Hi all, I'm sorry this is so tardy, but I just received confirmation from Tim Spahr and Matt Young that some crossbills I recorded in Grand County on 16 July 2021 are CASSIA CROSSBILLS. This would represent a new species for Colorado. I've submitted the record for review by the Colorado Rare Bird Records Committee.
All of the details, including sound recordings, are in my eBird checklist: https://ebird.org/checklist/S91855481 The Cassia Crossbill was elevated to the species level by the American Ornithological Society in 2017. They were formerly known as "Type 9" Red Crossbills. They are thought to be endemic to the South Hills and Albion Mountains of southern Idaho. A large swath of the South Hills burned in 2020, so those birds had to go somewhere. Why not Colorado? It wasn't until last week that I remembered I even had the tracks on my recorder. I downloaded the files and started to analyze them hoping for good tracks of Type 5 "Lodgepole Pine" Red Crossbills. Things just didn't look right when I saw the calls on the spectrogram. The calls resembled a horizontally flipped lower case "h". These calls matched Cassia Crossbill when compared to examples on eBird, within resources like https://ebird.org/news/crossbills-of-north-america-species-and-red-crossbill-call-types/ , and in Nathan Pieplow's "Peterson Field Guide to Bird Sounds of Western North America". The exact location is in my eBird checklist. Folks may still want to go look in case the birds have stuck around. They are normally more sedentary than other crossbills. But, no guaranteess that Grand Co. Rd 555 is open at this time of year. Google Maps shows it as closed, but who knows. It's a good dirt road and would be drivable with any vehicle as long as there isnt' any snow or mud. Happy birding, Christian Nunes<http://aka.ms/weboutlook> Longmont, CO -- -- You received this message because you are subscribed to the Google Groups "Colorado Birds" group. To post to this group, send email to cobirds@googlegroups.com For more options, visit this group at http://groups.google.com/group/cobirds?hl=en?hl=en * All posts should be signed with the poster's full name and city. Include bird species and location in the subject line when appropriate * Join Colorado Field Ornithologists https://cobirds.org/CFO/Membership/ --- You received this message because you are subscribed to the Google Groups "Colorado Birds" group. To unsubscribe from this group and stop receiving emails from it, send an email to cobirds+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/cobirds/CY4PR01MB27431841F6F21FE49B91345BBC9B9%40CY4PR01MB2743.prod.exchangelabs.com.
