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8925The "Bolsa Chica cormorant", and a minor update on Burris Basin tern colony

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  • Willick, Doug
    Aug 11, 2014
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      Just wanted to mention, for those that may be going to look for the juvenile Yellow-crowned Night-Heron at Bolsa Chica, and the reported Pelagic Cormorant, both found late last week (Friday I believe), that the cormorant that was photographed is actually a juvenile Brandt’s.  This bird is possibly not in good health, but in any case some very good close-up photographs have been posted to OC Birding (and good photos of the night-heron have also been posted to the website).  The cormorant was found along the Wintersburg Channel, near “the bridge at the half-way point (next to the pocket pond).”  I will admit that looking at the photos I was confused by it initially, as it looked like an all-dark juvenile cormorant, but thought the bill looked a little thick.  Robert McNab, however, pointed out that the cormorant was actually a Brandt’s. The original photos don’t show the throat very well, because of the angle, but the bird does have the pale (dull buffy) throat patch shown by juvenile Brandt’s (a little less contrasting than that of the adult).  The bird’s throat patch was more obvious on photos (obtained by Jeff Bray) that I was able to see later.  The bill is definitely more substantial (thicker based, etc.) than Pelagic, and is more consistent with a Brandt’s Cormorant.  One thing that also confused me is that I thought most juvenile/1st year Brandt’s show a fairly pale breast/underparts (paler than this Bolsa Chica cormorant), possibly even closer to Double-crested than Pelagic in this regard (e.g., Sibley depicts young Brandt’s has having a pale (“tan”) breast).  However, the Bolsa cormorant shows a fairly uniform and very dark brown breast (almost blackish brown).  As I learned by doing a search of Brandt’s Cormorant photos online, the underpart coloration on Brandt’s is apparently variable, somewhat like that of young Double-cresteds, which variable significantly in degree of paleness of the underparts.  So the Bolsa cormorant happens to be a Brandt’s with a relatively dark breast and belly.  Either species (Brandt’s or Pelagic) is quite rare at Bolsa Chica, and I’m not even sure if Brandt’s has been recorded there, since I don’t have the checklist for Bolsa handy.  I do know that Pelagic Cormorant has been recorded there a few times. 

       

      Sunday afternoon (10 Aug.) I made a visit to Burris Basin/Anaheim Coves Park, mainly to check on the status of the tern/skimmer nesting colony (on the island).  It looked like most of the large Forster’s Tern colony are pretty much wrapped up for the season, though there was still about 20 adults and what appeared to be a couple older fledglings still hanging around.  There was still large numbers of Black Skimmers present on the island (100-125 on the island, and perhaps 20-25 more flying around the basin).  It was nice to see a good number of fledgling skimmers (easily around 20), with still a few “runners” (pre-flyer aged birds) in the area where the skimmers have been breeding (at the north end of the island, where a few might still be on nests).   Most of the Least Terns appear to have departed, but on Sunday two or three were still flying around the Basin, and I was able to see an adult Least being followed by a juvenile a few times.  From what I’ve heard from biologists monitoring this Burris Basin tern and skimmer colony, there were quite a few Least Tern pairs present, and nesting, this summer (don’t have final numbers, but was possibly in excess of a dozen breeding pairs).  Not sure how successful they were this summer in raising young however (compared to past years), as the Forster’s Tern colony had very poor success, apparently due to very heavy predation pressure this year.  This evening a Peregrine Falcon was seen flying south just west of Burris, but it didn’t seem to be showing any interest in the tern/skimmer colony.

       

      Last weekend (on 3 Aug.), a juvenile Band-tailed Pigeon at Anaheim Coves Park was interesting, which was loosely associating with a few dozen Mourning Doves and Eurasian Collared-Doves along the southwestern edge of the park.

       

      Doug Willick

      Orange, CA