Contributor
Date
Location
- Age and sex
- Adult, Unknown sex - X
Observation details
Exact checklist location of bird. GPS coordinates 32°49'9" N 117°38'52" W. Approximately 18.7NM west of La Jolla. About half way across the San Diego Trough heading to the Thirty Mile Bank. A small snappy looking and strikingly black and white storm petrel at first glance perhaps could be confused with Wilson's Storm-Petrel due to size and stand out bright white rump. Short visible leg length, not projecting beyond the tail, white rump shape, and the molt condition, separating this bird from Wilson's Stom-Petrel. Typical forward movement quite dashing with fluttery stops and vertical dives to water surface. Very dark blackish color overall without warmer brown tones usually noticeable on Leach's Storm-Petrel (form chapmani seen hereabouts). Tail length short, about equal to rump length, with a shallow fork or just a notch in the tail when at a good parallel flight angle to observer. The "apparent" fork depth varies based on travel direction of bird towards or away from observer and also depends importantly on the degree which the tail sides are raised up in relation to center of tail. With tail sides up, a sort of tall V shape cross section, the outer tail feathers highest, the tail looks quite forked traveling towards the observer obliquely. Best photographs to determine the fork depth is perpendicular to observer and this shows the fork is quite shallow and matches examples I have examined in the collection of the SDNHM. White "thumbprint" apparent on sides of undertail coverts, extending from the white uppertail coverts. This appears as a white dot on many photographs of the underparts as the bird tilts away. Wings quite rounded looking. Pale upperwing panel appearing warmer toned and contrasting the colder blackish of the back and upper wing coloration. White uppertail coverts quite fluffy looking with a darker median line, looks like a shadow between bright white feathers to me but could perhaps be dark. Noticeably short legs match many other example photographs I have of this species.
Technical information
- Model
- Canon EOS 5D Mark IV
- Lens
- EF400mm f/4 DO IS II USM +1.4x III
- ISO
- 800
- Focal length
- 560 mm
- Flash
- Flash did not fire, auto
- f-stop
- f/8.0
- Shutter speed
- 1/2000 sec
- Dimensions
- 1000 pixels x 750 pixels
- Original file size
- 99.15 KB