San Mateo Co. Bird Observations from eBird
Full Year 2025
Click on a species name for a map & data.
PDF file available for download:
A Checklist Of The Birds Of
San Mateo County, California
Compiled by Peter J. Metropulos
for the Sequoia Audubon Society
April, 2006Download County Checklist
for printing on 8 ½ by 14 paper.
This page includes sightings from:
Peninsula Birding on groups.ioApril 2026
Dear San Mateo County Birders,
San Mateo County birders found a total of 28 species that were new for the year by the end of April. This brings the total species observed by the end of the third month to 272.
In reading the following, please note, the number in parenthesis next to the bird name is the rarity code assigned for San Mateo County birds. The definitions for the rarity codes can be found below the current month's list. The rarity code system was set up in 2009 By the late Kris Olson based on Peter Metropulos' codes on the San Mateo County Checklist which was published by The San Mateo County Bird Alliance (then Sequoia Audubon Society at time of publishing) in 2006. From this page, you can view the full list of the birds observed so far in 2025 plus download a checklist which shows seasonality, frequency, and county breeding information. Additionally, all monthly reports going back to 2009 can be found here.
Here are the new birds for April, their finders and locations where found:
Michael Long found a GARGANEY (6) at Nob Hill Pond. A county first! The addition of the Garganey brings a total of 482 recorded species in San Mateo County and its offshore waters. Excellent find Michael! VAUX'S SWIFT (3) were reported by Michael Rogers and Richard Jeffers at Miramontes Point. A San Francisco County focused pelagic trip out of Half Moon Bay on the Outer Limits went offshore and recorded RED-NECKED PHALAROPE (2), POMARINE JAEGER (3), SABINE'S GULL (2), LAYSAN ALBATROSS (4), and BLACK-FOOTED ALBATROSS (3) in San Mateo County waters. Even further offshore several repositioning cruises reported LONG-TAILED JAEGER (3), PARASITIC JAEGER (2), LEACH'S STORM-PETREL (4), MURPHY'S PETREL (6), HAWAIIAN PETREL (6), and COOK'S PETREL (6). From a seawatch at Pigeon Point, Ron Thorn reported PINK-FOOTED SHEARWATER (2). OLIVE-SIDED FLYCATCHER (3) was found by Ryan Mense along Whitehouse Canyon Rd. Alane Gray and Richard Hopf had WESTERN WOOD-PEWEE (3) at 2 different locations on the same day, Seaside School Rd. in San Gregorio and Windy Hill Open Space. HAMMOND'S FLYCATCHER (4) was encountered at Sem Lane in Belmont by Ron Thorn. Multiple Observer's reported ASH-THROATED FLYCATCHER (2) in expected habitat at different locations on the same day. A set of reports for CASSIN'S VIREO (2) were provided by Multiple Observers at different locations. Caitlin Chock found the first BANK SWALLOW (2) for the year at Bedwell Bayfront in Menlo Park. While biking Sawyer Camp Trail, Dorian Anderson observed PURPLE MARTIN (4) investigating probable nesting sites in a utility pole used by martins in the previous year. Multiple Observers reported SWAINSON'S THRUSH (2) at various riparian locations on the same date. GRASSHOPPER SPARROW (2) was recorded by Multiple Observers at La Honda Creek Opens Space. Ryan Mense found the first YELLOW-BREASTED CHAT (4) of the year at Año Nuevo. Aaron Maizlish and Richard Bradus discovered a YELLOW-HEADED BLACKBIRD (4) at Nob Hill Pond. A trip to Burleigh Murray State Park presented Alex Rinkert with a BULLOCK'S ORIOLE (2). Naomi Goodman observed a WESTERN TANAGER (2) in the San Francisquito Creek area. LAZULI BUNTING (2) caught Kent Forward's attention during a visit to La Honda Creek OSP.2026 has been a pretty epic year so far in terms of numbers of species reported. Our end of April total of 272 is the 2nd highest end of April total since this report began being produced in 2009. Only one other end of April total beats our current 2026 total with 2015 reporting 273 species by the end of the 4th month! Keep up the good work and let's see how the year pans out!
To stay informed of the latest bird news, consider creating an account with both Peninsula Birding (Pen-bird) and eBird. Please join and post your bird sightings to peninsula-birding@groups.io and/or www.eBird.org. When posting to Pen-bird, please include the date of your sighting in either the subject line or in the body of your email. When submitting records to eBird, if prompted for details for a rare or unusual bird, please add details which describe the bird using a physical description and field marks that helped you confirm the ID. Thank You eBird users for adding your descriptions and uploading your photos and audio to your checklists. To join eBird, simply go to https://ebird.org/home and create an account.
To join the Peninsula Birding group, join here: https://groups.io/g/peninsula-birding You can post your sightings there and be kept informed of sightings throughout the county including discussions about birds, population trends, where-can-I-find topics, events, field trips, webinars, pelagic trips and conservation issues. You can engage with other members of the birding community and can connect with online/offline discussions.
About this Report: As a volunteer for the San Mateo County Bird Alliance we gather content for this report, each month, by primarily using eBird and Pen-bird. When posting to Pen-bird, please include the location and date of your sighting in either the subject line or in the body of your email. If you don't use eBird or Pen-bird, you can always email me directly. Thank you!
If you have questions or comments regarding this report, please email: maliadances@yahoo.com
Malia DeFelice
San Mateo County Bird Alliance Volunteers
**Cumulative Year Report**
New Species Added per Month Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Total 2009 214 13 17 21 18 5 6 16 8 13 2 2 335 2010 206 5 19 31 10 7 11 2 11 9 3 2 316 2011 212 8 14 30 13 5 12 8 16 8 4 3 334 2012 211 9 12 30 5 7 5 13 12 9 3 2 318 2013 207 11 21 20 14 5 11 10 11 10 5 2 327 2014 221 5 10 24 9 1 12 7 22 11 2 2 335 2015 216 16 24 17 16 6 4 8 18 2 2 1 331 2016 216 17 15 20 12 1 13 6 15 5 4 4 328 2017 218 8 19 35 13 3 6 9 17 8 3 3 341 2018 216 12 16 26 15 6 8 9 10 4 3 7 332 2019 209 7 29 17 15 3 2 12 13 7 2 6 322 2020 211 8 16 22 21 9 5 11 12 14 4 4 337 2021 208 11 16 19 12 3 7 12 14 7 5 2 316 2022 215 6 13 30 14 4 1 10 23 12 4 2 334 2023 213 11 12 29 11 5 2 10 20 19 3 3 338 2024 206 13 16 28 7 4 8 9 21 9 6 5 332 2025 215 9 18 25 6 8 12 9 16 10 5 1; 334 2026 22 8 14 28 272
SAN MATEO COUNTY 2026 CUMULATIVE YEAR LIST - April Species Date *Rarity **Observer Fulvous Whistling-Duck 6 Emperor Goose 6 Snow Goose 1/9/26 4 GD Ross's Goose 1/7/26 4 RF Greater White-fronted Goose 1/1/26 4 M.Ob. Brant 1/2/26 2 M.Ob. Cackling Goose 1/1/26 4 CH Canada Goose 1/1/26 1 M.Ob. Tundra Swan 4 Wood Duck 1/1/26 3 RH Garganey 4/23/26 6 Mlo Blue-winged Teal 1/1/26 4 LHy, RT Cinnamon Teal 1/1/26 2 JTo Northern Shoveler 1/1/26 2 M.Ob. Gadwall 1/1/26 2 M.Ob. Eurasian Wigeon 1/1/26 4 RT American Wigeon 1/1/26 2 M.Ob. Mallard 1/1/26 1 M.Ob. Northern Pintail 1/1/26 2 M.Ob. Green-winged Teal 1/1/26 2 M.Ob. Canvasback 1/1/26 2 M.Ob. Redhead 1/22/26 4 DAB Ring-necked Duck 1/1/26 2 M.Ob. Tufted Duck 1/1/26 4 M.Ob. Greater Scaup 1/1/26 1 M.Ob. Lesser Scaup 1/1/26 1 M.Ob. King Eider 6 Harlequin Duck 1/1/26 4 DAB Surf Scoter 1/1/26 1 M.Ob. White-winged Scoter 1/19/26 4 RyM Black Scoter 1/1/26 4 M.Ob. Long-tailed Duck 1/20/26 4 RT Bufflehead 1/1/26 2 M.Ob. Common Goldeneye 1/1/26 2 M.Ob. Barrow's Goldeneye 1/1/26 3 M.Ob. Smew 6 Hooded Merganser 1/1/26 3 M.Ob. Common Merganser 1/3/26 2 M.Ob. Red-breasted Merganser 1/2/26 3 DAB, GC Ruddy Duck 1/1/26 1 M.Ob. Mountain Quail 5 California Quail 1/1/26 1 M.Ob. Pied-billed Grebe 1/1/26 2 M.Ob. Horned Grebe 1/1/26 2 M.Ob. Red-necked Grebe 1/11/26 4 LSo, VM Eared Grebe 1/1/26 2 M.Ob. Western Grebe 1/1/26 1 M.Ob. Clark's Grebe 1/1/26 2 M.Ob. Band-tailed Pigeon 1/1/26 2 CMi, ELe Common Ground-Dove 6 White-winged Dove 5 Mourning Dove 1/1/26 1 M.Ob. Greater Roadrunner XTP Yellow-billed Cuckoo 6 Lesser Nighthawk 6 Common Nighthawk 6 Common Poorwill 2/12/26 4 CH Chuck-will's Widow 6 Black Swift 4 Chimney Swift 6 Vaux's Swift 4/7/26 3 MMR, RGJ White-throated Swift 1/2/26 3 M.Ob. Black-chinned Hummingbird 6 Anna's Hummingbird 1/1/26 1 M.Ob. Costa's Hummingbird 6 Calliope Hummingbird 6 Rufous Hummingbird 3/18/26 2 LO Allen's Hummingbird 1/17/26 1 MX Broad-billed Hummingbird 6 Ridgway's Rail 1/8/26 3 CH Virginia Rail 1/3/26 3 M.Ob. Sora 1/2/26 3 KPi Common Gallinule 4 American Coot 1/1/26 1 M.Ob. Yellow Rail 6 Black Rail 5 Sandhill Crane 6 Black-necked Stilt 1/1/26 2 M.Ob. American Avocet 1/1/26 1 M.Ob. Black Oystercatcher 1/1/26 3 M.Ob. Black-bellied Plover 1/1/26 1 M.Ob. American Golden-Plover 5 Pacific Golden-Plover 1/7/26 4 RF Killdeer 1/1/26 2 M.Ob. Semipalmated Plover 1/1/26 2 M.Ob. Piping Plover 6 Mountain Plover 6 Snowy Plover 1/3/26 3 M.Ob. Hudsonian Whimbrel 1/1/26 2 M.Ob. Eurasian Whimbrel 6 Long-billed Curlew 1/1/26 2 M.Ob. Bar-tailed Godwit 6 Hudsonian Godwit 6 Marbled Godwit 1/1/26 1 M.Ob. Short-billed Dowitcher 1/1/26 1 DAB, EAy Long-billed Dowithcher 1/1/26 1 M.Ob. Wilson's Snipe 1/1/26 3 RT Wilson's Phalarope Red Phalarope 3/10/26 2 RT Red-necked Phalarope 4/18/26 2 SFPE Spotted Sandpiper 1/1/26 3 M.Ob. Solitary Sandpiper 4 Wandering Tattler 1/3/26 4 RyM Lesser Yellowlegs 1/8/26 4 M.Ob. Willet 1/1/26 1 M.Ob. Greater Yellowlegs 1/1/26 2 M.Ob. Ruddy Turnstone 1/2/26 3 Black Turnstone 1/1/26 1 M.Ob. Red Knot 1/1/26 3 M.Ob. Surfbird 1/1/26 2 DAB Ruff 6 Sharp-tailed Sandpiper 6 Curlew Sandpiper 6 Stilt Sandpiper 4 Buff-breasted Sandpiper 6 Sanderling 1/1/26 1 DAB, KTu Dunlin 1/1/26 1 M.Ob. Rock Sandpiper 4 Baird's Sandpiper 5 Least Sandpiper 1/1/26 1 M.Ob. Pectoral Sandpiper 5 Western Sandpiper 1/1/26 1 M.Ob. Semipalmated Sandpiper 4 Long-tailed Jaeger 4/22/26 3 CRSE Parasitic Jaeger 4/22/26 2 CRSE Pomarine Jaeger 4/18/26 3 SFPE South Polar Skua 3 Rhinoceros Auklet 1/3/26 1 M.Ob. Tufted Puffin 4 Horned Puffin 5 Cassin's Auklet 1/3/26 2 JTs Least Auklet 6 Parakeet Auklet 6 Long-billed Murrelet 6 Marbled Murrelet 1/3/26 3 M.Ob. Pigeon Guillemot 2/26/26 2 RT Common Murre 1/2/26 1 M.Ob. Ancient Murrelet 1/3/26 3 JTs Scripps's Murrelet 4 Guadalupe Murrelet 6 Craveri's Murrelet 6 Swallow-tailed Gull 6 Little Gull 6 Ross's Gull 6 Black-legged Kittiwake 2/18/26 3 CHe, MFr, Sabine's Gull 4/18/26 2 SFPE Bonaparte's Gull 1/2/26 2 M.Ob. Black-headed Gull 6 Laughing Gull 6 Franklin's Gull 4 Black-tailed Gull 6 Heermannn's Gull 1/1/26 1 M.Ob. Short-billed Gull 1/1/26 1 M.Ob. Ring-billed Gull 1/1/26 1 M.Ob. Western Gull 1/1/26 1 M.Ob. Kelp Gull 6 American Herring Gull 1/1/26 2 M.Ob. Vega Gull 1/25/26 6 ASun, PLi Glaucous Gull 1/16/26 4 CH Lesser Black-backed Gull 2/14/26 6 CH, MDF California Gull 1/1/26 1 M.Ob. Glaucous-winged Gull 1/1/26 1 M.Ob. Slaty-backed Gull 6 Iceland Gull 1/1/26 3 M.Ob. Black Skimmer 1/1/26 4 RT Least Tern 4 Gull-billed Tern 6 Caspian Tern 1/23/26 2 GC Black Tern 5 Forster's Tern 1/1/26 1 M.Ob. Arctic Tern 2 Common Tern 2 Elegant Tern 3/17/26 2 JMi Royal Tern 1/3/26 6 M.Ob. Red-billed Tropicbird 6 Red-tailed Tropicbird 6 Red-throated Loon 1/1/26 2 M.Ob. Arctic Loon 6 Pacific Loon 1/2/26 1 M.Ob. Common Loon 1/1/26 2 M.Ob. Yellow-billed Loon 6 Laysan Albatross 4/18/26 4 SFPE Black-footed Albatross 4/18/26 3 SFPE Short-tailed Albatross 6 Salvin's Albatross 6 Wilson's Storm Petrel 5 Fork-tailed Storm-Petrel 4 Leach's Storm-Petrel 4/22/26 4 CRSE Ashy Storm-Petrel 2 Black Storm-Petrel 2 Wedge-rumped Storm-Petrel 6 Least Storm-Petrel 6 Northern Fulmar 3/10/26 1 RT Murphy's Petrel 4/22/26 6 CRSE Hawaiian Petrel 4/22/26 6 CRSE Cook's Petrel 4/22/26 6 CRSE White-chinned Petrel 6 Streaked Shearwater 6 Pink-footed Shearwater 4/14/26 2 RT Flesh-footed Shearwater 5 Great Shearwater 6 Wedge-tailed Shearwater 6 Buller's Shearwater 2 Sooty Shearwater 3/28/26 1 RyM Short-tailed Shearwater 4 Manx Shearwater 5 Black-vented Shearwater 5 Mottled Petrel 6 Stejneger's Petrel 6 Parkinson's Petrel 6 Wood Stork 6 Magnificent Frigatebird 6 Northern Gannet 1/11/26 6 ADu Red-footed Booby 6 Cocos Booby 6 Masked Booby 6 Nazca Booby 6 Blue-footed Booby 6 Anhinga 6 Brandt's Cormorant 1/1/26 1 M.Ob. Pelagic Cormorant 1/1/26 2 M.Ob. Double-crested Cormorant 1/1/26 1 M.Ob. American White Pelican 1/1/26 4 JoM Brown Pelican 1/1/26 1 M.Ob. American Bittern 4 Least Bittern 6 Yellow-crowned Night Heron 6 Black-crowned Night Heron 1/1/26 3 M.Ob. Little Blue Heron 6 Snowy Egret 1/1/26 2 M.Ob. Green Heron 1/1/26 4 M.Ob. Western Cattle Egret 4 Great Egret 1/1/26 2 M.Ob. Great Blue Heron 1/1/26 2 M.Ob. White-faced Ibis 5 California Condor 6 Black Vulture 6 Turkey Vulture 1/1/26 2 M.Ob. Osprey 1/1/26 4 DAB, CGl White-tailed Kite 1/1/26 3 M.Ob. Golden Eagle 1/3/26 4 M.Ob. Northern Harrier 1/1/26 3 M.Ob. Sharp-shinned Hawk 1/1/26 3 BHo Cooper's Hawk 1/1/26 2 M.Ob. Northern Goshawk 6 Bald Eagle 1/1/26 4 M.Ob. Red-shouldered Hawk 1/1/26 2 M.Ob. Broad-winged Hawk 5 Swainson's Hawk 5 Zone-tailed Hawk 6 Red-tailed Hawk 1/1/26 2 M.Ob. Rough-legged Hawk 4 Ferruginous Hawk 1/3/26 4 CH, MDF American Barn Owl 1/1/26 3 KGr, STa Western Screech-Owl 1/3/26 2 AnKr, GD Snowy Owl 6 Great Horned Owl 1/1/26 2 RH Northern Pygmy-Owl 1/16/26 3 RH Burrowing Owl 1/1/26 4 M.Ob. Spotted Owl 6 Barred Owl 2/8/26 6 JSt Long-Eared Owl 3 Short-eared Owl 2/23/26 3 RT Northern Saw-whet Owl 1/14/26 3 GC Belted Kingfisher 1/1/26 3 M.Ob. Williamson's Sapsucker 6 Yellow-bellied Sapsucker 3/7/26 4 RyM Red-naped Sapsucker 1/9/26 4 RT Red-breasted Sapsucker 1/1/26 3 CNe Lewis's Woodpecker 4 Acorn Woodpecker 1/1/26 2 M.Ob. Downy Woodpecker 1/1/26 2 M.Ob. Nuttall's Woodpecker 1/1/26 2 M.Ob. Hairy Woodpecker 1/1/26 2 M.Ob. Pileated Woodpecker 1/2/26 4 CNe Northern Flicker 1/1/26 1 M.Ob. Crested Caracara 6 American Kestrel 1/1/26 2 M.Ob. Merlin 1/1/26 1 DAB, MKa Peregrine Falcon 1/1/26 4 CH Prairie Falcon 5 Olive-sided Flycatcher 4/5/26 3 RyM Western Wood-Pewee 4/23/26 3 AGr, RH Willow Flycatcher 5 Least Flycatcher 6 Hammond's Flycatcher 4/13/26 4 RT Gray Flycatcher 5 Dusky Flycatcher 5 Western Flycatcher 3/10/26 1 MHe Black Phoebe 1/1/26 2 M.Ob. Eastern Phoebe 5 Say's Phoebe 1/1/26 2 M.Ob. Vermilion Flycatcher 6 Dusky-capped Flycatcher 6 Ash-throated Flycatcher 4/5/26 2 M.Ob. Sulphur-bellied Flycatcher 6 Tropical Kingbird 4 Cassin's Kingbird 5 Thick-billed Kingbird 6 Western Kingbird 1/25/26 4 Adu, KF Eastern Kingbird 5 Scissor-tailed Flycatcher 6 White-eyed Vireo 6 Bell's Vireo 6 Hutton's Vireo 1/1/26 1 M.Ob. Yellow-throated Vireo 6 Cassin's Vireo 4/5/26 2 M.Ob. Blue-headed Vireo 6 Plumbeous Vireo 6 Philadelphia Vireo 6 Western Warbling Vireo 3/11/26 2 AE Red-eyed Vireo 4 Yellow-green Vireo 6 Loggerhead Shrike 1/3/26 3 M.Ob. Northern Shrike 6 Pinyon Jay 6 Steller's Jay 1/1/26 1 M.Ob. California Scrub-Jay 1/1/26 1 M.Ob. Yellow-billed Magpie 5 Clark's Nutcracker 6 American Crow 1/1/26 1 M.Ob. Common Raven 1/1/26 1 M.Ob. Mountain Chickadee 6 Chestnut-backed Chickadee 1/1/26 1 M.Ob. Oak Titmouse 1/1/26 1 M.Ob. Horned Lark 2/10/26 4 LF Bank Swallow 4/30/26 2 CCHo Tree Swallow 1/18/26 2 M.Ob. Violet-green Swallow 1/3/26 1 M.Ob. Purple Martin 4/27/26 4 DAB Northern Rough-winged Swallow 2/24/26 2 RT Barn Swallow 1/9/26 1 CRa Cliff Swallow 3/8/26 1 SnS Dusky Warbler 6 Bushtit 1/1/26 1 M.Ob. Wrentit 1/1/26 1 M.Ob. Ruby-crowned Kinglet 1/1/26 1 M.Ob. Golden-crowned Kinglet 1/2/26 2 MLo White-breasted Nuthatch 1/1/26 2 M.Ob. Pygmy Nuthatch 1/1/26 1 M.Ob. Red-breasted Nuthatch 1/7/26 2 AvK, BoK Brown Creeper 1/1/26 1 JTa, SK Blue-gray Gnatcatcher 1/25/26 3 RyM Rock Wren 1/10/26 4 JTo Canyon Wren 6 Northern House Wren 1/3/26 3 M.Ob. Pacific Wren 1/2/26 2 M.Ob. Sedge Wren 6 Marsh Wren 1/2/26 2 M.Ob. Bewick's Wren 1/1/26 1 M.Ob. American Dipper 4 Gray Catbird 6 Brown Thrasher 6 California Thrasher 1/1/26 2 RH Sage Thrasher 5 Northern Mockingbird 1/1/26 1 STa Western Bluebird 1/1/26 3 M.Ob. Mountain Bluebird 6 Townsend's Solitaire 3/20/26 4 HGo Varied Thrush 1/1/26 2 CNe, RH Swainson's Thrush 4/18/26 2 M.Ob. Hermit Thrush 1/1/26 1 M.Ob. American Robin 1/1/26 1 M.Ob. Bohemian Waxwing 6 Cedar Waxwing 1/1/26 1 DAB Phainopepla 5 White Wagtail 6 Red-throated Pipit 6 Siberian Pipit 6 American Pipit 1/1/26 2 MDa, TD Evening Grosbeak 4 House Finch 1/1/26 1 M.Ob. Purple Finch 1/1/26 1 KGR, STa Cassin's Finch 6 Red Crossbill 1/3/26 3 JPK, MHe Cassia Crossbill 6 Pine Siskin 1/1/26 2 M.Ob. Lesser Goldfinch 1/1/26 1 M.Ob. Lawrence's Goldfinch 4 American Goldfinch 1/1/26 1 CNi Lapland Longspur 5 Chestnut-collared Longspur 5 Snow Bunting 6 Rustic Bunting 6 Grasshopper Sparrow 4/5/26 2 M.Ob. Chipping Sparrow 1/1/26 2 CMi Clay-colored Sparrow 3/11/26 4 CH, MDF Black-chinned Sparrow 6 Field Sparrow 6 Brewer's Sparrow 4 Black-throated Sparrow 6 Lark Sparrow 1/18/26 4 CSa Lark Bunting 5 American Tree Sparrow 5 Fox Sparrow 1/1/26 1 M.Ob. Dark-eyed Junco 1/1/26 1 M.Ob. White-crowned Sparrow 1/1/26 1 M.Ob. Golden-crowned Sparrow 1/1/26 1 M.Ob. Harris's Sparrow 5 White-throated Sparrow 1/1/26 4 M.Ob. Sagebrush Sparrow 6 Bell's Sparrow 5 Vesper Sparrow 4 LeConte's Sparrow 6 Nelson's Sparrow 6 Savannah Sparrow 1/1/26 1 M.Ob. Song Sparrow 1/1/26 1 M.Ob. Lincoln's Sparrow 1/1/26 2 M.Ob. Swamp Sparrow 1/3/26 4 M.Ob. California Towhee 1/1/26 1 M.Ob. Rufous-crowned Sparrow 4 Green-tailed Towhee 1/1/26 5 M.Ob. Spotted Towhee 1/1/26 1 M.Ob. Yellow-breasted Chat 4/19/26 4 Rym Yellow-headed Blackbird 4/23/26 4 AMa, Rib Bobolink 4 Western Meadowlark 1/1/26 1 M.Ob. Orchard Oriole 4 Hooded Oriole 3/14/26 2 LB, RT Bullock's Oriole 4/19/26 2 ARi Baltimore Oriole 6 Scott's Oriole 6 Red-winged Blackbird 1/1/26 1 M.Ob. Tricolored Blackbird 1/3/26 1 M.Ob. Brown-headed Cowbird 1/1/26 2 CH Rusty Blackbird 6 Brewer's Blackbird 1/1/26 1 M.Ob. Great-tailed Grackle 1/2/26 3 JTo Ovenbird 5 Worm-eating Warbler 1/23/26 6 M.Ob. Northern Waterthrush 4 Golden-winged Warbler 6 Black-and-white Warbler 1/2/06 4 CH, SL Prothonotary Warbler 5 Tennessee Warbler 4 Orange-crowned Warbler 1/1/26 3 CH, MDa Lucy's Warbler 1/8/26 4 EdM, MF Nashville Warbler 1/2/26 4 CH, MDF Virginia's Warbler 4 Connecticut Warbler 6 MacGillivray's Warbler 3/29/26 3 RH Mourning Warbler 6 Kentucky Warbler 6 Common Yellowthroat 1/1/26 2 M.Ob. Hooded Warbler 4 American Redstart 1/2/26 4 M.Ob. Cape May Warbler 6 Northern Parula 4 Magnolia Warbler 4 Bay-breasted Warbler 6 Blackburnian Warbler 4 Northern Yellow Warbler 1/18/26 2 RT Chestnut-sided Warbler 4 Blackpoll Warbler 4 Black-throated Blue Warbler 4 Palm Warbler 1/3/26 4 Anon Yellow-rumped Warbler 1/1/26 1 M.Ob. Yellow-throated Warbler 6 Prairie Warbler 5 Black-throated Gray Warbler 1/4/26 2 GC Townsend's Warbler 1/1/26 1 M.Ob. Hermit Warbler 1/2/26 2 CH Black-throated Green Warbler 5 Canada Warbler 4 Wilson's Warbler 3/7/26 1 RyM Painted Redstart 6 Summer Tanager 1/5/26 5 LeA Scarlet Tanager 6 Western Tanager 4/5/26 2 NGo Rose-breasted Grosbeak 4 Black-headed Grosbeak 1/6/26 2 DAB Blue Grosbeak 4 Lazuli Bunting 4/12/26 2 KFo Indigo Bunting 4 Painted Bunting 1/20/26 6 DPom Dickcissel 6 Introduced Species; nesting species originally released from captivity Ring-necked Pheasant 4 Wild Turkey 1/1/26 3 RH, ZC Eurasian Collared-Dove 1/1/26 3 M.Ob. Rock Pigeon 1/1/26 1 M.Ob. European Starling 1/1/26 1 M.Ob. House Sparrow 1/1/26 1 M.Ob. 272 species recorded so far this year 51% of 482 total recorded species in San Mateo Co. and its offshore waters
* Rarity:
1 = Common to abundant in appropriate habitat, always present in large numbers
2 = Fairly common, always present in moderate to small numbers
3 = Uncommon, usually present and in small numbers
4 = Rare, observed in very small numbers and perhaps not in each year
5 = Extremely rare, fewer than 10 records of occurrence in season indicated
6 = Accidental, recorded fewer than 10 times in San Mateo County and offshore waters**San Mateo County Observers
ADu=Adam Dudley, AE=Alex Eisengart, AMa=Aaron Maizlish, AnKr=Andrew Kratter, Anon=Anonymous, ARi=Alex Rinkert, ASun=Aaron Sun, AvK=Ava Kornfeld
BHo=Bill Holland, BoK=Bob Kornfeld
CCho=Caitlin Chock, CGl=Curt Glosli, CH=Chris Hayward, CHe=Chris Henry, CMa=Curtis Marantz, CMi=Carol Miller, CNe=Christin New, CRa=Cricket Raspet, CSa=Carlos Salgado, CRSE=Commercial Cruise Line
DAB=DorianAndersonBike,
EAy=Erin Ayers, EdM=Eddie Monson, ELe=Eve Lempriere
GD=Gary Deghi
HGo=Haoning Gong
JMi=Joshua Mitchell, JoM=Joan Marshall, JPK=Jesse Pabros-Kraus, JSt=Joshua Stacy, JTa=Jane Tatchell, JTo=Jari Toivanen, JTs=John Tsortos,
KGr=Keith Gress, KPi=Karen Pinckard, KTu=Kirsten Tucker,
LB=Leonie Batkin, LeA=Leo Alley, LF=Leslie Flint, LHy=Laura Hyatt, LO=Leo O'Neill,
LSo=Logan Southall
MDa=Marj Davis, MDF=Malia DeFelice, MFr=Marty Freeland, MHe=Melissa Hero,
MKa=Malini Kaushik, MLo=Michael Long, MMR=Mike Rogers,
M.Ob.=Multiple Observers/Observations, MX=Maya Xu
NGo=Naomi Goodman
PGa=Paul Gater, PLi=Paige Liu
RF=Rich Ferrick, RGJ=Richard Jeffers, RH=Richard Hopf, RiB=Richard Bradus, RT=Ron Thorn, RyM=Ryan Mense
SFPE=San Francisco Pelagic, SK=Susan Kritzik, SnS=Snigdha Sharma, STa=Sam Talarigo
TD=Tom Duncan,
VM=Virginia Marshall,
ZC=Ziting Chen