Date: 4/8/24 9:28 pm From: Dominik Mosur <dominikmosur...> Subject: [SFBirds] misc. observations and a note to eBird users
happy spring everyone,
First I wanted to add to the Tropical Kingbird spring "departure"
dates. A quick search of the eBird database shows two SF last dates of
5/10 for the bird that wintered in the Sutro Baths area in 2021 and
Lake Merced in 2015.
But there are two much later dates nearby; 5/29/2014 for a bird that
was being seen around SamTrans Marsh in north San Mateo County and
6/2/2020 for a bird observed in Muir Beach Marin County.
Other news of local interest in reverse chronological order:
this evening (4/8) at Pine Lake Park I encountered the first 2024
model fledgling Song Sparrows. with a mean incubation period of 13
days and 10 days from hatching to fledging this would indicate eggs
laid on about 3/18 . This is on the early side although poring through
atlas dates from nearby counties earliest fledge date for Santa Clara
is 4/1.
during point counts on Mount Sutro yesterday (4/7) I noted a
persistently singing Orange-crowned Warbler along the Mystery trail. I
suspect this is the same bird that was singing away from this spot on
a March 18th survey and perhaps even the same bird that was singing
from this location last spring (2023). Orange-crowned warbler is a
rare/very localized breeder in SF. In the past two decades to my
knowledge it has been confirmed only from the Land’s End /West Wash
area and the coastal bluffs above baker beach in the Presidio but
suspected of attempted breeding (by virtue of presence on territory
through spring) on Mounts Davidson and Sutro.
Other birds of note on the survey included at least (5-6) persisting
Varied Thrushes which have been around all winter and a Red-breasted
Nuthatch. the latter a species not seen here since last November.
on (4/3) while biking to work along Clarendon at the edge of Laguna
Honda Canyon I observed an American Robin dismantling, killing and
ultimately consuming a California Slender Salamander.
heading to court for jury duty (3/26) a Black-throated Gray Warbler
was seen briefly in a street tree at the SW corner of 11th and
Harrison, far from any suitable habitat. This was possibly an early
side migrant or more likely another overwintering BT Gray.
Finally, I would like to mention to all the people who enter their
sighting into eBird two simple ways to make your data more valuable is
by briefly noting the weather conditions (temperature, cloud cover,
wind speed and direction) at the time and by using breeding codes
where appropriate. If you have questions on how to use the codes
please don't hesitate to contact me off list.
