[Leica] on Hawk Hill (long)

[Doug Herr <Telyt@compuserve.com>]

In the great fall migrations of North American raptors there are
spectacular concentrations of hawks in certain areas, where topography and
weather patterns conspire to reduce the hawks' superhighways in the sky to
one-lane paths.  Hawk Hill in Pennsylvania has been known for many years as
one of these places; on many days, thousands of broad-winged Hawks will be
seen to pass overhead from their Canadian breeding grounds to points south;
the Gulf Coast of Texas also has high concentrations of raptors, as the
birds fly south over land, reach the Gulf of Mexico and are forced to fly
along the coast in order to continue the southward movement.  Recently at a
hawk concentration point in Veracruz, Mexico, one million hawks were
observed flying past in a single day.

Hill 129 in the Marin County headlands is one such place.  Hawks migrating
south along the pacific coast are blocked from westward drift by the
Pacific Ocean, and as they approach the Golden Gate, San Pablo Bay keeps
them from wandering easward, funneling the birds to Hill 129.

During World War II the area was a military facility with anti-aircrafe
guns and bunkers to protect them.  More recently the area was home to
underground missile silos.  The military need for these installations now
gone, the area is open to the public for recreation.  Until the mid-1970s,
the west coast's greatest hawk concentration point was unknown to humankind
until Lawrence ("Laurie") Binford, then curator of Birds and Mammals at the
California Academy of Sciences in nearby Golden Gate Park, noticed unusual
numbers of hawks flying past his office.  He hopped into his Dodge Dart and
traced the stream of hawks back to the Golden Gate; crossing into Marin
County, he found the hill, now known as Hawk Hill, where these raptors
concentrate before the "leap" across the Golden Gate.

Finding myself temorarily without family obligations, I drove 2 hours from
Sacramento for my first visit to the Hill in eleven years.  I arrived in
mid-morning to brilliant sunshine, with the Golden Gate, well below the
Hill, covered in fog.  The twin towers of the Golden Gate bridge and part
of the city's skyline were all I could see of the City by the Bay.  Horns
in the fog warned watercraft of unintended landfall while on the Hill,
sunscreen seemed more appropriate than a coat.  It was Mark Twain who said
that the coldest winter he'd ever spent was a summer in San Francisco. 
Cold Pacific currents meeting the warm air over the land cover the area
with fog until the rains of winter cool the earth.

For many years, volunteers have stood on the Hill counting the hawks as
they pass in order to monitor populations.  Hawks, near the end of the food
chain, are good indicators of ecologial health and their population trends
over the years can give advance warning of dangers, such as the thin
eggshells of several species (and subsequent nesting failures) warned of
DDT's hazards.

As I arrived at the Hill, volunteers were already in place, waiting for the
action to begin.  They remarked at my Sacramento-style clothing, a t-shirt
and hiking shorts, how until this morning these would not have been
appropriate clothes.  During the entire previous week the Hill was socked
in with fog as much as the Golden Gate, below.  Not only were there no
hawks flying, but it had been darned cold standing around watching nothing.

What good fortune! Not only was my first visit in eleven years on a clear
day, but now the volunteers tell me the greatest numbers of hawks are
usually seen on the first clear day after the fall equinox!

I met with fellow LUGger and Bay Area resident George Hartzell on the Hill,
and as we talked of Leicas, photography, travels, kayaking, his new house
and the upcoming BALUG events, the hawk numbers began to build.  Most
numerous were the small accipiters, the Sharp-shinned and Cooper's hawks. 
Also present, and a delight to western birders, were several Broad-winged
Hawks.  Rarely seen in the west, they are almost common at the Hill in late
September.

During the summer and fall, the Sacramento Valley to the east bakes in the
sun until the air heats enough that it rises.  As the Valley's air rises,
westward air from the Pacific Ocean rushes in to take its place.  In
Sacramento we call this the "Delta Breeze" since it flows into the valley
through the Sacramento River delta, or more simply, we call it "ahhhhh...
cool air".  Along the coast, the Delta Breeze means more fog.  On the Hill,
the Delta Breeze means the Hill is making great ridge lift so the hawks
will fly much closer to the Hill.  In other words, it's Telyt time!

The 560 f/6.8 Telyt with the Leicaflex SL body was most useful to me as
hawks of many flavors gave photo-op after photo-op.  George had also
brought his SLR with 400mm lens (notice I didn't mention brand names!) and
our film use jumped dramatically.  A complete list of hawk species is at
the end of this post.

The early afternoon had brought the Delta Breeze, but it also brought the
fog closer to the Hill.  It also found me nervously glancing at my watch
every few minutes, since I had to be in Sacramento by 4:00 PM to pick up my
teen-age daughter who'd been at her drill team's practice all day.  Lets
see, 2 hours, plus a bit, driving time, plus a few minutes to drop by the
house to find the map to the practice site, means I'd have to leave the
Hill before 1:30.  By 1:00 the hawks had become downright cooperative in
their fly-bys and I between birds I was re-calculating the time I'd really
have to go.  I packed the 400 - another incredible photo-op - I pack the
extra film - another bunch of hawks.  Meanwhile the Delta Breeze was
pulling the fog closer to the Hill.

At 1:30 I forced myself to leave.  Backpack on, film cooler and fanny pack
in hand, I kept the 560 out, and was still shooting as I walked toward the
trail down the Hill.  Once on the trail the Delta Breeze pulled the first
few wisps of fog over the path.

An uneventful trip home, and I arrived just in time to retrieve Vanessa and
drop her off at her job.

Doug Herr
Sacramento
http://ourworld.compuserve.com/homepages/telyt


Hawk list:

Osprey (2)
Sharp-shinned Hawk (abundant)
Cooper's Hawk (numerous)
White-tailed Kite (1)
Red-tailed Hawk (common)
Red-shouldered Hawk (several)
Broad-winged Hawk (several, including one dark morph)
Bale Eagle (1, first of the season)
American Kestrel (a few)
Merlin (3 or 4)
Peregrine Falcon (1)

and that's all