance. I further thought the bill would have extended backward on the face to a point just beyond the rear edge of the auriculars. The forehead was sloping, the crown was gently rounded. The junction of the forehead and crown was angular and above and before the eye, but the junction of the crown with the nape was more sharply rounded, all on a head that was unremarkable in size for a gull. The neck was of medium length and it was rather stout where it met the body but tapering to where it joined with the head. The body was conspicuously plump, full-chested, and with a posture when the bird stood upright that was somewhat closer to horizontal than diagonal. I thought the wings were relatively long and I noted that they tapered to pointed wingtips that extended beyond the tail, but I failed to note in the field the primary projection, the number of primary tips exposed beyond the longest tertials, and the placement of the wingtips relative to the tip of the tail. I likewise noted that the tail was short and square-tipped when held closed, but I did not attempt to compare the length of the tail relative to that of the body. The legs were of unremarkable length and mass for a large gull, but I noted clearly both that the front three toes were fully webbed and that the halluces were quite short and not included in the webbing. When seen in flight, this bird’s structure was typical of a large gull, given long wings that were slim and tapering to pointed tips, that the head and neck extended forward of the leading edge of the wing a moderate distance, and that the tail was short and square-tipped to somewhat rounded when flared. This bird’s plumage patterns were similar to those of the juvenile Herring Gulls, though I thought it was a but paler than most of these birds. The forehead was whitish, as was the front part of the face between the bill and the eye, and this same color extended below the eye through the moustachial, submoustachial, and malar regions. Thee was encircled narrowly by darker coloration, though I was not if it was blackish or dark brown, and I noted fine, dark streaking on the forehead, the lower part of the face below the eye, and the auriculars, though the streaking on the latter may have been a bit bolder and maybe less sharply defined. The whitish forehead blended into medium brown on the crown, and this same color extended back to the nape and down through the superciliary region, all of which had some degree of darker streaking or clouding. I did not think this bird had a darker “mask” around the eyes like that noted on a Lesser Black-backed Gull seen shortly before, but I did notice on the bird’s left side a small, blackish marking in the loral region between the bill and the eye that appeared to reflect missing feathers or possibly an injury of some sort. The throat was whitish, but the foreneck, breast, and sides were clouded with grayish-brown, and seemingly with the centers of the feathers brownish and contrasting subtly with whitish edges to create what I thought was a more clouded or diffusely mottled rather than streaked appearance. The belly and flanks appeared to be slightly darker, more obscurely marked, and without the more discrete whitish edges to the feathers. The lower belly and undertail coverts appeared more purely white, but also with blackish barring that was relatively narrow, but also sharply demarcated. I never clearly saw the underside of the tail, but what I saw appeared to be rather dark. Returning to the upperparts, I thought the back and sides of the neck were similar in coloration and pattern to the foreneck and not contrasting strongly with the head, but I also though this bird lacked the coarse mottling of a Lesser Black-backed Gull, but instead having the more muted pattern of a Herring Gull. My recollection of the pattern on the mantle is not very good, but I think the smaller feathers had sooty to blackish centers that contrasted with narrow fringes of whitish to light gray to create a scaly pattern that was finer than that on the scapulars. The scapulars were generally larger, and with a pattern that combined a sooty center that was expansive with a wavy fringe of whitish to light gray that extended along both edges and around the tip of each feather to create coarsely mottled pattern when seen on the various feathers overall, but also apparently lacking the pale internal markings that were typical of most, but not all, of the young Hering Gulls. The wing coverts apparent in the closed wing, and thus presumably including the lesser, median, and greater coverts had crips barring of white and sooty-brown to blackish to produce a finely checkered pattern that appeared to extend throughout the secondary coverts, and without the greater coverts having a broad band of dark brown basally to produce a band along the lower part of the closed wing. The tertials were generally sooty-brown to blackish with whitish edges basally but these expanding distally to a series of clouded bands at the tips of at least the longest feathers. I thought the exposed primary tips visible in the closed wing were blackish and lacking obvious fringes. I saw the rump and tail primarily when the bird took flight, so my views were necessarily brief, but what I could see was that the rump and uppertail coverts were rather white, but also with blackish barring that was short, relatively narrow, and dispersed evenly out to the distal uppertail coverts. The tail was primarily a sooty-brown in color, so this bird did not appear to have the conspicuous band distally that contrasted with a white base that I associate with a Lesser Black-backed Gull. My photos do show a complex pattern of white barring on the outer several pairs of rectrices, but I found this to be relatively difficult to see clearly in the field. What I could see on the bird in flight was that the head, neck, and underparts were relatively pale, but also with an uneven appearance, and that both the primaries and secondaries were generally quite dark, but also with a paler panel on the inner primaries that seemed less conspicuous than I usually associate with a Herring Gull. By contrast, the rump and uppertail coverts stood out as whiter than on most Herring Gulls despite the dark barring, and as such they contrasted conspicuously with the mostly dark tail. I also thought the tertials contrasted more conspicuously with the paler and intricately marked wing coverts and rump. The bill generally appeared quite dark, but close inspection revealed that even though the upper mandible was mostly blackish, it had pinkish clouding that extended from the base out to the nares and even slightly beyond. Moreover, the base of the lower mandible was clearly pink and the pinkish clouding extended some distance out the sides of the lower mandible. The irides were dark brown and contrasting with a black pupil, the legs and webbed feet were a bubblegum-pink in color, and the claws were dark. I typed the description portion of this account from memory late in the evening on 22 November 2024 and extending into the early morning hours of 23 November 2024. I did look at some of my photos on the back of the camera to check exposure and focus, but I did this in the field when the bird was still in view.

Technické informace

Model

ILCE-7RM5

Objektiv

FE 200-600mm F5.6-6.3 G OSS

ISO

320

Ohnisková vzdálenost

318 mm

Blesk

Flash did not fire

Clonové číslo

f/8.0

Expoziční čas

1/2500 sec

Rozměry

5376 pixels x 3157 pixels

Původní velikost souboru

17.73 MB