Idaho's New Endemic Species
Prairie Falcon Audubon, Inc. (PFA), in Twin Falls, Idaho is happy to help you locate the Cassia Crossbill in the South Hills. Please contact us for more information. Our member contacts are excellent birders and if they are available, would be happy to help you out. PFA members enlisted to help folks tick off the Cassia Crossbill will happily accept gas money, lunch, and/or a donation to PFA.
There are several places to see Cassia Crossbill in our area (Cassia Crossbill Map). Two easy places to see them are the Porcupine Springs Campground and in the lodgepole pines surrounding the Diamondfield Jack parking lot/campground. Be sure to scan the ground as crossbill happily feed on dropped cones. It is important that you are able to hear the bird’s contact calls and to record if possible. This is really the only way to distinguish CACR from the other Red Crossbills that might be in the area (unless of course you see them in the dead of winter). To hear the birds clearly and to get good recordings, avoid the noise created by all of the ATVs in the area by birding during the week and by hiking the Eagle Trail loop between Petit Campground and Diamondfield Jack Campground.
These informative articles will help you add this awesome bird to your life list:
Obtaining Sound Recordings and Spectrograms
Be sure to study the contact calls. When you are in the field try to record the contact calls of the crossbills you encounter and compare with substantiated spectrograms. Here is a recording from idahobirds.net: