Mystery Murre 1

View 1 28K View 2 24K View 3 29K View 1-3 all show a curved culmen throughout length. Head plumage is classic non-breeding Thick-billed Murre. From the accounts below you would never see a Common Murre with this molt. You would see dark feathers on the lower face before the area behind the eye was totally black. Black and white pattern on flank seems to be caused by flank feathers riding up over dark wings. ID: Thick-billed Murre.

Mystery Murre 2

View 1 31K View 2 27K View 3 32K This bird shows a bold (it was even bolder in the original video) tomium stripe on both sides of the bill in View 1 & 2 and the bill is stubby though appears straighter than others but is also more distant. Also seems to show a short gonys. ID: Thick-billed Murre.

Mystery Murre 3

View 1 25K View 2 30K View 3 31K View 1 shows a short stubby bill with decurved culmen throughout length. View 2 shows some dark markings toward the rear on the flanks but I'm not sure this is the striations mentioned in Harrison (Comments? Murres 2 & 4 also show a single black streak along flank and butt). ID: Thick-billed Murre.

Mystery Murre 4

View 1 25K View 2 29K View 3 29K View 4 29K View 5 30K This bird is farthest along in its molt to breeding plumage and View 3 clearly shows a sharp inverted-V breast pattern. Diagnostic for a Thick-billed Murre. View 2 also shows a fairly distinct tomium stripe which is also a good mark. View 1 shows a short and stubby bill with culmen decurved throughout its length. ID: Thick-billed Murre.

Thanks to every one who sent in comments! I've included some of the more informative posts below.

From: "Bruce Mactavish" <bruce.mactavish1@nf.sympatico.ca> Subject: Re: [BIRDWG01] murre id (images on web) Date: Wed, 25 Feb 1998 23:01:33 -0330 These murres are all Thick-billed Murres. Bird # 1 the black of side of head sharply demarcated on the side of the head from a clean white lower side of head and throat can only be Thick-billed Murre. The bill is not long and shows a fairly strong curved culmen on photo 1 & 3 which is right for TBMU Bird # 2 bill longer with straighter culmen but fairly thick, not long and slim as in Common Murre. A hint of the pale tomium stripe visible on both sides of the bill. Bird # 3 Very short bill with strongly curved culmen as only a Thick-billed Murre could have. Sharply demarcated black and white face pattern typical of TBMU Bird # 4 Classic stubby bill with curved culmen. Hint of pale tomium stripe on both sides of bill. Deep inverted V of white on front of neck is excellent for TBMU. Common Murres loose their winter face pattern with a gradual peppering in of dark brown over the face and neck. A shadow imprint of the winter face pattern is visible through the early stages of the darkening in process. The molt to summer plumage is not a movement of solid black rolling down the face and closing in on the front of the neck ! The face patterns on Birds #1 & #3 should not ever happen on Common Murre. Bruce Mactavish St. John's, Newfoundland bruce.mactavish1@nf.sympatico.ca ------------------------------------------------------------------------ Date: Wed, 25 Feb 1998 14:28:26 -0800 From: Nick Lethaby <nick@ELANIX.COM> Subject: Re: [BIRDWG01] murre id ... >Murre 1 is the bird most debated. > To me this bird looks like a Thick-billed Murre. One point I've seen mentioned before is that Thick-billed Murres often show an obvious bump on the base of the upper mandible. I don't know how reliable this is, but photo 1 certainly shows this. It also shows a very strongly decurved culmen. I feel all the birds are Thick-billed. Nick Lethaby Director of Strategic Partnerships Elanix, Inc. Tel: 408 941 0223 Fax: 408 941 0984 ------------------------------------------------------------------------ Date: Wed, 25 Feb 1998 20:02:22 GMT From: Joseph Morlan <jmorlan@CCSF.CC.CA.US> Subject: Re: [BIRDWG01] murre id (images on web) ... >From the photos, I think all four birds are Thick-billed Murres. Bird #4 is definitely Thick-billed as one photo shows the distinctive inverted "V" on the foreneck. The bird is fairly far along in its prealternate molt. None of the specimens I've examined of Common Murres molting their forenecks has shown an inverted "V" like that. Instead the Common Murre Pattern comes in with a broad area of spotting on the foreneck. Bird #1 is still mostly in winter plumage. A Common Murre with this much white on the throat would also still show extensive white on the face and a trace of a black post-ocular stripe. The head pattern shown here is typical for Thick-billed Murre. Birds #2 and #3 look very similar to each other. They are also molting and I think both are also Thick-billed. Common Murres have strongly blurred spotting on the throat and chin before they molt in a dark face. Birds like these with white throats and no white face and no post-ocular stripe should be Thick-billed. It's interesting that #1-3 all show a partial breast mark and this is often seen on Thick-billed and not on Common. I can see this on some transitional plumage Thick-billed Murre photos from Alaska, but have not heard it mentioned elsewhere. The bill size and shape on all birds seem consistent with Thick-billed to me. #3 is clearly Thick-billed on bill (view 1). Light may be a factor, but all birds seem blacker above than the paler gray of most common Murres. Again this is consistent with Thick-billed. -- Joseph Morlan SF Bay Area birding, Rarity photos, ID quizes. 380 Talbot Ave. #206 http://hills.ccsf.cc.ca.us/~jmorlan/ Pacifica, CA 94044 jmorlan@hills.ccsf.cc.ca.us