[EBB Sightings] Osprey in Albany

Hi all,
During the atlas project there was an Osprey nest on
private property near Pt. Pinole Regional Shoreline. I
believe it was originally found by Kirk Swenson and
Ellen Blustein. It is possible that there is a nest
closer to Albany than that but see the text below (a
rough draft from the Contra Costa Breeding Bird Atlas)
for a discussion of how far they forage from the nest.
Steve Glover
Dublin

Osprey  (Pandion haliaetus)
Opening comments
Ospreys are uncommon wintering birds and migrants in
Contra Costa County with the vast majority of
sightings coming from August through April. Though
migrants and commuters may be seen virtually anywhere
in the county, most sightings are of wintering birds
frequenting the Richmond shoreline and the watershed
reservoirs of the Berkeley Hills. As breeding birds,
however, Ospreys are amongst the rarest of the rare
with but a single confirmation during the atlas
project.
Current status and distribution
The lone nest detected during the atlas project was
near Point Pinole Regional Shoreline. Birds are also
frequently recorded southwest along the bayshore,
particularly at Pt. Isabel Regional Shoreline. Inland
they are most often found hunting at the watershed
reservoirs of the Berkeley Hills and, since it?s
recent completion, at Los Vaqueros Reservoir at the
eastern edge of the Diablo Range. 
Numerous records from April-June in Richmond bayside
blocks and from the watershed reservoirs suggest that
an additional pair or two may have bred somewhere in
the county and simply avoided detection. On the other
hand, Ospreys are known to forage as far as 20 km from
the nest site and thus birds noted over inland
reservoirs may be commuting to the Pinole nest site or
another unknown site elsewhere. This idea is bolstered
by the fact that neighbors north of San Pablo
Reservoir have reported fish falling from the sky! (R.
Hartwell, pers. comm.)
Necessary conditions for breeding Ospreys includes a
steady, easily accessible supply of fish with 10-20 km
of the nest site, shallow water where fishing is
easier, and open elevated nest sites free from
predators (Poole et al. 2002). Ospreys in coastal
California almost exclusively use tall trees for
nesting (Shuford 1993) but the Pinole nest was in an
artificial tower. Elsewhere, Ospreys have responded
well to artificial nest towers but the one such tower
in the county, one constructed at San Pablo Reservoir,
has been used only for perching (R. Hartwell, pers.
comm.).
Historical occurrence
It is unclear if Ospreys historically nested in the
county but by the time of Grinnell and Wythe they were
known in the Bay Region only from the Russian River
region (G&W 1927). Grinnell and Miller (1944) state
that they were formerly much more common but ?now
(1944) much reduced in numbers, and known nesting
stations few.? There are apparently no published
records of Ospreys for Contra Costa during the 20th
century until the 1950s when at least five sightings
were recorded in The Gull. Still, sightings remained
noteworthy until the early 1980s when they began to be
recorded regularly. A nest, likely the first for
Contra Costa County, was reported at Briones Reservoir
in 1990 (Kite
..)
Breeding and natural history
Just a single pair of Osprey were confirmed nesting
during the five years of the atlas project, that being
a pair on a nest at Pinole 2-19 May 1998. In Napa
County (Napa-Solano Audubon Society 2003), nest
building was noted 30 April and 30 May, a nest with
young was found on 15 May and a fledgling was recorded
1 July. The Sonoma atlas found an occupied nest on 30
March and a nest with young on 1 July, suggesting that
the breeding cycle is a lengthier affair than our
meager data would suggest (Burridge 1995). 
Conservation
	Osprey populations during the 20th century suffered
significant declines due to pesticides, particularly
DDT and DDE (Poole et al. 2002). In Contra Costa
County, however, Ospreys are undoubtedly more common
than at any time during recorded history, despite the
presence of just one known breeding pair. It is
possible that the more widespread erection of
artificial nest platforms may lure a handful of
additional birds to remain to breed.

Poole, A. F., R. O. Bierregaard, and M. S. Martell.
2002. Osprey (Pandion haliaetus). In The Birds of
North America, No. 683 (A. Poole and F. Gill, eds.).
The Birds of North America, Inc., Philadelphia, PA.



--- Barbara Quein  wrote:

> Yesterday at 5:30 p.m. an osprey was searching for
> dinner at Albany  
> Beach, at the foot of Buchannan St. He did catch a
> fish and headed  
> north along the shore. Does anyone know the location
> of the nest ?
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