Malibu Lagoon Trip Report: 23 September, 2012
Don’t forget to visit our new page for the Malibu Lagoon 2012 Project, frequently updated with new photos. We just added 3 new interviews with Mark Abramson & Suzanne Goode, plus a link to the plant revegetation list.
It’s hard to see the channel area over the fence, but most of the grading seems to be done. The dike separating the channels area west basin from the lagoon reportedly comes down on Oct. 2, so presumably the grading will be done by then. A lot of fill dirt will then be trucked off, some already in piles (see photos), plus the removed portions of the dike. Revegetation utilizing 70,000 plants will begin soon.
Our heat wave continues: downtown L.A. had a record 103° earlier this week, and it was 80° at the lagoon before 11am. Our birding group was thin at the start, but people kept drifting in as time went by. Path-side brush birds were very quiet, so we quickly got to the lagoon. We almost missed the Pectoral Sandpiper reported the day before, and frankly, species diversity was low. Even Adamson House was un-birdy, possibly due to the many people checking out the exhibit of beautifully maintained Model-T Fords (plus a Woody & a McCord). It’s frightening to contemplate the number of human-hours it must take to keep these cars running and looking so stunning.
Dewatering seems intermittent: the main basin has a lot of water, and the discharge pipe started spouting water while we were checking out the offshore birds. Speaking of offshore, it’s quite likely that many of the birds usually loafing in the lagoon were in the very large congregation of birds many hundreds of yards offshore. There must have been a sizable fish shoal: besides the gulls, terns and pelicans diving, we could see dolphins cutting through the crowd. Even shearwaters got into the action, peeling off from a steady stream of north-bound birds. I counted about 70 shearwaters per minute passing by. They were probably either Pink-footed or Sooty, which typically migrate through SoCal this time of year, whereas Black-vented Shearwaters pass by Nov – early March. They were much too far away for me to tell the difference. They are in the species list below as “Shearwater sp.” (sp. means “species not determined.”), but they’re not included in any of the totals.
There is an island now in the channels area and the Western Gulls and Black-bellied Plovers have moved in and made themselves quite comfortable: I counted 36 of the former and 100 (at least) of the latter. Otherwise, channel area birds were few: 3 Mallard, 3 Double-crested Cormorant, 1 Brown Pelican, 1 Snowy Egret, 3 California Gull, 2 Black Phoebe, 1 American Crow, 2 Great-tailed Grackle, plus 1 Bewick’s Wren in the vegetation between the path and PCH.
This island reminded me of the long sand & gravel island which used to be in the middle of the lagoon. Until it disappeared during one of the El Nino winters in the ‘90’s, it was the favorite resting location for the birds. Except when feeding in the surf zone, they didn’t really use the beach much back then. Just like humans, they prefer feeling safe when they’re trying to sleep or loaf, and this island (except at the highest tides) gave them such protection.
The dead Brown Pelicans continue: I counted 8 in various stages of decomposition on the sand islands near the beach. The die-off, apparently due to starvation from lack of sufficient small fish, has been noted all along the U.S. west coast for many months.
While returning from Adamson House, Mary Prismon found the elusive Pectoral Sandpiper near the SE end of the PCH bridge, feeding in the mud among the reed stalks. I’d checked that area, but alas, it was not there for me. Thanks, Mary!
Our next three field trips: Bolsa Chica, 6 Oct. 8:30am; Malibu Lagoon, 28 Oct., 8:30am., Butterbredt Fall Campout, Nov 3-4, 8:30am.
Our next program: Tuesday, 2 October, 7:30 pm. Water Conservation and Sustainability – Kimberly O’Cain. The usual reminders will be emailed from the blog.
NOTE: Our 10 a.m. Parent’s & Kids Birdwalk remains canceled until the parking lot is again fully available.
Comments on Bird Lists Below
Total Birds: Sept. total birds of 1013 are 12% above average (Jul & Aug were down 9%), or 107 over the 6-year average of 906, which is not really significant. Brown Pelican numbers remain down, but Black-bellied Plover are well above average. Whimbrels and Elegant Terns are high, Snowy Plovers about average. Except for Starlings and Black Phoebes, passerines are down, probably due to the lack of vegetation. During the project so far, total bird numbers have been up & down, up & down, but usually not far from average either way, and such variations are typical.
Species Diversity: Of 115 total species appearing in September for 2007-12, no more than 68% of them appeared on any one count day. Since we began these 6-year comparisons in May, this “appearance rate” has fluctuated from 61% to 68% – intriguingly consistent. It seems to indicate that – whenever you visit – what you see is 1/2 – 2/3rds of what is possible at that time of year. September 2012 with 51 species is 20% below average. Reduced diversity was spread across all 9 categories of birds, but most significant in the passerines which was 7 species below the 6-year average of 22. We didn’t even have any swallows! The lack of vegetation, plus our inability to get to the remaining perimeter vegetation, seems to me to be the probable cause.
Summary of species diversity from the 6-year average so far: May +4%, June -10%, July +10%, August -6%, September -20%. September is the first significant variation from average, and was, in fact, the lowest September species count in 10 years. I suspect that census diversity will recover once we have full access to the lagoon perimeter and after vegetation (not yet planted) has taken hold, but we’ll have to wait and see. [Chuck Almdale]
|Tide Lo/Hi Height||H +4.5||H +5.7||H +3.9||H +5.54||H +5.33||L +2.88||Ave.|
|Great Blue Heron||7||10||5||5||2||5||5.7|
|Blk-throated G. Warbler||1||0.2|
|Totals by Type||9/23||9/28||9/27||9/26||9/25||9/23||Ave.|
|Gulls & Terns||107||122||120||249||124||207||155|
|Gulls & Terns||4||8||5||9||7||6||6.5|
|Totals Species – 115||65||59||62||78||68||51||63.8|