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[LACoBirds] Red Crossbill Irruption Update: Feb. 2024

10:24 pm

Forwarding from Lance Benner. It should be noted that the Type 3 and 4 crossbills in SD were recorded entirely thanks to Dan “cellphone quick draw” King at and near Windwood Park in Carmel Valley.

Matt Sadowski
———- Forwarded message ———
From: Lance Benner <lbenner@…>
Date: Mon, Feb 5, 2024, 22:02
Subject: [LACoBirds] Red Crossbill Irruption Update: Feb. 2024
To: <>, <>

Greetings Everyone,


Here’s another update on the red crossbill irruption that’s been underway across California for the last several months.   



In southern California, crossbills are being reported most frequently right now in San Diego County at a number of locations on the coastal slope and in the mountains.  To the best of my knowledge, three flight call types have been documented with recordings: types 2, 3, and 4.  This may be the first irruption when types 3 and 4 have been found in that county. 


Elsewhere in the southern part of the state, the UC Santa Barbara campus has had a number of flocks for weeks (with types 2, 3, and 4).  They have also appeared elsewhere nearby off-campus.


In San Bernardino County, there have been recent reports from Silver Lakes near Helendale, and around Big Bear Lake.  


In Riverside County, there have been quite a few reports since early January along route 74 (the Pines to Palms Highway) in Garner Valley.  Only one recording has been entered into eBird since last fall and it shows type 2s, which are the most common type found in the mountains in the southern part of the state.  But there could be others!


In Los Angeles County, so far there haven’t been any big groups found on the coastal slope. The reports concentrate in the desert at Apollo Park, Pearblossm Park, and Crystalaire, where types 2, 3, and 4 have been reported.


There have been regular reports near Inyokern and Ridgecrest in Kern County. More recordings there would be welcome: although type 2s were documented about two months ago, other types could be present.  There have also been some type 2s on the eastern side of Bakersfield (as have type 4).


Moving to the north, there are still numerous records in the  Bay Area and surrounding counties including in Monterey, near Santa Cruz, in Bear Creek Redwoods Open Space Preserve near Los Gatos, at Skylawn Cemetery in San Mateo County, in San Francisco, in Marin County, in Contra Costa County, Sonoma, Sacramento, and in Alameda County. Some of the birds in Alameda have been type 3s although they weren’t labelled as such.  The birds recently recorded in Santa Rosa were also type 3s.  The reports at Skylawn have slowed considerably with fewer birds reported than in November when several types were present.  We don’t know if Cassia Crossbills are still around.  


Obviously there’s much more to the state north of Sacramento, but I’m not very familiar with that area.  If someone else would like to discuss recent crossbill records in the northern third of the state, please do! 



Some notes about recordings obtained with the Merlin app:

Many of the red crossbill recordings entered into eBird were obtained on cell phones with the Merlin app.  Often recordings that are uploaded to eBird lists have no amplification, and as a result, the sounds are faint and difficult to hear.  Please amplify them! Perhaps the best way to do this is to transfer the recordings to a computer, load them into Audacity or Raven Lite (both are free), and amplify.  Some phone apps also have this capability but Merlin doesn’t seem to be among them.


Another option would be to use apps that are more sensitive souch as Song Meter Touch, Song Sleuth, and Voice Record Pro.  Song Meter Touch and Song Sleuth both include scrolling real-time sonograms.


In my experience, Merlin seems pretty good at indentifying that red crossbills are present but it isn’t equipped to tell you the flight call types.  I’m not aware of any phone app that can identify red crossbill flight call types, but you know otherwise, please tell us.



For an overview of the flight call types, with variants for each type, please see the article about this on the Finch Research Network’s website at:

In particular, scroll down to the first figure with sonograms.  The calls are variable and not all are shown.  


Red crossbills also make “excitement” calls (also known as “toop” calls) that are usually at a lower pitch than the flight calls.  The sonogram figure in the link above, unfortunately, does not show these.  They are often confused with flight calls but are different.



Finally, there are a couple of corrections/additions from my previous update:

1. The type 1 reported at Skylawn Cemetery last fall has been withdrawn.

2. Type 10 was reported in Monterey in November.   It’s the southernmost record in the state.



Once again, if you hear red crossbills, please record them!  Even if conditions are windy and loud, it’s worth a try, and you might get something notable.  







Lance Benner

Community Science Chair, Los Angeles Birders

Altadena, CA