Date: 4/25/26 10:27 pm From: Lance Benner via groups.io <lbenner...> Subject: [LACoBirds] California Bird Atlas Update: April 25, 2026
Hi Everyone,
Here's another update on progress with the California Bird Atlas in Los Angeles County.
These are results from 2026 April 25.
LA County eBird Atlasers: 605 (increase of nearly 80 in the last two weeks)
eBird Checklists: 9291
Atlas effort: 7146 hours
Atlas blocks with data: 341 (79% of the total)
Species with a breeding code: 235
Species with breeding confirmed: 120 (increase of 10 in the last two weeks)
44 species have been confirmed breeding in at least 10 blocks:
27 Canada Goose
10 Egyptian Goose
34 Mallard
10 Rock Pigeon
23 Mourning Dove
36 Anna's Hummingbird
47 Allen's Hummingbird
12 Killdeer
14 Great Blue Heron
15 Cooper's Hawk
15 Red-shouldered Hawk
45 Red-tailed Hawk
24 Great Horned Owl
15 Nuttall's Woodpecker
51 Black Phoebe
11 Say's Phoebe
11 Vermilion Flycatcher
20 Cassin's Kingbird
25 California Scrub-Jay
47 American Crow
100 Common Raven
27 Oak Titmouse
11 Northern Rough-winged Swallow
22 Cliff Swallow
77 Bushtit
11 Wrentit
21 Northern House Wren
30 Bewick's Wren
59 European Starling
30 Northern Mockingbird
26 Western Bluebird
10 American Robin
16 Scaly-Breasted Munia
58 House Sparrow
84 House Finch
29 Lesser Goldfinch
38 Dark-eyed Junco
42 Song Sparrow
47 California Towhee
10 Spotted Towhee
15 Hooded Oriole
10 Red-winged Blackbird
17 Orange-crowned Warbler
10 Common Yellowthroat
The number on the left gives the number of blocks where breeding for each species has been confirmed.
Two weeks ago there were 32 specees on the list above. Now it's 44!
Common Ravens, house finches, bushtits, European starlings, and house sparrows have been confirmed in the most blocks.
Los Angeles County blocks where breeding has been confirmed for at least 10 species:
11 Azusa SW
20 Baldwin Park NW
11 Beverly Hills NE
10 Bevery Hills NW
25 Burbank SE
10 El Monte CE
11 El Monte NE
10 El Monte NW
20 El Monte SE
18 Glendora SE
14 Hollywood CE
32 Hollywood NE
22 Hollywood SW
11 Inglewood CE
10 Juniper Hills CW
22 Long Beach CE
13 Long Beach CW
14 Long Beach NW
22 Long Beach SE
12 Long Beach SW
25 Los Alamitos CW
19 Los Alamitos NW
20 Los Angeles CW
11 Los Angeles NE
21 Los Angeles NW
15 Malibu Beach NW
11 Mount Wilson CE
30 Mount Wilson SE
27 Mount Wilson SW
22 Newhall CW
28 Ontario NW
37 Pasadena CE
27 Pasadena CW
10 Pasadena NE
25 Pasadena SE
10 Pasadena SW
11 Rosamond CW
25 San Dimas CE
44 San Dimas NE
21 San Fernando SE
10 San Pedro NE
12 Torrance SE
17 Val Verde SE
16 Valyermo NW
30 Van Nuys CW
29 Venice NE
13 Venice NW
11 Warm Springs Mountain CW
11 Whittier NE
12 Whittier NW
43 Whittier SE
Here the number on the left gives the number of species in that block that have been confirmed.
Two weeks ago there were 34 blocks on this list. Now there are 51!
Note that 30+ species have been confirmed breeding in six blocks:
Hollywood NE (32)
Mount Wilson SE (30)
Pasadena CE (37)
San Dimas NE (44)
Van Nuys CW (30)
Whittier SE (43).
Blocks with at least 50 species with breeding codes:
63 Baldwin Park NW
82 Burbank SE
50 Chilao Flat SW
64 El Monte SE
57 Glendora SE
67 Hollywood NE
59 Lake Hughes CW
56 Long Beach CW
51 Long Beach NW
55 Los Alamitos CW
67 Los Angeles NW
65 Malibu Beach NW
64 Mount Wilson CE
61 Mount Wilson CW
54 Mount Wilson SE
67 Mount Wilson SW
57 Ontario NW
76 Pasadena CE
61 Pasadena CW
53 Pasadena NE
68 Pasadena SE
51 San Dimas CE
82 San Dimas NE
82 San Fernando SE
65 Valyermo NW
68 Van Nuys CW
63 Venice NE
50 Whitaker Peak NE
65 Whittier SE
Here "coded" is the sum of possible + probable + confirmed breeding codes in the eBird portal for behavior such as singing, courtship displays, carrying nesting material, feeding young, etc.
The "coded" designation closely follows the protocols used in the first Los Angeles County Bird Atlas from 1995-1999 and allows direct comparisons with the numbers of birds found in each block now with results from ~30 years ago.
Two weeks ago 22 blocks had at least 50 coded species. Now the total is 29.
The numbers in several blocks have exceeded those from the first Los Angeles County Bird Atlas from 1995-1999, although in most cases, the numbers of species with breeding confirmed ~30 years ago was higher.
With the previous LA County Atlas in the 1990s, there was a target number of species for each block, and of those, observers tried to find (i.e., code) at least 90% and confirm breeding for at least 50%. At least 50% WERE confirmed in a large number of blocks, so the previous atlas set a pretty high standard for us to follow.
We're well ahead of where the previous atlas was only four months in but we still have a lot of work to do!
Some blocks in the county are approaching saturation. For example, two weeks ago Pasadena CE had 75 coded species, of which 38 were confirmed. Nearly 270 hours of effort have been devoted to that block. Now the total is 76 coded with the same number confirmed (although some at a higher level), so despite quite a bit of effort in that block, totals haven't changed much, and it's unlikely that we'll find many more species. I know that block well and estimate that we've probably found (i.e., coded) about 90% of the species that might breed there. However, we could probably still _confirm_ another 10+ species as the spring progresses.
Soon some of our efforts would be better directed to other blocks that haven't received much attention yet.
Again, to see how much effort has been contributed such as number of hours, number of species coded, confirmed, complete checklists, etc. go to:
Then you can zoom in to any particular part of the state, and if you click on each rectangle, you can see a summary of effort and species reported there.
There are 434 blocks in Los Angeles County and more than 90 still have zero data. If you're looking for good areas to contribute, check the map discussed above, zoom in on a block where there's little or no effort, and go birding there. We still need help just about everywhere, with large gaps in the Santa Monica Mountains (except at Malibu Creek State Park), in the western San Fernando Valley, in the mountains north of Santa Clarita, in the San Gabriel Mountains, the Antelope Valley, and the Los Angeles Urban Core.
We hope you'll join us!
Regards,
Lance
Lance Benner
Pasadena, CA
P.S. Please note that all the results above were obtained from the California Bird Atlas eBird portal. If you're using the _regular_ eBird portal then your results don't appear above, even if you're using breeding codes in the checklists.
