What's Behind the 2026 Pinyon Jay Irruption?

Pinyon Jays – an iconic bird of the American West known colloquially as piñonero or blue crow – are showing up in spots far outside of their normal range this year. Bird irruptions like this are always exciting, but also worrisome. What’s behind the birds straying so far from their regular territory – in this case, the foothills and lower mountainsides of the western U.S. and northern Mexico?

We asked Scott Somershoe, an expert on the species based in Denver, Colorado and biologist with the U.S. Fish and Wildlife Service, to weigh in. He remarked that although jays are known to wander outside of their year-round home ranges, this year’s Pinyon Jay irruption is “unprecedented … we have not seen the species in southern California and islands offshore (San Clemente Island, Channel Islands, and Santa Catalina Island).”

Irruptions take place “typically when food resources (in the case of Pinyon Jay, pine nuts from various species of pinyon pine) are inadequate to meet their needs. We had so little snow across the entire west last winter that I think it’s likely cones that were developing were largely aborted. Broadly speaking, there was probably a west-wide nut crop failure, not just for multiple pinyon pine species but ponderosa and Jeffrey’s pines as well.

“Cone production is cyclical (a good mast crop on average every couple years) and that varies by pinyon pine species. Some years of reduced production are more extreme than others. Persistent drought and increased temperatures, especially at key stages of cone development, can cause trees to abort cone development or produce cones with nonviable seeds. Cone development is a two-year process, so temperatures and precipitation need to be appropriate at the right times to facilitate cone and seed production. Trees can be loaded with cones, but the nuts may be nonviable, thus not available as a food resource.”

Somershoe continued, “It’s apparent that there was likely a large-scale crop failure in at least the southwestern portion of the range of the Pinyon Jay. There is generally some pine nut production every year, even if it is small-scale and local, which jays likely find and utilize, caching nuts for consumption through winter. It seems possible that even some of the more reliable producing stands did not produce adequate pine nuts this season.”

“Jays are highly intelligent and most, if not all, will return to their traditional home ranges in late winter,” Somershoe said. “The question that remains in my mind is, will the surviving birds after lean winters be physically fit enough to breed next spring? Jays will defer breeding after years with little or no pine nut production. Multiple years of poor pine nut crops may result in reduced and/or limited breeding efforts and potentially reduced reproductive output and recruitment of young into the population.

“I wonder how jay survival and reproductive output is affected by multiple, consecutive years of hotter, drier conditions and reduced or absent pine nut production? Are jays able to produce enough young birds after the next big mast event (when the cycle swings up) to recover their populations that likely declined during lean years through adult mortality? Are generally declining masting events (e.g., extent and volume of cone and nut production) across pinyon pine species having reproductive consequences that are resulting in slowly declining jay flock sizes?  In addition, some years with extreme drought and temperatures can cause large-scale mortality of pinyon pines, which further reduces availability of pine nut crops into the future.”

The Pinyon Jay has lost up to 85% of its historic population since the 1960s; the species is under review for possible listing under the Endangered Species Act.