Date: 9/24/26 5:31 pm From: 'Pete Sole' via mbbirds <mbbirds...> Subject: [MBBIRDS] Fox Sparrows at Loma Prieta
Hi birders,
Been meaning to write about the FOX SPARROWS at Loma Prieta for a couple
of days. I went to Loma Prieta on Tuesday Sept. 22nd and, as other
birders noted as well, there were many FOX SPARROWS. I conservatively
reported 7 individuals on my ebird checklist
<https://ebird.org/checklist/S395321875> for the morning, but there were
probably more.
Interestingly, a number of them were of the SLATE-COLORED subspecies,
including an individual that I was able to photograph. (Sadly the photos
are ahem, poor.)
Regardless, SLATE-COLORED FOX SPARROWS may be, a different species from
the SOOTY FOX SPARROW subspecies we more commonly see closer to the
coast. According to Cornell's Birds of the World reference site,
"analyses of mitochondrial DNA (mtDNA) detected significant amounts of
genetic structure, identifying 4 groups of Fox Sparrows corresponding to
those defined by plumage and morphology..". Cornell's site, lists 19
subspecies of Fox Sparrows, grouped into the 4 major groups; SOOTY,
THICK-BILLED, SLATE-COLORED, and RED. ( Source:
https://birdsoftheworld.org/bow/species/foxspa/cur/systematics )
What does this mean in plain English?
What our common reference books and apps mention as four subspecies of
Fox Sparrow, are actually groups of subspecies that may each be, a
separate species; SOOTY, THICK-BILLED, SLATE-COLORED, and RED.
Given the various contact points between the purported subspecies and
hybridization, ornithologists are still debating and collecting data.
Currently, some professional references already treat the four groups as
separate species. For example, the official International Ornithological
Committee (IOC), the predecessor to the International Ornithologists'
Union (IOU), lists the four Fox Sparrow groups as separate species. (To
see the IOC list, see this link:
This is a large searchable spreadsheet that may take time to load, even
on a fast internet connection.)
In any case, imho, it is worth it to try to list and document, the
separate Fox Sparrow subspecies that we can ID in the field. Who knows,
some day your report and photos may count as another species.
Fun birding,
Pete Solé
nerding out on bird speciation and migration in Soquel CA
