| [Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] |
|
In a message dated 8/6/2007 8:16:44 A.M. Pacific Daylight Time,
[[email protected]] writes:
Hey Guys, All,
In a brief discussion with Rick Fournier he said that he thought that there
was a local breeding record for Rose-breasted Grosbeak. I was wondering if
hatch year BHGR ever have pink bills? Has anyone found any BHGR photos or
drawings with streaking as broad as on the bird in question? Wouldn't
any hybrid normally have streaking that would be wider than that on
BHGR but narrower than that on RBGR? If we think that this bird is a hatch
year BHGR with abnormally wide streaking (even for a RBGR) then why can't it be
an abnormally fresh plumaged adult female RBGR. I was wondering if one did
a write-up on this bird with references to normal field marks (bill color and
wide streaking being key and with freshness and color of plumage being
subjective) would one accept it as an adult female RBGR? For
what it's worth this bird, when seen, was instantly identified as not being
a "normal" BHGR.
Take care,
Bob Reiling Get a sneak peek of the all-new AOL.com. |
--- Begin Message ---
- Subject: Re: [SBB] Pajaro River grosbeak
- From: "Roy Churchwell" <[[email protected]]>
- Date: Mon, 6 Aug 2007 08:15:46 -0700
- Organization: SFBBO
Hey Guys, I do know of at least one record of red-breasted grosbeak nesting in Marin County in the last five years. I thought I would just throw that into your discussion. Roy Churchwell Landbird Program Director San Francisco Bay Bird Observatory 524 Valley Way Milpitas, CA 95035 (408) 946-6548 ext. 11 [[email protected]] NOTICE NEW ADDRESS ----- Original Message ----- From: "michael mammoser" <[[email protected]]> To: "south-bay-birds" <[[email protected]]> Sent: Sunday, August 05, 2007 5:32 PM Subject: [SBB] Pajaro River grosbeak > All, > > There has been some discussion between myself, Mike > Rogers, and Steve Rottenborn about the identity of the > alleged Rose-breasted Grosbeak along the Pajaro River > last month. Some questions have been raised and I > thought it might be informative to the members of this > list to see that discussion. > > Michael Mammoser > > >> -----Original Message----- >> From: Mike Rogers >> Sent: Tuesday, July 24, 2007 >> To: Mike Mammoser; Steve Rottenborn >> Subject: Re: [SBB] Pajaro River etc. >> >> >> Based on the photos taken of the "Rose-breasted >> Grosbeak", it appears to be an HY bird. I doubt RBGR >> are breeding down there, which makes the ID >> questionable in my mind, given the time of year. The >> fact that the bird was not that different from Tom >> Grey's first photographed bird suggests to me that > it >> may be a heavily streaked juvenile BHGR, which Steve >> Rottenborn agreed with. Of course, I haven't seen > the >> bird - but it is not encouraging that nobody is >> getting photos or good looks at the center of >> the breast. Call notes would be helpful too... > > >> -----Original Message----- >> From: michael mammoser >> Sent: Monday, July 23, 2007 9:28 PM >> To: Mike Rogers; Steve Rottenborn >> Subject: Re: [SBB] Pajaro River etc. >> >> >> I was back and forth on that apparent RBGR, but I >> couldn't find any literature reference that > indicated >> a Black-headed would have streaking that heavy on > the >> underparts. What, in Tom's photo, indicated that the >> bird was a "bird-of-the-year"? > > >> -----Original Message----- >> From: Steve Rottenborn >> Sent: Tuesday, July 24, 2007 >> To: Mike Rogers; Mike Mammoser >> Subject: Re: [SBB] Pajaro River etc. >> >> >> I've been surprised that there hasn't been more >> discussion of the identity of the "RBGR" on SBB, >> especially since so many people have now claimed to >> have seen one. >> >> I'll be the first to admit that I haven't done any >> detailed research (e.g., using Pyle) to establish >> either the age or the identity of this bird using >> finer points of plumage, so my "analysis" is >> admittedly superficial. >> >> I think the bird in Tom Grey's photos is definitely >> a juvenile. The wing feathers appear very fresh, not >> worn at all. I think an adult female would be worn. >> Also, I could swear that bird still has enlarged >> pinkish rictal flanges. I can't find a photo of an >> adult RBGR on the web with enlarge pink rictal >> flanges. If it's a juvenile, the chances of it being >> a RBGR, or a hybrid, are greater than zero but still >> very, very low. >> >> MJM, in your post to SBB you mentioned that Rich >> said that the center of the breast is streaked. It >> is my understanding that female BHGR can have >> streaking on the center of the breast, but it is >> finer than on RBGR >> (see http://fog.ccsf.cc.ca.us/~jmorlan/grbkid.htm). > >> >> When I saw Peggy Don's photos, I thought that the >> streaking on that bird looked broader (not as fine) >> as I'd expect on a BHGR. However, if I had to guess, >> I'd bet that the bird is just a heavily streaked >> BHGR. The photo of a female RBGR on the following >> web page shows my impressions of a typical female >> RBGR: >> >> > http://www.wbu.com/chipperwoods/photos/rbgrosbeak.htm > >> >> The female shown on the following web page shows a >> bird with much, much less buff (and not nearly as >> orange) as on the Pajaro River bird. Interestingly, >> the streaking on this bird is even less extensive >> than on the Pajaro River bird: >> >> http://www.pbase.com/lilwings/image/60639418 >> >> I haven't seen the bird, nor have I done a detailed >> analysis of age or species using Pyle, so I'm not >> claiming that the bird is definitely a BHGR. > However, >> someone claiming a RBGR should do such an analysis > to >> age the bird and, if it is a juvenile, rule out > BHGR. > > >> -----Original Message----- >> From: Mike Rogers >> Sent: Tuesday, July 24, 2007 >> To: Mike Mammoser; Steve Rottenborn >> Subject: Re: [SBB] Pajaro River etc. >> >> >> The AHY (after hatch-year) female RBGR I saw along >> Stevens Creek on 2 June looked very much like: >> >> http://www.pbase.com/lilwings/image/43569873 >> >> http://www.pbase.com/lilwings/image/43669763 >> >> Broad streaks with similarly broad streaking across >> the mid-breast and some buff in the upper >> breast/flanks, but none of the orange of the Pajaro >> bird. >> >> I aged the Pajaro birds (Tom Grey's photos are of > two >> different birds) based on their very fresh, > uniformly >> aged plumage. As Steve pointed out, Tom Grey's > photos >> in particular show narrow yellow-green edges to all >> flight feathers, something I don't think an adult >> would ever show, especially this early in fall. >> >> It is my understanding that the pink bill (upper >> mandible) is only a good field mark for RBGR in > AHYs. >> >> I too still have to check Pyle on these birds, but >> I suspect that juveniles may be more extensively >> streaked than first-winters, which could explain the > >> heavier than expected streaking on the Pajaro bird. >> It's yellow underwing coverts rule out a male RBGR I > >> think (I know these are pink in male RBGRs by Sep >> anyway). > > >> -----Original Message----- >> From: michael mammoser >> Sent: Tuesday, July 24, 2007 3:40 PM >> To: Steve Rottenborn; Mike Rogers >> Subject: RE: [SBB] Pajaro River etc. >> >> >> I just looked at all the photos (I've dismissed Tom >> Grey's first 3 photos - they're obviously of a >> different bird) and these all seem to show virtually >> the same bird. So, I think everyone is on the same >> page in that regard. >> >> I don't think this bird is in "juvenal" plumage. > That >> plumage should show cinnamon wing bars and cinnamon >> edging to upperpart feathers. At a minimum this bird >> would be in 1st basic plumage, which, according to >> Pyle, can be held into the second year. >> >> Steve's comment about the rictal flanges is very >> interesting. I think these can be seen most easily > in >> Peggy Don's photo 47171_IMG5Q_RB_Grosbeak_Pajaro... >> This would seem to be indicative of a >> "bird-of-the-year", and unless your willing to >> believe that Rose-breasted Grosbeaks breed in Santa >> Clara County, or nearby...? >> >> After all, these aren't Swainson's Hawks :-) > > >> -----Original Message----- >> From: Steve Rottenborn >> Sent: Tuesday, July 24, 2007 >> To: Mike Mammoser; Mike Rogers >> Subject: RE: [SBB] Pajaro River etc. >> >> >> It's obviously an interesting bird. I'll try to > take >> a closer look at the photos later, but in the >> meantime, it wouldn't hurt to send them to Joe > Morlan >> (and others? Kimball Garrett?) for an opinion. >> We'll learn something one way or the other. > > > > > > _______________________________________________ > Do not post admin requests to the list. They will be ignored. > South-Bay-Birds mailing list ([[email protected]]) > Help/Unsubscribe/Update your Subscription: > http://plaidworks.org/mailman/listinfo/south-bay-birds_plaidworks.org > _______________________________________________ Do not post admin requests to the list. They will be ignored. South-Bay-Birds mailing list ([[email protected]]) Help/Unsubscribe/Update your Subscription: http://plaidworks.org/mailman/listinfo/south-bay-birds_plaidworks.org
--- End Message ---
_______________________________________________ Do not post admin requests to the list. They will be ignored. South-Bay-Birds mailing list ([[email protected]]) Help/Unsubscribe/Update your Subscription: http://plaidworks.org/mailman/listinfo/south-bay-birds_plaidworks.org