[EBB Sightings] Accipiter chases Flicker at Tilden Regional Park

Sorry for the late post:

Yesterday morning about 8 a.m., while walking out the road past Jewel Lake,
we heard a repeated and unfamiliar loud screeching.  We looked high and
low...till we spotted 2 birds darting through the eucalyptus trees along the
road just north of the lake.  It looked like pursuit -- rapid flight, pause,
rapid flight, pause -- and one bird was visibly larger.

Finally, a bird landed on a branch clear of foliage: a Common Flicker.  Then
an accipiter landed nearby.  In less than a minute, the Flicker took off,
only to be chased again by the accipiter.  This scenario repeated maybe 10
times in 15 minutes:  short bursts of flight, screeching/screaming, the
Flicker landing, then the accipiter landing in the vicinity.

After one such sally, the Flicker lighted in a eucalyptus on the west side
of the trail -- and the accipiter landed on the east.  Some crows had
trickled in, gathering around the accipiter; when it moved into the
Flicker's tree, the crows followed.  The accipiter dove at the nearest crow
(which hopped away) and came to rest about 20 feet above the Flicker.

The Flicker seemed oblivious to the location of the accipiter; rather than
stay still or fly in the opposite direction, it flew upward almost directly
to it.  Once again, the chase, the screeching -- into the canopy west of
Jewel Lake, out of view.  As we moved away, another round of screeching was
heard.  

On our return about an hour later, an accipiter in the same location was
being mobbed by Stellar's Jays.  Rather than take a direct flight out of the
area, it made short hops in the canopy, with its pursuers in tow.

Several views of the accipiter suggest "late immature" Sharp-Shinned Hawk:
vertical streaks on chest, dark crown, dark slate-gray wings, barred tail,
no white terminal band.  (Judith Dunham's post of August 30 mentioned 2
immature Sharp-Shinned Hawks in the vicinity.)

Questions:  It seemed that the Flicker was vocalizing, but maybe that was an
anthropomorphic assumption.  Has anyone ever heard of this kind of distress
call from a Flicker?  Or was it a warning-off screech from the accipiter?

thanks, and good birding

Lory Poulson
Richmond




> From: Judith Dunham 
> Date: Sun, 30 Aug 2009 13:01:20 -0700
> To: EBB 
> Subject: [EBB Sightings] Townsend's Warblers at Tilden Regional Park
> 
> This morning between about 10 and 11:30, I birded the lower Packrat
> Trail from the parking lot to Jewel Lake, returning along the
> boardwalk on the opposite side of the lake. When I emerged from the
> trail at the end of the lake near the dam, I was surrounded by a
> sizable mixed flock that included four or five Townsend's Warblers
> and three Warbling Vireos, plus Brown Creepers, Red-breasted
> Nuthatches, and an abundance of Chestnut-backed Chickadees. The flock
> was foraging in the tall redwoods and other trees along this end of
> the lake.
> 
> The other notable sighting occurred along the Packrat Trail where I
> heard three accipters vocalizing and saw them chasing one another
> deftly through the oaks and bays up the hill. They alighted several
> times, allowing me to identify two immature Sharp-shinned Hawks and
> one adult. They continued to call and fly about for nearly ten minutes.
> 
> The park's other birds were out and about: California Towhee, Spotted
> Towhee, Wrentit, Bewick's Wren,  Song Sparrow, Steller's Jay, Red-
> shouldered Hawk. A couple Swainson's Thrushes "whitted" from the
> underbrush.
> 
> Judith Dunham
> Berkeley