ML32090151
Contributor
Date
Location
- Age and sex
- Adult, Unknown sex - 1; Immature Unknown sex - 1
Media notes
The shape (rotund) and coloration (black on top, white on bottom), with the legs being near the rear of the bird (see them projecting behind it), and the short black bill all bespeak Thick-billed Murre. The light/dark pattern on its face is unique among any Alcidae that could be expected to appear in this area. The most similar of the potential ID-competitor species (when immature) is Razorbill, but the facial pattern of Razorbills has white extending upward behind the eye and a drooping black line from the rear of the eye. This bird has neither and, indeed, matches wonderfully an illustration of first-winter Thick-billed Murre in a high-quality field guide (i.e., "Birds of Europe" by K. Mullarney, L. Svensson, D. Zetterström, and P. J. Grant 1999, Princeton U. Press; p. 197, central panel). What is more, the bird in the photo has folded wings and tail that appear to end at about the same place, as in Thick-billed Murre (first-winter), but not as in Razorbill (first-winter), whose pointed tail extends far beyond the wings.
Observation details
Two individuals of this species are documented here, via photographs, an adult (long slender bill) and an immature individual (short, less slender bill). Three different photos are provided herewith, but each is provided in two different versions (but both versions involve some cropping from the full frame). One version of each shows it without any electronic correction to remove the bothersome and potentially misleading reddish color in the originals that was due to chromatic aberration (i.e., differential diffraction of wavelengths). The chromatic aberration presumably was due, in large part, if not entirely, to the fact that in all of the photos--but in some much more than in others--the optical axis of the camera lens had inadvertently been tilted a bit relative to that of the spotting scope. This was possible because the camera's lens was simply hand-held up to the eyepiece of the scope, and it was easy to displace it a bit, especially when triggering the shot by pressing a button on the camera. Nonetheless, this technique made possible photos adequate both for species identification and determination of age of both of the Thick-billed Murres. One was an adult and the other, a first-winter bird.
Technical information
- Model
- Canon EOS 10D
- ISO
- 400
- Focal length
- 50 mm
- Flash
- Flash did not fire
- f-stop
- f/1.8
- Shutter speed
- 1/30 sec
- Dimensions
- 2150 pixels x 1434 pixels
- Original file size
- 320.62 KB