48-B-2017 Pomarine Jaeger

STATUS
Accepted
DATE VOTING COMPLETED
1ST ROUND
7-0
HOW MANY OBSERVED?
1
DATE SIGHTING OCCURRED
DATE REPORT PREPARED
REPORTER
VERN TUNNELL
OTHER OBSERVERS
Cheryl Huizinga, Denise Hughes, RL Rowland, Jason Talbot, Bryce Robinson,
LOCALITY OF OBSERVATION
Cove Campground C.J Strike Resv. Owyhee County.
HABITAT WHERE THE BIRD WAS OBSERVED
Reservoir
SIGHTING DURATION, CONDITIONS, and EQUIPMENT USED
5 hours , binoculars and Camera . Mostly cloudy, wind 10-20mph. temp 55. Distance to bird 25-100 yards, bird was to the NW sun was to the SW. Used binoculars & camera with zoom
DID YOU TAKE NOTES?
Yes, during the observation
DID YOU CONSULT A FIELD GUIDE OR OTHER REFERENCE WORK?
Yes, during the observation
WHICH GUIDE(S) OR REFERENCE(S): DID YOU CONSULT?
National geographic mobile app.
DESCRIPTION OF THE BIRD(s)
Jeagar. light adult in basic plumage. Very dark back and undertail coverts, light underbelly with ragged edging along flanks when seen in flight . Carmel colored nape on a thick appearing neck. Long, stout bicolored bill.
BEHAVIOR OF THE BIRD(s)
Attacking gulls & grebe. One fight lasted over 15 min Jaeger finally killed the gull and began to eat it.
HOW AND WHEN DID YOU POSITIVELY IDENTIFY THE BIRD, AND WHAT CLINCHED THE IDENTIFICATION FOR YOU?
Not a bird I had seen before in this state. Dark body and head cap ruled out any common gull that would be there. Aggressive behavior and shape lead me to look at jaeger for possible ID. After consulting the guild. The body color head cap caramel colored neck band made me sure it was a Jaeger. Then further details bi colored bill and ragged edging along flanks isolated it to pomarine.
HOW DID YOU ELIMINATE SIMILAR SPECIES? WHAT WERE THEY?
No long tail ruled out long tailed jaeger . Lack of smooth transition of brown to white ruled out parasitic jaeger . Dark cap much more extensive in size than other jaegers. Dark cap and body color ruled out any gull species that would be present in the area. Tern has a white body. All gulls that would have a dark head have a withe body. Laughing gull has a red bill or solid black no bicolor and no color along it's flanks. Franklin's gull is very much smaller also no dark along it's flanks. Herring gull juv stages are mostly solid coloration no bi colored bill.
WHAT IS YOUR EXPERIENCE WITH THIS (AND SIMILAR) SPECIES?
None. Just spending 5 hours observing this bird and seeing it on nature TV shows.
DESCRIBE YOUR GENERAL BIRDING EXPERIENCE
Began birding in 2014. Spend several hours a week at this. Was top 7 in 2016 for ebird Idaho and broke the ebird Owyhee county year record by 20 species. I feel I am a very good birder in Idaho.
ADDITIONAL INFORMATION (If any)
[See eBird checklist for photos]
WERE PHOTO(S), VIDEO, AND/OR AUDIO OBTAINED FROM THIS SIGHTING?
Photo
SUPPORTING IMAGES

FIRST ROUND VOTING:

Cliff Weisse
Accept

Details support identification of Pomarine Jaeger.

Shirley Sturts
Accept

Description convincing - other jaegers and gulls eliminated

Jay Carlisle
Accept

Diagnostic photos and key points given for separation from other jaegers

Doug Ward
Accept

If left to only the observer’s description, would know they likely had a Jaeger (Stercorarius sp.) of some sort, but not enough structural detail provided to point to a specific identification. However, I believe the attached photos do indicate an adult Pomarine (S. pomarinus) based on the general bulk of the bird, primarily through the chest and belly, apparently broad based wings, but diagnostically (?) the number of primaries showing white shafts (>5; P4-10, so 7 total as seen in picture #3). Based on the photos, I am comfortable accepting in this round.

Carl Lundblad
Accept

Awesomely documented. Photos illustrate enormous size, heavy build, large heavy bill (I think I can tell it's bi-colored) extensive very dark cap, breast band, dark undertail coverts, pale belly oval, cream-yellow neck and nape.

Dave Trochlell
Accept

I'm convinced that this was a Pomarine Jaeger.

Darren Clark
Accept

photo and description support Pomarine and eliminate similar species