More about red crossbills 

George Walter

Jill Severn | The JOLT News

Last week’s column had a general description of red crossbills (and white-winged crossbills as well), including their crisscrossed bills and interesting feeding techniques. Messages I received from readers suggested they want more information about this interesting bird. 

Red crossbills feed almost exclusively on conifer seeds and, because of drought or some other reason, for some years these seed crops fail. In those years, large numbers of red crossbills will stop breeding and migrate long distances in search of new food sources. These dramatic migration years are called irruptions, and this winter has been one of those irruption years.   

Red crossbill in Washington breed in higher elevation conifer habitats, places that birders don’t often visit. Therefore, it is these occasional irruptions, when more crossbills show up in more places, that provoke our interest. But before getting to what you might find this winter, we need to review more about this species’ remarkable biology.  

That’s because red crossbills present an interesting puzzle for both birders and ornithologists. We all like to categorize things. Avian researchers write about bird species and birders want to know which box to tick on their checklist. Red crossbills confound this common impulse. 

Since the development some 20 years ago of good recording devices, and the ability to visually present vocalizations using spectrograms, observers have documented what many have heard — different populations of red crossbills have remarkably different flight calls. Bird books suggest simplicity, typically describing their call as jip-jip-jip, a call usually heard as the vocalizing birds fly overhead. But, it’s not that simple.  

The accumulated recording data have established that there are 12 different “call types” across North America and that these different types correspond to differences in bird forms and genetics, and to association with different food sources and nesting habitats.  

The crossbills most likely to be heard in Thurston County are types 3 and 4; if you visit conifer forests along the coast, you’re more likely to hear type 10. To listen to the several different red crossbill calls, check out this website from the Cornell Lab of Ornithology.

The different habitats and call types raises a question of great interest to people interested in expanding their avian Life List. When is one group of crossbills different enough from others to be classified by ornithologists as a separate species? 

In 2017, research led to establishing a new crossbill species, the Cassia crossbill (previously type 9), a nonmigratory species confined to a limited area of southeastern Idaho (mainly in Cassia County). In addition to its unique call type, this crossbill also feeds on the seed cones of local variety of lodgepole pine that other crossbill types cannot open.  

The crossbill periodic irruption pattern also complicates this interesting problem for species determination. Sometimes these irruptive flocks, when they find an abundant conifer seed crops, will initiate nesting at the new location, far from their usual range, and feed on cones of conifer species other than their usual ones. The actual life of bird populations may sometimes not fit neatly into the ornithological classification system. 

To help straighten out for us the various red crossbill types found in Washington, and there are a lot of them, I asked Liam Hutcheson, our column photographer, to write an account based on his experiences with red crossbills. In addition to being a superb photographer, he has an exceptionally well-trained ear for bird calls. Here is Liam’s report: 

If you are birding in Washington and have a good ear for calls, you might encounter up to seven of the 11 red crossbill types of North America. For rarer species, identification depends on spectrogram analysis of recorded vocalizations. Therefore, people interested in better understanding red crossbill distribution urge birders to make recordings of red crossbills they encounter. Here is a summary of the red crossbill types in Washington: 

T1 (Type 1) Appalachian: As its name suggests, this is a type mostly found in the Appalachian Mountains and the northeastern U.S.; however, there are records from the Great Lakes area and the Pacific Northwest. In Washington, they have been recorded on the outer coast and in South Puget Sound. This is a fairly rare type in Washington, and I have not yet encountered it here.  

T2 Ponderosa: This is a very widespread and common type in Washington, mostly found in the dry coniferous slopes of the Eastern Cascades and northern interior forests. However, it could wander into Western Washington, as there are many records.  

A red crossbill, Sitka spruce male.

Liam Hutcheson | For The JOLT News

A red crossbill, Sitka spruce female.

Liam Hutcheson | For The JOLT News

T3 Western hemlock: Type 3s are one of the most common types found in Thurston County and throughout the Pacific Northwest, mostly in Western Washington. There are also many records for the east side of our state.  

A red crossbill T4 on a Douglas fir, male.

Liam Hutcheson | For The JOLT News

A red crossbill, Douglas fir, female.

Liam Hutcheson | For The JOLT News

T4 Douglas fir: This is the other common red crossbill in Thurston County. It’s widely distributed throughout Washington but may be more common on the westside. This type centers in the Pacific Northwest, but there are many records of it wandering widely.  

T5 Lodgepole pine: This is a rarer type in Washington, and one that particularly fascinates me. They should be expected in northern portions of the eastern half of the state, but they are rarely detected. There are also a few records of T5 in Western Washington. This type is typical of the Rocky Mountains, extending north into southern British Columbia. 

T7 Enigmatic: This is the rarest of the types recorded in Washington, with only two well documented state records. They are rare everywhere and to date there are too few records to state with certainty their usual range, although most experts think their range is interior British Columbia. As it happens, I have the second of the only two state records with a bird I recorded on Steptoe Butte near Pullman Washington last fall. 

A red crossbill hemlock, male.

Liam Hutcheson | For The JOLT News

A red crossbill hemlock, female.

Liam Hutcheson | For The JOLT News

T10 Sitka spruce: Type 10 red crossbills are restricted to the spruce forests of outer coast in Washington; they range from British Columbia south to Northern California. There are very few records of this species away from the outer coast, with only three or four in the South Puget Sound region.  

If, after wading through all our red crossbill discussions you still want more, check out this website. It includes information about all the different crossbill types, including sound spectrograms and range maps.

George Walter is environmental program manager at the Nisqually Indian Tribe’s natural resources department; he also has a 45+ year interest in bird watching. He may be reached at george@theJOLTnews.com 

Photos for this column are provided by Liam Hutcheson, a 17-year-old Olympia area birder and avid photographer.