Message Board Search Tool
Banding Code Translator | Recent Rare Bird Sightings
©2017 Christopher Taylor (Kiwifoto.com)
Help Support!
calbirds        search ebird rarities [plot]
filter rba/cbc
  displaying last 15 messages...

trending birds in last 30 posts.
Last 5 Posts:
· 2017 June: Elf Owls In Joshua Tree National Park (Jul 21, 2017)
· Auklet & Traffic (Jul 21, 2017)
· Fwd: [MBBIRDS] More on the Pt. Pinos booby (Jul 21, 2017)
· More on the Pt. Pinos booby (Jul 21, 2017)
· Re: Parakeet Auklet viewable from the SF shore (Jul 20, 2017)
  1. 2017 June: Elf Owls In Joshua Tree National Park LINK
    DATE: Jul 21, 2017 @ 3:00pm, 1 day(s) ago
    At the request of Park Service, I've delayed sending this notice to any
    
    public forum.
    
    https://shadetreeimaging.com/2017-june-elf-owls-in-joshua-tree-national-park/
    
    --
    
    -- Jack --
    
    ==================================
    
    < http://shadeTreeImaging.com/ >
    
    Wildlife Photography with
    
    Emphasis on Birds
    
    ==================================
    
    858-442-1907
    
    Poway, California (San Diego Co.)
    
    N 32° 57' W 117° 04'
    
    At 508' Elevation
    
    ==================================
    
    ---
    
    This email has been checked for viruses by Avast antivirus software.
    
    https://www.avast.com/antivirus
  2. -back to top-
  3. Auklet & Traffic LINK
    DATE: Jul 21, 2017 @ 6:21pm, 1 day(s) ago
    Hi Everyone,
    
    If you plan to look for the Parakeet Auklet on July 23 the San Francisco Marathon is taking place that morning and driving to the parking area at the end of El Camino del Mar may not be possible until after 11 am.
    
    Race Traffic Advisory - The San Francisco Marathon
    
    Race Traffic Advisory - The San Francisco Marathon [tagline_box title=”We apologize for any inconvenience, and thank the residents of San Francisco for enabling us...
    
    Alan Hopkins
  4. -back to top-
  5. Fwd: [MBBIRDS] More on the Pt. Pinos booby LINK
    DATE: Jul 21, 2017 @ 5:00pm, 1 day(s) ago
    Perhaps this didn't post right
    
    Begin forwarded message:
    
    From: Don Roberson < creagrus@... >
    
    Date: July 21, 2017 3:54:11 PM PDT
    
    To: Mbbirds Bay Birds < mbbirds@... >
    
    Cc: calbirds < calbirds@yahoogroups.com >
    
    Subject: [MBBIRDS] More on the Pt. Pinos booby
    
    Thanks to the generosity of Bill Hill, Beth Hamel, Cooper Scollan, Fred Hochstaedter, and Blake Matheson , I've been able to put together of page of revealing photos of Slash -- our subadult Masked/Nazca Booby at Pt. Pinos currently -- amidst a discussion of potential identification points. The bird was still present this morning and will hopefully hang around a while.
    
    The page is at
    
    http://creagrus.home.montereybay.com/MTYbirdsBOOB.html
    
    Thanks,
    
    Don Roberson
    
    Pacific Grove CA
    
    http://creagrus.home.montereybay.com/
    
    --
    
    For Monterey Rare Bird alerts call 831-250-4550
    
    ---
    
    You received this message because you are subscribed to the Google Groups "mbbirds" group.
    
    To unsubscribe from this group and stop receiving emails from it, send an email to mbbirds+unsubscribe@... .
    
    To post to this group, send email to mbbirds@... .
    
    To view this discussion on the web visit https://groups.google.com/d/msgid/mbbirds/0B0D6EE9-13E2-4CD8-A82E-1A2DA6B02CCD%40montereybay.com.
    
    For more options, visit https://groups.google.com/d/optout.
    
    Don Roberson
    
    Pacific Grove CA
    
    http://creagrus.home.montereybay.com/
  6. -back to top-
  7. More on the Pt. Pinos booby LINK
    DATE: Jul 21, 2017 @ 3:54pm, 1 day(s) ago
    Thanks to the generosity of Bill Hill, Beth Hamel, Cooper Scollan, Fred Hochstaedter, and Blake Matheson
  8. -back to top-
  9. Re: Parakeet Auklet viewable from the SF shore LINK
    DATE: Jul 20, 2017 @ 8:46pm, 2 day(s) ago
    SF birder Adam Winer created this image which gives an excellent
    overview of the area; parking, walking route, location of PAAU. Click on
    the image for a larger version.
    
    https://snag.gy/uQqLzY.jpg
    
    Caveat: cell service in this area is rather spotty.
    
    cheers,
    
    Rudyard Wallen
    SF, CA
  10. -back to top-
  11. Another Cook's Petrel Year? LINK
    DATE: Jul 20, 2017 @ 8:06pm, 2 day(s) ago
    Howdy, Seabirders,
    
    Dave Pereksta’s awesome pelagic trip report from Ventura, July 16th, has many of us scratching our head’s and asking: Could this year be another COOK’S PETREL year similar to 2009
    
    In 2009, unprecedented numbers of COOK’S PETRELS were seen close to shore. It began in SoCal, but on Shearwater Journeys’ July 31, 2009 Monterey Bay pelagic trip, we also recorded a record 138 Cook’s petrels. The first sightings were only 13.3 miles offshore, Monterey. We haven’t see Cook’s Petrels like we did in 2009 since — think about that!
    
    I fully intend to put in a good search for Cook’s Petrels, and Hawaiian Petrels, too, on our upcoming trips. During this time period in 2009, a Stejneger’s Petrel and Short-tailed Albatross were also seen. We found a SHORT-TAILED ALBATROSS on our September 16, 2009 trip, as well.
    
    Here’s our program of trips: Spaces are available on all trips, except as noted below.
    
    MONTEREY: August 4* & 25*; September 1*, 7, 8, 10, 22, 23, 24, 30; October 8.
    Monterey trips run from 7 a.m. to 3 p.m. *Trips may be extended an hour or so to search for petrels.
    
    ALBACORE GROUNDS: OFFSHORE MONTEREY: September 9: 5:30 a.m. to 5:30 p.m. (Limited spaces available)
    
    FARALLON ISLANDS: August 6 & 13 7:30 a.m. to 4:30 p.m
    
    HALF MOON BAY: August 12 (one space available); September 2, 3, 15, 16; October 7.
    
    Please see our web site for more information:
    http://www.shearwaterjourneys.com/schedule.html
    
    To read more about the Cook’s Petrel Invasion of 2009, please see these reports:
    http://shearwaterjourneys.blogspot.com/2009/08/monterey-bay-cooks-july-31-2009-story.html
    http://shearwaterjourneys.blogspot.com/2009/08/short-tailed-albatross-july-30-2009.html
    http://shearwaterjourneys.blogspot.com/2009/08/captain-cooks-petrels-rage-on.html
    http://shearwaterjourneys.blogspot.com/2009/08/august-6-2009-cooks-petrel-chase-trip.html
    Cook’s Petrels off Point Pinos:
    http://shearwaterjourneys.blogspot.com/2009/08/monterey-bay-nearshore-cooks-petrels.html
    
    Short-tailed Albatross seen on Shearwater Journeys’ September 16, 2009 trip:
    http://shearwaterjourneys.blogspot.com/2009/09/sep-16-2009-trip-report-steller-day.html
    
    Farallon Islands reports:
    http://shearwaterjourneys.blogspot.com/2009/08/farallon-islands-aug-2-2009-awesome-day.html
    http://shearwaterjourneys.blogspot.com/2014/07/tufted-puffins-golden-gate-bridge.html
    
    About the Albacore Trip:
    http://shearwaterjourneys.blogspot.com/2015/07/about-albacore-offshore-monterey-trip.html
    
    We shall be covering many Monterey, Santa Cruz, San Mateo, and San Francisco Counties offshore.
    
    One thing is for certain— there is an awful lot of food out there, even nearshore. Spotters on the Farallon Islands, counted over 250 whales in one day. There’s krill and schooling fish, everywhere, it seems. It couldn’t be better! Many folks hesitated to jump on board for the Cook’s Petrels trips in ’09 and regretted that later. August seems to be the best month, although early September could be good, too. Escape the heat and enjoy a cooling, salty breeze!
    
    As many have heard me say, “It’s all about food.”
    Living the Salt Life on this side of the Pacific now,
    Debi
    
    DEBRA SHEARWATER
    Shearwater Journeys, Inc.
    PO Box 190
    Hollister, CA 95024
    831.637.8527
    debi@...
    www.shearwaterjourneys.com
    www.shearwaterjourneys.blogspot.com
    
    Celebrating 42 Years of Seabirding with Shearwater Journeys
  12. -back to top-
  13. Re: Parakeet Auklet viewable from the SF shore LINK
    DATE: Jul 20, 2017 @ 7:13pm, 2 day(s) ago
    The PAAU was seen at various times In the afternoon. http://digest.sialia.com/rm=one_list;id=63
    
    Rudyard Wallen
    San Francisco, CA
  14. -back to top-
  15. Parakeet Auklet viewable from the SF shore LINK
    DATE: Jul 20, 2017 @ 1:09pm, 2 day(s) ago
    A
    PARAKEET AUKLET appeared on Sunday morning 7/16, and was sighted again
    on Tue, and again this Thursday morning. It was looked for on Mon and
    Wed with no success. The current viewers are giving negative reports
    though the bird spends time where it was first found, on the seaward
    side of a stack called Hermit Rock, which stands guard on the southern
    end of Mile Rock beach. When I jokingly commented that it only appeared
    on even numbered days, Peter Pyle replied-
    
    I
    was thinking that too, and it makes some sense with alcid behavior
    patterns - a day feeding at sea and then time for some extracurricular. I
    think we've seen this on SEFI with banded non-breeding alcids.
    
    So
    maybe something to consider if traveling. Best seen from the Coastal
    Trail, most easily reached by parking in the USS San Francisco Memorial
    parking lot ( https://goo.gl/maps/ urhc1tHhqwD2 ),
    going down a short set of steep stairs to the trail, and then traveling
    in a northerly direction until Hermit Rock is visible through a break
    in the trees, located here https://www.google.com/ maps/place/37%C2%B047'08.7% 22N+122%C2%B030'34.5%22W/@37. 78575,-122.5115631,655m/data=! 3m2!1e3!4b1!4m5!3m4!1s0x0:0x0! 8m2!3d37.785754!4d-122.509593 hl=en
    
    Cheers
    
    Rudyard Wallen
    San Francisco, CA
    
    some pics and a vid https://flic.kr/s/ aHskZyJscz
  16. -back to top-
  17. Ventura pelagic trip report - 16 July 2017, Cook's Petrels, Craveri's Murrelets, and more! LINK
    DATE: Jul 20, 2017 @ 5:21pm, 2 day(s) ago
    Hi all
    
    On Sunday July 16, Island Packers hosted a 12-hour pelagic trip from the Ventura Harbor. With a favorable forecast, our goal was to go southwest to waters west and south of San Nicolas Island. Upon leaving the Ventura Harbor, our first destination was Anacapa Island where we would look for boobies, shearwaters, and some of the local nesting species we were not likely to see farther offshore. En route we encountered several flocks of shearwaters feeding around dolphin schools that included numbers of Black-vented (which were earlier in the season than expected), Sooty, and a few Pink-footed Shearwaters. We also saw two Common Murres in this area, which was nearly all we saw of that species for the day. As we worked the flocks of shearwaters looking for something uncommon or rare, shouts of BOOBY! rang out. The feeding activity in the area attracted two Brown Boobies. One took off quickly, but the other stayed for extended looks and great photo ops as it flew right past the boat several times. After the booby left, we worked the shore of Anacapa Island where we saw numbers of Pigeon Guillemots and other breeders including a few Black Oystercatchers.
    
    From Anacapa Island we headed west to several underwater features and the Anacapa Passage where there were large flocks of the common shearwaters and a variety of other species including Northern Fulmar, Cassin's Auklet, and Rhinoceros Auklet; all of which allowed close views. After thoroughly checking this area, we headed south and west to the waters west of San Nicolas Island. We had a steady trickle of birds (shearwaters, Cassin's Auklets, Red-necked Phalaropes, etc.) along our route highlighted by several South Polar Skuas, Ashy and Black Storm-Petrels, Scripps's Murrelets, and the first of our 45 +/-Craveri's Murrelets seen on the day. Yes...45 Craveri's Murrelets!! Not a typo. The thrill of the day followed soon after as we were looking at a blue whale; a gray bird with an "M" pattern across its back and clean white undersides zipped through our view, which led to simultaneous cries of COOK'S PETREL!! This was the first we have seen off southern California since 2010. Traversing that area led to us finding several more Cook's and a variety of other life, including a fin whale.
    
    Crossing the deep waters south of San Nicolas yielded more Cook's Petrels, several dozen Craveri's Murrelets, a Black-footed Albatross, and three loggerhead turtles. The turtles were a rare treat as we almost never see them on our pelagic trips. I shared our sightings with NOAA today and they informed me that loggerheads have increased in the Southern California Bight over the last few years (perhaps due to warmer water), so maybe we will start to see more of them. From San Nicolas we plotted our course north back to Ventura where wecontinued to see a variety of birds throughout the rest of the day including another Brown Booby, Red Phalarope, Black and Ashy Storm-Petrels, and the usual pelagic species. In addition to the great diversity of birds, we saw three species of whales, mako shark, blue shark, mola mola, two swordfish, a very cooperative northern fur seal, and a variety of dolphins and pinnipeds. We encountered so much wildlife on this trip that it felt like someone had left the zoo door open. Remarkable day at sea!
    
    I would like to thank the people that made this trip such a success including the captain and crew from Island Packers. Captain Jimmy McWaters did an incredible job getting us views of all the wildlife, which occasionally included speeding after skuas and petrels. He was as enthusiastic as we were and really worked with us to get to the areas we wanted to explore. Joel Barrett balanced his duties on the boat with spotting birds all day. His enthusiasm for doing these trips should ensure that we will continue to have pelagic trips running to the areas around and beyond the northern Channel Islands. He and I are talking about a number of options for exploring some areas that birders are drooling to get to on a day trip...stay tuned! I also want to thank the leaders we had on board including Bernardo Alps, Wes Fritz, Peter Gaede, Dan Maxwell, Todd McGrath, Hugh Ranson, and Adam Searcy. These guys work tirelessly all day spotting birds and helping participants get on the species they are looking for...all while having fun and sharing their great depth of knowledge on seabirds and other creatures of the deep.
    
    We have a 10-hour trip scheduled for Oct 7 so check out Island Packers website if you are interested in joining us. Trips can be booked over the phone by calling (805) 642-1393 or online at www.IslandPackers.comby clicking the Reserve Trip tab, select the Special Trips tab, and select your desired departure. The cost of the Oct trip is $170 per person.
    
    Also check out our "Southern California Pelagic Bird Trips" Facebook page.Later this evening, I will post this trip report with a number of photos from Sunday.
    
    Cheers
    
    Dave Pereksta
    Ventura, CA
  18. -back to top-
  19. Re: [CALBIRDS] Fwd: [MBBIRDS] Booby still present at Pt Pinos at 9:10 am LINK
    DATE: Jul 20, 2017 @ 3:35pm, 2 day(s) ago
    Alvaro,
    
    Thanks for the comments. My sample size was, as I had quoted [n = 33] and could easily be biased if not randomly selected among island populations or anything else, and is just one small sample.
    
    Here is what Jehl & Pitman (1998) Wilson Bull. 110: 155-170 have to say about tail differences between adults OB [orange-billed = Nazca] and YB [yellow-billed = Masked] in their published study which is the basis for today's split of the two species:
    
    > In addition, the central rectrices in OB birds tend to be pale at the base, as if dusted with flour, and the extent increasing with age, so that some older sub-adults appear white-rumped; in YB populations the rectrices average darker, and whitish bases, if present, are usually concealed by the upper tail coverts. In definitive plumage, OB and YB forms are similar, except that the dark areas tend to be a rich chocolate brown with a reddish tinge in OB birds, compared to dark brown to blackish in YB birds, and the central rectrices average paler and may be almost entirely white, a condition that is rare in all YB populations.
    
    Full paper at https://sora.unm.edu/sites/default/files/journals/wilson/v110n02/p0155-p0170.pdf
    
    I was just looking at slides I took on my one-day cruise on a NOAA ship through the Galapagos in 1989. Photos of two adults off Espanola appear black-tailed but another photo'd two days later to the southwest clearly has a long all-white central rectrix. Plate 8 in Nelson's The Sulidae (1978) Oxford Univ Press shows a pair of granti on Tower Island with a chick -- one adults has an all black tail and the other has a white pair of central rectrices. So the variation may be widespread and not confined to particular populations. More research needed.
    
    You may be right that the overall global percentage is not 60%-40% in favor adults with white centrals, but Jehl & Pitman describe the difference in terms tendencies and averages, increasing with age, but the language is consistent with some Nazcas being dark-tailed and, apparently, some rare Masked having white central rectrices. Presuming that they are correct, the presence of a white central rectrix would not entirely rule out Masked Booby. My point was that not too much emphasis should be placed in this variable character. So again it would mostly come down to bill color.
    
    As to bill color, as you know, it is not simply "yellow" in Masked and "orange" in adult Nazca. Jehl & Pitman describe Galapagos populations of Nazca as having bills that are "rosy pink in females, more orange in males." My paper described the variation as "bright orange to coral-red" in Nazca, whilst in Masked it was "greenish-yellow to bright yellow, sometimes with a small orangey tip." I wish people would not describe the difference as a simple "orange" versus "yellow" in adults. I also describe bill color in subadults in the paper, as do Howell et al. in their book.
    
    In addition, I would not rule out the potential usefulness of bill shape. Jehl & Pitman note that
    
    > Discriminant function analysis showed that OB birds are generally smaller, having shallower bills, shorter tarsi, and longer wings (Table 4, Fig. 2). The smaller size of OB birds is further indicated by body mass, which averages 12-14% lighter than S. d. personata (Anderson 1993). They are also more sexually dimorphic in bill, wing, and tarsus than YB boobies
    
    They go into further depth on bill shape differences in the paper. To my eye, a perceptible 'dip' in the culmen of Nazca about two-thirds out to the tip, and narrowing at that point, provides a different bill aspect than the more straight-culmened heft of Masked. It is a bit subtle and there will surely be overlap, so it is more of a suggestive point, similar to the tail topic.
    
    Look forward to hearing about your Galapagos trip.
    
    Thanks, Don
  20. -back to top-
  21. Re: [CALBIRDS] Fwd: [MBBIRDS] Booby still present at Pt Pinos at 9:10 am LINK
    DATE: Jul 20, 2017 @ 3:10pm, 2 day(s) ago
    Not arguing; just want to clarify a few germane issues Don raised:
    
    All the specimens I examined, both Nazca and Masked, were from several colonies in Mexico. These are colonies that are hard to access and because the 2nd-cycle bird I was analyzing appeared in San Diego waters after a period of sustained monsoon winds coming from the south paralleling the Mexican coastline, and not from the west or southwest, I felt it more likely to be a Mexican bird. That individual, whose molt progression is very similar to that of today’s Monterey bird, showed black-tipped white central rectrices.
    
    Specimens I looked at had been identified as Nazca either by genetic testing or because they’d been collected in the colony with parents of known species identity.
    
    When I look at photos or specimens from the Galapagos, they seem to have far more extensive white in the tails than the Mexican birds I looked at. But I was looking at only late 1st-cycle or 2nd-cycle birds, and it is possible that with each succeeding molt that the central rectrices become more extensively white in Nazca.
    
    Also, I found that the central rectrices were molting in early during the molt sequence. [So I would say that a bird as advanced in body molt as the Monterey bird is already showing 2nd-cycle central rectrices.]
    
    I also solicited from birders going to the Galapagos, series of photos of individual birds in which they would take many photos of a given bird from slightly different angles, so I might have some sense of how slight changes of light coming into the camera or reflecting off the bill in different ways might affect the apparent color of the bill. And it does.
    
    As I said, mine was a small, casual study with an inadequate N, but I was very surprised to see the difference in central rectrices between [Mexican] Nazca and Masked booby even early on in 2nd cycle.
    
    As for hybrids in Mexican colonies, I leave that for Bob Pitman to address.
    
    And like I said, my study was suggestive, not definitive. As is said in the final sentence of every scientific paper: "More study is needed.” : ))
    
    Stan Walens
    
    San Diego
  22. -back to top-
  23. RE: [CALBIRDS] Fwd: [MBBIRDS] Booby still present at Pt Pinos at 9:10 am LINK
    DATE: Jul 20, 2017 @ 2:26pm, 2 day(s) ago
    Don,
    
    From my experience, all Nazca Boobies I have looked at in the Galapagos
    
    have had white in the central tail feathers. I am surprised by your numbers.
    
    Given that most Nazca Boobies are from the Galapagos, I would say that world
    
    wide the proportion with white in the tail may be higher than your
    
    estimates. I will be in the Galapagos again in a few days and can check to
    
    see if I find any dark tailed Nazca Boobies.
    
    I agree that hybrids are extremely unlikely. Even if regular in some of
    
    the colonies north of the main Nazca range, their world wide abundance
    
    compared to pure birds is effectively zilch.
    
    Regards
    
    Alvaro
    
    Alvaro Jaramillo
    
    alvaro@...
    
    www.alvarosadventures.com
    
    From: CALBIRDS@yahoogroups.com [mailto: CALBIRDS@yahoogroups.com ] On Behalf
    
    Of Don Roberson creagrus@... [CALBIRDS]
    
    Sent: Thursday, July 20, 2017 1:39 PM
    
    To: Stan Walens < stan.walens@... >
    
    Cc: calbirds@yahoogroups.com
    
    Subject: Re: [CALBIRDS] Fwd: [MBBIRDS] Booby still present at Pt Pinos at
    
    9:10 am
    
    Stan et al.,
    
    To quote from my paper (Field Notes 52: 279), regarding adults: "All Masked
    
    Boobies have black tails. Of 90 photos reviewed, only one Masked had a bit
    
    of white in the central rectrices, and this bird was paired with a Nazca on
    
    Clipperton I. and may have been a bhyrid. In contrast, about 60% of Nazca
    
    adults (20 or 33 adults in photos reviewed) had extensively white central
    
    rectrices."
    
    I did not attempt to correlate the presence/absence of white in the tails of
    
    adult Nazca to particular breeding colonies. It is possible that the
    
    character is either restricted to local populations or is random through the
    
    global population. I am unaware of any research on that topic. Stan does not
    
    mention whether his study of Nazcas involved a one-island population or a
    
    broad spectrum. Nonetheless, as to its value in i.d. of vagrants, it is
    
    apparent that the presence of white central rectrices is a big positive in
    
    favor of Nazca, but equally true that the absence of white rectrices is not
    
    a negative, since as adults a significant percentage of the global
    
    population have all-dark tails.
    
    And as to the "dreaded Hybrid," I haven't looked at this topic in many
    
    years. At the time of the paper, I was aware of such hybridization only when
    
    a vagrant Nazca ends up in a huge Masked colony, so the percentage change of
    
    encountering a hybrid individual should be close to zero.
    
    Thanks, Don
    
    Don Roberson
    
    Pacific Grove CA
    
    http://creagrus.home.montereybay.com/
    
    
  24. -back to top-
  25. Re: [CALBIRDS] Fwd: [MBBIRDS] Booby still present at Pt Pinos at 9:10 am LINK
    DATE: Jul 20, 2017 @ 1:38pm, 2 day(s) ago
    Stan et al.,
    
    To quote from my paper (Field Notes 52: 279), regarding adults: "All Masked Boobies have black tails. Of 90 photos reviewed, only one Masked had a bit of white in the central rectrices, and this bird was paired with a Nazca on Clipperton I. and may have been a bhyrid. In contrast, about 60% of Nazca adults (20 or 33 adults in photos reviewed) had extensively white central rectrices."
    
    I did not attempt to correlate the presence/absence of white in the tails of adult Nazca to particular breeding colonies. It is possible that the character is either restricted to local populations or is random through the global population. I am unaware of any research on that topic. Stan does not mention whether his study of Nazcas involved a one-island population or a broad spectrum. Nonetheless, as to its value in i.d. of vagrants, it is apparent that the presence of white central rectrices is a big positive in favor of Nazca, but equally true that the absence of white rectrices is not a negative, since as adults a significant percentage of the global population have all-dark tails.
    
    And as to the "dreaded Hybrid," I haven't looked at this topic in many years. At the time of the paper, I was aware of such hybridization only when a vagrant Nazca ends up in a huge Masked colony, so the percentage change of encountering a hybrid individual should be close to zero.
    
    Thanks, Don
    
    Don Roberson
    
    Pacific Grove CA
    
    http://creagrus.home.montereybay.com/
  26. -back to top-
  27. Re: [CALBIRDS] Fwd: [MBBIRDS] Booby still present at Pt Pinos at 9:10 am LINK
    DATE: Jul 20, 2017 @ 12:33pm, 2 day(s) ago
    I’d like to make a few informal comments on this booby.
    
    In preparing a submission for the CBRC a few years ago, I did a non-expert but careful study of museum specimens of first- and second-cycle Masked and Nazca boobies, about 20 individuals of each, some in hand, and some in photos provided by curators of several ornithology collections [as well as many other photos online]. This is a small sample, and only suggestive for further research.And further research may disprove my hypotheses.
    
    I noted a number of things to look for as possible identification criteria, and some caveats on others.
    
    I hope as the CBRC does, as it announced, pursue further research and reaches out to experts on these species that this is something that others can look at and prove or disprove.
    
    First of all, I found that bill shape in immature birds was not a useful criterion. I did not do really detailed analyses with calipers, but differences in bill shape, though possibly suggestive, did not reach the level of statistical significance.However, trainer ornithologists with calipers, doing the proper measurements with far greater accuracy than I did, may find some differences, but I do not think that perceived bill differences would be reliable in the field as an identification criteron.
    
    Second, I found that bill color in photos is subject to a wide variety of photographic artifacts where the camera or computer interprets color erroneously. Photos of the bill of a given bird can look gray in one photo and yellow or pinkish in another taken only a few seconds later. [A reminder: the bill on a Nazca booby should turn orange proximally [closest to the body] before it turns orange distally [furthest from the body]. Also, since the bill is thinner at the tip, more light shines through it and can produce an erroneous pinkish tinge in photographs.
    
    Also, bills may change color slightly at different temperatures, because of different hormone levels, and other factors.]
    
    Third, there are 3 possibilities always to consider: Masked, Nazca, and the dreaded Hybrid.
    
    But, I did find one trait interesting, and it showed up in every individual that had molted from 1st to 2nd cycle. On Masked boobies, in 2nd-cycle the 2 central rectrices were black for at least 50% of their length distally.
    
    On Nazca boobies the 2 central rectrices were white for 75-100% proximally, any black if present being at most an inch or slightly more at the tip.
    
    All other rectrices on both species appeared similar.
    
    I did not study the rectrices on adults of either species.
    
    On the basis of the spread tail photos I see of this individual—and better photos are needed—I see extensive black on the central 2 rectrices, for me, pointing more towards Masked than Nazca.
    
    As I said, only some informal comments, but something I think worth looking at.
    
    Stan Walens
    
    San Diego
  28. -back to top-
  29. Re: [CALBIRDS] Fwd: [MBBIRDS] Booby still present at Pt Pinos at 9:10 am LINK
    DATE: Jul 20, 2017 @ 10:41am, 2 day(s) ago
    For those who might be interested, below are links to eBird checklists that have photos of the subadult Masked/Nazca Booby at Point Pinos. Unfortunately, because it is a slash taxa the checklists do not show up in any of the eBird alerts, so are not easily findable by the general public.
    
    Tom Benson
    San Bernardino, CA
    
    http://ebird.org/ebird/view/checklist/S38228455
    
    http://ebird.org/ebird/view/checklist/S38214515
    
    http://ebird.org/ebird/view/checklist/S38214488
    
    http://ebird.org/ebird/view/checklist/S38222232
    
    http://ebird.org/ebird/view/checklist/S38212156
    
    http://ebird.org/ebird/view/checklist/S38223748
    
    
  30. -back to top-


-revision history-
v1.30 - 01/05/16 - Revamped cloud logic, optimized database queries, linked to eBird rarities.
v1.23 - 12/08/11 - Added direct link to CBRC records.
v1.22 - 12/03/11 - Corrected GMT offsets on dates. Added last 5 posts at top.
v1.21 - 11/24/11 - Added direct link to range map for NA birds.
v1.2  - 11/23/11 - Greatly improved graphing technology - separates month vs. year by posts. Added species auto-complete functionality.
v1.14 - 11/22/11 - Added cloud bubble for common thread topics.
v1.13 - 11/22/11 - Added integrated photos where available.
v1.12 - 11/22/11 - Added multiple input boxes for additional refinement, negative search criteria (eg. -keyword).
v1.11 - 11/22/11 - Added banding code, species look-up. Also direct link to recent eBird observations.
 v1.1 - 11/22/11 - Added 'date' functionality. Shows top 'month/year' combinations for a query. Restrict results to that 'month/year'.
 v1.0 - 11/21/11 - Initial version coded. Currently archiving 'lacobirds' and 'calbirds'.