Field trip summary from Sunday and ecology report


Josiah Clark
 

Yesterday I led a biking and birding field trip through Golden gate Park to the Cliff House for the organization Shaping San Francisco.
     Scheduled for the cusp of spring, this field trip now its 4th year focuses on diversity as we try to observe as many residents, wintering birds and spring migrants as possible.
       The group observed 72 species during the trip. There did seem to be quite a few hawks and swallows moving over, though we didn’t find any unusual birds. 
Here are a few bird highlights. 
      Wilson’s Warbler-singing at north lake.
       Cinnamon Teal at Stow lake continuing
       The N shovelers had moved to spreckles
    The lone male lesser scaup had moved to N. lake 
     4 meadowlarks were at the bison paddock 
            Though I haven’t been writing about it much recently I’ve definitely been noticing pretty major changes to the bird life and ecology of our area in recent months.
 Some birds that seem conspicuously absent to me or nearly so are the rocky shore birds. Black turnstones that used to be very reliable in double digit groups at the cliff house have gotten quite uncommon or absent in recent years. (With great effort I finally saw just one for about 30 seconds at the Cliff House).
    The numbers of red-throated loon and large grebes on the ocean are very low compared to other years where large groups were expected, I saw just one of each yesterday. 
      The heron rookery at Stow Lake appears down to just one active nest compared to 5 last year. The big dead pine that held the rookery broke in half. At least one or two nests fell with it. 
  The incessant predation and pressure by the population explosion of ravens appears to be the most obvious cause for declines in many breeding birds large and small.
We observed ravens from the moment we met and they were present at every location throughout the course of the day. Some locations had over 20 and many actively hunting in coordinated groups. 
  As someone who grew up birding all of 
these places in San Francisco, I will say this is the quietest I have ever heard it at this time of year. 
I believe this is also the driest year of my life, not just in terms of lack of rain but also with drier offshore air flow, higher evaporative rates and decreased atmospheric moisture. This can be most obviously observed at reservoirs and lakes, which now in March are at the lowest levels they reached in the last drought. But the same evaporative process is also sucking moisture out of the land, vegetation and food sources for birds.
      I want nothing more than to be wrong, but I fear 2021 could be the year our state sees even more major changes to our ecology. 
     It seems during Covid times people have little bandwidth to absorb any other kind
 of news. “We are all in this together” they  say...
 If people would only do as much for the planet as they do for themselves.
 Like G.I. Joe said, “knowing is half the battle”.  
      
Josiah Clark | Habitat Potential | Consulting Ecologist | 415.317.3978
License #1043929


Joel Perlstein
 

I suspect that the lack of rocky shorebirds at the Cliff House area may have something to do with the widening beach there. It seems like there is much more of the day when people and dogs can access the beach below the rocky cliffs.


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Joel Perlstein
San Francisco


Alan Hopkins
 

Joel,

I don't think dogs have much to do with it. When I began birding here in the 70s mussel and barnacle covered rocks were exposed all the way down to the seawall at Ocean Beach at low tide. All the rocks along the shore are covered with sand now. I think that this is well worth remembering when people talk of sea level rise at the southern end of the beach. I don't doubt that sea level rise is happening but beaches are dynamic and sand moves over time. 

Alan S. Hopkins
San Francisco, CA



On Tuesday, March 30, 2021, 12:53:11 PM PDT, Joel Perlstein <joelperl@...> wrote:


I suspect that the lack of rocky shorebirds at the Cliff House area may have something to do with the widening beach there.  It seems like there is much more of the day when people and dogs can access the beach below the rocky cliffs.


--
Joel Perlstein
San Francisco