Contributeur
Date
Site d'observation
- Âge
- Non précisé
- Sexe
- Non précisé
Détails de l'observation
******MEGA. First state record accepted by the CBRC. Full details to CBRC. Description: Vocal: I heard this bird sing off and on for nearly 3 hours at varying distances and for varying lengths of time. It sang about three primary variations of song. One was the classic 4/6 note descending song, but a slight variation off this. One was a descending series of whistled notes, and one was a seemingly abbreviated version of the song, only 3 or so notes long. The classic song sounded spot on for eastern and the others sounded much better for eastern than for western. Additionally, it gave its buzzy rattle on several occasions much higher and buzzier than western that sounded completely consistent with my experience with eastern. No chuck notes were noted, nor any other vocalization that may elicit specific uncertainty. Visual: When the bird flew in (the only time I got truly good views of it), I was instantly struck by how different the overall impression of the bird was from an average western based on the face: very bold, contrasting black crown stripes, very pale face including entirely white malar and only faint light gray auricular patch. The black on the sides/flanks was distinctly streaked and not spotted, a mark I have seen used for Eastern. In flight the bird stood out from adjacent Western due to more extensive white in the tail. Photos appear to show a brown R1, a mixed-colored R2 (white inner shafts, brown outer shafts), and white R3,R4, and R5 (see tail photo). As far as I can tell, this pattern eliminates Western, which would show less white. Whether this pattern is more suggestive of “Eastern” Eastern or Lilian’s I don’t know. At least three very experienced observers think tail pattern presented in the photos may suggest Lilian’s, but one of those (who has seen the bird in the field) feels other marks point towards nominate Eastern. I have to look into this more before drawing a definitive conclusion Habits: while I am unsure of the dependability of this mark as a diagnostic field characteristic, the bird exhibited a flight behavior different than the adjacent westerns. It would flap in a few quick bursts and then glide for several seconds, flap a few more times and then glide again. This flight style has been likened to a Spotted Sandpiper, and I find that comparison apt. The adjacent Westerns, alternatively, either flapped relatively consistently, or interspersed glides into their flapping, in stark contrast to this bird’s gliding dominated style. Again, while I am unsure of the usefulness of this mark, I have been told it has been used by Arizona birders for decades to pick out Easterns (admittedly, Lilian’s) out of western swarms, so there is at least precedent for this observation (Ken Rosenberg, pers comm) Outside resources: I consulted many experienced observers both in California and from the East, and they unanimously agreed with Eastern. Most of the details mentioned above were cited by one collaborating observer or another. The bird was first heard from here 41.2146298,-121.3775120. It was singing persistently for periods and then silent for periods. It was singing from this field 41.2120852,-121.3787314. It was not excessively responsive to playback. It seemed to be paired with a Western Meadowlark.
Informations techniques
- Modèle
- Canon EOS 7D Mark II
- Lentille
- EF100-400mm f/4.5-5.6L IS II USM
- ISO
- 800
- Longueur focale
- 300 mm
- Flash
- Flash did not fire, auto
- f-stop
- f/8.0
- Vitesse d'obturation
- 1/1250 sec
- Dimensions
- 778 pixels x 591 pixels
- Taille originale du fichier
- 175.05 KB