ML132909031

Age

Not specified

Sex

Not specified

Observation details

This bird's coloration and plumage patterns were pretty typical of an adult tern in alternate plumage, however, my photos suggest that it may have been a one-year-old bird. Quite conspicuous was a black cap that was well-defined and relatively solid. The lower edge of the cap extended back from the base of the bill behind the nares to the lower edge of the eye. Behind the eye, the line angled slightly downward before curving back upward along what appeared to be the upper edge of the auriculars to then drop back downward where it met the crest, which either continued down the back of the neck or the shaggy feathers covered the neck. I noted some white flecking in the cap, but it was quite limited in its extent and restricted to the forehead and forecrown in front of the eye. Below the black cap, the bird was snow-white across the lower part of the face, including a narrow strip that extended to the base of the bill just above the gape. Also white were the auriculars, throat, sides and front of the neck, and the entire underparts from the breast and sides down across the belly, flanks, and undertail coverts. Contrasting only slightly with the white underparts, but much more so with the black cap, the upperparts and most of what was visible on the wings when the bird was on land were uniformly pale-gray. As far as I could determine, the mantle, scapulars, wing coverts, and tertials were the same shade of pale gray and entirely unmarked, with the exception of diffuse, whitish tips to the tertials and some of the inner scapulars. The only contrast that I noted on the closed wings resulted from two inner primaries that were a somewhat darker shade of gray, but with pale gray to whitish fringes that created a V-shaped pattern at the tip of each feather, and the four or five longer primaries in the wingtip, which were more blackish and without obvious fringes, this probably reflecting wear. I noted only when the bird was in flight that the rump and upperside of the tail appeared to be mostly, if not entirely, white. Evident in some of my photos, yet never noted in the field, is a weak, dark band across the secondaries that presumably indicates that this was a subadult bird. The bill was a bright orange color that was a bit deeper basally yet blending smoothly to yellowish-orange near the tip. The dark eyes were encircled by a very narrow orbital-ring (if not just the eyelids?) that was paler than both the eyes and the cap. What I saw of the legs was black, but I never clearly saw the feet.

Technical information

Model

Canon EOS 7D

Lens

EF400mm f/5.6L USM

ISO

320

Focal length

400 mm

Flash

Flash did not fire, auto

f-stop

f/8.0

Shutter speed

1/2000 sec

Dimensions

898 pixels x 679 pixels

Original file size

513.41 KB